Introduction: The World Health Organisation (WHO) defines overweight and obesity as a condition in which an abnormal or excessive fat accumulation exists to an extent in which health and well-being are impaired. The most recent South African National Health and Nutrition Examination Survey (SANHANES) reported that the prevalence of overweight and obesity, according to body mass index (BMI) classification, in all South African women was significantly higher than in men (24.8% and 39.2% compared to 20.1% and 10.6% for women and men, respectively). Blood pressure is often increased in obese patients and is probably the most common co-morbidity associated with obesity. Currently approximately one third (30.4%) of the adult South African population has hypertension. Hypertension is responsible for a significant percentage of the high rates of cardiovascular disease and stroke in South Africa. Limited South African data are available regarding the agreement between the measures of adiposity, including BMI, waist circumference (WC) and percentage body fat (%BF), and the association with high blood pressure. Measures of adiposity were found in previous research to be ethnicity, age and gender specific. Measuring %BF to classify adiposity takes body composition into account and is a more physiological measurement of obesity than BMI. Objective: This study aimed to investigate the agreement between adiposity classified by BMI categories and %BF cut-off points, and the association between the different measures of adiposity and high blood pressure. Method: A representative sample of black women (n=435), aged 29 years to 65 years from Ikageng in the North West Province of South Africa were included in this cross-sectional epidemiological study. Socio-demographic questionnaires were completed. Pregnancy and HIV tests were performed and those with positive test results or those who declined HIV testing were excluded. Weight and height were measured and BMI was calculated. WC, %BF using dual-energy X-ray absorptiometry (DXA), and blood pressure were measured. Results: The prevalence of overweight (BMI 25.0 kg/m² – 29.9 kg/m²) was 24.4% and obesity (BMI ≥ 30kg/m²) was 52.4%. High blood pressure was found to be present in more than two thirds of the study participants (68.5%). In this study BMI, WC and %BF as measures of adiposity were significantly correlated. There were significant agreements between combined overweight/obesity that was defined by %BF (≥35.8% 29-45 years; ≥37.7% ≥50 years) and BMI ≥ 25kg/m² (ᵡ²=199.0, p<0.0001; κ=0.68, p<0.0001), and between the presence of high %BF and obesity only, that was defined by BMI ≥ 30 kg/m² (ᵡ²=129.1, p<0.0001; κ=0.48, p<0.0001). The effect size of the agreement between the WHO BMI category for combined overweight/obesity and %BF cut-off points according to the kappa value of κ=0.68 was substantial (κ range 0.61-0.80). The effect size of the agreement between the WHO BMI category for obesity only and %BF cut-off points according to the kappa value of κ=0.48 was moderate (κ range 0.41-0.60). No association was found between high blood pressure and BMI categorised combined overweight/obesity (ᵡ²=3.19; p=0.74), but a significant association was found between high blood pressure and BMI categorised obesity only (ᵡ²=4.10; p=0.043). A significantly increased odds ratio (OR) of high blood pressure existed in the obesity BMI category (OR=1.52; p=0.045) as opposed to the overweight/obesity BMI category (OR=1.51; p=0.075). There were significant associations between high blood pressure and WC ≥ 80cm (ᵡ²=10.9; p=0.001; OR=2.08; p=0.001), WC ≥ 92cm (ᵡ²=20.1; p<0.0001; OR=1.79; p=0.011) and %BF above the age-specific cut-off points (ᵡ²=6.61; p=0.010; OR=1.70; p=0.011). Discussion and conclusion: This study found that in a sample of black urban South African women significant agreements existed between adiposity defined by %BF cut-off points for combined overweight/obesity and both WHO BMI categorised combined overweight/obesity (BMI ≥ 25 kg/m2) and obesity only (BMI ≥ 30 kg/m2), respectively. A stronger agreement was found between WHO categorised combined overweight/obesity and %BF. Furthermore, this study concluded that the BMI category according to the WHO cut-off point for overweight/obesity had insufficient sensitivity to detect the presence of high blood pressure, and that the BMI category according to the WHO cut-off point for obesity alone could detect the presence of high blood pressure. The WHO BMI classification for obesity, in contrast to the WHO BMI classification for combined overweight/obesity, is therefore appropriate to classify these black South African women at increased risk for high blood pressure. The WC and %BF cut-off points used which were specific to ethnicity, age and gender, had significant associations with high blood pressure and have good capacity to detect high blood pressure. In this study abdominal obesity as defined by the South African cut-off point of WC ≥ 92 cm had a stronger association with high blood pressure, than the international cut-off point (WC ≥ 80 cm). The South African cut-off point is, therefore, more appropriate to screen black South African women for increased risk for high blood pressure. The study therefore concluded that a stronger agreement was found between WHO categorised combined overweight/obesity and %BF than with obesity only (BMI ≥ 30 kg/m2). To ensure consistency and accuracy, and to take body composition into consideration, it is recommended that, where possible, in clinical practice the appropriate WC and %BF cut-off points together with BMI categories should be used as measures of adiposity for diagnosis of overweight and obesity and to screen or detect an increased risk for high blood pressure. / MSc (Dietetics), North-West University, Potchefstroom Campus, 2015

