Periodic cues, including scheduled exercise, social interactions, sleep habits, and feeding time, have been shown to alter the circadian system. A disruption in circadian rhythms has been shown to have negative effects on health. Frequent skin temperature measures have been shown to be a valid method of assessing circadian rhythm parameters. The purpose of this study was to determine group mean differences in temperature amplitude, stability and lag measures among groups of young men of varying (optimal, fair and poor) adiposities. The strength of the association among the temperatures parameters and measures of body composition, physical fitness and activity, nutritional intake, lipid concentrations, and sleep were also examined. Findings indicated that men with poor adiposity had significantly lower mean amplitude and stability than the optimal or fair groups; with no significant differences in lag among the groups. Factors including physical fitness, physical activity and late night eating contributed to the variance in amplitude; physical activity, time spent in moderate to vigorous activity, late night snacking, and fat mass to stability; and sleep hours and lipid ratios to lag. These findings contribute to the identification of targeted intervention strategies that may improve the circadian synchrony and health of young men.

BACKGROUND: Type 2 diabetes and cardiovascular disease (CVD) are among the leading causes of death in the United States. The Metabolic Syndrome, which comprises a cluster of cardiometabolic risk factors, puts individuals at increased risk for these diseases. It is therefore important that people with Metabolic Syndrome, at high risk for CVD and type 2 diabetes, are identified and treated. Since it may not often be practical to obtain the laboratory measures necessary for diagnosing the Metabolic Syndrome, simple anthropometric measures are a useful way of quickly identifying individuals at increased risk for the Metabolic Syndrome. OBJECTIVE: The purpose of this thesis is to evaluate the utility of three of the most commonly used anthropometric measures – Body Mass Index (BMI), Waist Circumference (WC), and Waist-to-Height Ratio (WC) – for classifying individuals with and without the Metabolic Syndrome and its component risk factors in the United States. Using Receiver Operating Characteristic (ROC) curve analysis and Area Under the Curve (AUC) statistics, this thesis will assess the utility of each body measurement and compare it to BMI. METHODS: A large, multi-ethnic, nationally representative sample from the National Health and Nutrition Examination Survey (NHANES) 2007-2010 was used for this analysis. The study sample was restricted to adults aged 20-65 with complete information on height, weight, waist circumference, blood pressure, HDL cholesterol, fasting glucose, and triglycerides (n=3,769). In order to compare the utility of different anthropometric measures for classification, weighted ROC curves were constructed for each anthropometric measure-outcome combination and AUC statistics were compared. AUC statistics were calculated by approximating the definite integral of the ROC curves with the trapezoidal rule. Variances for AUC statistics and differences in AUC statistics were estimated with jackknife repeated replication. Analyses were completed for the entire sample and separately for non-Hispanic whites, non-Hispanic blacks, and Mexican Americans. RESULTS: For the entire sample, WC (AUC=0.752) did a better job than BMI (AUC=0.728) at classifying individuals with and without the Metabolic Syndrome (p CONCLUSION: Waist circumference should be considered, especially over BMI, for risk stratification in clinical settings and research. Further research should attempt to identify optimum waist circumference cut points for use in the US population.

