Doutoramento versão final2
UNIVERSITAT DE LLEIDA
Institut Nacional d'Educació Física de Catalunya
INSTITUTO POLITÉCNICO DE SANTARÉM
Escola Superior de Desporto de Rio Maior
Fonaments Metodològics de la Recerca de l'Activitat Física i
l'Esport
TESI DOCTORAL
Effects of a Physical Activity and Dietary Education Intervention
in a Population with type 2 Diabetes
Mellitus
Félix Luís de Lima e Cunha Hopffer Romero
Director: Pedro Manuel Marques Vidal PhD
LLEIDA, 2010
UNIVERSITAT DE LLEIDA
Institut Nacional d'Educació Física de Catalunya
INSTITUTO POLITÉCNICO DE SANTARÉM
Escola Superior de Desporto de Rio Maior
Fonaments Metodològics de la Recerca de l'Activitat Física i
l'Esport
TESI DOCTORAL
Effects of a Physical Activity and Dietary Education Intervention
in a Population with type 2 Diabetes
Mellitus
Félix Luís de Lima e Cunha Hopffer Romero
Director: Pedro Manuel Marques Vidal PhD
LLEIDA, 2010
Effects of a Physical Activity and Dietary Education Intervention in a Population with type
2 Diabetes Mellitus
During our lives our paths cross with those of many other people, and some of them, one way or the
other, become more important to us. This work would not have been possible without the help of many
of them. Some were already friends. I became close to others through force of circumstances, and now I
like to think of them as friends as well. It´s now time to thank them all:
To my thesis director, Pedro Marques Vidal PhD, for his excellence in guiding this work, and for all I have
learned about the organization of scientific work;
To my tutor in INEFC, Salvador Olaso PhD, for his friendship and support;
To José Rodrigues PhD and Master Abel Santos, the former and present Directors of ESDRM, for having
created the conditions that allowed this work to be accomplished. Their role in supporting research in
ESDRM was vital and all their support and encouragement was decisive;
To S. João Health Centre Director Drª Virginia Munhá, for being at the birth of this project, allowing its
implementation and solving every little problem that arose;
To S. João Health Centre nurses, Leopoldina Moreira Inácio and Cristina Fernandim Costa, for their
dedication to diabetic patients and for their commitment to this program;
To all the staff in the S. João Health Centre for their sympathy and professionalism;
To the nutritionists Rita Martelo, Rita Almeida and Lilian Santos for their voluntary contributions in
giving regular nutrition consultations to the patients involved in this program;
To my students Cláudia Sécio, David Brás, Edgar Borja, Filipa Maia, Lisa Josete, Marta Matilde, Sofia
Fernandes and Tânia Estevão, who contributed to this program by supervising physical activity classes.
As part of their professional training, they gave their best;
To José Alves PhD for all that I have learned from him over all these years in ESDRM. For his support and
all the help given in the analysis of psychological data;
To Joana Sequeira also for her help in the analysis of psychological data;
To the nutritionist Ana Luísa Duarte, for her collaboration in the analysis of dietary data;
To Madalena Caninas for her help formatting this work;
To the "Expresso da linha" - Diogo Carmo, Rita Santos Rocha and Teresa Bento, for all their support and
for endless hours of discussion about this thesis;
To Paulo Mendonça, Tatiana Lopes and Oleguer Camerino for their support and help in the translation;
To João Miguel Ubach Chaves for his friendship and unconditional support;
To Tia Mené for a life dedicated to teaching;
To Ruca, Frederico and Inês, for the time taken from the family, due to this work, and for their patience
in the most difficult moments. They are the reason for all this.
Félix Hopffer Romero
Effects of a Physical Activity and Dietary Education Intervention in a Population with type
2 Diabetes Mellitus
Antecedents: la diabetis tipus 2 és cada vegada més freqüent en la població general. L'activitat física
adequada i els hàbits alimentaris són les pedres angulars per al tractament de la diabetis i per tant els
programes d'intervenció de millora de l'estil de vida poden ser de valor, però l'impacte d'aquests
programes necessita més estudi.
Mètodes: 43 persones diagnosticades amb diabetis tipus 2 van ser assignades a un grup de control (12
homes i 12 dones, 68,9 ± 11,3 rang 46-84 anys) i altre grup a una intervenció (6 homes i 13 dones, 69,5 ±
8,9 rang 52-81 anys), en funció de la seva voluntat. El grup d'intervenció va rebre un programa d'estil de
vida incloent classes d'activitat física i d'assessorament dietètic per a un període de 9 mesos. El grup
control va rebre l'atenció habitual. Van ser avaluats els canvis en els hàbits d'activitat física i alimentaris
i les seves conseqüències en les variables biològiques (pes, composició corporal, pressió arterial, perfil
lipídic, HbA1c i glucèmia), de fitness (força física, resistència aeròbica, flexibilitat i agilitat), psicològiques
(Profile of Mood States) i econòmiques (despeses individuals i els de l´Estat en referència als
Resultats: Els participants del grup d'intervenció tendeixen a augmentar la seva activitat física en
general (p = 0,020), i a adoptar millors patrons en la dieta (p = 0,050). No obstant això, els canvis en
l'estil de vida van ser lleus: l'increment de l'activitat física general fora del programa va ser no
significatiu i els canvis en la conducta alimentària no van ser suficients per a, de forma significativa,
modificar el percentatge de participants que complien les recomanacions dietètiques per a la població
portuguesa. Canvis significatius van ser trobats en la força de l'extremitat inferior (p = 0,014), de les
extremitats superiors (p = 0,001), la resistència aeròbica (p = 0,001) i la flexibilitat de les extremitats
superiors (p = 0,040). Per altra banda, no es van trobar canvis significatius en la composició corporal,
pressió arterial, perfil lipídic, o el control glucèmic. El perfil dels estats d'ànim va mostrar una disminució
significativa en el factor fatiga-inèrcia (p=0,002). Les despeses de la medicació va incrementar
substancialment per a l'Estat (p = 0,028) però no per als individus.
Conclusions: Els subjectes sotmesos al programa d'intervenció de millora de l'estil de vida van obtenir
un èxit moderat en relació al canvi de comportament, però no suficient per a obtenir un impacte
significatiu en la majoria de les variables clíniques i biològiques. Gràcies al programa de fitness van
millorar i la fatiga percebuda es va reduir. Els nostres resultats suggereixen que per a ser més efectius, la
intervenció ha de començar tan ràpid com sigui possible, ja que la seva implementació en persones
grans resulta més complicada. Això permetria una resposta major al programa i una implicació en
l'activitat física més intensa.
Félix Hopffer Romero
Effects of a Physical Activity and Dietary Education Intervention in a Population with type
2 Diabetes Mellitus
Antecedentes: la diabetes tipo 2 es cada vez más frecuente en la población general. La actividad física
adecuada y los hábitos alimentarios son las piedras angulares para el tratamiento de la diabetes y por lo
tanto los programas de intervención de mejora del estilo de vida pueden ser de valor, pero el impacto
de estos programas necesita más estudio.
Métodos: 43 personas diagnosticadas con diabetes tipo 2 fueron asignadas a un grupo de control (12
hombres y 12 mujeres, 68,9 ± 11,3 rango 46-84 años) y otro grupo a una intervención (6 hombres y 13
mujeres, 69,5 ± 8,9 rango 52-81 años), en función de su voluntad. El grupo de intervención recibió un
programa de estilo de vida incluyendo clases de actividad física y el asesoramiento dietético para un
período de 9 meses. El grupo control recibió la atención habitual. Fueron evaluados los cambios en los
hábitos de actividad física y alimentarios y sus consecuencias en las variables biológicas (peso,
composición corporal, presión arterial, perfil lipídico, HbA1c y glucemia), de fitness (fuerza física,
resistencia aeróbica, flexibilidad y agilidad), psicológicas (Profile of Mood States) y económicas (gastos
individuales y los del Estado con los medicamentos).
Resultados: Los participantes del grupo de intervención tienden a aumentar su actividad física en
general (p = 0,020), y a adoptar mejores patrones en la dieta (p = 0,050). Sin embargo, los cambios en el
estilo de vida fueron leves: el incremento de la actividad física general fuera del programa fue no
significativo y los cambios en la conducta alimentaria no fueron suficientes para, de forma significativa,
modificar el porcentaje de participantes que cumplían las recomendaciones dietéticas para la población
portuguesa. Cambios significativos fueron encontrados en la fuerza de la extremidad inferior (p = 0,014),
de las extremidades superiores (p = 0,001), la resistencia aeróbica (p = 0,001) y la flexibilidad de las
extremidades superiores (p = 0,040). Por otra parte, no se encontraron cambios significativos en la
composición corporal, presión arterial, perfil lipídico, o el control glucémico. El perfil de los estados de
ánimo mostró una disminución significativa en el factor fatiga-inercia (p = 0,002). El coste de la
medicación incrementó substancialmente para el Estado (p = 0,028) pero no para los individuos.
Conclusiones: El programa obtuvo un éxito moderado en relación al cambio de comportamiento, pero
no suficiente para obtener un impacto significativo en la mayoría de las variables clínicas y biológicas. El
fitness mejoró y la fatiga percibida se redujo. Nuestros resultados sugieren que para ser más efectivos,
la intervención debe comenzar tan pronto como sea posible, ya que su implementación en personas
mayores resulta más complicada. Esto permitiría una respuesta mayor al programa y a una intervención
de actividad física más intensa.
Félix Hopffer Romero
Effects of a Physical Activity and Dietary Education Intervention in a Population with type
2 Diabetes Mellitus
ABSTRACT
ABSTRACT
Background: Type 2 Diabetes is becoming increasingly prevalent worldwide at an alarming rate. Physical
activity and adequate dietary patterns are cornerstones for the treatment and prevention of diabetes.
Lifestyle intervention programs can be effective, but their application to the elderly needs further study.
Methods: overall, 43 individuals with diagnosed type 2 diabetes were assigned to control (12 men, 12
women; age 68.9 ± 11.3, range 46- 84 years) or intervention (6 men 13 women; age 69.5 ± 8.9, range 52-
81 years) groups based on their own choice. The intervention group received a lifestyle program
including physical activity classes and dietary counseling for a 9 month period. The control group
received the usual care. Improvement in physical activity and dietary patterns was assessed as well as
changes in biological (weight, body composition, blood pressure, lipid profile, HbA1c, glycemia), fitness
(strength, aerobic endurance, flexibility, agility), psychological (profile of mood states) and economic
variables (individual and state cost of medications).
Results: participants in the intervention group tended to increase their overall physical activity
(p=0.020) and to adopt better dietary patterns (p=0.050). However changes in lifestyle were mild:
changes in overall physical activity outside the program were non-significant and no significant changes
were found in the percentage of compliers with the dietary recommendations for the Portuguese
population. Significant changes were found in lower limb strength (p=0.014), upper limb strength
(p=0.001), aerobic endurance (p=0.001) and upper limb flexibility (p=0.040). Conversely no significant
changes were found for body composition, blood pressure, lipid profile or glycemic control. The profile
of mood states showed a significant decrease in the Fatigue-Inertia factor (p=0.002). The cost of
medication increased substantially for the State (p=0.028) but not for individuals.
Conclusions: The program achieved moderate success in relation to behaviour change, but not enough
to have a significant impact on most clinical and biological variables. Fitness was improved and
perceived fatigue reduced. Our results suggest that in order to be more effective, intervention should
begin as early as possible, as its implementation among elderly subjects is difficult. This would lead to a
larger response to the program and to a more intense physical activity intervention.
Félix Hopffer Romero
Effects of a Physical Activity and Dietary Education Intervention in a Population with type
2 Diabetes Mellitus
TABLE OF CONTENTS
ACKNOWLEDGMENTS . i
TABLE OF CONTENTS . v
LIST OF FIGURES . vii
LIST OF TABLES . viii
LIST OF ABREVIATIONS . x
1. INTRODUCTION . 1
2. REVIEW OF THE LITERATURE . 5
2.1. CONCEPTS. 5
2.2. DEFINITION AND AETIOLOGY OF TYPE 2 DIABETES . 7
2.3. CO-MORBIDITIES OF DIABETES . 14
2.4. DIABETES: A PUBLIC HEALTH ISSUE . 16
2.5. ECONOMIC BURDEN OF DIABETES . 19
2.6. PREVENTION OF DIABETES . 23
2.6.1. PRIMARY/SECONDARY PREVENTION . 23
2.6.2. TERTIARY PREVENTION . 31
2.7. TREATMENT OF DIABETES . 38
2.7.1. DRUG TREATMENT . 38
2.7.2. DIET . 39
2.7.3. PHYSICAL ACTIVITY . 40
2.8. IMPLEMENTATION OF LIFESTYLE CHANGES . 45
2.8.1. TREATMENT AND DISEASE CHARACTERISTICS . 50
2.8.2. INDIVIDUAL FACTORS . 52
2.8.3. INTERPERSONAL FACTORS . 53
2.8.4. ENVIRONMENTAL FACTORS . 55
2.9. MOOD STATES AND PHYSICAL ACTIVITY . 57
2.10. MOTIVATION THEORIES . 60
3. OBJECTIVES . 68
4. MATERIALS AND METHODS . 71
Félix Hopffer Romero
Effects of a Physical Activity and Dietary Education Intervention in a Population with type
2 Diabetes Mellitus
4.1. SÃO JOÃO HEALTH CENTRE . 71
4.2. SAMPLING AND STUDY DESIGN . 73
4.3. DATA COLLECTED . 77
4.3.1. PHYSICAL ACTIVITY HABITS . 77
4.3.2. DIETARY HABITS . 79
4.3.3. CLINICAL AND BIOLOGICAL ASSESSMENT . 81
4.3.4. FITNESS ASSESSMENT . 83
4.3.5. PSYCHOLOGICAL ASSESSMENT . 84
4.3.6. ECONOMIC ASSESSMENT . 87
4.4. PROCEDURES . 89
4.5. STATISTICAL PROCEDURES . 90
5.1. DROP-OUT ANALYSIS . 93
5.2. LIFESTYLE DATA . 93
5.2.1. PHYSICAL ACTIVITY DATA . 93
5.2.2. DIETARY DATA . 100
5.3. CLINICAL AND BIOLOGICAL DATA . 106
5.4. FITNESS DATA . 114
5.5. MOOD STATES DATA . 119
5.6. ECONOMIC DATA . 126
5.7. FINAL INTERVIEW DATA . 129
6. DISCUSSION . 133
6.1. LIFESTYLE . 135
6.1.1. PHYSICAL ACTIVITY . 136
6.1.2. DIETARY HABITS . 139
6.2. CLINICAL AND BIOLOGICAL VARIABLES . 141
6.3. FITNESS . 146
6.4. MOOD STATES . 150
6.5. ECONOMIC ANALYSIS . 152
6.6 FINAL INTERVIEW ANALYSIS . 154
7. CONCLUSIONS . 157
8. REFERENCES . 161
Félix Hopffer Romero
Effects of a Physical Activity and Dietary Education Intervention in a Population with type
2 Diabetes Mellitus
LIST OF FIGURES
Figure 1 – S. João Health Centre and its intervention area. 71
Figure 2 – Flow chart showing recruitment and affiliation to groups of study subjects . 75
Figure 3 – Scheme of the intervention study after inclusion in the control and intervention groups . 89
Figure 4 - Time spent in walking at baseline and at the end of the study, by group. Results are expressed
in minutes per week. 96
Figure 5 - Time spent in moderate physical activity at baseline and at the end of the study, by group.
Results are expressed in minutes per week. 96
Figure 6 - Median contribution of walking, and moderate and vigorous physical activity to overall
physical activity at baseline and at the end of the study, by group. Results are expressed in minutes per
Figure 7 - Differences in overall physical activity, by group. Results are expressed in Met-min per week.
Figure 8 – Percentage of non-compliers for each dietary recommendation at baseline and at the end of
the intervention, by group. 103
Figure 9 – Dietary scores at baseline and at the end of the study (%) . 104
Figure 10 – Trends in dietary habits, by group. The results are expressed as a % of the participants. 105
Figure 11 - Percentage of subjects at risk for lipid profile at baseline and end of the study, by group . 114
Figure 12 - POMS at baseline and at the end of study for the control group. Data are means in each
factor. TA -Tension - Anxiety, DD-Depression-Dejection, AH -Anger – Hostility, VA -Vigor – Activity; FI -
Fatigue – Inertia and CB -Confusion – Bewilderment. 122
Figure 13 - POMS at baseline and at the end of study for the intervention group. Data are means in each
factor. TA -Tension - Anxiety, DD-Depression-Dejection, AH -Anger – Hostility, VA -Vigor – Activity; FI -
Fatigue – Inertia and CB -Confusion – Bewilderment. 123
Figure 14 - POMS at baseline and at the end of study for subject nº 20. Data are means in each factor.
TA, Tension–Anxiety; DD, Depression-Dejection; AH, Anger–Hostility; VA, Vigor–Activity; FI, Fatigue–
Inertia and CB, Confusion–Bewilderment. 125
Figure 16 - POMS at baseline and at the end of study for subject nº 24. Data are means in each factor.
TA, Tension–Anxiety; DD, Depression-Dejection; AH, Anger–Hostility; VA, Vigor–Activity; FI, Fatigue–
Inertia and CB, Confusion–Bewilderment. 126
Figure 17 - Costs at baseline and at end of study, by group. Results are expressed in €/month for
participants (left) and the government (right) . 129
Félix Hopffer Romero
Effects of a Physical Activity and Dietary Education Intervention in a Population with type
2 Diabetes Mellitus
LIST OF TABLES
Table 1 – Tertiary lifestyle interventions according to country, sample, age, intervention and results . 34
Table 2 – Categories and Dietary recommendations for the Portuguese population. Units are portions. 79
Table 3 - Parameters and tests included in Rikli and Jones (2001) battery of test items . 83
Table 4 - Physical activity at baseline and at the end of the study. Results are expressed as medians and
(1st quartile, 3rd quartile). PA, physical activity. Comparison between control and intervention groups by
Mann Whitney's U test. 94
Table 5 - Evolution of each type of physical activity, by group. PA, physical activity. Statistical analysis by
Wilcoxon signed rank test. 95
Table 6 - Reported changes in physical activity levels. Results are expressed in number of subjects and
(percentages). 100
Table 7 - Percentage of compliers with Portuguese population dietary recommendations within each
group. Comparison between control and intervention groups by Fisher's exact test. 101
Table 8 – Statistical results of the evolution of compliance with the Portuguese dietary
recommendations within each group (Wilcoxon sign ranks test). 102
Table 9 - Clinical and biological data at baseline and at the end of the study, according to intervention
group. The results are expressed as medians and (1st quartile, 3rd quartile). Comparison between
control and intervention groups by Mann Whitney's U test. 107
Table 10 - Clinical and biological data, by group. Statistical analysis by Wilcoxon signed rank test. 109
Table 11 - Percentage of individuals in each of the American College of Sports Medicine's categories, by
Table 12 – Percentage of individuals with hypertension, treated hypertension and controlled
hypertension at baseline and at the end of the study, by group. Comparison between control and
intervention groups by Fisher exact test. 111
Table 13 - Fitness data at baseline and at the end of the study. Results are expressed as medians and
(1st quartile, 3rd quartile). Comparison between control and intervention groups by Mann Whitney's U
Table 14 - Evolution of fitness data, by group. Statistical analysis by Wilcoxon signed rank test. 117
Table 15 - Profile of Mood States data at baseline and at the end of the study. Results are expressed as
medians and (1st quartile, 3rd quartile). Comparison between control and intervention groups by Mann
Whitney's U test. 119
Table 16 - Profile of Mood States data, by group. Statistical analysis by Wilcoxon signed rank test. 121
Félix Hopffer Romero
Effects of a Physical Activity and Dietary Education Intervention in a Population with type
2 Diabetes Mellitus
Table 17 – Medication costs (€) at baseline and at the end of the study. Results are expressed as
medians and (1st quartile, 3rd quartile). Comparison between control and intervention groups by Mann
Whitney's U test. 127
Table 18 – Medication costs (€), by group. Statistical analysis by Wilcoxon signed rank test. 128
Table 19 – Interview data regarding the intervention group. 130
Félix Hopffer Romero
Effects of a Physical Activity and Dietary Education Intervention in a Population with type
2 Diabetes Mellitus
LIST OF ABREVIATIONS
BMI – Body Mass Index
CHD – Coronary Heart Disease
CVD – Cardio Vascular Disease
DBP – Diastolic Blood Pressure
DSME – Diabetes Self-Management Education
IFG – Impaired Fasting Glucose
IGT - Impaired Glucose Tolerance
IPAQ – International Physical Activity Questionnaire
MET - Metabolic Equivalent
POMS – Profile of Mood States
SBP – Systolic Blood Pressure
Félix Hopffer Romero
Effects of a Physical Activity and Dietary Education Intervention in a Population with type
2 Diabetes Mellitus
1. INTRODUCTION
worldwide, as a consequence of technological development in
the last century, has had a substantial impact on health.