Introduction: The World Health Organisation (WHO) defines overweight and obesity as a condition in which an abnormal or excessive fat accumulation exists to an extent in which health and well-being are impaired. The most recent South African National Health and Nutrition Examination Survey (SANHANES) reported that the prevalence of overweight and obesity, according to body mass index (BMI) classification, in all South African women was significantly higher than in men (24.8% and 39.2% compared to 20.1% and 10.6% for women and men, respectively). Blood pressure is often increased in obese patients and is probably the most common co-morbidity associated with obesity. Currently approximately one third (30.4%) of the adult South African population has hypertension. Hypertension is responsible for a significant percentage of the high rates of cardiovascular disease and stroke in South Africa. Limited South African data are available regarding the agreement between the measures of adiposity, including BMI, waist circumference (WC) and percentage body fat (%BF), and the association with high blood pressure. Measures of adiposity were found in previous research to be ethnicity, age and gender specific. Measuring %BF to classify adiposity takes body composition into account and is a more physiological measurement of obesity than BMI. Objective: This study aimed to investigate the agreement between adiposity classified by BMI categories and %BF cut-off points, and the association between the different measures of adiposity and high blood pressure. Method: A representative sample of black women (n=435), aged 29 years to 65 years from Ikageng in the North West Province of South Africa were included in this cross-sectional epidemiological study. Socio-demographic questionnaires were completed. Pregnancy and HIV tests were performed and those with positive test results or those who declined HIV testing were excluded. Weight and height were measured and BMI was calculated. WC, %BF using dual-energy X-ray absorptiometry (DXA), and blood pressure were measured. Results: The prevalence of overweight (BMI 25.0 kg/m² – 29.9 kg/m²) was 24.4% and obesity (BMI ≥ 30kg/m²) was 52.4%. High blood pressure was found to be present in more than two thirds of the study participants (68.5%). In this study BMI, WC and %BF as measures of adiposity were significantly correlated. There were significant agreements between combined overweight/obesity that was defined by %BF (≥35.8% 29-45 years; ≥37.7% ≥50 years) and BMI ≥ 25kg/m² (ᵡ²=199.0, p<0.0001; κ=0.68, p<0.0001), and between the presence of high %BF and obesity only, that was defined by BMI ≥ 30 kg/m² (ᵡ²=129.1, p<0.0001; κ=0.48, p<0.0001). The effect size of the agreement between the WHO BMI category for combined overweight/obesity and %BF cut-off points according to the kappa value of κ=0.68 was substantial (κ range 0.61-0.80). The effect size of the agreement between the WHO BMI category for obesity only and %BF cut-off points according to the kappa value of κ=0.48 was moderate (κ range 0.41-0.60). No association was found between high blood pressure and BMI categorised combined overweight/obesity (ᵡ²=3.19; p=0.74), but a significant association was found between high blood pressure and BMI categorised obesity only (ᵡ²=4.10; p=0.043). A significantly increased odds ratio (OR) of high blood pressure existed in the obesity BMI category (OR=1.52; p=0.045) as opposed to the overweight/obesity BMI category (OR=1.51; p=0.075). There were significant associations between high blood pressure and WC ≥ 80cm (ᵡ²=10.9; p=0.001; OR=2.08; p=0.001), WC ≥ 92cm (ᵡ²=20.1; p<0.0001; OR=1.79; p=0.011) and %BF above the age-specific cut-off points (ᵡ²=6.61; p=0.010; OR=1.70; p=0.011). Discussion and conclusion: This study found that in a sample of black urban South African women significant agreements existed between adiposity defined by %BF cut-off points for combined overweight/obesity and both WHO BMI categorised combined overweight/obesity (BMI ≥ 25 kg/m2) and obesity only (BMI ≥ 30 kg/m2), respectively. A stronger agreement was found between WHO categorised combined overweight/obesity and %BF. Furthermore, this study concluded that the BMI category according to the WHO cut-off point for overweight/obesity had insufficient sensitivity to detect the presence of high blood pressure, and that the BMI category according to the WHO cut-off point for obesity alone could detect the presence of high blood pressure. The WHO BMI classification for obesity, in contrast to the WHO BMI classification for combined overweight/obesity, is therefore appropriate to classify these black South African women at increased risk for high blood pressure. The WC and %BF cut-off points used which were specific to ethnicity, age and gender, had significant associations with high blood pressure and have good capacity to detect high blood pressure. In this study abdominal obesity as defined by the South African cut-off point of WC ≥ 92 cm had a stronger association with high blood pressure, than the international cut-off point (WC ≥ 80 cm). The South African cut-off point is, therefore, more appropriate to screen black South African women for increased risk for high blood pressure. The study therefore concluded that a stronger agreement was found between WHO categorised combined overweight/obesity and %BF than with obesity only (BMI ≥ 30 kg/m2). To ensure consistency and accuracy, and to take body composition into consideration, it is recommended that, where possible, in clinical practice the appropriate WC and %BF cut-off points together with BMI categories should be used as measures of adiposity for diagnosis of overweight and obesity and to screen or detect an increased risk for high blood pressure. / MSc (Dietetics), North-West University, Potchefstroom Campus, 2015