Type 2 diabetes and cardiovascular disease (CVD), major public health concerns in Canada and worldwide, are the main outcomes of Metabolic Syndrome (MetS). MetS is a clustering of five chronic disease risk factors, including abdominal obesity, dyslipidemia (elevated triglycerides and reduced high-density lipoprotein cholesterol level), hypertension, and elevated fasting plasma glucose. Abdominal obesity and insulin resistance are the main factors contributing to development of MetS and thus CVD and diabetes. Further, dyslipidemia (specifically the total cholesterol/HDL-C ratio) is necessary to be monitored in people with these diseases or risk factors. The Canadian Health Measures Survey (CHMS) has direct health measurements that provide the opportunity to identify risk factors associated with chronic disease. Further, dietary intake has been assessed in CHMS, which can be utilized to evaluate the association with diseases and risk factors controlling for potential covariates. To examine the association between dietary intake with MetS and associated risks and diseases in Canadian adults and adolescents, data from CHMS cycle1, 2007-2009 (n=5604, aged 6-79 y) were used in which dietary intake was assessed using a semi-quantitative food frequency questionnaire. Frequency of food intake (times/day) and the distribution of individuals with and without disease or risk factors by socio-demographic characteristic was determined. Further, the association between dietary intake and each disease or risk factor was evaluated using logistic models. Data manipulation, cleaning, and creation of new variables were done using IBM SPSS statistics for windows, version 20. All statistical analyses were conducted by STATA/SE 11, StataCorp. As per Statistics Canada’s recommendation, data were weighted and bootstrapped using specific commands in STATA in order to be representative of the Canadian population. Physically active Canadians had significantly more milk and dairy product, fresh fruit and vegetable, and fruit and vegetable juice intake compared to inactive Canadians. Low-income households had significantly greater intakes of sugar-sweetened beverages (SSBs) and lower amounts of fresh fruit and vegetables than high-income households. Individuals with the lowest level of education had greatest potato and lowest fruit and vegetable juice intake. The prevalence of abdominal obesity (12-79 y), elevated TC/HDL-C ratio (20-79 y), MetS (12-79 y), and diabetes (20-79 y) was 35.7%, 20.5%, 18.3%, and 7.5%, respectively. The overall estimated percent risk of CVD over 10 years in adults aged 30-74 y was 8.66%. Abdominal obesity had the greatest contribution (~90%) to development of MetS in each age group compared to other components of MetS. Also, abdominal obesity was a strong significant predictor for development of other risk factors and chronic diseases including elevated TC/HDL-C ratio, diabetes, and CVD (OR: 6.12, CI: 2.68-13.96; OR: 2.25, CI: 1.24-4.06, OR: 1.4, CI: 1.06-1.87, respectively). High consumption of diet soft drink was associated with increased risk of abdominal obesity, Mets, diabetes, and elevated TC/HDL-C ratio. High consumption of fruit and vegetables and cereal was associated with decreased risk of CVD over 10 years whereas potato intake increased the risk. Intake of nuts appeared to be associated with reduction in the risk of MetS among Canadians. Dietary fat intake of one to less than 5 times/week was associated with increased risk of abdominal obesity in individuals over 40 years of age compared to 12-19 y individuals. Further, “ever drinking” alcohol compared to “never drinking” alcohol was associated with decreased risk of diabetes and elevated TC/HDL-C ratio. Low level of education contributed to development of abdominal obesity. Thus, abdominally obese individuals with specifically elevated TC/HDL-C ratio are at risk of developing MetS, CVD, and diabetes. They need to be educated with specific focus on physical activity, and greater intake of fruit and vegetables, nuts, and lower intake of dietary fat, diet soft drinks, and potato. Additionally, considering the social determinants which might contribute to increase the risk of chronic diseases or risk factors such as income, housing, accessibility to facilities in neighborhoods, school programs, or community programs is essential.

Despite inconsistent results in the literature, high protein diets are being promoted for the management of metabolic syndrome parameters primarily due to their proposed favorable effects on weight loss. Therefore, lean and fa/fa Zucker rats were given normal and high protein diets with varying protein sources for 12 weeks. A high protein diet with a mixture of animal and plant protein sources was the most effective for improving metabolic syndrome parameters, specifically insulin resistance and hepatic steatosis. A high protein soy diet was the second most effective diet, while a high protein casein diet demonstrated no benefits compared to the other two high protein diets and minimal benefits compared to a normal protein casein diet. Interestingly, high protein diets did not affect body weight regardless of protein source. These findings suggest that the source of protein within a high protein diet is critical for improving metabolic syndrome parameters and that improvements can be observed independent of weight loss.

No description available.