This is particularly the case among western populations,
where the considerable decrease in physical activity levels
has led to a parallel increase in obesity and obesity-
related diseases (Blair, 2003).
Physical activity, through structured exercise programs,
has been shown to be an efficient method of preventing
sedentary-related
targeting particular populations, should be tailor-made to
the specific needs and pathologies of those populations and
be provided by multidisciplinary teams.
Subjects with type 2 diabetes can benefit the most from an
increase in physical activity through structured exercise
represents one of the main treatment options for this
prescribed to prevent or treat type 2 diabetes (American
College of Sports Medicine, 2000; Hawley, 2004; Praet & van
Loon, 2008). Furthermore several co-morbidities associated
with type 2 diabetes can limit the structuring of physical
exercise programs, particularly the duration and intensity
effectiveness. Several recommendations regarding the design
of exercise programs for diabetics have been issued
Félix Hopffer Romero
Effects of a Physical Activity and Dietary Education Intervention in a Population with type
2 Diabetes Mellitus
(American Diabetes Association & American College of Sports
Medicine, 1997) covering in particular the training loads
to be applied. It is however important to assess whether
interventions with lower training loads, possibly easier to
implement and with lower dropout rates, show similar levels
of effectiveness.
Large changes in populations' dietary patterns are another
decisive aspect that over the 20th century contributed to
an increase in the prevalence of diabetes. Economic
globalization and the success of the fast food industry
have led to high energy density food choices now becoming
not only available, but often the lowest cost option to the
consumer (Darmon, Ferguson, & Briend, 2002). This trend was
also noted in Portugal where people are moving away from
the traditional Mediterranean diet at a faster rate than in
other Mediterranean countries (Chen & Marques-Vidal, 2007).
These changes in the environment make it more important
that the population is educated towards healthy lifestyle
choices and there is more responsibility on health
departments to provide and promote the adoption of these
It was in this line of action that the program "Saúde em
Movimento" was implemented in a primary health care unit -
the S. João Health Center. This program aims to grant type
2 diabetic patients free access to a structured physical
exercise and nutritional educational program. Currently,
this program is being used by elderly subjects (mean age 69
Félix Hopffer Romero
Effects of a Physical Activity and Dietary Education Intervention in a Population with type
2 Diabetes Mellitus
The present study aims to characterize their physical
activity and dietary habits as well as to determine their
profile regarding clinical and biological variables related
to parameters of diabetic control and to fitness. A
psychological profile - the profile of mood states was also
established and an economic analysis was done regarding
costs with medications. Changes occurred in these variables
after 9 months participation in the program were assessed
and compared with a control group following a conventional
Félix Hopffer Romero
Effects of a Physical Activity and Dietary Education Intervention in a Population with type
2 Diabetes Mellitus
Félix Hopffer Romero
Effects of a Physical Activity and Dietary Education Intervention in a Population with type
2 Diabetes Mellitus
2. REVIEW OF THE LITERATURE
Throughout this work the following concepts will be used:
• Adherence – the extent to which a person's behaviour
in terms of taking medications, following diets or
making lifestyle changes corresponds with the agreed
recommendations of the health care provider. Adherence
connotes a willingness of the patient to follow the
Organization, 2003b);
• Compliance – the degree to which an individual's
behaviour (taking pills, following diets or changing
lifestyle) is congruent with medical or health advice
• Exercise – a type of physical activity, is defined as
planned, structured, and repetitive bodily movement
done to improve or maintain one or more components of
physical fitness (American College of Sports Medicine,
• Health – a complete state of physical, mental and
social well being (World Health Organisation, 1947);
• Health behaviour – a behaviour adopted with the
objective of preventing illness (Ogden, 2004);
• Health-related physical fitness – the ability to
Félix Hopffer Romero
Effects of a Physical Activity and Dietary Education Intervention in a Population with type
2 Diabetes Mellitus
associated with a low risk of premature development of
hypokinetic diseases. Health-related components of
fitness include cardio-vascular endurance, muscular
composition (American College of Sports Medicine,
• Hyperglicemia – abnormally increased glucose in the
blood such as in diabetes
mellitus (Dorland, 2007);
• Incidence – the number of new cases arising in a given
period in a specified population (Beaglehole, Bonita,
& Kjellström, 1993);
• Lifestyle – the set of habits and customs that are
influenced, changed, encouraged or restricted by a
process of socialization throughout life. It includes
the use or consumption of substances such as alcohol,
tobacco, tea or coffee, eating habits, exercise, etc.,
which have important implications on health and are
the subject of epidemiological investigations (Last,
• Physical Activity – a type of bodily movement that is
produced by the contraction of skeletal muscles and
(American College of Sports Medicine, 2009a);
• Physical Fitness – a set of attributes that people
possess or achieve that relates to the ability to
perform physical activity (American College of Sports
Medicine, 2009a);
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Effects of a Physical Activity and Dietary Education Intervention in a Population with type
2 Diabetes Mellitus
• Prevalence – the number of cases in a defined
population at a specified point in time (Beaglehole et
• Primary Prevention – set of measures aimed to limit
the incidence of disease by controlling causes and
risk factors. Primary prevention targets the total
population, selected groups and healthy individuals
(Beaglehole et al., 1993);
• Relative Risk – risk of an event (or of developing a
disease) relative to exposure. Relative risk is a
ratio of the probability of the event occurring in the
exposed group versus a non-exposed group (Last, 1995);
• Secondary prevention – set of measures aimed to cure
patients and reduce the more serious consequences of
Secondary prevention targets patients in the early
stages of the disease (Beaglehole et al., 1993).
• Tertiary prevention – set of measures aimed at
reducing the progress or complications of established
disease (Beaglehole et al., 1993). Tertiary prevention
targets patients with established disease and tries to
Armstrong, Macrena, & Pankau, 1999).
2.2. DEFINITION AND AETIOLOGY OF TYPE 2 DIABETES
Diabetes mellitus can manifest over different clinical
types. Type 2 diabetes results from a relative lack of
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Effects of a Physical Activity and Dietary Education Intervention in a Population with type
2 Diabetes Mellitus
insulin with a higher or lower degree of insulin resistance
and is the most common type of diabetes mellitus. It is
mainly due to a decrease in the number of insulin receptors
among peripheral cells, leading to a decreased glucose
uptake and increased levels of glycaemia. In order to
compensate for this decreased insulin sensitivity, the
pancreatic beta cells increase insulin excretion, leading
to hyperinsulinemia. This process worsens with age, because
the pancreas progressively fails to produce enough insulin
to compensate cells resistance (Bonen, 2001; Hornsby &
Albright, 2003; Steinberger & Daniels, 2003).
The criteria for the diagnosis of diabetes mellitus are
complications arise, rather than from deviation from
population normal parameters (A. Powers, 2006):
unexplained weight loss) plus fasting (defined as no
caloric intake for at least 8 hour) or nonfasting
plasma glucose ≥ 200 mg/dl.
2 - Fasting plasma glucose ≥ 126 mg/dl.
3 - Plasma glucose ≥ 200 mg/dl, 2 hours after an oral
glucose tolerance test with a 75 g load.
If hyperglycaemia is not unequivocal, the diagnosis should
be confirmed by a second test performed on a different day
(American Diabetes Association, 2004a; A. Powers, 2006).
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Effects of a Physical Activity and Dietary Education Intervention in a Population with type
2 Diabetes Mellitus
Some individuals have glycemic levels that, although not
reaching the above mentioned criteria, are too high to be
considered as normal. This group is defined as having:
• Impaired Fasting Glucose (IFG) if fasting plasma
glucose is between 100 mg/dl and 126 mg/dl;
• Impaired Glucose Tolerance (IGT) if plasma glucose
is between 140 mg/dl and 200 mg/dl 2 hours after an
oral glucose tolerance test.
These individuals have a 40% risk of developing diabetes
within a 5 year period (A. Powers, 2006) and, for this
reason, are referred as having "pre-diabetes" (American
Diabetes Association, 2004a).
The causes of diabetes can be separated into genetic and
environmental, with possible interactions between them
(Pratley, 1998). The genetic component of diabetes has been
shown through family (A. Powers, 2006; Weires et al.,
2007), or twins studies (Kyvik, Green, & Beck-Nielsen,
1995; Medici, Hawa, Ianari, Pyke, & Leslie, 1999; A.
Powers, 2006). The higher prevalence of diabetes in some
specific populations is other evidence of the genetic
component. The fact that populations sharing the same
genetic background but living in different environments
have distinct diabetes prevalence shows the importance of
the environmental component(Liao et al., 2002).
The causes of the epidemic growth of diabetes prevalence
must thus be looked for in the environmental component
because, as stated by Roberts and Barnard (2005): "100% of
the increase in the prevalence of Type 2 Diabetes and
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obesity in the United States during the latter half of the
20th century must be attributed to a changing environment
interacting with genes because 0% of the human genome has
changed during this time period". Some evidence of an
environmental component is provided by history - two
hundred years ago diabetes was a rare disease that affected
a privileged minority that could afford to be physically
inactive and had access to a rich diet (Lehmann, 1998).
In the last century the decrease in physical activity due
to technological progress associated with changes in
dietary patterns resulted in an unbalanced energy state
leading to obesity, a strong risk factor for type 2
diabetes (Blair, 2003; Swinburn & Egger, 2004).
Evidence of the role played by inappropriate dietary habits
and sedentary behaviour in the development of diabetes has
been accumulating over the past few years:
• The incidence of obesity and type 2 diabetes among
environments was compared. Individuals living in rural
Mexico with their traditional lifestyle of heavy
physical activity and a low fat diet showed lower
incidence rates than individuals living in Arizona
with a more sedentary life and a more westernized diet
(Kriska et al., 1993; Kriska et al., 2003; Ravussin,
Valencia, Esparza, Bennett, & Schulz, 1994). Similarly
the higher prevalence of type 2 diabetes among
American Japanese than among Japanese residing in
Japan can be explained by different lifestyles, with
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2 Diabetes Mellitus
lower levels of physical activity and a higher caloric
intake from fat (Liao et al., 2002).
• In a prospective study covering 42,504 male health
professionals a higher risk of type 2 diabetes was
found among subjects who reported high intakes of red
meat, high-fat dairy products, refined grain, sweets
and desserts, compared to subjects who had a diet
based on vegetables, fruit, fish, poultry and whole
grains (Roberts & Barnard, 2005).
• G. Hu et al(2004) found 120 new cases of diabetes when
analyzing the results of 2,017 men and 2,352 women
without a history of known or newly diagnosed diabetes
in a prospective study with an average duration of 9.4
years. The conclusion was that there is a higher risk
for obese, inactive and normoglycemic subjects of
becoming diabetic, compared to subjects with IGT, but
active and with a normal Body Mass Index (BMI).
• In another study, 5,159 men aged 40 to 59 years,
without a history of diabetes, and with no recall of
physician diagnosis of stroke or coronary heart
disease (CHD), were followed during an average of 16.8
years. During this period 196 new cases of diabetes
occurred (Wannamethee, Shaper, & Alberti, 2000). Again
an inverse relationship between incidence of type 2
persisted after adjusting for age, smoking, alcohol
intake, social class, BMI and pre-existing undiagnosed
CHD (measured through responses to a World Health
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possible myocardial infarction, or electrocardio-
graphic evidence of definite or possible myocardial
ischemia or myocardial infarction).
• G. Hu et al.(2003) followed 6,898 men and 7,392 women
without history of diabetes, CHD or stroke for an
average of 12 years. During this period, 373 new cases
of diabetes appeared. Again the protective effects of
exercise were found: 0.70 and 0.74 for moderate and
active work respectively; similarly the relative risks
for diabetes were 0.67 and 0.61 for moderate and high
leisure time physical activity. The benefits were
independent of the age, sex, arterial tension, smoking
habits or education. However, when adjusted to the
BMI, the results were not significant.
• F. B. Hu et al.(1999) conducted a prospective study
that included 70,102 female nurses and found that
greater physical activity level is associated with
substantial reduction in risk of type 2 diabetes,
including physical activity of moderate intensity and
duration. the relative risks of developing type 2
diabetes across quintiles of physical activity (least
to most) were 1.0, 0.77, 0.75, 0.62, and 0.54 (P for
Until the 20th century individuals performed most physical
activity as part of their occupations or in subsistence
activities. With the progress and the search for city life,
occupation-related physical demands have declined, and the
availability of leisure time has grown. Some studies on the
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effects of physical activity are focused only on leisure
• When comparing, throughout 10 years, the diabetic risk
for 1,340 men and 1,500 women with high, moderate and
Miilunpalo, Vuori, Oja, and Pasanen, (1997) found,
respectively, relative risks of 1,0;1,17 and 2,64 for
women and 1,0;1,21 and 1,54 for men. In this study
evidence was found that increased activity intensity
had a role in the reduction of the risk of diabetes.
• F. B. Hu, Leitzmann et al. (2001) used indirect
measures of leisure time physical activity noting the
time spent watching TV. They followed 37,918 subjects
over a 10 year period. Those who watched TV for over
21 h/week had a relative risk for type 2 diabetes of
2.16 when compared to the control group (≤1 hours/week
of TV). The relative risk was further increased to
2.87 in the group that watched TV for over 40 hours a
• The combined effect of diet and physical activity on
the relative risk for type 2 diabetes was assessed in
a study that followed 84,941 nurses for a period of
16 years (F. B. Hu, Manson et al., 2001). A low risk
group was defined according to a set of five variables
considered to have a protective effect against the
occurrence of diabetes: BMI <25 kg/m2; a diet rich in
cereal fibre and polyunsaturated fat, low in trans fat
and with a low glycemic load; at least 30 minutes of
moderate to vigorous physical activity per day; no
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smoking; moderate consumption of alcohol. During the
study 3,300 new cases of diabetes were diagnosed.
Participants from the low risk group had a relative
risk for diabetes of 0.09 (95% CI: 0.05-0.17) compared
to the added risk group.
These studies have identified the variables that possess
predictive value relative to the risk of diabetes, which
has allowed the construction of instruments for risk
stratification used in clinical practice (Lindstrom &
Tuomilehto, 2003).
2.3. CO-MORBIDITIES OF DIABETES
Diabetes is strongly associated with other metabolic
disorders which are, of themselves, hazards for death and
premature morbidity.
Most patients with insulin resistance or type 2 diabetes
are overweight or obese (Hawley, 2004; Hornsby & Albright,
2003; Steinberger & Daniels, 2003), and 60% to 90% of type
2 diabetes cases develop in obese subjects (Kelley &
Goodpaster, 2001; Shephard, 1997). In young populations,
the increase in the prevalence of type 2 diabetes seems to
parallel the increase in the prevalence of obesity
(Steinberger & Daniels, 2003; Rena R. Wing et al., 2001).
Hypertension and a degraded lipid profile are also related
to type 2 diabetes and insulin resistance (American
Diabetes Association, 2008b; American Diabetes Association
& American College of Sports Medicine, 1997; Buse et al.,
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considered one the most critical aspects in the care of the
patient with diabetes (Buse et al., 2007) because it
represents an independent risk factor for cardiovascular
disease (CVD), the major cause of morbidity and mortality
among diabetic patients (American Diabetes Association,
2008b). The prevalence of CVD can be as high as 40% among
middle-aged patients with type 2 diabetes and over 60% in
older patients (Kesavadev, Short, & Nair, 2003). It is
estimated that the risk of cardiovascular events starts at
a blood pressure higher than 115/75 mmHg, and doubles for
every 20 mmHg systolic or 10 mmHg diastolic increase.
Dyslipidemia is also an independent risk factor for CVD. A
lipid profile characterized by a low HDL cholesterol, a
high LDL cholesterol and high triglycerides has been
reported in obese and non obese adults with type 2
diabetes, in non obese adults with IGT and in obese
normoglycemic adults (Kesavadev et al., 2003; Steinberger &
Daniels, 2003). Lowering LDL cholesterol is considered the
primary objective of lipid lowering therapy by both the
American Diabetes Association and the American Heart
Association (Buse et al., 2007).
In the early stages, type 2 diabetes is asymptomatic and
may stay so for about 10 years (American Diabetes
Association, 2008b; Bonen, 2001). As a consequence, many
individuals are unaware of the disease, resulting in about
50% of undiagnosed cases (American College of Sports
Medicine, 2000; Kim, Rolland, Cepeda, Gammack, & Morley,
2006). Many diabetics seek medical advice only when
symptoms or other conditions associated with diabetes arise
and compromise daily well-being. In the final stages the
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consequences of diabetes include blindness, kidney failure,
American College of Sports Medicine, 1997; Booth & Winder,
Finally, the consequences of diabetes are not limited to
biological issues(Stanton, Revenson, & Tennen, 2007).
According with these authors, an important psychological
burden may be present. The very definition of chronic
disease – "illnesses that are prolonged, do not resolve
spontaneously, and are rarely cured completely" – carries
with it a sense of inevitability.
2.4. DIABETES: A PUBLIC HEALTH ISSUE
Diabetes is the most frequent metabolic disease and is now
one of the main public health problems worldwide. The
prevalence of diabetes is between 1 and 5% , but due to the
asymptomatic characteristics of the early stages of the
disease it is estimated that actually only 50% of cases are
diagnosed(Bonen, 2001; Wild, Roglic, Green, Sicree, & King,
2004). Thus the true prevalence of diabetes may be as high
as 10%, and type 2 diabetes accounts for 80 to 95% of all
cases (Bonen, 2001; Eichner, 2002; Heyward, 1991; Hornsby &
Albright, 2003; Miller & Dunstan, 2004; Steinberger &
Daniels, 2003; Strine et al., 2005).
The prevalence of diabetes is growing fast. Hawley (2004)
reported a six fold increase in type 2 diabetes between
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1958 and 1993 in the American adult population, while
McGinnis (2002) reported an increase from 4.9 to 6.5%
between 1990 and 1998 for the same population. Booth and
Winder (2005) reported diabetes as being the fifth leading
cause of death in the United States. In a study aimed at
estimating the prevalence of diabetes worldwide for years
1995, 2000 and 2025, King et al. (1998) predicted a further
increase in diabetes prevalence from 4.0% in 1995 to 5.4%
in 2025. Overall an estimated 300 million persons worldwide
will be suffering from diabetes in 2025. In that study
different trends were noted between developed and develop-
ping countries: a 42% increase is expected in developed
countries (51 to 72 million individuals), whereas in
developing countries this increase is much steeper (170%,
from 84 to 228 million individuals). Furthermore, in the
development and other factors: for instance in developed
countries there are more diabetic women than men, while in
developing countries the prevalence of diabetes is similar
in both genders. These authors also point that in
developing countries the major increment will occur in the
45-64 years age group, while in developed countries it will
occur in the over 65 year group. Once those were the age
groups that already had the largest proportion of diabetes
subjects in 1995, this trend will therefore be accentuated.
It has been estimated that, even if obesity were to stay
the same until 2030, which is not likely, diabetes
prevalence in the world will double because of ageing and
the search for an urban lifestyle (Wild et al., 2004).
Furthermore differences in diet, physical activity and
other socioeconomic factors result in a higher prevalence
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of diabetes in urban compared with rural areas (H. King et
al., 1998). The current population migrations from a rural
to an urban environment could thus be a contributing factor
to an increase in diabetes prevalence.
Based on data from the National Health Survey it is
estimated that diabetes prevalence in Portugal increased
from 4.7% in 1999 to 6.7% in 2006 and then to 8.2% in 2007.
Estimates for 2025 point to 9.8% prevalence(Direcção Geral
de Saúde, 2008).
Diabetes is not just getting more prevalent; it's growing
across the lifespan too. For a long time type 2 diabetes
was considered to be a disease of adults, mostly because
most cases usually occurred after the age of 40 (Bonen,
2001; Hornsby & Albright, 2003; H. King et al., 1998).
However the increase in the prevalence of diabetes is no
longer restricted to this age group; indeed diabetes is
increasingly affecting younger individuals (Bonen, 2001;
Lehmann, 1998; Sinha et al., 2002; Steinberger & Daniels,
2003). Between 1982 and 1994 the prevalence of diabetes
increased tenfold in adolescents and currently about 30% of
newly diagnosed cases occur in subjects aged between 10 and
19 years (Kabadi, 2004). The increasing prevalence amongst
young subjects was reported by Sinha (2002)who found in a
study of 167 children and obese adolescents that 25% of the
children aged between 4 and 10 years and 21% of adolescents
aged between 11 to 18 years old had IGT, while 4% of the
adolescents were diabetics.
The current prevalence of pre-diabetic individuals is also
high. In the United States 34% of the total adult
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population have IFG, while 15% have IGT and 40% have one or
both of these conditions (Centers for Disease Control and
Prevention, 2003). The situation is particularly serious
among the elderly, and it has been reported by Lehmann
(1998) that a quarter (25%) of subjects aged over 70 have
IGT. In Portugal IGT prevalence is estimated at 10.1%
(Direcção Geral de Saúde, 2008).