Motivation: Abdominal obesity (hereafter referred to as "obesity") is becoming the biggest "global epidemic" of our modern times. It is associated with a range of diseases, including cardiovascular diseases and hypertension. Recent research showed that an increase in sympathetic activity is of central importance in the pathogenesis of obesity-related diseases. Increased leptin levels and impaired baroreflex sensitivity have both been independently associated with abdominal obesity and increased sympathetic activity. A perception of poorer health may also contribute to the physiological characteristics of obesity-related diseases. A lack of data regarding sympathetic activity, leptin levels, baroreflex sensitivity and perception of health in Africans, serves as a motivation for conducting this study. Objective: To investigate the contributions of leptin levels, baroreflex sensitivity and perception of health data to increased sympathetic activity in lean and obese African women from South Africa. Methodology: The manuscript presented in Chapter 2 made use of the data obtained in the POWIRS (Profiles of Obese Women with the Insulin Resistance Syndrome) study. A group of 102 urbanized African women, living in the North-West Province of South Africa, was recruited according to body mass indexes. Only 85 subjects were included for analysis due to incomplete datasets. For this study, subjects were divided into lean and obese groups according to their waist circumferences. Anthropometric measurements were done according to standardized methods. Resting cardiovascular measurements were obtained from Finometer observations. Resting, fasting levels of leptin were calculated after radioimmunoassay analyses. Subjective perception of health was determined by means of the 28-item General Health Questionnaire. Comparisons between the groups were done using analysis of covariance (ANCOVA) whilst adjusting for cardiovascular risk factors (age. smoking, alcohol consumption and physical activity). Correlation coefficients were determined to indicate any associations between leptin, baroreflex sensitivity and perception of health with sympathetic activity (represented by heart rate) and other cardiovascular variables. The study was approved by the Ethics committee of the North-West University and all the subjects gave informed consent in writing. The reader is referred to the Methods section in Chapter 2 for a more detailed description of the subjects, study design and analytical procedures used in this dissertation. Results and conclusion: Results from this study indicate that obese African women, compared to lean African women, were older, reported higher physical activity, and exhibited higher diastolic and mean blood pressure, heart rate, cardiac output, arterial compliance, leptin and hypertension prevalence rate values. In lean African women social dysfunction was positively associated with diastolic and mean blood pressure and arterial resistance, and negatively with arterial compliance. In obese African women baroreflex sensitivity was negatively associated with diastolic blood pressure, which could be an indication of impaired baroreflex sensitivity. In this obese group a perception of social dysfunction was associated with decreased heart rate. Although leptin and heart rate were significantly higher in the obese Africans, no significant correlations existed between these variables to reflect leptin's enhancement of sympathetic activity. However, leptin correlated weakly but positively with cardiac output (p = 0.054, r = 0.32). In conclusion, baroreflex sensitivity (although similar between groups) and leptin seem to contribute to blood pressure and thus hypertension in obese African women, possibly through increased sympathetic activity and volume loading. A perception of poorer health, especially a perception of social dysfunction, could possibly contribute to this image. / Thesis (M.Sc. (Physiology))--North-West University, Potchefstroom Campus, 2007.