Motivation: The metabolic syndrome is characterized by a group of risk factors for cardiovascular disease (CVD) that includes obesity, dyslipidemia, high blood pressure, insulin resistance, glucose intolerance or non-insulin dependant diabetes mellitus, pro-thrombotic state and pro-inflammatory state. The NHANES I11 study showed the prevalence of this syndrome to be 24.0% in men and 23.4% in women in the USA. These figures translate to more than 47 million US residents having the metabolic syndrome. In the THUSA (acronym for Transition and Health in the Urbanization of South Africans) study in South Africa it was found that 12% and 28.4% of men and women, respectively, of the black population of the North West Province had three or more disturbances characterizing this syndrome. Therefore, it is evident that the metabolic syndrome is a health problem not only for developed countries but also for developing countries. As a result, this syndrome has been identified as a target for dietary therapies to reduce the risk of CVD and type 2 diabetes. Epidemiological studies have consistently demonstrated an inverse association between nut consumption and coronary heart disease (CHD) morbidity and mortality in different population groups. Nut consumption may not only offer protection against heart disease, but also increase longevity. Recently, the benefits of nuts consumption were acknowledged by the U.S. Food and Drug Administration when they approved a qualified health claim that eating nuts (1.5 ounces/day ≈ 42.8 g/day) may reduce the risk of CHD. In this regard, the most comprehensively studied mechanism involved the favourable lipid lowering effects of nuts. There is, however, a lack of data in the literature regarding the effect of nuts on the metabolic syndrome. Objective: The main objective of this study was to examine the effects of a high walnut diet and a high unsalted cashew nut diet on markers of the metabolic syndrome in humans. In order to provide a foundational body of evidence for the aforementioned, a secondary objective included conducting a systematic review that investigates the effects of nuts on the lipid profile. Methods: The main project consisted of a controlled feeding trial with a parallel, randomized controlled study design on participants having the metabolic syndrome. Sixty-four subjects having this syndrome (29 men, 35 women) with a mean (±SD) age of 45±10 y and who met with the selection criteria were all fed a 3-week run-in control diet. After this period, participants were grouped according to gender and age and then randomized into three groups, namely, those that received a controlled feeding diet including walnuts (20% energy (E), 60-100g/day; protein:carbohydrate:fat=18:42:40%E). or unsalted cashew nuts (20%E 66- 1 15g/day; protein:carbohydrate:fat=l9:44:37%E) or no nuts (protein:carbohydrate:fat=20:47:33%E) for 8 weeks. The participants' physical activity and weight were maintained for the duration of the study. For the systematic review. human intervention trials that investigated the independent effects of nuts on lipid concentrations were included. Medline and Web of Science databases were searched from the start of the database to August 2004 and supplemented by cross-checking reference lists of relevant publications. These papers received a rating based upon the methodology as it appeared in the publication. No formal statistical analysis was performed due to the large differences in study designs of the dietary intervention trials. The main outcome measures for the systematic review, were percentage differences between treatment and control groups for total blood cholesterol (TC), low-density lipoprotein cholesterol (LDLC), high-density lipoprotein cholesterol (HDL-C) and triacyglycerols (TG). Results: Regarding the main objective, we found that both the walnut and unsalted cashew nut intervention diets had no significant effect on the lipid profile, serum fructosamine, insulin, insulin sensitivity, insulin resistance, serum high sensitivity C-reactive protein, blood pressure and serum uric acid concentrations when compared to the control dict. All three groups experienced highly significant increases in serum insulin concentrations when comparing the baseline to end (P<0.05). In turn, insulin resistance increased while insulin sensitivity decreased in all three groups. Plasma glucose concentrations increased significantly in the cashew nut group compared to the control group (P<0.05). By contrast, serum fructosamine was unchanged in the cashew nut group while the control group had significantly increased concentrations of this short-term marker of glycaemic control. The literature search for the systematic review yielded 41 5 publications. After screening, 23 nut studies were included in the review with most of these studies including heart-healthy diets. The majority of the studies were short (4-6 weeks) with only one study lasting 6 months. The number of subjects in most of the studies was sufficient to