2.5. ECONOMIC BURDEN OF DIABETES
diabetes, different kinds of costs may be considered
(International Diabetes Federation, 2006a):
• Direct costs to patients with diabetes and their
families. Living with diabetes leads to the patient
and his/her family carrying a significant economic
burden through the cost of medications and frequent
medical visits. Diabetic patients also have a higher
probability of being admitted to a hospital (Bo et
al., 2004), a greater risk of disability (American
Diabetes Association, 2003), and their family income
is frequently reduced when diabetes interferes with
their work (International Diabetes Federation, 2006b).
The economic impact of the disease can thus be
considerable, especially in the poorest countries,
where diabetic patients and their families bear almost
the entire cost of whatever medical care they can
afford. In those countries insulin is not subsidized
by governments (who instead tax it heavily), and it is
often not available at any price, which results in
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high rates of premature death (International Diabetes
Federation, 2006b). For instance in India the poorest
individuals with diabetes spend an average of 25% of
their income on private care, whereas in Latin America
40 to 60% of diabetes care costs are paid for directly
2006b). In Portugal the expense of drugs directly
associated with diabetes is borne entirely by the
healthcare system. However the treatment of co-
policies for each pathology.
• Direct costs to healthcare systems. Since diabetes is
peripheral cardiovascular, endocrine/metabolic, renal,
vascular and ophthalmological), part of the costs
related to those diseases can be attributed to
diabetes. That amount is calculated by comparing the
health care use pattern between subjects with and
without diabetes. In the United States of America the
direct costs attributable to diabetes amounted to
$91.8 billion in 2002. Diabetes accounts for about 10%
of acute hospitalizations (Shephard, 1997), and it has
been estimated that the 4.5% of Americans with
confirmed diabetes represent 14.6% of United States of
Hospitalisation (43.9%) and nursing home care (15.1%)
were the major expenditure groups (American Diabetes
Association, 2003). Also in the United States of
America the
per capita annual healthcare costs reached
$13,243 for diabetic vs. $2,560 for non-diabetic
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patients; when corrected for age, ethnicity and
gender, diabetic patients still had 2.4 times higher
healthcare costs than non-diabetic (American Diabetes
Association, 2003). These results are in line with
estimates done by Rubin, Altman, and Mendelson (1994)
or by Nogueira (1999) who found, respectively, a 3 and
a 2.5 times increase in
per capita health care
expenditures among diabetics. In Spain it is estimated
that 6.3 to 7.4% of total public health expenditure is
attributable to diabetes (Oliva, Lobo, Molina, &
Monereo, 2004) and hospitalization (35-39%) and drugs
(31-36%)were the most important items. In this study
p
er capita annual expenditure was €1,290 to €1,476 for
diabetics and €860 for non-diabetics. In Portugal, the
direct healthcare costs attributable to diabetes for
(Nogueira, 1999). The abovementioned sums are actually
underestimated, because in all studies subjects with
undiagnosed diabetes were considered as non-diabetics.
Also this value does not take into account the cost of
diabetes apply more frequently. Finally it should be
stressed that inadequate diabetic control and the
treatment costs (Gonçalves, 2001).
• Indirect costs. Diabetes leads to increased work
absenteeism and premature retirement, thus reducing
productivity (Gonçalves, 2001; Nogueira, 1999). The
stress and anxiety of daily living and, in some
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situations, the pain, are costs that are intangible
and therefore unquantifiable.
CVD is the major cause of morbidity and mortality among
individuals with diabetes, and it is also the largest
contributor to both the direct and indirect costs of
diabetes (American Diabetes Association, 2009). In the
United States of America direct and indirect expenditure
associated with diabetes reached $132 billion in 2002
forecast $156 billion expenses by 2010 were actually
surpassed by the $174 billion spent in 2007 (American
Diabetes Association, 2008a). Lifestyle changes could help
in attenuating this situation but in most modern societies
pharmacological interventions are preferred, and this leads
to an increased economic burden (Bonen, 2001)
.
The economic analysis of programs designed to encourage the
efficiency; however the programs usually imply short term
expenses and long term benefits(Cefalu, 2004). This author
points that these studies are generally made in respect of
a specific disease but, because some risk factors for type
2 diabetes, such as obesity, smoking, hypertension or
hyperlipidemia, are also risk factors for other diseases
and seem to be correlated to each other, these studies may
underestimate the actual economic effectiveness of such
Several economists and public health experts have tried to
identify strategies to achieve population-wide lifestyle
changes (Hill, Sallis, & Peters, 2004). In this study the
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main conclusions were that psycho-social models aimed at
changing individual behaviours are worthwhile, but only
reach a small number of participants and have low
maintenance rates. To these authors, individual behaviour
will change only if there is concerted action across the
environments and policies, producing a synergistic effect.
It is essential that a study be made of market driving
forces especially in the food business and also in a varied
set of industries that relate to physical activity and
sedentary behaviours, perhaps without being conscious of
their role in this problem.
2.6. PREVENTION OF DIABETES
2.6.1. PRIMARY/SECONDARY PREVENTION
Due to the long period of development of the illness, the
majority of the studies on diabetes prevention are
conducted on samples with high-risk participants (usually
with IFG or IGT), as in such cases about 30 to 50% of the
participants will develop diabetes within 10 years time
(Tuomilehto, 2005).
Three large randomized controlled trials assessed the
efficiency of lifestyle changes in diabetes prevention: The
Diabetes Prevention Program(The Diabetes Prevention Program
Research Group, 1999), the Finnish Diabetes Prevention
Study(Tuomilehto et al., 2001) and the Da Quing Prevention
Study(Pan et al., 1997).
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Since 1999 the Diabetes Prevention Program Research Group
implemented a randomised clinical trial in order to test
strategies to prevent and delay the development of type 2
diabetes. This program (The Diabetes Prevention Program
Research Group, 2002b) randomly assigned 3,234 individuals
with IGT aged 25-85 years, with a wide distribution of
obesity and ethnic backgrounds (The Diabetes Prevention
Program Research Group, 2000), to three groups: a control
group that received a placebo, a diet and exercise group
(moderate exercise for 150 min /week) and a pharmacotherapy
group that received metformin (The Diabetes Prevention
Program Research Group, 1999). Lifestyle intervention
information regarding nutrition, physical activity and
sessions following the core curriculum were also scheduled
(The Diabetes Prevention Program Research Group, 2002a).
Dietary advice was focused on reducing total fat, and
participants were taught and asked to self monitor fat and
calory intake and to keep a log of their physical activity.
Supervised physical activity was provided twice a week but
attendance was voluntary. Both control and metformin groups
received standard lifestyle recommendations, i.e. written
information and an annual 20 to 30 minutes individual
session that emphasized the relevance of a healthy
lifestyle. After 3 years of follow-up, the diet and
exercise group lost 5 to 7% of body weight and had a risk
reduction of 58% (95% CI: 48-66%) compared with the control
group. Metformin was also effective, but in this group only
a 31% (95% CI: 17-43%) risk reduction was achieved (The
Diabetes Prevention Program Research Group, 2002b). These
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interventions were estimated to delay the development of
diabetes by 11 years (lifestyle) and 3 years (metformin)
and to reduce the incidence of diabetes by 20% and 8%
respectively (Herman et al., 2005). The impact of these
interventions on CVD risk factors such as hypertension,
dyslipidemia was also assessed (The Diabetes Prevention
Program Research Group, 2005a). Reduction in hypertension
metformin groups for both systolic and diastolic pressures.
Among hypertensive individuals at baseline, control was
achieved for the lifestyle group with a 5% additional
hypertensive therapy, while in the control and metformin
groups a 15% increase was necessary. Total cholesterol and
LDL showed no statistical differences between groups.
Triglycerides fell in all groups but significantly more in
the lifestyle group. HDL levels increased significantly in
the lifestyle group compared to metformin or control
groups. Conversely, there were too few CVD events for an
effectiveness of these interventions was compared both from
a societal perspective including direct (medical and non-
medical) and indirect costs, and from a health care
perspective that considered only direct medical costs (The
Diabetes Prevention Program Research Group, 2003). The
lifestyle intervention was the most cost–effective in both
analyses, followed by the metformin intervention: from a
societal point of view the lifestyle and metformin
intervention had respectively costs of $24,400 and $34,500
per case of diabetes delayed or prevented. From a health
care point of view those costs were $15,700 for the
lifestyle and $31,300 for the metformin interventions.
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In the Finnish Diabetes Prevention Study, (Tuomilehto et
al., 2001) a study was made of 522 middle-aged individuals
with impaired glucose tolerance, randomly assigned to a
control group (general oral and written information about
intervention that included individualised dietary advice by
a nutritionist (7 sessions in the first year and every
three months afterwards) and exercise for at least 30
minutes a day (supervised aerobic activities and circuit
training). After the 3.2 years follow-up, the risk of type
2 diabetes was 58% (hazard ratio 0.4; 95% CI: 0.3-0.7; p
<0.001) lower in the intervention group than in their
control counterparts. Compared with the control group, the
intensive lifestyle intervention group had a significantly
greater reduction in weight, waist circumference, fasting
and 2 hours glycaemia after oral glucose challenge, total
cholesterol and triglycerides, systolic blood pressure
(SBP), diastolic blood pressure (DBP) and HbA1c, and higher
HDL cholesterol levels (Lindstrom et al., 2003; Tuomilehto
Also in the Finnish Diabetes Prevention Study, Laaksonen et
al (2005) followed 487 individuals for 4.1 years with
impaired glucose tolerance. The purpose of the study was to
determine the role of leisure time physical activity (LTPA)
in the prevention of diabetes. Individuals who had
increased their levels from moderate to vigorous LTPA had a
63 to 65% risk reduction. Walking and low intensity LTPA
increases were also effective, but in a more modest way.
Results were attenuated when corrected for changes in diet
and body weight. A follow-up of the participants was
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counselling (Lindström et al., 2006). A relative risk
reduction of 36% was still found in the intensive lifestyle
intervention group. This reduction was related to achieved
goals for weight loss, reduced intake of total and
saturated fat, increased intake in dietary fibre and
increased physical activity.
The Da Qing Prevention Study (Pan et al., 1997) followed
577 middle-aged individuals for 6 years. Participants were
randomized to one of four groups: control, diet only,
exercise only and diet plus exercise. Compared to the
control group, significant reductions in the risk of
developing type 2 diabetes were obtained (31%, 46% and 42%
for the diet only, exercise only and diet plus exercise
groups respectively), after adjustment for baseline BMI and
fasting glucose.
The findings of these three seminal studies were further
confirmed by others. In the Malmö Preventive Trial,
Eriksson & Lindgärde (1998) followed 6,956 men and compared
mortality rates among 4 different groups: normoglycemic
individuals (control group), a "usual care" IGT group, an
IGT lifestyle intervention group and a type 2 diabetes
lifestyle intervention group including systematic dietary
advice and exercise. After 12 years follow-up, the
mortality rate in the diabetes group was the highest - 22.6
per 1,000 person years (95% CI: 15.6-31.5) followed by IGT
routine treatment group - 14.0 per 1,000 person years (95%
CI: 8.7-21.4). The lowest mortality rates were found in the
IGT lifestyle group - 6.5 per 1,000 person years (95% CI:
4.1-9.9) and in the normoglycemic group - 6.2 per 1,000
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person years (95% CI: 5.7-6.8). These groups showed no
significant differences between them. In that study BMI,
SBP, smoking or cholesterol failed to predict mortality
among individuals with IGT.
Lower reductions in diabetes risk were found in the Indian
Diabetes Prevention Program where 531 individuals with IGT
were followed during 3 years (Ramachandran et al., 2006).
Participants were randomly distributed into 4 groups:
control (usual care), metformin alone, lifestyle alone and
lifestyle plus metformin. Lifestyle intervention consisted
of dietary and physical activity advice. Compared with the
control group significant risk reductions were found for
lifestyle plus metformin groups (-28.2%). Interestingly the
combination lifestyle plus metformin did not provide
additional protection relative to each intervention alone.
These results do not confirm those obtained in the Diabetes
Prevention Program, the study of Da Quing or the Finnish
Diabetes Prevention Study. The fact that the intervention
was limited to counselling, did not have supervised
physical activity and that the population studied had
different characteristics (the participants were younger
and leaner) compared to the participants analyzed in those
studies, might partly explain those findings.
Mensink, Feskens, Saris, de Bruin, and Blaak, (2003)
evaluated the effect of a lifestyle intervention program in
102 both gender individuals with IGT. 30 minutes of daily
physical exercise were recommended to the intervention
group, and free access was granted to physical activity
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lessons integrating aerobic and resistance components.
Personal nutrition advice was also given to this group,
aimed at a weight loss of between 5 and 10% over a one-year
period. The control group was informed of the benefits of
exercise and of a healthy diet. The results confirmed the
intervention efficiency: a mean weight loss of 2.7Kg,
improved tolerance to glucose (-0.8 mmol/l) and improvement
of cardio-respiratory capacity (0.1 l/min in VO2max).
Kosaka, Noda, and Kuzuya (2005) conducted a randomized
trial assigning 458 individuals with IGT to a control and
an intervention group. Subjects from the control group
received standard information, were advised to take 5-10%
smaller meals and to increase their physical activity.
Those recommendations were explained again every 6 months.
The intervention group received individual counselling
regarding adequate food consumption and 30 to 40 minutes
walking each day was recommended. The intervention group
also had their physical activity and usual dietary patterns
assessed every 2-3 months. After 4 years diabetes incidence
was 9.3% in the control group and 3.0% in the intervention
(p<0.001). The authors noted that the reduction in
incidence of diabetes in the intervention group was steeper
than expected simply on the basis of the reduction of BMI.
Also Liao et al. (2002) showed a lifestyle intervention
directed at patients with IGT to be effective. In that
study 64 subjects were randomized to a control or
intervention group. The intervention included diet (less
than 30% of total calories as fat, less than 7% saturated
fat, 55% carbohydrate and 200 mg cholesterol daily) and
Félix Hopffer Romero
Effects of a Physical Activity and Dietary Education Intervention in a Population with type
2 Diabetes Mellitus
endurance exercise for 1 h three times a week. The control
group was also prescribed a diet (less than 30% of total
calories as fat, less than 10% saturated fat, 50%
carbohydrate and 300 mg cholesterol daily) and a stretching
exercise for 1 h three times a week. After 6 months the
intervention group showed significantly greater reduction
in BMI and percent body fat and an increase in cardio
respiratory fitness (VO2max).
In a meta-analysis regarding efficiency of lifestyle based
interventions on subjects with a high risk for type 2
diabetes (Yamaoka & Tango, 2005), 9 randomized controlled
trials were found. From a combined analysis their authors
concluded that it is possible to reduce risk for type 2
diabetes by about 50%. This reduction seems to be effective
for different BMI levels as proven by the American Diabetes
Prevention Program and the Finnish Diabetes Prevention
Study that reach the same conclusions about populations
with different BMIs. However lifestyle interventions might
have effects that are not mediated by weight reduction (F.
B. Hu, Manson et al., 2001; G. Hu et al., 2004; Kosaka et
al., 2005; LaMonte, Blair, & Church, 2005; Pan et al.,
1997; Wannamethee et al., 2000).
In short, and despite the considerable heterogeneity in the
content and the way the interventions in these studies were
implemented, it was possible to identify some similar
results such as increased insulin sensitivity (Carr et al.,
2005; Mayer-Davis et al., 1998; Perseghin et al., 1996; R.
R. Wing, Venditti, Jakicic, Polley, & Lang, 1998), improved
glycemic control (J. Eriksson et al., 1999; Galani &
Schneider, 2007; Kosaka et al., 2005; Lindstrom et al.,
Félix Hopffer Romero
Effects of a Physical Activity and Dietary Education Intervention in a Population with type
2 Diabetes Mellitus
2003; Tuomilehto et al., 2001) better lipid profile (Galani
& Schneider, 2007; Lindstrom et al., 2003; Petrella,
Lattanzio, Demeray, Varallo, & Blore, 2005; Stefanick et
al., 1998; The Diabetes Prevention Program Research Group,
2005a; Tuomilehto et al., 2001; R. R. Wing et al., 1998),
weight/ BMI reduction (Carr et al., 2005; J. Eriksson et
al., 1999; Galani & Schneider, 2007; Kosaka et al., 2005;
Liao et al., 2002; Lindstrom et al., 2003; Mensink,
Feskens, Saris, de Bruin, & Blaak, 2003; The Diabetes
Prevention Program Research Group, 2005b; Tuomilehto et
al., 2001; R. R. Wing et al., 1998), lowered blood pressure
(J. Eriksson et al., 1999; Galani & Schneider, 2007;
Petrella et al., 2005; Stefanick et al., 1998; The Diabetes
Prevention Program Research Group, 2005a; Tuomilehto et
al., 2001; R. R. Wing et al., 1998) and better cardio
respiratory fitness (Carr et al., 2005; Mensink et al.,
2003; Petrella et al., 2005; R. R. Wing et al., 1998).
2.6.2. TERTIARY PREVENTION
The impact of lifestyle change programs in individuals with
diagnosed type 2 diabetes has equally been studied.
Table 1
presents a summary of these studies.
Improvements identified in secondary prevention trials are
confirmed in tertiary prevention: lifestyle interventions
directed to type 2 diabetic patients tend to improve
glycemic control. For HbA1c, improvements can reach as much
as 10-20% of baseline (American Diabetes Association &
American College of Sports Medicine, 1997).
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The influence of the type of exercise was analysed in a
meta-analysis (Snowling & Hopkins, 2006) that found that
small to moderate reductions in HbA1c occur as a result of
either resistance, aerobic or combined training in programs
of at least 12 weeks duration. Combined training appeared
to be the most effective, with decreases in HbA1c
comparable to those obtained through diet or insulin (0.6-
Using continuous glucose monitoring, Macdonald, Philip,
Harrison, Bone and Watt (2006) concluded that moderate
exercise improved glycemic control for a 20 hours period in
obese individuals with type 2 diabetes. Periods of 24 to 72
hours are also referred (Horowitz, 2007; Sigal, Kenny,
Wasserman, Castaneda-Sceppa, & White, 2006). This acute
effect of exercise depends on exercise intensity and
duration and can be increased in trained individuals
(Colberg, 2006). Regularity in exercise is therefore
important, because this acute effect is the most important
effect of exercise on glycemic control (A. Kirk, N. Mutrie,
P. MacIntyre, & M. Fisher, 2004; Miller & Dunstan, 2004).
Regarding exercise intensity, there is some evidence that
more intense exercise has an increased effect on glycemic
control. American Diabetes Association recommendations
(Sigal et al., 2006) encourage type 2 diabetic individuals
who are already exercising to increase their exercise
intensity in order to achieve better glycemic control and
improved aerobic fitness.
In their meta-analysis of the effects of aerobic exercise
interventions on cardio-respiratory fitness in adults with
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2 Diabetes Mellitus
type 2 diabetes, Boulé, Wells, Sigal, Kenny and Haddad
(2003) selected only interventions that lasted for over 8
weeks. They found larger reductions in HbA1c in studies
with more intense exercise interventions, but they also
noted that these more intense interventions were done with
younger samples and therefore an age effect might be
present. Interventions resulted in an overall increase in
VO2max of 11.8% versus a 1% decrease in the controls.
Considering only intervention groups submitted to moderate
intensities, an increase of 9.5% of VO2max was achieved.
Even if trainable, exercise capacity may be compromised in
diabetic or even pre-diabetic patients (Fang, Sharman,
Prins, & Marwick, 2005). In older individuals with type 2
diabetes exercise capacity may be seriously limited and the
ability to increase exercise intensity may be very
low(Kesavadev et al., 2003).
Besides that, in these individuals, the effect of exercise
over insulin sensitivity may be much milder(Kesavadev et
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Table 1 – Tertiary lifestyle interventions according to country, sample, age, intervention and results
Reference
Age (years)
69.5 ± 5.1
For 16weeks- three
↑ Exercise capacity,
(Tessier et
(Control)
times a week 1 hour
Glycemic control
al., 2000)
(20C; 19I)
69.3 ± 4.2
aerobic, strength,
(Intervention group)
stretching session
↓risk of cardiovascular
(F. B. Hu,
5,125 female
events with increase in
Stampfer et
hours of moderate to
al., 2001)
vigorous PA
=Total cholesterol,
(Castaneda
16 weeks with a 3
(borderline),HDL,LDL, DBP
(31C; 31I)
↓ HbA1c, FPG, and SBP for
intervention group
(Maiorana,
(group A 6-
↑ Cardio respiratory
O'Driscoll,
training combining
fitness; muscular
Goodman,
Australia
strength and ↓ HbA1c FPG,
Taylor, &
resistance exercise
HR for trained group
group B 10-
trained last
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Effects of a Physical Activity and Dietary Education Intervention in a Population with type 2 Diabetes Mellitus
↑ HbA1c, Total
Cholesterol and SBP for
(A. Kirk et
Physical activity
control group
Scotland
57.6 ± 7.9
al., 2004)
(35C; 35I)
↓ HbA1c, Total
Cholesterol and SBP for
intervention group
=BW;BF;HbA1c,FPG, VO2max
55.3 ± 3.2
For 6 months 20 to 40
for control group
minutes sessions 4
↑VO2max and
al., 2004)
59.5 ± 2.5
↓BW;BF;HbA1c,FPG for
intervention group
↓ HbA1c, weight ,waist
Individual and group
53.3 ± 8.4
al., 2004)
(73C; 74I)
prescription medications
dieticians advice
for intervention group
(Tokmakidis
, Zois,
4 months strength and
↑ upper and lower body
Volaklis,
55.2 ± 6.7
aerobic training
strength
↓ HbA1c, FPG
Touvra,
2004)
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Effects of a Physical Activity and Dietary Education Intervention in a Population with type 2 Diabetes Mellitus
No change after 4 weeks
control period.