Objectives: The aim of this study was to determine the prevalence of MetS among different African populations using the new Joint Statement Criteria. Hereafter we aimed to determine whether waist or neck circumference is the best predictor of MetS risk after ethnic, gender and age-specific cut-points were developed. Lastly, we aimed to determine whether afore-mentioned cut-point can predict albumin:creatinine ratio as a marker of target organ damage. Methods: The study sample (N=409) comprised of urban African (men, N=101; women, N=99) and Caucasian (men, N=101; women, N=108) teachers from the Dr. Kenneth Kaunda Education district in the North-West Province, South Africa. Participants were aged between 25 and 65 years. Anthropometric measurements, albumin:creatinine ratio and other markers of the metabolic syndrome (MetS) (systolic and diastolic blood pressure [SBP and DBP], glucose, triglycerides [TG] and high density lipoprotein [HDL]) were determined. Results: Africans (65 and 63 % for men and women) and Caucasian men (73%) showed high prevalence of MetS; ROC analysis determined neck circumference (NC) cut-points of 39 and 35 cm for young and older African men, 32 and 35 cm for young and older African women, 40 and 41 cm for Caucasian men and 34 and 33 cm for Caucasian women. This NC cut-point can be used to determine metabolic syndrome risk in all groups, except in African women; ROC developed waist circumference (WC) cut-points were 91 cm for all African male groups, 84, 81 and 84 cm for young, older and total group of African women. Suggested WC cut-points for Caucasian men were 93 cm for the young group and 97 cm for older as well as total Caucasian male groups, while cut-points for Caucasian women were 87 cm, 79 cm and 84 cm for young, older and total Caucasian women. These WC cut-points were good measures of metabolic syndrome risk in all groups; neither cut-point of WC nor NC could increase the risk of albumin:creatinine ratio. Conclusion: African women as a group present with few MetS risk factors and glucose is associated with renal function risk in Africans; NC cut-points may be used as an additional anthropometric marker to predict the metabolic syndrome in a South African cohort, but not in African women; WC cutpoints demonstrated to be good predictors of the metabolic syndrome in the same South African cohort, especially among men; WC would seem to be the best measure of MetS risk in all African populations, although NC can also be used for this purpose in all African populations, except in African women. / Thesis (PhD (Human Movement Science))--North-West University, Potchefstroom Campus, 2012

Obesity is a serious health problem that leads to several chronic diseases and premature deaths. TheIn this project,was used to evaluate the effectiveness of the the Weigh Forward (WF) program, a 10-week weight-loss program administered in retail clinics, was evaluated, and it is provided in retails stores. The project analysis was completed on a limited data set on The population consisted of 15 obese participantsmembers of the program, 18 years and above, at 13 dispersed clinics in Maryland and Virginia.in the WF program from 13 dispersed clinics in Maryland and VirgiObesity is a body mass index (BMI) > 30 kg/m2. Participants were 18 years and above The theory of planned behavior (TPB) was used as the framework from which to view the project. The project was usedpurpose was to determine the efficacy of the WF program for weight reduction by comparing the baseline body mass index (BMI) and the waist circumference (WC) to the BMI and WC at the end of the program. Descriptive The aanalysis was done using correlation coefficient on the 15 participants,, who completed the 10-week WF program. The result, showed the mean and mode for BMI reduction to be 2 kg/m2, and the mean and mode for the WC reduction was 3 inches. The percentage weight loss varied from 3-11%, with the completion rate for the enrolled participants at 29%. Thise study has implications for the social change because the findings support intensive behavioral modification as an effective approach to weight loss. The study can help healthcare providers appreciate the is the need to complete preventive care assessment on patients, identify patients with obesity, and provide these patients with the requisite information on the need to lose weight. Also, the clinicians provide the patients with information and available resources to enable help them lose weight. The mean and mode of 2 kg/m2 for BMI reduction, and 3 inches for the reduction in WC at the end of 10 weeks, showed that the WF program was effective for weight loss because the participants lost significant amount of weight. The findings from the project can guide the development of practice guidelines for administering the WF program in the retail clinic.

Rapid development of domain specialized medical imaging tools is essential for deploying medical imaging technologies to advance clinical research and clinical practice. This work describes the development process, deployment method, and evaluation of modules constructed within the 3D Slicer environment. These tools address critical problems encountered in four different clinical domains: quality control review of large repositories of medical images, rule-based automated label map cleaning, quantification of calcification in the heart using low-dose radiation scanning, and waist circumference measurement from abdominal scans. Each of these modules enables and accelerates clinical research by incorporating medical imaging technologies that minimize manual human effort. They are distributed within the multi-platform 3D Slicer Extension Manager environment for use in the computational environment most convenient to the clinician scientist.

