3. Electronic Theses and Dissertations (ETDs) - All submissions
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Item Prevalence and determinants of self-reported hypertension in urban poor settlements of Johannesburg(2017) Kinara, Fossa OgakeBackground: Hypertension is the leading risk factor for cardiovascular disease in Africa. Cardiovascular disease is rated as the number one cause of death in Africa. Previously, hypertension was known to predominantly affect the affluent population but recently the condition has been emerging even among the poorer population, rendering it a greater burden. In South Africa its prevalence level has significantly escalated, particularly in urban areas, with higher incidence among the poor. The prevalence of self-reported hypertension and its risk factors is not well documented in the urban impoverished settlements. Understanding determinants and the prevalence of self-reported hypertension in these areas will help develop improved awareness, prevention and control strategies. This study aimed to determine the prevalence and determinants of self-reported hypertension in five urban impoverished sites in Johannesburg, South Africa. Methods: Secondary data analysis was done on data from the HEAD study which involved a sample of households from five urban poor areas. Prevalence levels of self-reported hypertension were estimated within the study areas. Summary measures of the data were computed and presented in a descriptive table. Distribution of the potential risk factors by prevalence of self-reported hypertension was also done. Lastly, binary logistic regression was used to model the unadjusted and adjusted association between the identified risk factors and self-reported hypertension. iv Results: The prevalence of self-reported hypertension among households in the five urban impoverished sites was 20 percent (n=107). The independent predictors of hypertension were study area (Riverlea, Hillbrow), race, age, gender (0.25-0.49 and ≥0.75), work (0.5-0.74, and ≥0.75), monthly income (ZAR 1000-2000, 2001-5000, and >5000), presence of another non-communicable disease and socioeconomic status (middle). Results from the adjusted model showed that race, sex, age and presence of at least one other non-communicable disease are were significantly associated with self-reported hypertension Conclusion: The study’s findings strengthen the case that age, sex, race, and co-morbid non-communicable diseases are associated with self-reported hypertension. Interventions that target the urban poor population and that focus on increasing awareness and context specific risk reduction are recommended. Further, the association with these factors should be confirmed by carrying out a more robust population-based study to inform policyItem Cost analysis and comparison of two global cardiovascular risk scores in hypertensive patients at Mafikeng provincial hospital: a preliminary exploratory study(2018) Mbuilu, Jody PukutaA preliminary study was done where South African Hypertension guideline risk score was compare with the WHO Cardiovascular risk score (for Southern Africa). At Mafikeng Provincial hospital 130 hypertensive patients were assessed using both scoring algorithms. Ninety (69%) of the 130 patients were high risk. The WHO risk score was able to classify 84 (93%) of the high risk patients by SA risk calculator also as high risk and 36 (90%) of the 40 low risk patients also as low risk. The WHO risk calculator has a sensitivity of 93% and a specificity of 90% with 89% accuracy.Item A psychosocial study of cardiovascular diseases, health behaviours and risk perception among retail pharmacy workers in Johannesburg, South Africa(2016) Buldeo, PriyaThis thesis is based on a descriptive and exploratory psychosocial study which investigates the underlying factors that shape cardiovascular diseases, health behaviours and risk perception among retail pharmacy workers in Johannesburg, South Africa. It further examines help-seeking behaviours and the meanings attached to ‘The Body’, self and identity as related to symbolic interactionism. A review of literature presents a background to the local and global context and engages classic and contemporary discourses and debates on health, illness and chronic diseases. The unique context of non-communicable diseases in South Africa is interrogated by utilising the Integrative Model of Behavioural Prediction as a guiding theoretical framework. A mixed methods research design incorporated (i) a survey (N=400) and (ii) in-depth follow-up interviews (N=60). Data were analysed using descriptive statistics and thematic content analyses for deeper reflections on the topic. The findings revealed that cardiovascular disease knowledge and risk perception is shaped by one’s family, community, workplace, colleagues and the media. It found that workers have an understanding of cardiovascular diseases, the problem, however, is that individual risk perception is overlooked. Social networks, cultural norms and gender contributed to the public framings of bodies and the sociocultural anxieties surrounding juxtapositions – thin/fat, healthy/unhealthy, acceptable/unacceptable, good/bad – prominent in ‘Othering’ deliberations. These illuminated the symbolic and material dimensions of how workers conceptualise their bodies. ‘Good’ health behaviours were associated with physical attractiveness, social acceptance and health improvement and maintenance. ‘Bad’ health behaviours were linked to time constraints, long working hours, financial stress and family responsibilities. The discussion and conclusion consolidate the study’s sociological significance and the multi-layered aspects of health, illness and chronic diseases. This thesis challenges sociocultural expectations of ‘The Body’ in ways which contrast some of the available literature in Africa. It further contributes to the existing knowledge on non-communicable diseases while introducing innovative ways of (re)thinking about chronic conditions and the practical implications as related to the study. The pertinent issues raised regarding non-communicable disease diagnosis, management and treatment, as well as food consumption and body weight perceptions complicate an ever-changing South African risk society. This thesis, therefore, paves the way for further research on the perceived and actual cardiovascular disease risks in the South African context.Item Chronic non-communicable diseases in black South African population living in a low-resource community(2016) Pretorius, Susan SIntroduction: The African continent, particularly sub-Saharan Africa, is facing a high burden of disease from the human immunodeficiency virus (HIV) pandemic and nutritional deficiencies, while at the same time, facing ever increasing rates of cardiovascular diseases (CVDs). The mortality rates from CVD are almost equal to the death rates from communicable diseases. In Sub-Saharan countries CVD prevention and management faces many barriers. One such difficulty is the shortage of data for the descriptive epidemiology of CVD risk factors. In an attempt to address this shortage of data, we established the Heart of Soweto (HOS) study in one of the largest African urban communities in South Africa. The purpose of this study was to identify and describe some of the factors contributing to the emergence of chronic diseases of lifestyle, such as heart disease, high blood pressure, diabetes and obesity in a black urban African population, within the framework of the HOS study. We also investigated the impact of a dietary intervention on cardiac function in subjects with chronic heart failure (CHF) in this black urban cohort. Methods: Data was collected as part of the “Heart of Soweto” (HOS) study, which was a prospectively designed registry that recorded data relating to the presentation, investigation and treatment of patients with newly diagnosed cardiovascular disease presenting to Chris Hani Baragwanath Hospital (CHBH), Soweto in 2006. Data collected included socio-demographic profile and all major cardiovascular diagnoses. Heart disease was defined as non-communicable (ND) e.g. coronary artery disease or communicable (CD) e.g. rheumatic heart disease. A survey was also conducted on consecutive patients attending two pre-selected primary care clinics in Soweto (644 and 667 patients from the Mandela Sisulu and Michael Maponya clinics, respectively). Data collected included, ethnicity, duration of residence in Soweto, highest level of education and employment status. Clinical data collected included prior or current diagnoses of diabetes and hypertension and pharmacological therapy related to the treatment of hypertension, as well as smoking status and exposure to second-hand smoking. Weight, height, and waist and hip circumference were measured. Questions were asked regarding the duration of night-time sleep and napping during the day. Descriptive studies were undertaken at the Heart Failure Clinic at CHBH, Soweto to firstly describe the food choices and macro-and micronutrients intake of 50 consecutive patients presenting with heart failure using an interviewer-administered quantitative food frequency questionnaire (QFFQ). Food data were translated into nutrient data using the Medical Research Council (MRC) Food Finder 3, 2007, which is based on South African food composition tables. Secondly we performed a randomized controlled study of a multidisciplinary, community-based, chronic HF management program in Soweto, compared with usual care, at CHBH Heart Failure Clinic located at the Soweto Cardiovascular Research Unit (SOCRU), or at the General Cardiac ix Clinic (standard care) in Soweto. In this study 49 consenting, eligible patients were individually randomized on a 1:1 basis to either usual care or to the study intervention and cardiac function was measured before and after the intervention. Results: Data collected at Chris Hani Baragwanath hospital (CHBH) cardiology clinic from 5328 suspected cases of heart disease, demonstrated that the most prevalent form of heart disease was hypertensive heart failure (22.0%). It was found that those participants who presented with ND (35.0%) were older and had higher BMI and mean systolic blood pressure (SBP) and diastolic blood pressure (DBP) than those with CD (39.0%; all comparisons p<0.001). Within this cohort of 5328 de novo cases of heart disease, 2505 (47%) were diagnosed with HF, of which 697 (28%) were diagnosed with r i g h t h e a r t f a i l u r e ( RHF). There were more women than men diagnosed with RHF (379 vs. 318 cases), and on an adjusted basis, compared with the remainder of the Heart of Soweto cohort (n = 4631), RHF cases were more likely to be African (adjusted OR 2.33, 95% CI 1.59 – 3.41), with a history of smoking (OR 1.72, 95% CI 1.42 – 2.10), a lower body mass index (OR 0.96, 95% CI 0.94 – 0.97 per kg/m2) and were less likely to have a family history of heart disease (OR 0.79, 95% CI 0.64 – 0.96). Data collected at 2 primary health care clinics in Soweto from 862 women (mean age 41 ± 16 years and mean BMI 29.9 ± 9.2 kg/m2) and 449 men (38 ± 14 years and 24.8 ± 8.3 kg/m2) indicated that in females, former smokers had a higher BMI (p<0.001) than current smokers, while exposure to second hand smoking was associated with a lower BMI (p<0.001) in both genders. Longer sleep duration in females was associated with a lower BMI (p=0.01). Napping during the day for > 30 minutes in males was related to a lower BMI and waist circumference (β=-0.03, p<0.05 for both) and lower systolic (β=-0.02, p<0.05) and diastolic BP (β=-0.02, p<0.05). Longer night time sleep duration was associated with lower diastolic (β=0.004, p<0.01) and systolic BP (β=0.003, p<0.05) in females. Within this same cohort, o b e s i t y w a s m o r e p r e v a l e n t i n f e m a l e s ( 4 1 . 8 % ) t h a n m a l e s ( 1 4 . 1 % ; p < 0 . 0 0 1 ) , 16% (n = 205) had an abnormal 12- lead ECG with more men than women showing a major abnormality (24% vs. 11%; OR 2.63, 95% CI 1.89–3.46). Of 99 cases (7.6%) subject to advanced cardiologic assessment, 29 (2.2%) had newly diagnosed heart disease which included hypertensive heart failure (13 women vs. 2 men, OR 4.51 95% CI 1.00–21.2), coronary artery disease (n = 3), valve disease (n = 3), dilated cardiomyopathy (n = 3) and 2 cases of acute myocarditis. Nutritional deficiencies were observed in a cohort presenting with HF at the cardiology outpatient clinic, CHBH. In women, food choices likely to negatively impact on heart health included added sugar [consumed by 75%: median daily intake (interquartile range) 16 g (10–20)], sweet drinks [54%: 310 ml (85–400)] and salted snacks [61%: 15 g (2–17)]. Corresponding figures for men were added sugar [74%: 15 g (10–15)], sweet drinks [65%: 439 ml (71–670)] and salted snacks [74%: 15 g (4–22)]. The women’s intake of calcium, vitamin C and vitamin E was only 66%, 37% and 40% of the age-specific requirement, respectively. For men, equivalent figures were 66%, 87% and 67%, respectively. Mean sodium intake was 2 372 g/day for men and 1 972 g/day for women, 470 and 294% respectively, of daily recommended intakes (DRI). In men, vitamin C intake was 71 ± 90 (79% of DRI). Similarly, in women vitamin C intake was 66 ± 80 (88% of DRI). Data collected from our HF management programme study supported the deficient intake of vitamin C in African subjects presenting with heart failure. Thus, plasma vitamin C concentrations (normal range 23 – 85 μmol/L) were markedly deficient in both standard care [6.53 (3.80, 9.22) μmol/L] and managed care [3.65 (1.75, 8.23) μmol/L] groups. In terms of clinical presentation, males were significantly older (49.9 ± 10.9 years; p<0.005) than females (37.2 ± 12.8) and at follow-up females had a significantly higher ejection fraction (34.8 ± 9.56 %) than males (29.5 ± 8.27; p<0.05) and when the groups were combined, the ejection fraction was significantly higher (32.2 ± 9.27; p<0.05) at follow-up compared to baseline (29.9 ± 8.80). We found that heart rate was significantly lower at follow-up (89.9 ± 14.6 beats/min) compared to baseline (93.4 ± 17.2; p<0.05) only in the managed care group. Furthermore, if diastolic blood pressure increased over the follow-up period, ejection fraction fell by 5.98% (p=0.009) in comparison to cases where diastolic blood pressure remained the same or fell. In addition, thiamine levels at baseline correlated negatively with systolic blood pressure (r=-0.68, p=0.04) at follow-up. Conclusion: Non-communicable heart disease and other diseases of lifestyle, such as high blood pressure, obesity and diabetes, are drastically increasing in Sub-Saharan Africa in general and in a black urban African community, such as Soweto, specifically. Soweto can clearly be described as a community in epidemiological and nutrition transition and is facing a double or even triple burden of disease. This is a community that is still being burdened by historically prevalent forms of communicable or infectious diseases juxtaposed against people who have lived their whole lives in Soweto and are increasingly suffering from newer or non-communicable diseases of lifestyle. Women seem to be especially burdened by this increase in non-communicable diseases, with a predominance of women suffering from heart disease and obesity. Certain exacerbating risk factors have been