4 week control period
After PRT: ↑ leg and arm
(Ibanez et
66.6 ± 3.1
maximal strength; insulin
al., 2005)
sensitivity
=BMI; ↓subcutaneous
abdominal fat
↑HDL and ↓SBP, DBP, BMI,
59.3 ± 6.2
Wandell,
For 4 months - 45
Total cholesterol, LDL
(Control)
minutes brisk walking
for intervention group
(26C; 26I)
Engfeldt,
= HbA1c, FPG for both
= HbA1c,;SBP; DBP for
30minutes videotape
56.6 ± 9.6
both groups
(39C; 37I)
guided home based
al., 2008)
↓BMI for intervention
exercise 5 days/week
BF – Body Fat; BMI -Body Mass Index; BW – Body Weight; C-Control; DBP –Diastolic Blood Pressure; FPG – Fasting Plasma Glucose; HR – Heart Rate; I – Intervention; PA –Physical Activity; PRT – Progressive Resistance Training; SBP Systolic Blood Pressure.
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Tessier et al. (2000) studied the effect of aerobic
exercise in 39 type 2 diabetics, aged over 65 years,
submitted to a supervised exercise program 3 times a week.
Each 60 minute exercise session comprised a 10 minute warm–
up phase, a cardiovascular phase consisting of a 20 minute
rapid walk, a 20 minute strength/endurance phase comprising
2 sets of 20 repetitions involving major muscle groups, and
a 10 minute stretching/relaxation phase. After 16 weeks,
significant improvements were found in cardio-respiratory
fitness for the experimental but not in the control group.
However no significant decreases were found in HbA1c,
neither in the control nor in the intervention group.
Although these results point to a limited effect of
exercise in older individuals regarding glycemic control,
they also stress its importance in the improvement of
respiratory fitness and thus in the reduction of CVD risk
factors. This is an important goal in tertiary prevention,
because CVD is one of the major complications of diabetes.
F.B. Hu, Stampfer et al. (2001), followed 5,125 diabetic
women for 14 years and found a significantly lower risk for
physical activity, including walking. Indeed walking is the
exercise of choice for many diabetics because it is simple
to do and does not require a formal structured exercise
program (Bonen, 2001; Laffrey, 2000). For instance a two-
fold reduction in all-cause mortality risk and a five-fold
reduction of non-CHD CVD was found in older adults with
type 2 diabetes who walked over a mile per day (Tyler,
Deborah, Besa, Kritz-Silverstein, & Barrett-Connor, 2006).
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2.7. TREATMENT OF DIABETES
Glycemic control is the major objective of diabetic
capillary glycaemia, but the control of glycosylated
haemoglobin (HbA1c) is considered the primary goal of
diabetes therapy because it expresses the average glycemic
control achieved in the last 2-3 months (Eichner, 2002; A.
Powers, 2006). Target values for HbA1c may vary according
to patient functional status and co-morbidities, but in a
healthy individual or in an adequately treated type 2
diabetic, HbA1c should stand below 7% (American Diabetes
Association, 2009; A. Powers, 2006).
Three main distinctive intervention areas are cornerstones
in fighting diabetes: pharmacotherapy, diet and physical
2.7.1. DRUG TREATMENT
Pharmacotherapy is beyond the scope of this study, and,
therefore, we will refer to this subject only marginally.
Oral antidiabetic drugs include sulfonylureas, biguanides
and alpha glucosidase inhibitors, which can be taken
isolated or combined. In more severe cases, and despite
adequate compliance with diet, exercise and oral agents,
glycemic control is still poor. In those cases insulin
administration is mandatory.
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2.7.2. DIET
Diet is a key element for the management and prevention of
diabetes. Diets should be planned taking into account the
usual eating habits and preferences of the patient (Klein
et al., 2004) and, whenever possible, should be tailored to
increase compliance. Albeit the fundamental principle is a
nutritionally balanced diet (Kesavadev et al., 2003), a
reduction in fat intake is commonly recommended. Indeed
most successful diets are usually low fat diets, where fat
intake represents 25-30% of total calories (Klein et al.,
2004). Further due to the high prevalence of overweight and
obesity among diabetics, most diets are also designed to
achieve weight control. Beattie (2001) refers to different
• Individualised moderate energy deficit diet: daily
energy requirements are estimated taking into account
age, sex, weight and physical activity level. A diet
is established based on a 600 calories deficit
relative to this value. This diet should allow a loss
of 0.5-1 kg/week.
• Fixed moderate energy diet: standardized diets with
1200-1300 calories per day. This kind of diet allows a
weight loss of about 1 kg/week but has a high dropout
due to restricted food choice that leads to monotony.
• Calory-counting diets: these diets are rarely used in
the clinical setting; they are more flexible regarding
food choices but they also imply a good knowledge of
food calory contents and the ability to control
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portion sizes. The lack of professional advice may
lead to undesirable results.
• Very low calorie diets (250-800 calories/day) are not
effective in the long term (P. Powers, 2005). Usually
liquid based they lead to substantial weight loss due
to severe energy depletion. Weight rebound and loss of
lean mass are common and medical complications may
If weight control is the objective, an appropriate goal
setting is fundamental. Unattainable objectives usually
lead to treatment failure and decreased compliance. Indeed
a 5% weight loss may have a significant effect on health
and is an attainable and reasonable initial goal (Klein et
2.7.3. PHYSICAL ACTIVITY
The role of physical activity and exercise in the
prevention and treatment of type 2 diabetes is recognized
by the American Diabetes Association, the American College
of Sports Medicine, the North American Association for the
Study of Obesity or the American Society for Clinical
Nutrition (American Diabetes Association & American College
Association, the North American Association for the Study
of Obesity, & American Society for Clinical Nutrition,
It is consensual that moderate intensity physical activity
provides an adequate protective effect, and guidelines from
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type 2 Diabetes Mellitus
the American College of Sports Medicine, the American
Diabetes Association (American Diabetes Association &
American College of Sports Medicine, 1997), the North
American Association for the Study of Obesity or the
American Society for Clinical Nutrition (Klein et al.,
2004) recommend moderate intensity physical activity for
about 30 minutes most days of the week (U.S. Department of
Health and Human Services, 1996).
In each session a 5 to 10 minutes warm up period is
required before progressing to moderate intensity exercise
(American College of Sports Medicine, 2009b). In the core
part of the session, activities that use large muscles in a
rhythmic and continuous way should be emphasized (American
College of Sports Medicine, 2009b). Exercise intensity
should correspond to 50 to 80% of the heart rate reserve,
corresponding to a rating of perceived exertion of 12 to 16
on a 6 to 20 scale(American College of Sports Medicine,
2009a). If the exercise intensity is too high, the release
of epinephrine and norepinephrine will be exaggerated,
leading to an increased glucose production, which may
result in transient hyperglycaemia in a diabetic patient
(Colberg, 2006). A cool down period is required to prevent
a sudden reduction in venous return and to allow a gradual
redistribution of blood from the extremities to other
tissues(American College of Sports Medicine, 2009b).
During exercise insulin production is decreased due to the
action of catecholamines and glucagon, two hormones that
increase the release of glucose by the liver. This action
is intended to compensate the increase in glycogen
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hypoglycaemia. Exercise duration is therefore important,
because muscles' carbohydrate stores are limited, and even
in a healthy individual hypoglycemia may arise (Colberg,
2006). In exercising type 2 diabetic patients this decrease
in insulin production may not be enough. In this case, the
production of an adequate blood glucose level (over 65
mg/dl) may be compromised and the risk of hypoglycaemia
rises substantially (Colberg, 2006).
During the process of restoration of muscle glycogen after
physical activity, glucose is taken up from the blood in an
insulin-independent process (Kesavadev et al., 2003).
Exercise enhances tissue glucose uptake for a period that
may last for 24 to 72 hours(Sigal et al., 2006), and is the
most important effect of exercise in glycemic control
(Colberg, 2006; Horowitz, 2007). There is some doubt about
how much of the benefit is due to a training effect and how
much is due to replenishment of glycogen stores, but after
exercise the muscle is more sensitive to insulin action
(Bonen, 2001; Shephard, 1997). Thus regularity of exercise
is important, not because of its long term effect, but in
order to ensure the continuous acute effect of exercise.
Exercise planning for individuals with type 2 diabetes
should take into account the following points:
• Before engaging in an exercise program, type 2
diabetes patients should have an extensive medical
evaluation where the cardiovascular, nervous, renal
and visual systems should be screened for related
diabetic complications (American College of Sports
Medicine, 2009a);
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type 2 Diabetes Mellitus
• Sports that involve intense body contact should be
detachment (Sigal et al., 2006);
• Isolated sports practice should also be prevented,
especially if it occurs in hazardous environments
(such as diving or parachuting) due to the potentially
fatal consequences of a hypoglycaemia (Barata, 1997);
• Competitive exercises that lead to exhaustion might
cause excessive levels of stress. Moderate exercise is
characteristics, with the promotion and keeping of
self-esteem, with satisfaction with life and with a
better quality of life (Cruz, Machado, & Mota, 1996);
• Aerobic training appears to be associated with better
glycemic control while high intensity exercise may
result in transient hyperglycemia and may not be
appropriate especially for older people (Colberg,
• Glucose monitoring before and after exercise is
required (American College of Sports Medicine, 2009b);
• Exercise should be avoided if fasting glucose levels
are over 250 mg/dl or if non-fasting glucose levels
are over 300 mg/dl (Albright, 1997; Sigal et al.,
• Participants should be aware of hypoglycaemia
symptoms. In older people these symptoms may be less
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type 2 Diabetes Mellitus
intense than in younger people (Kesavadev et al.,
2003; Williamson, 2011);
• A supervised environment is recommended until
• Quantifiable and reproducible ways of exercise are
desirable, because exercise prescription and load
dynamics are easier to adjust (American College of
Sports Medicine, 2009b);
• Proper footwear is required and special attention
should be paid to foot–gel or air mid-soles. Polyester
Diabetes Association & American College of Sports
Medicine, 1997);
• A diabetes identification bracelet or shoe tag should
be clearly visible when exercising (American Diabetes
Association & American College of Sports Medicine,
• A source of rapidly acting carbohydrate must be
available during exercise (Albright, 1997; Colberg,
2006; Williamson, 2011);
• Exercise should include proper warm-up and cool-down
periods (American Diabetes Association & American
College of Sports Medicine, 1997; Williamson, 2011);
• Proper hydration is required during exercise
(Albright, 1997; American Diabetes Association &
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Effects of a Physical Activity and Dietary Education Intervention in a Population with
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American College of Sports Medicine, 1997; Williamson,
2011). Physical Activity in the heat needs special
attention (American Diabetes Association, 2004b);
• Prolonged exercise (over 1 h) may cause hypoglycaemia.
This situation is enhanced by the use of insulin or
oral hypoglycemic agents, therefore, a pre-exercise
carbohydrate ingestion may be needed, aiming at a
blood glucose level of 100 mg/dl. Adjustments in
therapy might also be needed(Kesavadev et al., 2003);
• High-resistance exercise using weights may be
acceptable for young people with diabetes, but not for
diabetes(American Diabetes Association, 2004b);
• Individuals with neuropathy in the legs and feet may
experience balance and gait problems and should avoid
patterns(Williamson, 2011);
• Exercise should be done daily. If that is not
possible, the maximum interval between exercise bouts
should be minimized (Sigal et al., 2006).
2.8. IMPLEMENTATION OF LIFESTYLE CHANGES
Exercising regularly as well as keeping a proper diet,
requires, in the vast majority of cases, a fundamental
change in lifestyle. The problem is not so much the
effectiveness of lifestyle changes but how to promote these
changes in a sustainable manner. In this chapter strategies
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Effects of a Physical Activity and Dietary Education Intervention in a Population with
type 2 Diabetes Mellitus
to implement lifestyle changes and factors related to
compliance will be briefly reviewed.
Compliance with diabetes treatment implies a wide set of
health behaviours: continuous control over diet, increasing
physical activity, taking pills, daily assessment of
glycaemia, daily checking of feet and periodical clinical
exams. The degree of involvement of the patient is very
high, as it demands not only knowledge about the disease,
but also a considerable compliance effort (Eichner, 2002).
Very often patients do not adhere to the prescribed
treatment plan (Eichner, 2002). Lifestyle changes regarding
diet and exercise may be complex and are aimed at the long
term, leading to reduced compliance.
Diabetic patients require continuing medical care and self-
management education in order to prevent both acute and
long term complications. Due to the complexity and
diversity of the areas involved in the treatment, the
constitution of a multidisciplinary, physician coordinated
team, that prepares, guides and supports the diabetic
patient on his treatment, is more effective (Kim et al.,
2006; Mensing et al., 2006). This team might integrate
professionals from distinct disciplines such as physicians,
nurses, psychologists, social assistants, dieticians or
exercise physiologists.
It is difficult to achieve long term adherence to diabetic
treatment. A rebound is common in weight control programs
after one year, and typically 30% of initial weight loss is
put back on in that period. After 3 to 5 years most
patients are back to the baseline (Lindstrom et al., 2003;
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Effects of a Physical Activity and Dietary Education Intervention in a Population with
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Rena R. Wing et al., 2001). Drop-out rates of 50% within 6
months (Resnick, 2000) and 75% within 2 years are common
(A. Kirk et al., 2004) in physical activity programs.
Compliance with diet recommendations is also difficult to
achieve. Hsia et al. (2002) studied the compliance of
13,777 participants with hypercholesterolemia with dietary
recommendations from the National Cholesterol Education
Program. Only 20% of the participants followed those
recommendations about total fat and saturated fat intake.
Lower compliance was associated with high BMI, sedentary
lifestyle and smoking.
Studying 1,480 adults with type 2 diabetes Nelson, Reiber
and Boyko (2002) found that almost two thirds of the sample
got over 30% of their daily calories from fat and 10% of
total calories from saturated fat. Likewise 62% of the
sample did not follow guidelines in respect of fruit and
It is imperative that patients with diabetes see themselves
as playing an active role in their care (Clark, 2003).
Diabetes Self-Management Education (DSME) is an integral
part of diabetes care and specific and detailed information
about the disease must be provided to patients (Mensing et
al., 2006). After assessment of the particular needs of
individuals with diabetes DSME might include information on
the following topics (Funnell et al., 2007):
• Description of the diabetes disease and treatment
• Inclusion of nutritional management into lifestyle;
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Effects of a Physical Activity and Dietary Education Intervention in a Population with
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• Using medication safely and with maximum therapeutic
• Monitoring blood glucose and other parameters and
management decision making;
• Preventing detecting and treating acute complications;
• Developing personal strategies to address psychosocial
issues and concerns;
• Developing personal strategies to promote health and
behaviour change.
Studying 22,682 patients with type 2 diabetes, Strine et
al. (2005) found that about 48% of them never received DSME
and estimated that 50 to 80% of patients with diabetes knew
little about the management of their disease. Those
ophthalmologic examination, to have regularly checked their
feet for sores or their blood sugar and HbA1c levels.
Information about the disease may be essential, but it is
not enough to guarantee compliance. Albarran et al.(2006)
studied 48 diabetic patients and 38 relatives divided into
six discussion groups (6 to 8 members each). During the
intervention period 5 meetings took place to discuss
lifestyles and knowledge about diabetes. After 8 months the
knowledge about diabetes had increased significantly, but
no significant risk-reduction was observed. Also Ogden
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Effects of a Physical Activity and Dietary Education Intervention in a Population with
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(2004) notes the importance of keeping patients informed
about the disease as a way of increasing compliance with
the treatment, but the author also points that in some
cases the relationship between information about the
benefits of physical activity and compliance is very weak.
Patient empowerment is defined as helping patients develop
the capacity to be responsible for one's own life. The role
of the patients is to be well informed active partners in
their own care. The role of the health professionals is to
help patients make informed decisions and through education
help them to overcome barriers (Funnell & Anderson, 2004).
Goal setting should be a negotiated process between
professionals, experts about diabetes and its treatment,
and patients, experts about their own personal goals
(Funnell & Anderson, 2004; Lerman, 2005). Goals should
preferably be expressed in a way that is most related to
the patient's personal goals (Clark, 2003).
Thus an intervention based on a partnership between
physician and patient is recommended. The use of a
linguistic level appropriate to the patient is critical, so
that the patient is able to negotiate and take part in the
expectations and health-beliefs are crucial in the design
of therapies so that they can be accepted and accomplished
"adherence" should replace "compliance" as the latter term
feels paternalistic and is associated with obedience,
whereas the former relates to a fundamental part of the
process: the agreement and commitment of the patient to the
prescribed treatment.
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Effects of a Physical Activity and Dietary Education Intervention in a Population with
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Adherence to treatment depends on a large number of
factors, and over 200 variables might influence adherence
to treatment (Silva, Pais-Ribeiro, & Cardoso, 2005) but
adherence studies are difficult due to the lack of adequate
standardized methods to measure adherence. Most studies
used patients' self reports, but it is probable that this
procedure overestimates compliance because patients tend to
desirability. Therefore reports of non-compliance are more
trustworthy than those of compliance. Adherence is a
dynamic event: it may happen in different degrees, and
behaviour can change considerably over a short period of
time (Lerman, 2005).
Four main clusters of correlates of adherence behaviours in
diabetes were proposed by the World Health Organization
characteristics,
intrapersonal, interpersonal and environmental factors.
2.8.1. TREATMENT AND DISEASE CHARACTERISTICS
According to the psychosocial typology of the illness the
adaptation of the subject to the illness is related to the
following variables (Rolland, 1994; Steinglass, 1987):
• Beginning of the illness (sudden or sharp, insidious
or gradual, mainly focusing on the perception that the
subject has of the illness, and not so much on its
physical symptoms).
• Evolution: gradual, constant or episodic (associated
with how quickly the illness progresses, with the
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necessity of care, with the role and task/function
changes in the personal, family and social life of the
• Result: death, gradual and/or fatal damage, or other
expected result which will vary from time to time
(according to the prognosis for the illness, to
information about the illness and to clarification of
patient's fears).
• Incapacity: degree of damage from the cognitive,
sensorial and motor point of view, which also involves
the disseminated social constructions of the illness
(i.e estimates that the several levels of damage and
its combinations can provoke different types of
incapacity - none, average, moderate, severe).
• Other factors, such as the visibility of the symptoms,
severity of the crises, genetic contribution, type of
treatments and the age of appearance are also
prominent in the process of psychological and psycho-
social adaptation to the illness and are associated
with treatment adherence.
Disease characteristics will influence expectancies about
disease control, therefore changing the locus of control.
Commitment to health behaviours and to medical treatments
doesn't always assure control over the disease's outcome
(Stanton et al., 2007).
For type 2 diabetes the study of adherence to the different
components of its treatment must be made in an independent
form (World Health Organization, 2003). In the World Health
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Organization report (2003) adhesion rates varied from 23%
to 33% for glucose monitoring, from 70 to 80% for taking
pills, from 37 to 70% for diet and from 26 to 52% for
prescribed physical activity.
Some aspects of the treatment influence adherence. Paes,
Bakker, and Soe-Agnie (1997) found a 79%, 65% and 38%
adherence for a once, twice and three-daily regime
respectively of oral hypoglycemic drugs. Complexity of
treatment and treatment length are thus important issues to
consider. Short term treatments have higher adherence than
Organisation, 2003).
2.8.2. INDIVIDUAL FACTORS
Once diabetes is diagnosed, an adjustment process occurs.
There is evidence of adjustment processes' heterogeneity
whether from individual to individual or within the same
individual across time (Stanton et al., 2007). Individual
coping abilities will greatly influence behaviour towards
the disease. Referring to an individual's perception about
the underlying main causes of events in his/her life, the
locus of control is a key element(Rotter, 1966). If it's
external, the individual will consider the disease as being
out of his/her control. Adherence to treatment will then be
compromised. If it's internal responsibility over his/her
health will then lay on future behaviour, and adherence to
treatment is more likely.
Willis and Campbell (1992) analysed the general population
and found fatigue, lack of time, lack of facilities and
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lack of knowledge about fitness as the main barriers
affecting adherence to exercise programs. These authors
considered that fatigue is often a psychological issue more
than a physical one. Lack of time may be due to spending
time on other behaviours not related to health (like
watching TV) and lack of facilities or equipment may mean
lack of pleasant facilities or equipment.
