Background: In addition to the influence of an individual’s socioeconomic status, the neighbourhoods in which people live may influence health-related behaviours including smoking. This study therefore sought to determine the influence of the socioeconomic context in which South African adults lived on their smoking behaviour, and explore the potential gender differences of contextual influences. Method: This study involved a representative sample of South African adults (≥16 years) who participated in the 2010 (n=3,112) and 2011 (3,003) South African Social Attitude Survey (SASAS). The 2009 General Household Survey (n =25,548 households) was used to obtain the socioeconomic characteristics of the neighbourhoods where SASAS participants lived, including proportion of households with access to tap water, access to flush toilets and the level of employment in the area (3-item deprivation index; α=0.84). Information obtained from SASAS included participants’ tobacco use status and socio-demographic characteristics, including participants’ self-rated socioeconomic position within the society. Data analysis included a multi-level Poisson regression analysis. Results: Of the respondents who participated in the 2010/2011 survey, 19.4% (n=1302) were current smokers (30% men and 9.8% women). Smoking was more prevalent among those living in areas in the upper-third socioeconomic status (SES) than in areas in the lower-third SES (22.9% vs. 13.5%; p= 0.01). The neighbourhood socioeconomic context had a greater influence on the prevalence of smoking among women than among men. In particular, the gender gap in smoking prevalence was higher among those living in areas in the lowest-third SES (24.6% men vs. 4.6% women) than among those in areas of highest-third SEP (31.5% men vs. 15% women). Overall, smoking was less likely among those with greater than high school education than among those with less than high school education (OR=0.68; 95%CI=0.56-0.82). Conclusion: The findings suggest a greater neighbourhood socioeconomic contextual influence on women than men and highlight the need for community-level interventions targeting the least educated living in areas of highest socioeconomic position in South Africa. Interventions and public health policies to decrease tobacco smoking should be developed with some neighbourhood-specific modifications and should also be actively implemented. / Dissertation (MPH)--University of Pretoria, 2015. / tm2015 / School of Health Systems and Public Health (SHSPH) / MPH / Unrestricted

INTRODUCTION - Plasminogen activator inhibitor type-1 (PAI-1) has a known relationship with obesity and more specifically with central obesity. Traditionally the physiological contribution of PAI-1 is seen as an indicator of fibrinolysis with increased PAI-1 levels contributing to decreased fibrinolysis. In more recent years, assays have been developed that not only uses proxy markers, such as PA-1, which is considered to be representative of fibrinolysis , but global assays that report on the global fibrinolytic potential of an individual, often reported as clot lysis time (CLT). Investigations into the relationship of CLT with obesity are scarce. Preliminary evidence shows that the relationship of CLT with obesity may differ from that of PAI-1 with obesity although in depth investigations in this regard are lacking. Therefore, the aim of this study was to investigate the association between fibrinolysis markers (PAI-1act and CLT) and various markers of body composition in the South African Prospective Urban and Rural Epidemiology (PURE) data collected during 2010. METHODS - Data collected in the PURE study in 2010 were cross-sectionally analysed. The participants (n = 1288) were apparently healthy black South-African men and women 35 years and older, residing in urban and rural settlements in the North-West Province. Experimental methods included anthropometric measurements such as height, weight, hip circumference, waist circumference, skinfolds (triceps, chest, abdominal, thigh and supra iliac skinfolds) and body composition measurements by means of air-displacement plethysmography and biolelectrical impedance analysis. Laboratory analysis of fibrinolysis markers, PAI-1act and CLT were also performed. MAIN FINDINGS - In men, similarities were seen regarding the relationship between PAI-1act and body composition markers and the relationships observed between CLT and body composition markers. In contrast, in the women more and stronger associations were observed between CLT and body composition markers compared to that observed between PAI-1act and body composition markers. CLT showed a linear relationship with body composition markers where PAI-1act levels plateaued at higher body composition categories. Possible reasons for the observed differences may be related to differences in adipose tissue distribution and sequence of accumulation between men and women. PAI-1 is associated with visceral adipose tissue (VAT) where high amounts of stromal cells are found. In men preferential