study the effects on TC and LDL-C but not for HDL-C and TG. The results of three almond (50-100g/day), two peanut (35-68g/day), one pecan nut (72g/day) and four walnut (40-84g/day) studies showed convincing evidence for a lipid lowering effect of TC between 2-1 6% and LDL-C between 2- 19%, when compared to their control diets. Currently, there are indications from inadequately designed intervention studies that hazelnuts (lg/day/kg body weight) and pistachios (20%E) may have a lipid lowering effect. At this stage the evidence for macadamia nuts is less convincing. Furthermore, it is apparent that the components in nuts further reduce TC and LDL-C concentrations beyond the effects predicted by equations based solely on dietary fatty acid profiles. Conclusions: In the controlled feeding trial, subjects displayed no improvement in the markers of the metabolic syndrome after following a walnut or unsalted cashew nut diet compared to a control diet while maintaining body weight (8 weeks). Finally, we suspect that the dramatic increase in insulin resistance may have masked the protective effects of the walnut and cashew nut diets in our subjects with the metabolic syndrome Further research is warranted before a consensus can be reached. From the systematic review it was concluded that the consumption of ≈50-100g (≈1.5-3.5 servings) of nuts five or more times/week as part of a heart-healthy diet with total fat content (high in mono- and /or polyunsaturated fatty acids) of ≈ 35% of energy may significantly decrease TC and LDL-C in normo- and hyperlipidemic individuals. Recommendations: A similar nut controlled feeding trial with some form of calorie restriction, should be done on participants having the metabolic syndrome. Future research should use randomized controlled studies with larger sample sizes and longer duration to investigate the effects of nuts on HDL-C and TG concentrations. Also, studies should investigate the effects on the lipid profile of mixed nuts and those individual nuts not yet considered. In addition, the unique nutrient and non-nutrient composition of nuts requires further research in order to elucidate the possible mechanisms responsible for the LDL-C lowering effect / Thesis (Ph.D. (Nutrition))--North-West University, Potchefstroom Campus, 2005.

The prevalence of obesity in both the developed and developing world have increased, which leads to diverse health outcomes and is placing a heavy burden on the economy. Abdominal obesity proved to be one of the main features in predicting metabolic and cardiovascular disease (CVD) risk and may be the link that unifies the metabolic syndrome (MS) through pro-inflammatory pathways. While the pathogenesis of the MS and each of its components are complex and not well understood, abdominal obesity remains the mechanism that relates to increased lipolysis causing the liver to increase blood glucose and very low lipoprotein output. This in turns leads to raised blood glucose, triglycerides, low-density lipoprotein cholesterol (LDL-C), blood pressure and inflammatory markers (C-reactive protein, interleukin-6 and tumor necrosis factor-a) and decreased high-density lipoprotein cholesterol (HDL-C). Prevention of the metabolic syndrome and treatment of its main characteristics are now considered of utmost importance in order to combat the increased CVD risk and all-cause mortality. Decreasing sedentary behaviour through regular physical activity is a key element in successful treatment of obesity through an increase in energy expenditure, but the ability to decrease low-grade systemic inflammation may be an even greater outcome. Aims The aims of this study was firstly, to determine by means of a literature review, how obesity could be related to a state of chronic systemic inflammation (increased CRP and IL-6). Secondly to determine whether physical activity could serve as a suitable method to decrease inflammation associated with obesity and related disorders. Thirdly to determine if abdominal obesity is a predictor of the metabolic syndrome and CVD and finally, to determine if measures of obesity can predict risk for the metabolic syndrome and CVD risk. Methods For this review study, a computer-assisted literature search were utilized to identify research published between 1990 and 2005. the following databases were utilized for the search: NEXUS, Science Direct, PubMed and Medline. Keywords related to obesity (abdominal obesity, overweight), metabolic syndrome (insulin resistance syndrome, dysmetabolic syndrome, syndrome X), cardiovascular disease (coronary heart disease, coronary artery disease), cardiovascular risk factors (hypertension, dyslipidemia, diabetes mellitus, physical activity), inflammatory markers (CRP, IL-6, chronic low-grade inflammation) and physical activity (fitness, exercise and training) were included as part of the search, including the references identified by previous reviewers (not identified as part of the computerized literature search). Results and conclusions