The inflammatory process is important in protecting the body against the invasion of pathogens, but recent research has suggested that a long-term inflammatory response may lead to chronic diseases (e.g., Black, 2003; Wu, Dorn, Donahue, Sempos, & Trevisan, 2002). Two factors that have been implicated in the inflammatory and disease processes are stress and obesity (Black, 2003). While their individual lines of research continue to grow, few researchers have attempted to integrate these factors into one model to explain their effects on inflammation. This study aimed to replicate previous findings suggesting relationships between stress, obesity and inflammation and test an integrated model of stress and obesity by examining a possible interaction between the effects of stress and obesity on inflammation. Socioeconomic Status (SES) and depression were employed to examine the association between stress and the inflammatory marker, c-reactive protein (CRP). The study utilized the data resulting from the National Health and Nutrition Examination Survey (NHANES; National Center for Health Statistics, 2006). Included in the dataset are 4998 adults (2416 males and 2582 females) ranging in age from 18 years to over 85 years (M = 47.13, SD = 20.86). A subsample (N = 589) completed the Major Depression module of the Composite International Diagnostic Interview (CDCI). The results indicate that body mass index, waist circumference, income, education, and depression symptoms significantly predict CRP. The data also suggest an interaction between the adiposity variables and the SES variables. This supports the hypothesis that the inflammatory effect of stress on an individual is moderated by adiposity.

Thesis (M.Sc. (Physiology))--North-West University, Potchefstroom Campus, 2007.

Adiposity has been linked to impaired respiratory function in adults but whether the distribution of adipose tissue has a differential effect on pulmonary function is still uncertain. Moreover, in children, the relationship between adiposity and lung dysfunction is not clearly understood. A two-stage multivariate analysis was conducted using data from 5604 Canadians aged 6 to 79 years who participated in the Canadian Health Measures Survey (CHMS). The associations of various anthropometric and skinfold measures with lung function were examined separately in adults and children. After adjustment of covariates, waist circumference and subscapular skinfold thickness showed the strongest inverse associations with FVC and FEV1 in men. In women, BMI and sum of five skinfolds had the largest impact on pulmonary function. FVC and FEV1 in boys were most affected by waist-to-hip ratio and triceps skinfold. In girls, adiposity was not linked to the lung function testing variables. Adiposity measures have differing effects on respiratory function depending on age and sex group.

Abstract Validity of waist-to-height ratio as a screening tool for type 2 diabetes risk in non-Hispanic Whites, non-Hispanic Blacks, and Mexican American Adult Women, from the ages 20-65 years of age. Background: A prominent screening measure for type 2 diabetes is a simple measure of waist circumference. Waist circumference is an aggregate measurement of the actual amount of total and abdominal fat accumulation and is a crucial correlate of the complexities found among obese and overweight patients. However, waist circumference does not take into consideration the frame of an individual. Hence, recent epidemiologic data have suggested the use of height adjusted waist circumference (waist-to-height ratio). The use of waist-to-height ratio in screening for type 2 diabetes is poorly understood. Aims: The aim of this study is to determine racial/ethnic differences in the association of the independent variables waist-to-height ratio and waist circumference, with type 2 diabetes in non-Hispanic Whites, non-Hispanic Blacks, and Mexican American adult women, ages 20-65 years old. Methods: Data from the NHANES 2007-2008 surveys were used. Race/ethnic specific odds ratios from univariate and multivariate logistic regression models were to estimate the associations of waist-to-height ratio and waist circumference with type 2 diabetes. In the multivariate models, adjustments were made for age and alcohol use. Results: In the univariate models, WC was associated with 1.06, 1.07 and 1.04 increased odds of type 2 diabetes in Mexican Americans, non-Hispanic Whites and non-Hispanic Blacks, respectively. The corresponding values waist-to-height ratio were 2.85, 3.20 and 1.88, respectively. On adjusting for confounders, WC was associated with 1.07, 1.05, and 1.05 increased odds of type 2 diabetes in Mexican Americans, non-Hispanic Whites and non-Hispanic Blacks, respectively. WHtR was associated with 2.95, 2.38, and 2.37 increased odds of type 2 diabetes in Mexican Americans, non-Hispanic Whites and non-Hispanic Blacks, respectively. Conclusion: This study indicates that WHtR may be a powerful anthropometric predictor of risk for type 2 diabetes for Mexican American, non-Hispanic White and non-Hispanic Black American women ages 20-65.The literature on WHtR as a screening tool for type 2 diabetes in American women is lacking. This study is one of the first to examine the association between WHtR across varying races of American women. Future researchers should explore populations of women and men in the US with more races represented.