accumulation of VAT may explain similarities in the relationship of PAI-1act with body composition and that of CLT with body composition. Proportionally less VAT, but more subcutaneous adipose tissue in women may explain the observed increase in CLT compared to PAI-1act levels that plateaued over body composition tertiles and categories. CONCLUSION - PAI-1act has a stronger association with central obesity while CLT has a stronger association with total body fat. In women PAI-1act and CLT showed different associations with body composition markers, whereas associations of PAI-1act and CLT with body composition were similar in men. PAI-1act is strongly influenced by type of body fat accumulation whereas CLT is associated with obesity independent of type and sequence of body fact accumulation. Significant associations observed between CLT and body composition variables are, therefore, at least in part, independent of PAI-1act. Additional factors such as, thrombin activatable fibrinolysis inhibitor (TAFI), α-2-antiplasmin, plasminogen, prothrombin and fibrin clot structure that influence CLT and are also related to obesity may additionally contribute to the link between CLT and obesity. / MSc (Dietetics), North-West University, Potchefstroom Campus, 2014

INTRODUCTION - Plasminogen activator inhibitor type-1 (PAI-1) has a known relationship with obesity and more specifically with central obesity. Traditionally the physiological contribution of PAI-1 is seen as an indicator of fibrinolysis with increased PAI-1 levels contributing to decreased fibrinolysis. In more recent years, assays have been developed that not only uses proxy markers, such as PA-1, which is considered to be representative of fibrinolysis , but global assays that report on the global fibrinolytic potential of an individual, often reported as clot lysis time (CLT). Investigations into the relationship of CLT with obesity are scarce. Preliminary evidence shows that the relationship of CLT with obesity may differ from that of PAI-1 with obesity although in depth investigations in this regard are lacking. Therefore, the aim of this study was to investigate the association between fibrinolysis markers (PAI-1act and CLT) and various markers of body composition in the South African Prospective Urban and Rural Epidemiology (PURE) data collected during 2010. METHODS - Data collected in the PURE study in 2010 were cross-sectionally analysed. The participants (n = 1288) were apparently healthy black South-African men and women 35 years and older, residing in urban and rural settlements in the North-West Province. Experimental methods included anthropometric measurements such as height, weight, hip circumference, waist circumference, skinfolds (triceps, chest, abdominal, thigh and supra iliac skinfolds) and body composition measurements by means of air-displacement plethysmography and biolelectrical impedance analysis. Laboratory analysis of fibrinolysis markers, PAI-1act and CLT were also performed. MAIN FINDINGS - In men, similarities were seen regarding the relationship between PAI-1act and body composition markers and the relationships observed between CLT and body composition markers. In contrast, in the women more and stronger associations were observed between CLT and body composition markers compared to that observed between PAI-1act and body composition markers. CLT showed a linear relationship with body composition markers where PAI-1act levels plateaued at higher body composition categories. Possible reasons for the observed differences may be related to differences in adipose tissue distribution and sequence of accumulation between men and women. PAI-1 is associated with visceral adipose tissue (VAT) where high amounts of stromal cells are found. In men preferential accumulation of VAT may explain similarities in the relationship of PAI-1act with body composition and that of CLT with body composition. Proportionally less VAT, but more subcutaneous adipose tissue in women may explain the observed increase in CLT compared to PAI-1act levels that plateaued over body composition tertiles and categories. CONCLUSION - PAI-1act has a stronger association with central obesity while CLT has a stronger association with total body fat. In women PAI-1act and CLT showed different associations with body composition markers, whereas associations of PAI-1act and CLT with body composition were similar in men. PAI-1act is strongly influenced by type of body fat accumulation whereas CLT is associated with obesity independent of type and sequence of body fact accumulation. Significant associations observed between CLT and body composition variables are, therefore, at least in part, independent of PAI-1act. Additional factors such as, thrombin activatable fibrinolysis inhibitor (TAFI), α-2-antiplasmin, plasminogen, prothrombin and fibrin clot structure that influence CLT and are also related to obesity may additionally contribute to the link between CLT and obesity. / MSc (Dietetics), North-West University, Potchefstroom Campus, 2014