Several research studies concluded that obesity could be an inflammatory disorder due to low-grade systemic inflammation. Adipose tissue is known to be a sectretory organ producing cytokines, acute phase reactants and other circulating factors. The synthesis of adipose tissue TNF-a could induce the production of IL-6, CRP and other acute phase reactants. CRP is a acute phase reactant, synthesized primarily in hepatocytes and secreted by the liver in response to a variety of inflammatory cytokines of which IL-6 and TNF-a are mainly involved. CRP increases rapidly in response to trauma, inflammation and infection. Thus, enhanced levels of CRP can be used as a marker of inflammation. Several studies of large population cohorts provide evidence for an inverse, independent dose-response relation between plasma CRP concentration and level of physical activity in both men and women. Trends for decreased IL-6, TNF-a and CRP concentrations were linear with increasing amounts of reported exercise in most of the research studies, physical activity proved effective in lowering measures of adiposity (BMI, WHR, WC and percentage body fat) and obesity related inflammatory markers (CRP & IL-6). Thereby indicating a potential anti-inflammatory effect. In the studies reviewed in this article abdominal obesity is identified as a predictor and independent risk factor for CVD in both men and women. High levels of deep abdominal fat have also been correlated with components of the metabolic syndrome, glucose intolerance, hyperinsulinemia, hypertension, diabetes, increases in plasma triglyceride levels and a decrease in HDL-C levels (dyslipidemia) in many of the studies. Prospective epidemiological studies have revealed that abdominal obesity (determined by WC and WHR) conveys an independent prediction of CVD risk and is more relevant compared to general obesity (determined by BMI). Abdominal fat has been linked to metabolic risk factors like high systolic blood pressure, atherogenic dyslipidemia, with increased serum TG and decreased HDL-C, and glucose intolerance. Although magnetic resonance imaging (MRI) and computerized tomography (CT) have been used successfully in many studies to measure adipose compartments of the abdomen (subcutaneous and visceral fat), anthropometrical measures like WHR and WC have been proven to be an effective measure in predicting the metabolic syndrome. WC has also been included in the metabolic syndrome definitions of the WHO, ATP Ill and new IDF. / The prevalence of obesity in both the developed and developing world have increased, which leads to diverse health outcomes and is placing a heavy burden on the economy. Abdominal obesity proved to be one of the main features in predicting metabolic and cardiovascular disease (CVD) risk and may be the link that unifies the metabolic syndrome (MS) through pro-inflammatory pathways. While the pathogenesis of the MS and each of its components are complex and not well understood, abdominal obesity remains the mechanism that relates to increased lipolysis causing the liver to increase blood glucose and very low lipoprotein output. This in turns leads to raised blood glucose, triglycerides, low-density lipoprotein cholesterol (LDL-C), blood pressure and inflammatory markers (C-reactive protein, interleukin-6 and tumor necrosis factor-a) and decreased high-density lipoprotein cholesterol (HDL-C). Prevention of the metabolic syndrome and treatment of its main characteristics are now considered of utmost importance in order to combat the increased CVD risk and all-cause mortality. Decreasing sedentary behaviour through regular physical activity is a key element in successful treatment of obesity through an increase in energy expenditure, but the ability to decrease low-grade systemic inflammation may be an even greater outcome. Aims The aims of this study was firstly, to determine by means of a literature review, how obesity could be related to a state of chronic systemic inflammation (increased CRP and IL-6). Secondly to determine whether physical activity could serve as a suitable method to decrease inflammation associated with obesity and related disorders. Thirdly to determine if abdominal obesity is a predictor of the metabolic syndrome and CVD and finally, to determine if measures of obesity can predict risk for the metabolic syndrome and CVD risk. Methods For this review study, a computer-assisted literature search were utilized to identify research published between 1990 and 2005. the following databases were utilized for the search: NEXUS, Science Direct, PubMed and Medline. Keywords related to obesity (abdominal obesity, overweight), metabolic syndrome (insulin resistance syndrome, dysmetabolic syndrome, syndrome X), cardiovascular disease (coronary heart disease, coronary artery disease), cardiovascular risk factors (hypertension, dyslipidemia, diabetes mellitus, physical activity), inflammatory markers (CRP, IL-6, chronic low-grade inflammation) and physical activity (fitness, exercise and