Psychological aspects may indeed be highly relevant in the
success or failure of adjustment and disease management
(Rolland, 1994; Steinglass, 1987). There is some evidence
that high self-concept and self-esteem are associated with
high levels of diabetes self management (Laffrey, 2000;
Silva et al., 2005).A low self-esteem is associated with
comfort eating, excess alcohol intake or physical activity
reduction, thus inducing lethargy and lack of motivation
(Swinburn & Egger, 2004). Mood states also influence
treatment outcomes through changing adherence (Silva et
al., 2005; Rena R. Wing, Phelan, & Tate, 2002). Its
analysis will be made in a subsequent chapter.
2.8.3. INTERPERSONAL FACTORS
One of the most influential aspects on adherence to
treatment seems to be social support (Lerman, 2005). The
support. Family and social support systems may help
patients to take medications on time or by their calling
attention to a larger than usual meal. On the other hand,
if interpersonal relationships are poor, well intended
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advice may be regarded as criticism, generate stress and
anxiety and contribute to an even poorer relationship.
Sluzki (1996) identifies a recursive relationship between
personal social network (in the several types of aid and
support made available) and health/illness. He concludes
that the quality of the personal social network, and the
way that its elements function, have a relevant impact on
the promotion of healthy lifestyles. Equally the personal
social network is also fundamental to the aid given to
patients, particularly in the way that they can adapt to
the illness, and people from the network can assume an
active and collaborative role in the treatment.
The quality and frequency of contact between the patient
Compliance with healthy lifestyles may be accomplished more
easily if the contact with health team members is more
frequent (Eichner, 2002; Miller & Dunstan, 2004; Rafferty,
Anderson, McGee, & Miller, 2002; Trento et al., 2001).
Tuomilehto et al.(2001) report an increase in health–
related behaviours among intervention group participants
during the follow-up examinations. This group had frequent
contacts with health team members, especially nutritionists
and exercise monitors.
Working with groups of patients seems to be a valid way to
intervene: it allows the patient to meet other individuals
with the same problem and on the other hand it increases
contact time with health care providers (Gucciardi, DeMelo,
Lee, & Grace, 2007; Trento et al., 2001).
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individuals, Rafferty, Anderson, McGee and Miller (2002)
found that compliance was higher among subjects who were
told by their clinician that they had high blood pressure.
The perceived threat might be an important element in the
adoption of health behaviours.
2.8.4. ENVIRONMENTAL FACTORS
Environmental factors that condition adherence to treatment
differ according to culture and lifestyle. Exposure to
unhealthy environments, such as to an environment that
favours low physical activity or to one with easy access to
high caloric food, is a major obstacle to lifestyle
In a diabetes intervention program conducted in Mexico most
individuals complied with the minimum recommended physical
activity despite the lack of government effort to promote
physical activity. The levels of physical activity found in
this study were higher than those in the USA for both
healthy Mexican-Americans and adults with type 2 diabetes
(Bacardí, Rosales, & Jiménez, 2005). In Greece a meta-
analysis of participation in physical activity and exercise
found low levels of participation (Tzormpatzakis & Sleap,
2007), and Parks, Housemann and Brownson (2003) found
differences between urban and rural areas.
The heterogeneity of the cultural characteristics of the
environment may therefore influence adherence to one or
other components of the treatment, such as physical
activity recommendations.
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Other environmental aspects that influence behaviour change
include access to healthy food or to facilities for
exercise. Socioeconomic factors play here a crucial role
(Weinberg & Gould, 1995).
A higher quality diet is associated with a low–energy-
density food choice and to higher diet costs (Darmon,
Briend, & Drewnowski, 2004; Drewnowski, Monsivais, Maillot,
& Darmon, 2007). Sugars, refined grains and fats often
increasing the percentage of total energy intake from this
kind of food and consequently decreasing the percentage of
energy from the more expensive fruits and vegetables
(Darmon et al., 2002). This pattern of choices is
affordability of foodstuffs may also depend on the type and
number of grocery stores in a particular area (Block &
A low socio economic status may directly affect adherence
to treatment by conditioning access to health care or,
indirectly, by making depression and anxiety more common.
In fact individuals with low socio-economic status find
life events more stressful and at the same time have fewer
social and psychological resources to manage them (Everson,
Maty, Lynch, & Kaplan, 2002; Stanton et al., 2007).
The patient's educational level is another factor that
influences adherence to treatment. Higher education levels
were found to be associated with higher levels of physical
activity as well as with increased compliance with dietary
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advice (Drewnowski & Specter, 2004; Hsia et al., 2002; A.
King et al., 2000; Lerman, 2005; Rafferty et al., 2002;
Strine et al., 2005).
In western societies the concept of an ideal (thin) body
leads to body dissatisfaction and even guilt feelings
towards one's body in obese and overweight individuals.
Still in this case some activities might be discretely
introduced into daily life in order to increase physical
activity, such as getting out of the bus one stop in
advance and walking a little more or using the stairs
rather than the lift (Beattie, 2001). Increased body weight
may be a disincentive for exercise and physical activity:
overweight individuals tend to do fewer and less demanding
activities, generating further weight gain (Swinburn &
mechanical problems like arthritis, lower back pain or
exercising adequately(Swinburn & Egger, 2004).
2.9. MOOD STATES AND PHYSICAL ACTIVITY
Despite the fact that physical activity is part of the
recommended treatment in type 2 diabetes, there is a
considerable lack of data regarding the psychological
benefits of participation in physical activity programs
(Biddle & Mutrie, 2001). Indeed in their joint position
American College of Sports Medicine consider exercise to be
a first line measure against diabetes. Nothing is said
however about the psychological advantages of exercise or
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about compliance or dropout rates in exercise programs
(American Diabetes Association & American College of Sports
Medicine, 1997).
Exercise can play an important role in fighting depression
because exercise can reduce stress and increase the sense
of control that leads to a positive attitude about life, as
referred to by Mutrie (2001). Exercise may enhance
perceptions of well-being which are important predictors
for staying active in older ages. These effects might be
explained by the larger release of endorphins - natural
brain opiates - that occurs during exercise, as well as by
the more intense social activity usually associated with
exercise (Ogden, 2004).
A meta–analysis of 39 studies and 20,218 subjects over
comorbid depression in adults found a double likelihood of
depression amongst individuals with diabetes (Anderson,
Freedland, Clouse, & Lustman, 2001).
Other meta–analysis of the psychological advantages of
exercise were done by Biddle and Mutrie (2001) and Leith
(1994). Both of these studies found an inverse relationship
between exercise and depression. These findings are in line
with those of Ruuskanen and Ruoppila, (1995) who found a
relationship between a higher prevalence of depression and
no regular exercise. The Surgeon's General Report (U.S.
Department of Health and Human Services, 1996) notes the
role of exercise in relieving anxiety symptoms, promoting
well-being and reducing the risk of depression. This seems
to be a consensual conclusion.
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Blumenthal et al. (1999) conducted a study of patients with
depression who were aged over 50 years. Three groups were
exercise, another had pharmacotherapy and the last one
received both treatments. The authors concluded that all
three methods were effective in fighting depression. The
pharmacotherapy group got quicker results but the exercise
group achieved the same results after 16 weeks. Furthermore
exercise interventions are also associated with better
quality of life than pharmacotherapy interventions (The
Diabetes Prevention Program Research Group, 2003).
Aikens, Aikens, Wallander, and Hunt (1997) studied 72
retired individuals, aged 59 or older, with type 2
diabetes. They found a strong association between stress
and poor glycemic control among individuals with low levels
of physical activity. These individuals are consequently
more vulnerable to daily undesirable events.
In order to access changes in mood states as a consequence
of exercise a large variety of studies used the Profile of
Droppleman, 1971), a 42 item questionnaire grouped in six
factors of mood states: Tension - Anxiety, Depression -
Dejection, Anger – Hostility, Vigor – Activity; Fatigue –
Inertia and Confusion – Bewilderment. Physical activity
appears to promote an "iceberg profile" (Alves, 2005;
Biddle & Mutrie, 2001; Leith, 1994) – an increase in Vigor
– Activity and a decrease in every other factor considered.
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2.10. MOTIVATION THEORIES
The research about the reasons why people adhere to healthy
lifestyles, and the barriers that prevent that adherence,
are of great importance. Only by understanding what
motivates individuals is it possible to promote well
designed programs, adapted to their needs.
In a meta-analysis Biddle and Mutrie,(2001) identified 6
main theories that try to explain human behaviour related
to exercise adherence:
• Theory of reasoned action(Ajzen & Fishbein, 1980;
Fishbein & Ajzen, 1975): based on the assumption that
intention is a determinant of behaviour. Individuals
will, before adopting a given behaviour, evaluate
positive and negative consequences of that particular
behaviour, developing an attitude towards it. External
variables will exert their influence over what is
perceived as positive or negative in a particular
environment. Subjective normative factors will work as
a social regulator of attitudes. Both subjective
forecast intention;
• Theory of planned behaviour (Ajzen, 1985): not very
different from the previous, but rather a remodelling,
this theory introduces the concept of "Perceived
intention. In fact the theory of reasoned action
failed to explain the lack of volitional control that
occurs in the adoption of some behaviours. The
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perceived ease or difficulty of performing a specific
behaviour might influence intention to perform that
behaviour or the behaviour itself. Opportunities and
resources, as well as perceived power over behaviour,
are included in this construct. Some health behaviours
such as quitting smoking or engaging in a weight
control program may not be adopted because individuals
belief to have poor control over their own behaviour
and don't even try to adopt them as habits;
• Health belief model(Rosenstock, 1974): this model
predicts that people will not adopt health protective
threatening, have minimal levels of health motivation
and knowledge, find themselves as vulnerable, believe
in the efficacy of the behaviour and find the
behaviour easy to adopt;
• Protection motivation theory(R. W. Rogers, 1975):
similar to previous puts emphasis on the perceived
threat to health, which depends on the perceived
severity and the perceived probability of threat. The
coping appraisal depends on the perceived efficacy of
the preventive behaviour and the perceived self-
efficacy of the individual. The threat appraisal and
the coping appraisal determine the intention to
protect and thus the adoption of the protective
• Self-determination theory(Deci & Ryan, 1985; Ryan &
Deci, 2000): incorporating four theories, this is a
macro-theory of human motivation and personality,
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focusing on the dialectic between the active organism
and the social context on the one hand, and the degree
to which human behaviours are determined by personal
choice on the other. The theory states that there are
three innate, essential and universal psychological
needs - competence, autonomy and relatedness – that,
when met, will improve intrinsic motivation, mental
health and well-being. Conversely, when not met, a
person will function sub-optimally and will show
evidence of low motivation and ill-being;
• Self Efficacy Theory(Bandura, 1977): the rationale
behind this model is that individuals tend to choose
competent. These situations allow positive emotions,
low anxiety and an internal locus of control.
According to this theory, past experiences with a
particular behaviour will influence the adoption of
that behaviour in the future. Perceived self efficacy
may also be enhanced by comparison with others, if the
individual finds him/herself more competent than
others in a particular behaviour, or through social
These 6 theories overlap considerably, and different
attempts to form an integrated model have been made,
usually based on the theory of planned behaviour. This
transtheoretical
different stages of adherence to a behaviour adoption:
• Pre-contemplation: there is no intention to adopt the
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• Contemplation: a behaviour change is considered;
• Preparation: small changes occur in behaviour;
• Action: a new behaviour is adopted for less than a 6
• Maintenance: the adoption of the new behaviour is
sustained over a 6 month period.
This theory has supported the work of A. Kirk et al. (2004)
who analysed changes in stages of behavioural adoption
after 12 months of physical activity counselling. The
objective was the adoption of 20 minutes of moderate to
hard exercise three times a week (American College of
Sports Medicine guidelines in 1990). The intervention
included 30 minute consultations every 6 months and follow-
consultation. The stage of exercise behaviour changed over
the intervention period for the experimental group, while
no changes occurred in control group (A. Kirk, N. Mutrie,
P. MacIntyre, & M. Fisher, 2004). The experimental group
also had significantly better results than the control
group in glycemic control, blood pressure and total
A counselling strategy to promote the adoption and
maintenance of physical activity by type 2 diabetic
patients was proposed by Di Loreto et al (2003). The
strategy comprised an initial 30 minute session where 7
keys points were made:
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• Motivation: the benefits of regular exercise were
• Self-efficacy: the patient was asked to collaborate in
accomplishable. Realistic goals were established;
• Pleasure: previous experiences with exercise were
asked about. Several activities (outdoor/indoor) were
• Support: The patients' partners were also invited to
engage in the program;
• Comprehension: Patients were asked about the
established program to ensure they had understood it.
• Lack of impediments: potential obstacles to exercise
were identified and the patient suggested ways to
overcome those barriers.
• Diary: patients were asked to keep a log of their
performed Physical activity. This way self-efficacy
This intervention group was followed up with a phone call
after the initial session and with a 15 minute session
every 3 months. In this study the intervention group was
compared with a control group that received standard
counselling. The results showed a significant improvement
in physical activity for the intervention group after a two
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year intervention. Significant improvements in BMI and
HbA1c were also found.
Some strategies based on these theories have been proven to
have some positive effect on adherence and should be
adopted in future programs:
• Physical activity programs should have a pedagogical
scope, where the benefits of increased physical
psychological ones. Participants' knowledge about such
benefits should never be taken for granted. (Willis &
Campbell, 1992);
• The program must ensure that the participants have
understood the given information (Di Loreto et al.,
• Adequate goal setting (particularly about weight or
accomplishable physical activity) (Rena R. Wing et
• Look for social support – a group or a partner
committed to the same objective (Di Loreto et al.,
2003; Lerman, 2005);
• Program participation must be as simple as possible
• The program should provide frequent contacts with
health team members (Eichner, 2002; Miller & Dunstan,
2004; Trento et al., 2001; Tuomilehto et al., 2001);
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• Patients should keep logs to track eating and physical
activity habits in order to identify situations that
physical activity objectives, and should develop
strategies to avoid them (Di Loreto et al., 2003);
• Patients should be taught that default from a diet or
from a physical activity program should not be seen as
an irreversible failure but as part of the process.
Patients should be able to cope with small lapses.
(Beattie, 2001; P. Powers, 2005).
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3. OBJECTIVES
The objectives of this study were:
• To characterize the daily physical activity of a
mellitus,
particularly the time spent in vigorous and moderate
physical activity as well as the time spent walking.
• To characterize the dietary habits of the same
population, and particularly the degree of compliance
with the dietary recommendations for the Portuguese
• To assess the effectiveness of a 9 month lifestyle
intervention consisting of a low workload physical
activity program and a nutritional education program
aimed at the adoption of a more active lifestyle and
better nutritional habits.
• To assess the impact of such a program on:
o clinical and biological variables: parameters of
diabetic control;
o fitness: progress achieved in different physical
qualities such as strength, aerobic endurance,
flexibility and agility;
o psychological: evolution of mood states;
o economic: cost of medication.
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The rationale for those objectives was that physical
activity and diet are the cornerstones of diabetes
management and that intervention programs targeting these
areas should look to help bring about a synergistic effect
Guidelines from major international organizations recommend
moderate physical activity for 30 minutes most days of the
week (American Diabetes Association & American College of
Sports Medicine, 1997; Klein et al., 2004; U.S. Department
of Health and Human Services, 1996). However research on
the effectiveness of physical activity programs with lower
intervention loads is needed (LaMonte et al., 2005).
activity with lower workloads may be easier to implement,
with increased adherence and lower dropout rates, and might
have reduced costs. When applied to type 2 diabetic
patients, supervised classes should be seen as "centres for
behaviour change", providing information about the disease
and helping patients to adopt healthier lifestyles.
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4. MATERIALS AND METHODS
4.1. SÃO JOÃO HEALTH CENTRE
This interventional study took place at São Joã
Centre, a primary health care unit located in central
Lisbon, which covers about 40,000 people (
Fi
area where this unit is
level and a rather elderly population.
At the São João Health Centre about 1,90
registered as diabetics, and they
the health centre physicians and specialized nurses. Out of
Effects of a Physical Activity and Dietary Education Intervention in a Population with
type 2 Diabetes Mellitus
those, only about 300 diabetic patients come to a
specialized nurse consultation regularly, despite these
consultations being advised by physicians and free of
charge. The history of the diabetic patient is recorded
here and his/her ability for disease self management is
evaluated. Instructions on self-glycaemia control and about
the disease are given as well as general lifestyle
counselling, including nutrition and physical activity.
Specific patients' problems are also discussed. Patients
attend the consultation with a periodicity of between 15
days and 4 months depending on the nurse's evaluation of
the achieved control.
This health unit has recently implemented a program named
"Saúde em Movimento" – Health in Motion – directed at type
2 diabetic patients. This program was the result of the
cooperation between S. João Health Center, Escola Superior
de Desporto de Rio Maior - Instituto Politécnico Santarém
and the Centro de Nutrição e Metabolismo - Instituto de
Medicina Molecular.
The main purpose of this program is to provide, apart from
the already mentioned care services, individual dietary
activities occur in the unit's facilities. With this in
mind, a multi-disciplinary team was set up including a
physician, a nurse, a nutritionist and a physical activity
After being launched, the program and its objectives were
cooperation was asked in order to advise all diabetic
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patients with no contraindication to exercise to attend the
specialized nurse consultation and join the program.
It was expected that the regular and frequent contact
between patients and members of this multi-disciplinary
team would help patients to adopt better health behaviours.
To ensure a coordinated work, several meetings took place
between the health centre director, specialized nurses,
nutritionists and the physical activity instructor. In
these meetings the work of every member was described and
analysed in order to allow each one to have a complete
knowledge of the program and to make sure that no
contradiction would be found in the information provided to
the patient. The channels of communication were established
and the specialised nurse was appointed as the one
responsible for reporting to each patient's physician.
nutritionists every fortnight and the physical activity
instructor monthly.
4.2. SAMPLING AND STUDY DESIGN
The S. João Health Centre has around 1.900 diabetic
patients registered and out of those, only about 300
consultations. Invitations to participate in the study were
made to these 300 patients.
The inclusion criteria were:
• Diagnosed type 2 diabetes;
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• Absence of contraindication to exercise;
• Agreement to participate in the experiment (written
Exclusion criteria included:
• contraindication to exercise;
• pregnancy or lower limb amputation;
• inability to follow the program regularly - a minimum
of 75% attendance was set.
Initially, only 47 subjects complied with these criteria
but during the study period 4 individuals dropped out
requested from each participant in the study. Data was
gathered between February 2005 and July 2006 with a 9 month
period between each subject observation. The sample was
then divided into two groups according to the participant's
choice. Those who were willing to participate in the
experiment but not to engage in physical activity classes
or nutritionist consultations were assigned to the control
group (n=24, 12 men and 12 women, age 68.9±11.3). The
control group wasn't submitted to any additional treatment
apart from the regular medical and specialized nurse
consultations already mentioned.
Those who were willing to participate fully in physical
activity classes and nutritionist consultations engaged in
the "Saúde em Movimento" program and were assigned to the
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intervention group (n=19, 6 men and 13 women, age
Figure 2 summarizes the sampling process.
Individuals identified as
diabetics in the Health Center
Regular attendance to nurse consultations?
Compliance with inclusion and exclusion criteria at the beginning of the study?
Compliance with inclusion and exclusion criteria at the end of the study?
Individuals that agreed to participate
Individuals that agreed to participate
in the intervention group
in the control group
Figure 2 – Flow chart showing recruitment and affiliation to groups of
study subjects
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The intervention group was given dietary advice and
physical activity classes. Dietary advice was provided in
monthly consultations by trainee nutritionists under the
supervision of the Centro de Nutrição e Metabolismo -
Instituto de Medicina Molecular. This advice was adapted to
specific needs and individual preferences. The main dietary
guidelines included:
• Eat every 2.5 hours with a special focus on breakfast
and evening meal.
• Increase vegetable and fruit consumption (max 3
• Reduce food with a high glycemic index such as sweets,
During the nutritional consultation, recommendations to
increase physical activity were also provided.
Physical activity classes of 50 minutes each were provided
twice a week in the Health Centre facilities by a Health
and Fitness trainee under the supervision of Escola
Superior de Desporto de Rio Maior. A typical class included
a 10 minutes warm-up period, a 30 minutes core part and a
10 minutes cool down period. The physical activity classes
were low impact and had a high percentage of aerobic
exercises which required the use of large muscles in a
rhythmic and continuous fashion. Exercise intensity was
moderate according to both the American College of Sports
Medicine (ACSM) recommendations and criteria (American
College of Sports Medicine, 2006). Borg's scale of
perceived exertion was taught to participants, and an
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intensity target value of 12-13 on a 6-20 scale was
sought(Borg, 1970). Walks and outdoor classes occasionally
took place in order to allow a change of environment. Apart
from providing extra physical activity, the program had the
additional goal of promoting the increase of individual
daily physical activity. Various simple strategies to raise
daily activity were taught:
• Elevators should be avoided and stairs should be used
as much as possible.