training) were included as part of the search, including the references identified by previous reviewers (not identified as part of the computerized literature search). Results and conclusions Several research studies concluded that obesity could be an inflammatory disorder due to low-grade systemic inflammation. Adipose tissue is known to be a sectretory organ producing cytokines, acute phase reactants and other circulating factors. The synthesis of adipose tissue TNF-a could induce the production of IL-6, CRP and other acute phase reactants. CRP is a acute phase reactant, synthesized primarily in hepatocytes and secreted by the liver in response to a variety of inflammatory cytokines of which IL-6 and TNF-a are mainly involved. CRP increases rapidly in response to trauma, inflammation and infection. Thus, enhanced levels of CRP can be used as a marker of inflammation. Several studies of large population cohorts provide evidence for an inverse, independent dose-response relation between plasma CRP concentration and level of physical activity in both men and women. Trends for decreased IL-6, TNF-a and CRP concentrations were linear with increasing amounts of reported exercise in most of the research studies, physical activity proved effective in lowering measures of adiposity (BMI, WHR, WC and percentage body fat) and obesity related inflammatory markers (CRP & IL-6). Thereby indicating a potential anti-inflammatory effect. In the studies reviewed in this article abdominal obesity is identified as a predictor and independent risk factor for CVD in both men and women. High levels of deep abdominal fat have also been correlated with components of the metabolic syndrome, glucose intolerance, hyperinsulinemia, hypertension, diabetes, increases in plasma triglyceride levels and a decrease in HDL-C levels (dyslipidemia) in many of the studies. Prospective epidemiological studies have revealed that abdominal obesity (determined by WC and WHR) conveys an independent prediction of CVD risk and is more relevant compared to general obesity (determined by BMI). Abdominal fat has been linked to metabolic risk factors like high systolic blood pressure, atherogenic dyslipidemia, with increased serum TG and decreased HDL-C, and glucose intolerance. Although magnetic resonance imaging (MRI) and computerized tomography (CT) have been used successfully in many studies to measure adipose compartments of the abdomen (subcutaneous and visceral fat), anthropometrical measures like WHR and WC have been proven to be an effective measure in predicting the metabolic syndrome. WC has also been included in the metabolic syndrome definitions of the WHO, ATP Ill and new IDF. / Thesis (M.A. (Human Movement Science))--North-West University, Potchefstroom Campus, 2006.

The aim of this study was to explore, from different perspectives, whether obesity related variables are associated with facets of psychological well-being, with a vision to future enhancement of health and the quality of life of people in the African context. This study was undertaken from the perspective of positive psychology and focused on the metabolic syndrome and obesity as biological facets. This research was conducted as part of the multidisciplinary POWIRS (Profiles of Obese Women with Insulin Resistance Syndrome) project. African (n=102) and Caucasian (1 15) women took part in a cross-sectional design. The thesis consists of 3 articles: I) Childhood relationships and bio-psycho-.gocia1 well-being in African women, 2) Psychological well-being and rhe metabolic syndrome in African and Caucasian women, and 3) Psychological wellbeing and (the absence of obesity in African and Caucasian women. In this study psychological well-being was conceptualized and operationalized by means of the General Health Questionnaire (GHQ); Sense of Coherence Scale (SOC-29); Affectometer 2 (AFM) (short form); Fortitude Questionnaire (FORQ); Cognitive Appraisa1 Questionnaire (CAQ); Psychological Well-being Scales (SPWB); Quality of Childhood Relationship Questionnaire (QCR); Satisfaction with Life Scale (SWLS) and the Jarel Spiritual Well-Being Scale (SWS-H). These scales were chosen to include hedonic as well as eudaimonic psychological well-being facets, but also an index of psychological symptoms. As far as possible, scales with acceptable psychometric properties as described in international as well as South African context were selected. The first article focused on whether African women with a recalled higher level of quality of childhood relationships mould differ significantly with regard to biological, psychological and social well-being from women with a recalled lower level of quality of childhood relationships. Body mass index (BMI) was used as objective measure of obesity to operationalize physical health. Findings were that the recalled quality of childhood relationships is linked with obesity and psycho-social well-being in this group of African women. The second article focused on psychological well-being and (the