• Leaving the bus one stop before destination and walk
the remaining distance.
• Participants were given a list of physical activity
The role of physical activity classes as "behaviour
modification centres" was enhanced by the physical activity
instructor, not only in relation to physical activities but
also in relation to dietary compliance. Also whenever
significant changes occurred in a patient's health a
physician consultation was advised.
4.3. DATA COLLECTED
4.3.1. PHYSICAL ACTIVITY HABITS
Physical activity was measured through the International
Physical Activity Questionnaire (IPAQ) - short form. This
questionnaire, originally created by Booth et al (1996), is
now validated in 12 countries including Portugal (Craig et
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al., 2003). Its short form evaluates the time spent in a
week doing physical activity. For this purpose three
different kinds of physical activity were considered:
• Vigorous activity - Activities considered as being
within this category imply intense physical effort
such as lifting heavy objects, digging, taking aerobic
or step classes, fast cycling, running, swimming,
considered if practised for at least 10 minutes. An
average Metabolic Equivalent (MET) of 8 was given to
these activities("Guidelines for Data Processing and
Questionnaire (IPAQ) – Short and Long Forms," 2005).
• Moderate activity - This category includes activities
which promote breathing adaptation such as carrying
light objects, cycling, hunting, gardening, playing
table tennis, domestic activities like scrubbing or
cleaning. A minimum of 10 minutes is necessary for it
to count in the calculation of physical activity. An
Questionnaire (IPAQ) – Short and Long Forms," 2005).
• Walking time – All the walking time should be included
in this category, covering: travel to home or work,
walks done for leisure, sports or just moving around.
As in the other categories, walking time should be
included if it lasted for at least 10 minutes. An
average metabolic equivalent (MET) of 3.3 was given to
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these activities("Guidelines for Data Processing and
Questionnaire (IPAQ) – Short and Long Forms," 2005).
In order to estimate the questionnaire reliability in this
population, intra-class correlation coefficient was used
with a test-retest applied to 10 subjects with a 2 week
interval. Relative reliability was 0.99 for vigorous and
moderate activity and 0.98 for walking time.
4.3.2. DIETARY HABITS
Dietary intake was assessed by a nutritionist using the 24
hour recall method. The participant had to indicate and
provide approximate sizing of all foodstuffs and drinks
he/she consumed in the 24 hours prior to the interview.
Each participant was subsequently classified as complier or
non-complier according to the dietary recommendations for
the Portuguese population (
Table 2). For example if the
consumption of a single average sized fruit in one day is
reported, and considering that the recommended consumption
is between 3 and 5 portions per day, this subject would be
classified as a non-complier.
Table 2 – Categories and Dietary recommendations for the Portuguese
population. Units are portions.
Vegetables Fruit
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Also a dietary score was computed for each participant for
each evaluation time according to the number of categories
where that individual is a complier. Hence a participant
with a healthy dietary score of 4 had a better dietary
intake according to the Portuguese recommendations than a
participant with a dietary score of 2. The changes in the
subject's dietary habits were subsequently classified. All
individuals with negative scores were classified as having
worsened their dietary patterns, those who had 0 has having
no change, and all with positive scores as having improved
their dietary habits.
However any favorable change in dietary behaviour (even if
the desired outcome was not reached) could be considered as
relevant. This analysis was made leaving out of account
whether or not the changes were enough
per se to change the
categories were defined: negative (-1) when moving away
from the reference interval; maintenance (0) when no
improvement (1) when the change was towards the interval
reference, independently of reaching it or not. Another
score (Dietary Habits Evolution) was computed as the sum of
dietary evolutions of the different categories. Thus a
subject that kept his dietary behaviour in two categories,
got closer to reference values in 4 categories and worsened
in 1 category would have a score of 3.
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4.3.3. CLINICAL AND BIOLOGICAL ASSESSMENT
Weight and height were measured on a SECA scale and a
recommendations. The body mass index (BMI), defined as the
ratio between weight and height (in meters) raised to the
square was then calculated. Subjects
according to the American College of Sports Medicine
criteria (Going & Davis, 2001): underweight if BMI<18.5
kg/m2; normal weight if BMI between 18.5 and 24.9 kg/m2;
overweight if BMI between 25.0 and 29.9 kg/m2 and obese if
Body composition was determined through bipolar manual
bioimpedance with an OMRON BF-300 Body fat monitor (OMRON,
Japan) and the results were expressed as a percentage of
Blood pressure was measured by a certified nurse, with a
manual sphygmomanometer, in resting conditions, prior to
physical tests. Hypertension was considered as SBP≥140 mmHg
and/or DBP≥90 mmHg (American College of Sports Medicine,
2009a), or if the patient took antihypertensive drugs.
The prevalence of hypertensive patients was assessed and,
among these, the percentage taking antihypertensive drugs
and the percentage of patients with controlled blood
pressure, defined as SBP<140 and DBP<90 mmHg. The
treatment
rate was defined as the ratio between the number of
individuals receiving antihypertensive treatment and the
total number of hypertensives. The
control rate was
obtained by dividing the number of treated and controlled
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hypertensives by the total number of hypertensives (Macedo
As there are no laboratory facilities in the health unit,
blood analyses were performed in different laboratories
external to the health unit. In order to avoid bias due to
different calibration processes, participants were asked to
use the same laboratory throughout the study period. Total
cholesterol levels were considered as adequate if below 200
mg/dL; intermediate risk was defined as values between 200
and 240 mg/dL and high risk for values >240 mg/dL.
Triglyceride levels were considered high when they were
>150 mg/dl, and a minimum of 40 mg/dl was set to define
adequate HDL cholesterol levels ("Third Report of the
National Cholesterol Education Program (NCEP) Expert Panel
on Detection, Evaluation, and Treatment of High Blood
Cholesterol in Adults (Adult Treatment Panel III) Final
Report," 2002). LDL concentration was estimated through the
formula proposed by Friedewald, Levy and Fredrickson
(1972): LDL = Total Cholesterol – HDL – (Triglycerides/5).
A maximum of 130 mg/dL was adopted as the cut value to
define a low risk zone for LDL ("Third Report of the
National Cholesterol Education Program (NCEP) Expert Panel
on Detection, Evaluation, and Treatment of High Blood
Cholesterol in Adults (Adult Treatment Panel III) Final
Report," 2002).
In relation to diabetes, hyperglycaemia was defined as
glucose values >126 mg/dL (A. Powers, 2006), and inadequate
diabetic control was defined as glycated haemoglobin
(HbA1c) levels above 6.5% (Direcção Geral de Saúde, 2008).
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4.3.4. FITNESS ASSESSMENT
Physical fitness was evaluated through Rikli and Jones
(2001) battery of test items. These battery tests are
presented in
table 3.
Table 3 - Parameters and tests included in Rikli and Jones (2001)
battery of test items
Parameters evaluated
Stand–ups in 30s,
sitting in a chair
without arm help Arm flexions in
- forearm flexion
(Women - 2.27 Kg, Men – 2.63 Kg)
- 2 min stepping in
Aerobic Endurance
Distance between
Lower Flexibility
and toes. Distance between
- reaching behind
Upper Flexibility
behind back Time
- Sit, walk 2.44 m
chair, walk 2.44m
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4.3.5. PSYCHOLOGICAL ASSESSMENT
Mood States – Mood states were evaluated through the short
version of the Profile of Mood States Questionnaire –
(McNair, Loor & Droppleman, 1971), which was translated
into Portuguese and validated by Viana (2001). It includes
42 items grouped in six factors of mood states: Tension -
Anxiety, Depression - Dejection, Anger – Hostility, Vigor –
Activity; Fatigue – Inertia and Confusion – Bewilderment.
In each item the respondent, in relation to a particular
mood, must mark the word that best describes his or her
feelings in the last seven days: nothing; a little;
moderately; much; very much.
For each factor, the mean of the composing items was found,
Tension - Anxiety items nº 1;12;16;20;29;31
Depression – Dejection items nº3; 7; 11; 15; 17; 21;
23; 30; 33; 36; 38; 42
Anger – Hostility items nº 2; 9; 14; 25; 28; 37
Vigor – Activity items nº 5; 8; 10; 27; 32; 39
Fatigue – Inertia items nº 4; 13; 19; 22; 34; 41
Confusion – Bewilderment items nº 6; 18; 24; 26; 35;
Ten individuals were subjected to a test-retest situation
with a 2 week interval in order to estimate test
reliability. The intra-class correlation coefficient was
calculated for each factor. The results were:
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Tension - Anxiety – 0.84
Depression – Dejection - 0.93
Anger – Hostility - 0.96
Vigor – Activity - 0.93
Fatigue – Inertia - 0.97
Confusion – Bewilderment - 0.83
It was considered to be an iceberg profile if the Vigor –
Activity factor was higher than any other factor(Leith,
In order to confirm the data collected on physical activity
and dietary changes a small directed interview was
conducted in the 2nd observation. This interview was also
intervention period and to get a final opinion about the
benefits of the program. An
a posteriori categorization was
done considering the answers to the following questions:
• "What do you yourself consider your degree of
compliance with the dietary advice that was given to
you?" Answers were categorised as "High Compliance" or
Low Compliance";
• "In the last 9 months did you significantly change
your dietary pattern?" Answers were categorised as
"Steady dietary pattern" or "Changed dietary pattern".
If the answer was affirmative the next question was
"in which way?" and the answers were categorised in
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"yes" or "no" as to the occurrence of quantitative
changes and qualitative changes.
• "In the last 9 months did you significantly change
categorised as "Unchanged physical activity habits" or
"Changed physical activity habits". If the answer was
affirmative the next question was "in which way?" and
the answers were categorised as "increased physical
activity" or "reduced physical activity".
• "How many days have you been hospitalized in the last
Two more questions were added for the intervention group:
• "What are the greatest benefits you've got from
participating in the program?"
Dimensions that arose from the answers given were:
o Biological Advantages
In this dimension 3 categories were considered:
⇒ General Health Control - "I feel better" or "My
blood pressure is lower"
⇒ Diabetes Control – "I have better glycaemias"
⇒ Physical Fitness – "I have improved my balance" or
"Now I move better"
o Psychological Advantages
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⇒ Dietary Habits - "It's easier to control my food
⇒ Physical Activity Habits - "I walk more"
⇒ Mood States - "After classes I'm in a good mood" or
" I'm not so tired" or " I used to spend too much
o Social Advantages
⇒ Acquaintanceship - " I've met interesting people"
• "Would you recommend the program to your friends?"
The answers were categorised as "yes" or "no".
4.3.6. ECONOMIC ASSESSMENT
The cost of treatment was assessed by summing up the costs
of all prescribed medicines and treatment for each
participant. In short, for each drug the total number of
units (pills) consumed per month was calculated based on
the physician prescription, and the corresponding costs
alternative was considered. The cost of treatment was
further split into:
• Direct costs for participants: the percentage of
medication cost not covered by the Portuguese health
system. The Portuguese health system divides people
into two different kinds according to income: 1)
regular users and 2) pensioners with an annual
per
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capita income of less than 14 times the minimum
monthly wage (385.90€). Pensioners pay less for
medicines and they pay no treatment charges. As the
coverage of medicines varies according to the socio-
economic characteristics of the subjects, this was
also taken into account in the calculations. It should
be noted that patients with chronic diseases, such as
diabetes, can obtain their treatment for free.
• Costs for the State: equals the difference between the
public sale price of medicines and the cost to
Hospitalization days – the self-reported days hospitalized
during the intervention period.
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Figure 3 schematizes the intervention study after inclusion
in the control and intervention groups.
2nd consultation with nurse
1st consultation with nurse
to exercise
Contact with patient. Invitation
to participate in the program.
Blood pressureBlood analysisTherapeutic dataIPAQPOMSBioimpedanceFitness tests
consultations with nurse
(Periodicity based on
achieved control)
Last consultation with nurse
Blood pressureBlood analysisTherapeutic dataIPAQPOMSBioimpedanceFitness testsFinal Interview
Figure 3 – Scheme of the intervention study after inclusion in the
control and intervention groups
In a first specialized nurse consultation the program was
presented to the patient and its objectives and associated
tasks were explained. If the patient agreed to participate,
a medical authorization to exercise was asked. In a second
consultation, if medical consent was given, data was
All variables were collected at the beginning (baseline)
and at the end of the study.
The first collection was made during the regular nurse
consultation following medical consent was given. Height,
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weight, blood pressure, blood analysis and therapeutic data
were gathered by the nurse during the consultation. These
elements are part of the regular clinical record of each
The patient then moved to a contiguous individual cabinet
where he/she was submitted to IPAQ and POMS questionnaires,
bioimpedance and the Rikli and Jones battery of tests, in
that order. Those tests were performed by the study
coordinator. A trial period for each test was allowed in
physical tests until the correct performance was achieved.
After a small rest period each test was performed. In the
same week dietary data was collected by a nutritionist
during a nutritional consultation.
The second data collection was scheduled according to the 9
month period defined.
4.5. STATISTICAL PROCEDURES
Statistical analysis was conducted using SPSS version
17(SPSS Inc, USA) and Excel 2007 (Microsoft Corporation).
Descriptive statistics were expressed as median, 1st and 3rd
qualitative data. Comparisons between first and second
intervention and control groups were made using Mann
Whitney‘s U and Chi-square tests. Fisher's exact test was
used whenever the conditions to apply Chi square were not
present. Non-parametric statistics were preferred due to
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the skewed distribution of most variables. Statistical
significance level was set at p≤ 0.05.
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5. RESULTS
5.1. DROP-OUT ANALYSIS
Four out of the 47 subjects (8.5%) who initially agreed to
participate in the study dropped out and their initial data
were therefore excluded from the analysis. The reasons for
dropping out were: 1 control and 1 intervention moved away;
1 control was too ill to be tested and 1 control refused to
be tested again.
5.2. LIFESTYLE DATA
5.2.1. PHYSICAL ACTIVITY DATA
The average attendance rate for the physical activity
program was 81%. Physical activity at baseline and at the
end of the study was analyzed for each IPAQ's level and the
results are summarized in
table 4. Overall no difference
was found between groups at the beginning or at the end of
the study period. Still pairwise analysis showed that the
intervention group significantly increased walking time and
overall physical activity, although this latter increase
was mainly due to the physical activity classes (
Table 5).
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Table 4 - Physical activity at baseline and at the end of the study.
Results are expressed as medians and (1st quartile, 3rd quartile). PA,
physical activity. Comparison between control and intervention groups
by Mann Whitney's U test.
a) Leaves out of account time spent at PA classes
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Table 5 - Evolution of each type of physical activity, by group. PA,
physical activity. Statistical analysis by Wilcoxon signed rank test.
a) Leaves out of account time spent at PA classes.
No differences were found between the control and the
intervention group regarding the amount of time spent
walking at baseline or at the end of the study. But
pairwise analysis showed that the intervention group
significantly increased the amount of walking time, while
no such increase was found in the control group (
Figure 4).
The median change in the time spent walking was 0 and 105
min per week in the control and intervention groups
respectively (Mann Whitney's U=153, p=0.066), and excluding
the outliers did not change the results (Mann Whitney's
U=117; p=0.065). Finally the percentage of subjects that
increased the amount of walking time was 46% and 74% in the
control and the intervention groups respectively (Χ2=3.38;
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Figure 4 - Time spent in walking at baseline and at the end of the
study, by group. Results are expressed in minutes per week.
differences were found between groups either at baseline or
at the end of the study. Interestingly the control group
showed a 45 min median decrease, whereas the intervention
group showed a two-hour median increase in the time spent
doing moderate PA per week, although these changes were not
statistically significant (
Figure 5).
Figure 5 - Time spent in moderate physical activity at baseline and at
the end of the study, by group. Results are expressed in minutes per
week.
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Considering that the physical activity classes provided for
the intervention group were mostly of moderate intensity
and that the study goal was to increase physical activity
on a daily basis, we also compared moderate physical
activity levels between groups after excluding class time
in the intervention group. Again no significant differences
were found. The median change in moderate physical activity
levels was a 45 min/week decrease and a 20 min/week
increase in the control and the intervention groups
respectively (Mann Whitney's U=200, p=0.493), and excluding
potential outliers did not change the results (Mann
Whitney's U=140, p=0.190). Finally, the percentage of
subjects that increased the amount of moderate physical
intervention groups respectively (Χ2=1.61; p=0.223).
Very few subjects reported performing vigorous physical
activity: 3 at baseline (2 control, 1 intervention) and 2
(both intervention) at the end of the study period. It is
worth noting that the two subjects from the control group
decreased their levels during the study period.
Overall physical activity was calculated by adding up the
different types of physical activity (walking, moderate and
vigorous physical activity). At baseline 20.8% of the
control group and 10.5% of the intervention group did not
comply with the 3.5 hours/week of physical activity. The
contributions of each type of physical activity at baseline
and at the end of the study for each group are summarized
in
figure 6. Overall physical activity in both groups was
mainly due to moderate physical activity, with walking
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being less important and there be
b ing virtually no vigorous
physical activity.
e 6 - Median co
When Met-min per week was calculated, no significant
differences were found between groups, ne
nor at the end of the study. However pairwise analysis
showed a significant increase in metabolic equivalents
i tervention group, while no such
h control group (
Table 5).
changes in overall physical activity levels by
summarized in
figure 7 The median ch
physical activity was a
a 116.3 Met.min/week decrease and a
intervention group respectively (Mann Whitney's U=159;
x luding potential outlier values led to
somewhat different results, the increase being greater in
the intervention group (Mann Whitney's U=118; p=0.05).
Effects of a Physical Activity and Dietary Education Intervention in a Population with
type 2 Diabetes Mellitus
Finally the percentage of subjects that increased their
overall physical activity was 33% and 74% in the control
and intervention groups respectively (Χ2=6.9; p=0.009).
Figure 7 - Differences in overall physical activity, by group. Results
are expressed in Met-min per week.
The results of the interview conducted on the second
observation are summarized in
table 6. In order to allow
activity levels, compared with only 17% in the control
group (Χ2=13.11; p=0.001).
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Table 6 - Reported changes in physical activity levels. Results are
expressed in number of subjects and (percentages).
Finally cross tabulation of changes in overall physical
activity levels as assessed by IPAQ with those assessed by
the interview showed a good agreement (Χ2=8.12, p<0.01).
5.2.2. DIETARY DATA
Portuguese dietary recommendations for each food group are
shown in
table 7. The statistical results within each group
are summarized in
table 8 (next pages).
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Table 7 - Percentage of compliers with Portuguese population dietary
recommendations within each group. Comparison between control and
intervention groups by Fisher's exact test.
Cereals and equivalent
Cereals and equivalent
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Table 8 – Statistical results of the evolution of compliance with the
Portuguese dietary recommendations within each group (Wilcoxon sign
ranks test).
The recommendations on fats and oils are the most
frequently achieved in both groups and in both assessment
times. Conversely the recommendations on vegetables and
pulses were less implemented (
Figure 8).
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Figure 8 – Percentage of non-compliers for each dietary recommendation
at baseline and at the end of the intervention, by group.
There were no significant differences between groups at any
time in the percentages of participants meeting the dietary
recommendations, with the exception of dairy products at
the end of study. This is due to the increased number of
recommendations. Similarly no significant differences were
found for compliance with dietary recommendations between
the first and the second evaluation periods, in both the
control and intervention groups.
The results for the dietary score are shown in
figure 9. At
baseline there were no significant differences between
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groups (Mann Whitney's U=163.5; p=0.822), but at the very
end the intervention group showed significantly higher
dietary scores compared to the control group (Mann
Whitney's U=100.5; p=0.031). An improvement in those in the
intervention group with lower levels of compliance was also
noted: the lowest compliance rate was 2/7 at the end of the
Figure 9 – Dietary scores at baseline and at the end of the study (%)
The evolution of dietary behaviour was compared, regardless
of whether or not the subjects were complying with the
Portuguese dietary recommendations. The rationale for this
analysis was that there could be an improvement in dietary
habits even without achieving the recommended dietary level
for each food category. Therefore when changes in dietary
habits were classified into better, maintained or worsened
(
Figure 10), significant differences were found, the
control group showing a higher percentage of worsening
dietary habits (Χ2=6.005; p =0.05).
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Figure 10 – Trends in dietary habits, by group. The results are
expressed as a % of the participants.
From the 23 participants interviewed in the control group,
17 (74%) were classified as having maintained their dietary
behaviour during the study period. Among the remaining 6
(26%) who were classified as having made significant
changes during the study period, all reported qualitative
changes, and 4 also reported quantitative changes. Among
the 17 participants who didn't change their dietary
patterns, 8 were classified as already compliant with the
dietary recommendations.
From the 19 participants in the intervention group
interviewed, 8 (42%) were classified as having maintained
their dietary behaviour during the study period, while the
remaining 11 (58%) were considered to have made significant
improvements, 2 only qualitative and one only quantitative
improvements. Among the 8 participants who didn't change
their dietary patterns, 7 were considered to have already
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Between-group comparisons showed that the increase in
compliance with the dietary recommendations was higher in
the intervention compared with the control group (Χ2=4.369;
p=0.037). Because participants with a high compliance at
the beginning of the study had a low margin to improve
their dietary habits, it is also important to look at the
final outcome about compliance, independently of behaviour
change. At the end of the study about 26% of the control
group and 60% of the intervention group reported that they
were high compliers (Fisher's exact test, p=0.038).
5.3. CLINICAL AND BIOLOGICAL DATA
The clinical and biological data according to intervention
group and assessment period are summarized in
table 9.
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Table 9 - Clinical and biological data at baseline and at the end of the study, according to intervention group. The
results are expressed as medians and (1st quartile, 3rd quartile). Comparison between control and intervention
groups by Mann Whitney's U test.
Total Cholesterol
Glycaemia (mg/dl)
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Total Cholesterol
Glycaemia (mg/dl)
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The results of the statistical analysis of the changes
within each group are summarized in
table 10.
Table 10 - Clinical and biological data, by group. Statistical
analysis by Wilcoxon signed rank test.
Total Cholesterol
There were no significant differences between groups in
relation to weight, BMI and percentage of fat mass, either
at the beginning or at the end of the study. It should be
noted that only 29.2% of participants in the control and
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21.1% in the intervention group had a normal BMI at the
initial evaluation (
Table 11). A median increase of 1 kg in
weight in the control group was noted, versus a 1.5 kg
median decrease in the intervention group; still the
differences were not statistically significant. Similarly
no significant changes were found regarding the evolution
of BMI in the control and intervention groups. In relation
to body composition, there was a significant increase in
the percentage of fat mass in both groups: the median
increase was 1.1% for the control and 2.4% for the
intervention group. The percentage of participants who
presented an increase in body fat was 21% of the control
and 10% of the intervention group (Χ2=0.827, p=0.36).
Table 11 - Percentage of individuals in each of the American College
of Sports Medicine's categories, by group.
The percentages of individuals with hypertension, having
treatment for hypertension and with controlled hypertension
are given in
table 12.
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Table 12 – Percentage of individuals with hypertension, treated
hypertension and controlled hypertension at baseline and at the end of
the study, by group. Comparison between control and intervention
groups by Fisher exact test.
The individuals taking anti-hypertensive medication were
the same at baseline and at the end of the study.
At baseline, although most hypertensive subjects were
treated, less than half were adequately controlled. Changes
regarding prevalence of hypertension during the period of
the study were non-significant both for the control group
(Χ2=0.978, p=0.32). Likewise changes in treatment rate were
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not significant for the control (Χ2=0.798, p=1.0) and
intervention (Fisher's exact test p=0.655) groups. Changes
in control rate were also non-significant in control
(Χ2=0.936, p=0.48) and intervention (Χ2=0.480, p=0.70)
groups. No between-group differences were found regarding
blood pressure values, either at the beginning or at the
end of the study. Similarly, no differences were found
regarding trends in blood pressure levels within groups
over the study period.
Regarding total cholesterol, the median reductions were 23
mg/dl in the control and 17 mg/dl in the intervention
group. But this reduction is statistically significant only
in the control group. It should be noted that at baseline
68.5% of the participants in the intervention group were
already within the desired values, while the figure was
only 26.4% in the control group. The result is that,
although at the beginning of the study the intervention
group had significantly lower total cholesterol values than
the control group, this difference was only borderline
significant (p=0.06) at the end of the study.
No between group differences were found regarding HDL
cholesterol at the beginning or at the end of the study.
Similarly no within group differences were found in respect
of the median increases in HDL cholesterol: +2 mg/dl in the
control and +4 mg/dl in the intervention group. Also no
differences were found regarding the trends in the
percentage of participants with adequate HDL cholesterol
levels: increase of 13.3 to 20.0% in the control (Χ2=0.577
p=0.448) and no change (7.1%) in the intervention group.
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Both at the beginning and the end of the study LDL
intervention group, which also had a lower percentage of
subjects with high LDL cholesterol (16.7% vs. 71.4% of the
control group). During the study period reductions in LDL
cholesterol levels occurred in both groups, but only in the
control group was this reduction statistically significant.
At the end of the study period 57.2% of the participants in
the control group had adequate LDL cholesterol levels
(Χ2=5.600 p=0.018), while in the intervention group all
participants had adequate levels. At the end of the study
both groups remained significantly different.
As for triglycerides the groups had no significant
differences at baseline or at the end of the study. Both
groups showed a reduction of triglycerides median value,
but only in the control group did that reduction have
statistical meaning. The conclusions did not change after
correction for hypolipidemic drugs. The percentage of
subjects presenting with high lipid levels at baseline and
at the end of the study is summarized in
figure 11.
At the beginning of the study, 71% of both the control and
the intervention group presented hyperglycaemia. At the end
of the study both groups reduced their blood glucose
significant in the control group. At the end of the study
62% of the control (Χ2=0.933 p=0.334) and 65% of the
intervention group (Χ2=0.283 p=0.595) still presented
Félix Hopffer Romero
Also the HbA1c values showed a reduction in bo
but this reduction was not statistically significant. In
the control group the percentage of parti
t cipants with high
HbA1c values was 63% at the beginning and at th
study, while in the intervention group th
significant reduction from 60 to 53% (Χ2=0
5.4. FITNESS DATA
The results of the fitness tests according to group and
evaluation period are summarized in
table 13.
Effects of a Physical Activity and Dietary Education Intervention in a Population with type 2 Diabetes Mellitus
Table 13 - Fitness data at baseline and at the end of the study. Results are expressed as medians and (1st quartile,
3rd quartile). Comparison between control and intervention groups by Mann Whitney's U test.
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2 Diabetes Mellitus
The results of the paired analysis (baseline – end) for
each group are presented in
table 14.
Table 14 - Evolution of fitness data, by group. Statistical analysis
by Wilcoxon signed rank test.
30 second chair stand
2 minute step in place
Chair sit and reach
Lower limb strength was assessed by the 30 second chair
stand test, while upper limb strength was assessed by the
arm curl test. At baseline the intervention group fared
significantly better than the control group in respect of
lower limb strength. (
Tables 13 and 14). A similar
difference, albeit non-significant (p=0.08), was found for
upper limb strength. During the study a significant
increase in upper and lower limb strength was found in both
groups but this increase was greater in the intervention
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Effects of a Physical Activity and Dietary Education Intervention in a Population with type
2 Diabetes Mellitus
Aerobic endurance was assessed by the 2 minute step in
place test. No differences were found between the two
groups (p=0.093) at the beginning of the study, but at the
end of the study the differences were significant (p=0.033)
with the intervention showing better results than the
control group (
Table 13).
Lower flexibility was assessed by the chair sit and reach
test, while upper flexibility was assessed through the back
intervention group showed significantly better results than
the control regarding lower flexibility. On the other hand
the difference was no longer significant at the end of the
study, probably due to a large intra-group variability in
increased, although the trend was not significant (
Table
12). No differences were found between the two groups at
baseline in respect of upper limb flexibility. During the
study period a significant worsening was found in the
control group, whereas in the intervention group a
significant improvement was noted. Even so at the end of
borderline significant (p=0.068).
Agility was assessed by the 2.44 m up and go test. At
baseline no significant differences were found between the
two groups. During the study period a trend towards a fall
in the median time was noted in both groups, but in the end
there was still no significant differences between the two
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Effects of a Physical Activity and Dietary Education Intervention in a Population with type 2 Diabetes Mellitus
5.5. MOOD STATES DATA
Data regarding the profile of mood states is presented in
table 15.
Table 15 - Profile of Mood States data at baseline and at the end of the study. Results are expressed as medians and
(1st quartile, 3rd quartile). Comparison between control and intervention groups by Mann Whitney's U test.
Tension – Anxiety
Depression – Dejection
Anger – Hostility
Vigor – Activity
Fatigue – Inertia
Confusion – Bewilderment
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Tension – Anxiety
Depression – Dejection
Anger – Hostility
Vigor – Activity
Fatigue – Inertia
Confusion – Bewilderment
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The statistical significance of the changes which occurred
within each group is shown in
table 16.
Table 16 - Profile of Mood States data, by group. Statistical analysis
by Wilcoxon signed rank test.
Tension – Anxiety
Depression – Dejection
Anger – Hostility
Vigor – Activity
Fatigue – Inertia
Confusion – Bewilderment
There are no significant differences between groups in any
of the factors that make up the POMS, either in the initial
or in the final evaluations. However borderline values were
found at the end of the study: the intervention group
scored higher than the control in the Vigor – Activity
factor, whereas the opposite result (lower score) was found
in the Fatigue – Inertia factor.
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p (
Figure 12)
f r Vigor-Activity
o . TA -Tension - Anx
o
figures
12 and
13 in
Effects of a Physical Activity and Dietary Education Intervention in a Population with type 2
Diabetes Mellitus
For illustrative purposes three cases will be addressed:
• Case 1: a woman in the control group. At baseline her
POMS had an iceberg profile, but this was no longer
the case at the end of the study (
Figure 14). The
decrease in the Vigor-Activity factor is clear, as
Tension-Anxiety,
Depression-Dejection and Anger- Hostility factors.
• Case 2: a woman in the intervention group. At baseline
her POMS had an iceberg profile, which was maintained
at the end of the study with improvements in all
factors (
Figure 15).
• Case 3: a man in the intervention group. His initial
POMS did not have an iceberg profile (
Figure 16). But
over the course of the intervention it improves in all
Confusion-Bewilderment.
result, at the very end it already has an iceberg
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Effects of a Physical Activity and Dietary Education Intervention in a Population with type 2
Diabetes Mellitus
Figure 14 - POMS at baseline and at the end of study for subject nº 20.
Data are means in each factor. TA, Tension–Anxiety; DD, Depression-
Dejection; AH, Anger–Hostility; VA, Vigor–Activity; FI, Fatigue–Inertia
and CB, Confusion–Bewilderment.
Figure 15 - POMS at baseline and at the end of study for subject nº 6.
Data are means in each factor. TA, Tension–Anxiety; DD, Depression-
Dejection; AH, Anger–Hostility; VA, Vigor–Activity; FI, Fatigue–Inertia
and CB, Confusion–Bewilderment.
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Effects of a Physical Activity and Dietary Education Intervention in a Population with type 2
Diabetes Mellitus
Figure 16 - POMS at baseline and at the end of study for subject nº 24.
Data are means in each factor. TA, Tension–Anxiety; DD, Depression-
Dejection; AH, Anger–Hostility; VA, Vigor–Activity; FI, Fatigue–Inertia
and CB, Confusion–Bewilderment.
When the results were analysed for the presence/absence of
an iceberg profile, at the beginning of the study 10 (42%)
of the control group presented an iceberg profile, versus 7
(37%) participants of the intervention group (Χ2=0.103;
p=0.748). At the end of the study the values were 10 (42%)
and 13 (68%) in the control and intervention groups
respectively (Χ2=3.051; p=0.081).
5.6. ECONOMIC DATA
Most participants had serious economic limitations. For
instance, 44% of them had an annual income below 14 times
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Effects of a Physical Activity and Dietary Education Intervention in a Population with type 2
Diabetes Mellitus
the minimum monthly wage (385.90€), 37.5% in the control
and 52% in the intervention group. The monthly cost of
medications during the study period is summarized in
table
Table 17 – Medication costs (€) at baseline and at the end of the
study. Results are expressed as medians and (1st quartile, 3rd quartile).
Comparison between control and intervention groups by Mann Whitney's U
test.
costs (€/month) (0; 14.0)
costs (€/month) (0; 27.4)
The comparison of the cost of treatments at baseline and at
the end is shown in
table 18.
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Effects of a Physical Activity and Dietary Education Intervention in a Population with type 2
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Table 18 – Medication costs (€), by group. Statistical analysis by
Wilcoxon signed rank test.
Individual costs
There were no significant differences between groups at
baseline in regard to medication costs either incurred by
the participants or borne by the State (
Figure 17). It was
the same at the end of the study. But when the changes in
costs within each group are analyzed, the control group had
a median increase of 4.70€ in monthly individual expenses
and of 3.30€ in monthly charges for the government, these
intervention group the 3.10€ monthly median increase in
whereas the increase in 8.80€ in relation to government
costs is statistically significant.
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Diabetes Mellitus
Figure 17 - Costs at baseline and at end of study, by group. Results
are expressed in €/month for participants (left) and the government
(right)
Finally 5 hospitalizations occurred in the control group
during the study, as opposed to 3 in the intervention
significant (Fisher exact test p=0.493)
5.7. FINAL INTERVIEW DATA
The perceived advantages of program participation were
found from the answer to the question "what are the main
benefits you've found from program participation?". The
data obtained by interview is summarized in
table 19.
Biological advantages were referred to the most and, among
them, the general health control category, which included
imprecise and vague statements like "I feel better".
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Table 19 – Interview data regarding the intervention group.
Perceived Advantages
General health control
Diabetes control
Physical fitness
Physical activity habits
Acquaintanceship
Changes in physical activity habits were the most valued
advantages among the psychological benefits from program
participation. On the other hand changes in dietary habits
were referred to less as advantages linked to program
More than two thirds of the intervention group stated that
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Effects of a Physical Activity and Dietary Education Intervention in a Population with type 2
Diabetes Mellitus
acquaintanceship provided by the program was a relevant
All members of the intervention group declared they would
recommend the program to their friends.
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6. DISCUSSION
The implemented program was an important change to
usual care practices provided by the health centre to the
(dietician and physical activity instructor) in the health
care team demanded preparation and coordination and the
dissemination of their work to the team made it possible
for common goals to be defined and knowledge of the
complete program to be shared.
Despite a low adherence to the program (only 1% of the 1900
registered diabetic patients adhered to the program in the
intervention group), physical activity habits among those
who have engaged in the program improved. This improvement,
however, was mainly due to participation in supervised
unsupervised physical activity did not increase. Positive
changes in dietary behaviour occurred, but compliance with
recommendations was not increased. Body fat rose and there
were no significant changes in blood pressure, lipid
profile or glycemic control. On the other hand significant
improvements were found in most variables relating to
fitness, especially aerobic endurance, upper and lower
strength and flexibility. Most factors in the profile of
mood states showed no significant alterations, but fatigue-
increased (borderline). Over the 9 months intervention
period there was a significant increase in the cost of
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Effects of a Physical Activity and Dietary Education Intervention in a Population with type 2
Diabetes Mellitus
medications for the State, but not for the people in the
An unexpected finding was that a considerable number of
diabetic patients do not seek treatment or counselling.
Indeed out of the 1,900 patients with type 2 diabetes
identified by the Health Centre, only 300 (16%) actually
Furthermore out of the 300 subjects that benefited from
these consultations, only 47 (16%) agreed to participate in
this study, and only 20 agreed to be included in the
intervention group. Despite our efforts it was not possible
to reach the initially planned sample size (n=60). These 20
subjects represent approximately 1% of the above-mentioned
1,900 patients with type 2 diabetes. In some cases physical
inability or logistical constraints might justify this non-
adherence. The health centre limitations in providing these
consultations and such delays may deter patients from
attending. In other cases non-adherence might reveal the
little concern that diabetics have with their health. This
situation is in agreement with the literature (Bonen, 2001)
and it has been suggested that this low adherence to
treatment might be due to the lack of physical symptoms
(i.e. pain) in the early stages of the disease (World
transtheoretical model of behaviour change, the benefits of
a healthy behaviour are low in the early stages of change
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Effects of a Physical Activity and Dietary Education Intervention in a Population with type 2
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but increase when the stages of change also increase (World
Health Organisation, 2003). Most of these individuals are
in a pre-contemplation phase and therefore perceived gains
from a possible change to a healthier behaviour are low.
This represents a challenge to secondary and tertiary
prevention programs because individuals should engage in
those programs as early as possible, in order to prevent or
delay disease progression. In diabetic individuals the
consequences of late intervention might be the early
development of chronic major complications that diminish
quality of life and are hardly reversible. In these
conditions treatment efficacy is limited (U.S. Department
of Health and Human Services, 1996).
A question therefore remains about how to increase healthy
behaviours among the vast majority of diabetics, i.e. those
who do not look for advice.
One of the objectives of this study was to induce sustained
lifestyle changes, particularly regarding physical activity
and diet, and to develop a greater awareness of individual
health responsibility, thus enhancing patient empowerment.
During program participation information about the disease
was provided either individually or in groups. Contact with
the healthcare team members was substantially increased,
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Effects of a Physical Activity and Dietary Education Intervention in a Population with type 2
Diabetes Mellitus
mainly due to participation in physical activity classes
intervention there was only one dropout in the intervention
group, and for a reason unrelated to the program itself.
Other indicators of the good acceptance of the intervention
were the high attendance rate and the fact that all the
elements of the intervention group have, in their final
interview, answered that they would recommend the program
to their friends.
6.1.1. PHYSICAL ACTIVITY
The participants had adequate levels of physical activity
at baseline, both in the control and the intervention
groups. The sum of the median time spent walking and
performing moderate physical activity for instance was 7
and 10 hours per week for the control and intervention
groups respectively. Only 20.8% of the control and 10.5% of
the intervention group did not meet the recommended 3.5
hours/week of physical activity. This should be compared to
data indicating that about 70% of the Portuguese population
aged over 55 years has no physical activity at all, and 78%
do not meet this recommendation of the National Program for
Obesity Control (Direcção Geral de Saúde, 2005).
The characteristics of the physical activity program were
not in accordance with the recommendations from the
literature in relation to the workload provided. Most
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Effects of a Physical Activity and Dietary Education Intervention in a Population with type 2
Diabetes Mellitus
guidelines recommend 30 minutes of physical activity at
least 5 times per week (American Diabetes Association,
2004b; American Diabetes Association & American College of
Sports Medicine, 1997; U.S. Department of Health and Human
Services, 1996). But the objective of this study was to
assess the effectiveness of intervention programs with
interventions, possibly easier to implement and with lower
dropout rates, are also effective (LaMonte et al., 2005).
Our program included only two sessions of 50 minutes and
was more designed as a "centre of behaviour change" aimed
to promote an increase in physical activity levels outside
classes. Hence throughout the intervention the participants
were urged to adopt strategies that would maximize their
increase in daily physical activity so as partly to offset
the missing workload recommended in the above mentioned
Although no significant differences between groups were
found at the end of the study regarding physical activity
levels, a significant increase in walking time was noted in
the intervention group. It must be emphasized that the
hilly and steep terrain around the health centre is an
obstacle to this particular behaviour change. So this
change in behaviour denotes an intention to comply with the
advice given. This is an important result because physical
activity tends to decline with ageing (Direcção Geral de
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Effects of a Physical Activity and Dietary Education Intervention in a Population with type 2
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Despite the fact that the physical activity classes were
reported as "moderate physical activity", no differences
between the two groups were found for this category. A
possible explanation lies in the diversity of situations
found in the control group, especially at the end of the
study. The slight but non significant increase in moderate
contributed to the increase in total energy expenditure at
the end of the study. The fact that this did not happen in
the control group makes us believe that the program was
effective in increasing the total energy expenditure in the
relevant: first the program did not increase physical
significantly higher than in the control group. Probably
the high initial physical activity level from both groups
prevented any further substantial increase. Further the
increase in total energy expenditure in the intervention
group was achieved only through direct intervention with
the physical activity classes, because, if this activity is
not taken into account, the change in total energy
intervention group was not sufficient by itself to have a
objective of increasing total energy expenditure outside
physical activity classes was therefore not achieved in
this study. These findings highlight the importance of
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Effects of a Physical Activity and Dietary Education Intervention in a Population with type 2
Diabetes Mellitus
exercise supervision as reported by Alam (2004). Comparing
a group submitted to supervised exercise with another
submitted to unsupervised exercise, these authors found
significant improvements in weight, body composition, lipid
profile and glycemic control in the supervised compared to
the unsupervised group.
6.1.2. DIETARY HABITS
At baseline, more than half of the subjects did not meet
the dietary recommendations for the Portuguese population
for each food category. The highest rates of non-compliance
both at the beginning and at the end of the study were in
vegetables and pulses. This could be related to the cost of
those foods, and also to the fact that they are perishable
(Darmon et al., 2004; Darmon et al., 2002, Drewnowski et
al., 2007; Drewnowski & Specter, 2004). Our results are
thus consistent with the literature (Hsia et al., 2002;
Nelson et al., 2002) that also found over two thirds of
individuals with inadequate dietary intakes in respect of
vegetables and fruits.
Despite being a more motivated group, and having access to
specialized dietician consultations, the dietary pattern of
the intervention group was far from optimal. The reasons
for such a finding can only be speculated, but lack of
comprehension by the participants or economic difficulties
in buying selected foodstuffs are most likely. Indeed, a
sizeable fraction of the participants lived on less than
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Effects of a Physical Activity and Dietary Education Intervention in a Population with type 2
Diabetes Mellitus
400€ a month, which considerably reduces their food budget.
This might also explain the difficulties in changing
dietary habits when strong economic constraints exist.