absence of) the metabolic syndrome (MS). It explored the possible association between comprehensive psychological well-being and MS in different cultural contexts, and explored whether African and Caucasian women without MS markers and those with MS differ on specific indices of psychological well-being. The criteria of the NCEP ATPIII mere implemented to determine markers of MS, and the absence of markers of MS was used as measure of physical health. Findings were that an association is found in Caucasian women between comprehensive psychological well-being and the absence of the metabolic syndrome, but not in the case of African women. Caucasian women without metabolic syndrome markers had significantly higher levels of psycho-social wellbeing than uomen with the metabolic syndrome. but a less apparent pattern of differences emerged for African women. MS markers for African women should be further explored. The third article explored facets of psychological well-being as predictors for (the absence of) obesity (measured by BMI and WHR) in African and Caucasian women, and whether similar or different psychological well-being facets will emerge as predictors of obesity in different cultural contexts. Obesity was operationalized in terms of waist-hip-ratio (WHR) and body-mass-index (BMI). The finding was that clusters of psychological well-being facets are practical significant predictors of obesity (measured by BMI and WHR) and that these clusters differ in some respects for African and Caucasian women. It was concluded that, firstly. findings support holistic conceptualizations of health such as proposed by the WHO (1999). Secondly, it may be worthwhile to include facets of psychological well-being in already existing intervention programmes. The development of strengths that focus on life skills and behaviours related to positive interpersonal relationships, optimistic cognitive attributional styles, finding a sense of purpose and meaningfulness in life, may be particularly beneficial. Sensitivity for cultural contexts is indicated. In view of the increase in the occurrence of obesity in childhood and adolescence it is recommended that educational training programmes should be implemented early in life in order to facilitate protective strengths and to promote bio-psycho-social health in individuals and communities. Advocacy for more attention to psycho-social and protective factors in public health is needed. / Thesis (Ph.D. (Psychology))--North-West University, Potchefstroom Campus, 2006.

Obesity is currently the most common and costly nutritional problem in developed countries and ten percent of the world's school-aged children are estimated to be overweight to some extent. Low-grade systemic inflammation is increasingly emerging as a significant component of the metabolic syndrome. Youth in lower income families are particularly vulnerable because of poor diet and limited opportunities for physical activity. In developing countries obesity among youth is rising among the urban poor, possibly due to their exposure to Westernised diets coinciding with a history of under-nutrition. The aim of this study was to assess the association between serum CRP and physical activity and to assess the association between serum CRP and body composition in black high-school children from a township in the North West Province (NWP), South Africa. Methods and results: The study group consisted of 193 school children between the ages 13 to 18 years (78 boys and 115 girls) residing in lkageng, the township outside of Potchefstroom in the North West Province, South Africa. Children were from a black ethnic group, living in a poor socioeconomic setting. Demographic and body composition measurements were taken and fasting blood samples were drawn for serum C-reactive protein (CRP) measurements. The difference between serum CRP of overfat versus girls with a normal fat percentage was non-significant (p = 0.46). Boys with body fat percentage >20% (n=16) had .a mean serum CRP of 1.42 2.16 mg/L and for boys with a normal fat percentage (n=53) mean serum CRP was 0.89 k 1.62 mg/L. The Mann-Whitney U-test for the difference between mean CRP of the two groups of boys was Z=1.39, p=0.16 (no significant difference), but with a trend of higher serum CRP concentration in the boys with higher % body fat. For the boys, the only positive partial correlation was between serum CRP and triceps skinfold (r=0.327, p=0.045). In the girls' group no statistically significant partial correlations were found between CRP and body composition variables. There was no significant difference between serum CRP concentrations of the three physical activity categories of girls. Interestingly, there was an inverse correlation between percentage body fat and fitness in the boys' group (r=-0.509 and p= 0.008). The difference in log CRP between activity groups showed a trend of lower serum CRP with higher physical activity in the girls. Conclusion: This study showed no statistically significant associations between serum CRP and body composition, except for the positive correlation between triceps skin fold and serum CRP in boys, or CRP and physical activity, but clear trends were noted of an inverse association between CRP and physical activity in the girls. / Thesis (M.Sc. (Nutrition))--North-West University, Potchefstroom Campus, 2007