Also no significant improvements were noted for both the
control and intervention groups regarding compliance with
the dietary recommendations for the Portuguese population.
Despite this at the end of the study the intervention group
had significantly more compliers than the control group in
the category of milk and derivatives, and also a better
dietary score. This indicates that, despite a statistically
non-significant progress in each food category, the overall
dietary pattern improved in the intervention compared to
the control group. These findings suggest that it might be
more important to assess the overall effect of dietary
intervention rather than the effect on selected foodstuffs.
Further if we consider the changes in dietary behaviour
irrespective of agreement with guidelines, the intervention
behaviour (
figure 10). These findings suggest that even if
the participants fail to comply fully with the dietary
recommendations their dietary intake tends to improve.
Conversely a bi-modal trend was found in the control group
with about half of the subjects improving and the other
half decreasing the quality of their dietary behaviour. The
reasons for such a trend are currently unknown. Overall our
literature (Hsia et al., 2002, Nelson et al., 2002) that
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describe the difficulty of achieving changes in eating
behaviour in the long term.
6.2. CLINICAL AND BIOLOGICAL VARIABLES
At baseline over two thirds of participants were either
overweight or obese. Such results are consistent with the
literature: data from the National Health Survey (INSDRJ,
2009) indicates that for individuals aged over 55 years the
prevalence of overweight and obesity is around 64.1%. This
value is further increased among subjects with diabetes.
Examination Survey (NHANES III), 1988-1994, and the NHANES
1999—2002, shows a prevalence of 85.2% for overweight and
obesity among individuals aged over 20 years with diabetes,
(Centers for Disease Control and Prevention, 2004).
The increased fat mass percentage found in both groups may
be caused by a reduction in fat-free mass due either to
sarcopenia (American College of Sports Medicine, 2009b;
Kesavadev et al., 2003; Short & Nair, 2001), or to the
reduction of bone mineral density, both characteristics of
the ageing process (American College of Sports Medicine,
2009b). Contrary to the literature, that showed reductions
in weight and percentage of fat from physical activity
(Alam et al., 2004, Fritz et al., 2006; Krousel-Wood et
al., 2008), our results suggest that a low intensity
intervention is not adequate to improve BMI or body
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Diabetes Mellitus
composition. However, the previous studies were conducted
in younger subjects and an age effect might be present.
Also it is likely that younger individuals might be able to
exercise at higher intensities.
At baseline hypertension was present in 83.3% and 68.4% of
the control and intervention groups respectively. Such
values are in line with the literature and match those of
the general population of the same age group. In a sample
of 5,023 adults aged 18 to 90 years representative of the
general Portuguese population (Macedo et al., 2007), the
prevalence of hypertension was 42.1% for the total sample
and 79% for the group aged over 64 years. In our study
treatment rates (70.0% and 84.6% at baseline for the
slightly higher than in the referred study for the same age
group: 55.9% for men and 69.6% in women. Usually treatment
rates increase with age due to the more frequent health
monitoring of elderly people. The same process also applies
to diabetics and may explain the differences between our
study and the one referred to. Finally the rates of
controlled hypertension (35.0% in the control and 46.2% in
the intervention group) were higher than in the referenced
study, albeit no data is available regarding the control
levels for age, but it is noted that individuals with
controlled hypertension are younger. Indeed, the median
baseline SBP and DBP values in our study (140 mmHg and 70
mmHg for both groups) were lower than those found in the
cited article for individuals over 74 years (150 mmHg and
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Effects of a Physical Activity and Dietary Education Intervention in a Population with type 2
Diabetes Mellitus
85 mmHg), probably due to the higher rate of controlled
individuals. Another study that included 1,031 Portuguese
aged over 55 of both genders reported similar results: a
hypertension prevalence of 67.6% (95% CI: 64.6-70.5%), with
41.6% of treated individuals and 27.4% of treated and
controlled subjects (Clara, Macedo, & Pego, 2007). Still no
clinical effect of the intervention on blood pressure
levels or on hypertension control was found. Again the
results suggest that, in order to achieve adequate blood
pressure control, more stringent conditions should be
As for the lipid profile, the groups differed significantly
at baseline regarding total cholesterol and LDL, the
intervention group presenting lower values. The total
cholesterol values at baseline of the intervention group
were comparable to those from the literature, namely for
subjects aged over 60 years in the NHANES study (Schober,
Carroll, Lacher, & Hirsch, 2007), and those found by
Castaneda (2002) in a sample with the same age profile than
our study. The baseline LDL cholesterol levels for the
literature (Castaneda et al., 2002; Fritz et al., 2006; A.
Kirk et al., 2004; Maiorana et al., 2002). A possible
explanation might be a lower dietary compliance among the
control group. The triglyceride values at baseline were
similar to those found by Castaneda (2002) but lower than
those referred to by other authors (Fritz et al., 2006; A.
Kirk et al., 2004; Maiorana et al., 2002). The control
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Diabetes Mellitus
group presents a median 10mg/dl higher values than the
statistically significant.
LDL-cholesterol,
triglyceride values, was statistically significant only in
the control group, probably due to the greater progression
intervention group completed the study without any subject
with high LDL-cholesterol values. This is an important
result because elevated LDL cholesterol is the primary
target of lipid-lowering therapy according to the American
Diabetes Association and the American Heart Association
(Buse et al., 2007). The fact that the dietary category
"Fats and oils" has one of the highest percentage of
compliers in both groups might partly explain these
results, as a reduction in saturated fat leads to a
decrease in LDL cholesterol levels (Hsia et al., 2002).
Non-significant improvements in median values for total,
LDL and HDL cholesterol, and triglycerides were found in
both groups. This could be due to the lack of statistical
power caused by the small sample size and high data
variability. In general, these results are in line with the
literature (Castaneda et al., 2002; Fritz et al., 2006; A.
Kirk et al., 2004; Maiorana et al., 2002) where non-
significant trends were found. One exception is the work of
Fritz et al.(2006), where significant differences were
found for LDL and HDL levels, but those trends were found
in both the control and the intervention group.
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At baseline the percentage of participants with a HbA1c
under 6.5% was 37% for the control and 40% for the
intervention group. Compared with the literature (Castaneda
et al., 2002; A. Kirk et al., 2004; Krousel-Wood et al.,
2008; Maiorana et al., 2002; McDonald, Hertz, Unger, &
Lustik, 2009; Tokmakidis et al., 2004; Wolf et al., 2004),
our results indicate a relatively good glycemic control
among the diabetic subjects. Further both groups had
reductions in both glycaemia and HbA1c over the study
period. However those changes were significant only for
glycaemia in the control group. These findings are in
agreement with some studies (Castaneda et al., 2002; A.
Kirk et al., 2004, Maiorana et al., 2002; Tokmakidis et
al., 2004, Wolf et al., 2004), but not with others
(Baynard, Franklin, Goulopoulou, Carhart, & Kanaley, 2005,
Fritz et al., 2006; Krousel-Wood et al., 2008). Possible
intervention group include the already low values found at
baseline as well as the age of the sample. Indeed it has
been shown that in older individuals the improvement of
glycemic control is considerably more difficult (Kesavadev
et al., 2003). According to Boulé (2003), interventions
with more intense physical activity are more effective in
glycemic control. This is thus a limitation of the program,
because it was not appropriate to increase the intensity of
the sessions of physical activity in our study sample. In
the case where significant differences were found, they
ranged between 0.2%(A. Kirk et al., 2004) and 1.1%
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(Castaneda et al., 2002). The work of Wolf et al. (2004)
points to a relevant issue: a possible rebound effect.
After 4 months the intervention group presented significant
lower HbA1c than the "usual care" group, but at 12 months,
baseline values nor from the "usual care" group. It is of
relevance that in this study there was a weight regain in
the last 4 months of intervention, a rebound effect that
can also happen regarding glycemic control.
Overall, the clinical and biological results of our study
may be explained by the characteristics of the program.
Regarding physical activity, the program was below the
recommendations of international organizations regarding
the frequency of sessions. This was due to the difficulty
in increasing total metabolic expenditure outside classes
and thus the program fell short of the recommended total
workload. Furthermore, the high age of the participants
conditioned not only the intensity of the sessions, but
also the magnitude of the results, because the effects of
intervention tend to decrease with age (Kesavadev et al.,
A significant rise, both in upper and lower strength, was
found in the intervention group; and the significance of
the rise in upper was greater than that in lower strength.
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The fact that a significant improvement was verified also
in the control group may be explained by an adaptation to
the test itself. Despite the time given to adapt to the
test doing a specific warm up, and the large period between
individuals have learned to manage their effort more
efficiently. Differences between baseline and the end of
study were however more significant in the intervention
group both for lower and upper strength.
These results are in line with those found in the
Maiorana et al.(2002) found after an 8 weeks circuit
training program a significant increase in strength in 16
both gender subjects with type 2 diabetes. In this study
assessed as a sum of strength measures on each of 7
different exercises.
Tokmakidis et al.(2004)found a significant upper (13%) and
lower(14%) strength improvement in 9 women with type 2
diabetes after an exposure to a 4 months combined strength
and aerobic exercise program.
Ibanez et al. (2005)exposed 9 subjects with type 2 diabetes
to a program that included two sessions per week of
progressive resistance training at an intensity of 60% of 1
repetition concentric maximum (1RM), without a concomitant
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Effects of a Physical Activity and Dietary Education Intervention in a Population with type 2
Diabetes Mellitus
weight loss diet. Significant improvements in upper (18%)
and lower (17%) strength were found.
The abovementioned results were obtained with younger
samples than in our study, but the fact that those results
can be reproduced in older individuals is an important
result, because in that case deficits in strength can
affect autonomy and, particularly in lower limb strength,
may contribute to impaired balance, thus increasing the
risk of falls (M. Rogers, Rogers, Takeshima, & Islam,
This problem is especially important among older adults
with diabetes, who have a two-to threefold increased risk
of physical disability (Kesavadev et al., 2003; Park et
al., 2006) and tend to be weaker. Andersen, Nielsen,
Mogensen and Jakobsen (2004) compared type 2 diabetic
patients with control subjects matched for sex, age,
weight, height, and physical activity. They found a
significant strength reduction in ankle flexors (17%) and
extensors (14%) and also in knee flexors (7%) and extensors
Our results confirmed that it is possible to resist the
strength loss that comes with age, even in an elder and
diabetic population.
intervention groups. At baseline the intervention group had
Félix Hopffer Romero
Effects of a Physical Activity and Dietary Education Intervention in a Population with type 2
Diabetes Mellitus
differences were of borderline significance. At the end of
significant, i.e. the improvement was steeper in the
intervention group.
These results are in line with those obtained by several
authors (Alam et al., 2004; Maiorana et al., 2002; Tessier
et al., 2000) which found an increase in cardio respiratory
fitness as a result of intervention programs. In all of
these studies, the program included, at least partially,
aerobic exercise.
Considering that low cardio respiratory fitness is a risk
factor for cardiovascular events (F. B. Hu, Stampfer et
al., 2001) and an independent predictor of all cause
mortality in individuals with type 2 diabetes (Wei,
Gibbons, Kampert, Nichaman, & Blair, 2000), these results
point towards a risk reduction as a consequence of
participation in aerobic exercise.
flexibility. In upper flexibility there was a significant
decrease for the control group and a significant increase
for the intervention group.
The importance of flexibility is sometimes undervalued
among fitness variables. It can be determinant of the
quality of life, particularly in elderly subjects. In
diabetic patients this might be an important issue, because
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Effects of a Physical Activity and Dietary Education Intervention in a Population with type 2
Diabetes Mellitus
joint structures may be affected, and complaints of "frozen
shoulders" are common (Herriott, Colberg, Parson, Nunnold,
In the intervention group upper limbs had a steeper
evolution compared with the lower limbs, in relation to
strength and flexibility. This fact may signify that in
this population daily physical activity does not make equal
demands on lower and upper limbs. Thus the applied program
might represent a substantial increase in physical activity
for the upper limbs, but not for the lower limbs.
important outcome of the program because, in elders, these
autonomy, this effect is not confined to be a biological
psychological, social and economic areas, and have a
profound impact on the quality of life of the patients and
their relatives.
6.4. MOOD STATES
At baseline the intervention group had an iceberg profile
in relation to mood states, and that profile increased
during the study due to the decrease shown in the Fatigue-
Inertia factor and the borderline increase in Vigor-
Activity. Changes in these factors are significant and had
no parallel in the control group. At the end of the study
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individuals in the intervention group perceived themselves
more active and less tired than at baseline. These results
are probably related to the improvements found in aerobic
endurance and in upper and lower strength for this group.
This was also an important result from the psychological
point of view. In order to keep individuals motivated and
committed to their treatment, it is important to value, and
to make the patient value every little progress achieved,
because it enables the patient to find himself as having a
say in his own fate. This change in the locus of control
over the disease from external to internal is a crucial
step towards compliance with treatment and towards patient
empowerment. If the patient has an external locus of
control he will see the disease as a fate, as something he
is not able to control. In this situation the commitment to
a treatment plan will be very hard to achieve. On the other
hand if the patient has an internal locus of control he
will see himself as having a good level of control over the
disease, and will, hopefully try to improve it. The
interest in acquiring knowledge about the disease and the
commitment to a treatment plan is therefore, more likely
(Stanton et al., 2007).
The reduction in the subjective perception of fatigue is a
change that can easily be valued by the patient because it
has an impact on his/her quality of life, especially in
more aged individuals. This effect can be used to promote a
change towards an internal locus of control, which should
be a target for every lifestyle intervention program.
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Effects of a Physical Activity and Dietary Education Intervention in a Population with type 2
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Despite no reductions having been found in most factors of
profile of mood states, the above mentioned changes were
enough to increase the percentage of individuals in the
intervention group with an iceberg profile which rose from
37 to 68%. In the control group this percentage remained
unaltered at 42%. These results are in agreement with the
literature (Biddle & Mutrie, 2001; Leith, 1994) concerning
the appearance of an iceberg profile following an increase
in physical activity.
6.5. ECONOMIC ANALYSIS
In order to be implemented lifestyle programs must also
prove to be cost-effective (Imai & Zhang, 2005). In this
research the cost of medications to the individual and the
State were assessed. Inflation in the 9 months period
during which the research was implemented was not taken
into account, and therefore increments in costs must be
interpreted as higher doses or more expensive medication
prescriptions. The figures obtained may be underestimated,
as the calculations were made based on the cheapest drugs
allowed in the prescription. Overestimation may also be
possible due to lack of compliance with the prescribed
No national data is available to compare but, at baseline,
the cost of medication per individual could reach as much
as 103.84€ per month. Thus the economical constraints
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considering that 44% of the sample had an income of less
than 385.90€ per month.
From the individual point of view, both groups increased
significant only in the control group. The State expenses
rose significantly in both groups. The explanation for the
different evolution of individual and State expenses may
lie in the healthcare system itself: albeit antidiabetic
medications are entirely supported by the Portuguese health
Therefore, it is possible that in the intervention group
the program delayed some co-morbidities of diabetes thus
complications of diabetes are responsible for more than one
third of diabetic health expenses (Oliva et al., 2004) and
postponing them is one of the main objectives of tertiary
prevention, as stated in the Portuguese national program
for diabetes prevention and control (Direcção Geral de
Saúde, 2008). Therefore this result is encouraging.
A higher number of hospitalizations and a longer period of
hospitalization were reported in the control group, but
those differences did not reach statistical significance.
It was likely that this was due to the sample size and to
the low number of hospitalizations which occurred within
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Diabetes Mellitus
The economic burden of antidiabetic medication is generally
low for individuals but high for society. The cost-
effectiveness of lifestyle programs is difficult to assess
interventions does not apply to lifestyle interventions.
In pharmacological interventions the costs are linked with
interventions costs are upfront and cost-effectiveness
depends largely on the long term maintenance of health
variability of health outcomes found in different lifestyle
programs further complicates the economic analyses (Jacobs-
van der Bruggen et al., 2009).
6.6 FINAL INTERVIEW ANALYSIS
Data obtained in the final interview confirms the one
gathered about physical activity and dietary habits by the
IPAQ questionnaire and by the 24 hour recall respectively.
The questions asked to the intervention group regarding
program participation revealed that perceived advantages
were mostly biological. Only 10.6% of participants do not
refer this kind of outcome. Diabetes' control was the less
referred biological category which is consistent with the
variables. On the other hand, the high percentage of
Félix Hopffer Romero
Effects of a Physical Activity and Dietary Education Intervention in a Population with type 2
Diabetes Mellitus
participants that reported "general health control" and
answers on the improvement this group had on most fitness
variables and also in the profile of mood states in what
"fatigue-inertia"
"vigor–activity"
psychological advantage of program participation. This
seems to reveal that the participants were aware that their
efforts to improve compliance with dietary recommendations
were not enough.
Physical Activity habits was the most referred category
amongst psychological advantages. In fact the participation
in the structured physical activity classes represented to
this group a significant change in physical activity
habits. Participants may however have considered this
change as sufficient and have neglected the advice to
increase its unstructured daily physical activity. The
significant raise in the time spent walking and the
unchanged moderate physical activity were not sufficient to
promote significant differences in the overall physical
activity, leaving out of account the time spent at physical
activity classes.
The perceived changes regarding mood states are also in
line with changes found in POMS questionnaire namely
"fatigue-inertia"
"vigor–activity"
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Data gathered by interview was therefore consistent with
data collected from the other sources.
The fact that 68.4% of the subjects in this group referred
that acquaintanceship was a significant advantage from
program participation, highlights the importance for the
individuals of the enlargement of their social network.
This might be related with the age of the sample since in
older ages it is common to witness a substantial reduction
in the social network (Findlay, 2003; Victor, Scambler,
Bond, & Bowling, 2000).
The contribution that participation in this kind of
programs has in the extension of the social network is an
especially in elder populations because there is some
evidence of relation between social support and personal
coping resources with chronic diseases(Auslander & Litwin,
1991; Penninx et al., 1997).
The last question "would you recommend the program to your
friends?" would reflect a final judgment about program
participation. All things considered, all participants
found the program participation as an experience they would
recommend. Despite the unanimous response, it is to
consider a possible bias due to the social desirability of
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Diabetes Mellitus
7. CONCLUSIONS
Daily life self-reported levels of physical activity were
higher than expected considering the age of the sample.
Vigorous physical activity is avoided by most individuals
and the core part of the energy expenditure is reached
through moderate physical activity and walking.
Dietary habits were poor and recommendations for the
individuals on most of the food categories. Cultural,
social and economic reasons may help explain this non-
compliance amongst a population that has on dietary habits
one cornerstone in the treatment of their disease.
The program achieved a moderate success in changing
behaviours. Structured physical activity was well accepted
but the increase of unstructured physical activity in daily
life is more difficult to achieve. This stresses the
importance of supervised physical activity classes.
Improvements in dietary habits took place but were tenuous
and insufficient to significantly change the compliance
with recommendations for the Portuguese population.
The above mentioned improvements in both physical activity
and dietary habits had no significant impact on most
clinical and biological variables, namely blood pressure
and lipid profile.
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Diabetes Mellitus
Fitness was improved and perceived fatigue diminished. This
can have a direct impact on the quality of life but can
also be an important point to keep individuals motivated.
The program may help to control individual costs of
medications, and it probably delays the occurrence of the
chronic complications of diabetes.
This study was useful to identify some barriers that hinder
the development of this kind of program, and the experience
gained will be important for the future implementation of
similar (and hopefully more efficient) interventions.
Our results suggest that in order to be more effective,
intervention should begin as early as possible, as its
implementation among elderly subjects is difficult. This
would lead to a larger response to the program and to a
more intense physical activity intervention.
This was a quasi-experimental pilot study. The fact that
participants were affiliated to groups based on their own
choice rather than randomly is a limitation because the
probabilities for the two groups were not equivalent. It is
plausible that individuals in the intervention group were
more motivated and had a higher commitment to their health.
Adherence to the program conditioned sample size, leading
to a low statistical power. Despite our efforts it was not
possible to reach the initially planned sample size (n=60).
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Another important aspect in the interpretation of the
results is the mean age of the sample (69.1 years), which
is considerably older than most studies. The comparison of
our results with those of other studies must thus consider
a possible age effect.
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Source: http://repositorio.ipsantarem.pt/bitstream/10400.15/383/1/Doutoramento%20F%C3%A9lix%20Romero.pdf
Little Peoples Place Early Learning Centre Diversity Calendar 2016 Celebrations can be as diverse as each of the children in a child care service. When incorporated into children's services appropriately, celebrations can be used to bring people together, to create a feeling of belonging and to develop a sense of community amongst families, educators and children.
Oral Ondansetron for Gastroenteritis in a Pediatric Emergency Department Stephen B. Freedman, M.D.C.M., Mark Adler, M.D., Roopa Seshadri, Ph.D., and Elizabeth C. Powell, M.D., M.P.H. From the Division of Pediatric Emergency Vomiting limits the success of oral rehydration in children with gastroenteritis. We Medicine, Hospital for Sick Children, Uni- conducted a double-blind trial to determine whether a single oral dose of ondanse-