MOTIVATION: The increasing prevalence of metabolic syndrome (MetS) is creating immense concern worldwide. In 2009, the International Diabetes Federation (IDF) announced the new MetS definition. MetS is diagnosed by any 3 of the following 5 indicators being present: increased waist circumference (WC), blood pressure (BP), triglycerides, and fasting glucose values, and decreased high–density lipoprotein cholesterol (HDL–C) concentrations. Psychosocial stress relating to an urban environment or acculturation greatly influences the prevalence of both MetS and target organ damage (TOD). Furthermore, in urban Africans, active coping (AC) responses have been associated more with MetS and the related cardiovascular pathology than avoidance. A further synergistic effect of MetS and AC responses was also revealed in African men, in strong association with both subclinical atherosclerosis and renal impairment. Microalbuminuria was four times higher in Africans with MetS, than in those without any MetS indicators. Furthermore, Africans, especially those utilising AC responses, present with greater carotid intima–media thickness (CIMT) than their Caucasian counterparts, although they exhibit a lipid profile that is anti–atherogenic. OBJECTIVES: The objectives were firstly to indicate and compare differences regarding AC responses in the African and Caucasian men, in accord with the prevalence of MetS indicators. Secondly, the extent to which AC responses and MetS indicators predict endothelial dysfunction was investigated. METHODOLOGY: This comparative target population study is nested in the Sympathetic Activity and Ambulatory Blood Pressure in Africans (SABPA) study, which was conducted from February until the end of May in both 2008 (Africans) and 2009 (Caucasians), avoiding seasonal changes. The Ethics Committee of the North–West University approved the study, and all volunteers gave written informed consent prior to participation. Procedures were conducted according to the institutional guidelines of the Declaration of Helsinki. The participants included 202 male teachers of which 101 were African and 101 Caucasian. Ambulatory blood pressure (BP) measurements were recorded with the Cardiotens CE120 at 30 minute intervals during the day and 60 minutes at night. Actical accelerometers determined physical activity (PA). Registered clinical psychologists supervised completion of the psychosocial questionnaires, including the Coping Strategy Indicator. Participants fasted overnight; after the last BP recording, disconnection of the Cardiotens CE120 and Actical followed. A fasting 8 hour overnight collected urine sample was obtained from each participant. Anthropometric measurements followed, after which a registered nurse commenced blood sampling. The SonoSite Micromaxx was used for the scanning of CIMT. MetS indicators (glucose, triglyceride, and HDL–C), together with gamma glutamyl transferase, cotinine, and ultrahigh–sensitivity C–reactive protein (hs–CRP), were analyzed with Konelab 20i. The albumin–to–creatinine ratio and CIMT determined TOD. Participants were stratified according to ethnicity and median splits of AC response scores (high AC and low AC). Diabetic medication users (n= 8), and participants with renal impairment (n= 2) or HIV positive (n= 13), were excluded from analyses. 2×2 ANCOVA’s determined significant interactions for ethnicity and AC. Partial correlations between MetS indicators and TOD were performed within each ethnic and AC group, independent of age, alcohol consumption and PA. Regression analyses were performed for four models, firstly with microalbuminuria and secondly with CIMT as dependent variables. Significant values were noted as p 0.05, r 0.35, and adjusted R2 0.25. RESULTS: Caucasian men were physically more active than African men, whilst BP, alcohol consumption and hs–CRP levels were significantly higher in African men. Psychological variables revealed higher avoidance scores in Caucasian men and higher social support scores in African men. More MetS indicators exceeded the IDF cut–off points in high AC African men (14.71%) than in their Caucasian counterparts (3.33%). Furthermore, more MetS indicators predicted endothelial dysfunction in African men, especially the high AC responders. CONCLUSION: The following hypotheses were accepted: high AC responses in urban African men were associated with a higher prevalence of MetS indicators than in their Caucasian counterparts, while MetS indicators were associated with a marker of TOD in urban high AC African men, but not in their Caucasian counterparts. / Thesis (M.Sc. (Physiology))--North-West University, Potchefstroom Campus, 2011.