identified from the HOS in this community, namely the gender specific effects of sleep, smoking and other environmental factors on BMI and blood pressure, and the adverse effects of changing dietary patterns particularly the increased consumption of refined and processed foods, high in sugar, salt and fats and insufficient intakes of fruits and vegetables. Although there are some limitations to our HF management study, it serves as an indication that targeted, culturally sensitive care, adapted to an urban African population, might contribute to improved patient outcomes. However, prevention should always be our first priority through community-based and gender specific screening and the development and implementation of targeted prevention programs.Item Cardiovascular risk profile of kidney transplant recipients at the Charlotte Maxeke Johannesburg Academic Hospital.(2014-04-25) Muhammad, Aminu SakajikiINTRODUCTION Cardiovascular diseases (CVD) are more common in kidney transplant recipients (KTRs) than in the general population. The high incidence of CVD in the KTRs can be attributed to traditional risk factors, additional risk factors associated with graft dysfunction and those specifically related to transplantation. Carotid intima-media thickness (cIMT) is a proven surrogate of atherosclerosis; it correlates with vessel pathology and is precisely imaged using ultrasound technology. This study was aimed at determining the prevalence and predictors of cardiovascular risk among KTRs at the Charlotte Maxeke Johannesburg Academic Hospital (CMJAH) and to examine the relationship between cardiovascular risk factors and carotid intima media thickness. METHODS Patients aged 18 years and above who received a kidney transplant at the CMJAH between January 2005 and December 2009 were recruited. A questionnaire that captured cardiovascular risk factors was administered. Patients records were assessed for information on their post transplant follow up. All patients had echocardiography and carotid doppler done for measurement of intima-media thickness. The Framingham Risk Score was used to categorize patients into low, moderate, high risk and very high risk groups. Results were analyzed using statistical package for social sciences (SPSS) version 17, p value of 0.05 was considered significant. RESULTS One hundred (KTRs) 63 male (63%) and 37 female (37%) were recruited ranging in age from 19 to 70 years, with a mean age of 42.2 ± 12.42. Thirty six patients (36%) were found to have high cardiovascular risk. Multiple regression showed proteinuria (p = 0.022), higher cumulative steroid dosage (p = 0.028), elevated serum triglycerides (p = 0.04) and the presence of plaques in the carotid artery (p = 0.012) as predictors of higher cardiovascular risk.Carotid intima-media thickness correlates with higher CVD risk. Fourteen patients (14%) had a carotid artery plaque. Twenty five patients (25%) had cIMT of >0.7 mm. CONCLUSION Kidney transplant recipients in CMJAH were found to have high cardiovascular risk (36%) and carotid intima-media thickness correlates with this high CVD risk. Routine follow up of KTRs should include measurement of cIMT as it provides a simple non-invasive assessment of subclinical atherosclerosis.Item The implementation of current guidelines regarding the treatment of cardiovascular risk in type 2 diabetics(2012-01-10) Pinchevsky, YacobBackground: Type 2 diabetes mellitus (T2DM) is defined by an increase in serum glucose, however, this leads to the belief that only the serum glucose levels need be monitored and treated. Hence many other risk factors such as obesity, lipids and blood pressure which increase the risk of coronary heart disease, myocardial infarction, stroke and peripheral vascular disease are neglected. Consequently, T2DM patients that are at greater risk of developing cardiovascular disease (CVD), are often not receiving optimal comprehensive care. Aims: To identify the treatment gaps of cardiovascular risk factors in patients with T2DM using both national and international current treatment guidelines. Methods: Using a public sector database, data was obtained on the treatment of 666 T2DM patients. Records of patients were selected on the basis of established T2DM diagnoses, receiving oral hypoglycaemic and/or insulin therapy. The following patient data was recorded: demographics (age, gender, ethnicity), systolic blood pressure (SBP), diastolic blood pressure (DBP), glycated haemoglobin (HbA1c), total cholesterol (TC), triglycerides (TG), HDL-cholesterol (HDL-C), LDL-cholesterol (LDL-C) , family history, cardiovascular history and all chronic medications. The following parameters were applied to the cohort: SBP <130 mmHg, DBP <80 mmHg. In the event of proteinuria: SBP ≤120 mmHg, DBP ≤70 mmHg. HbA1c <7.0%, TC <4.5 mmol/L, LDL-C <2.5 mmol/L, HDL-C >1.0 mmol/L (males), HDL-C >1.2 mmol/L (females) and TG <1.7 mmol/L. In patients with established CVD, LDL-C target: ≤1.8 mmol/L. Results: The study cohort consisted of 666 T2DM-patients. 55% females. Mean age was 63 years (SD: 11.8), mean HbA1c was 8.7% (SD: 2.4). The mean SBP and DBP readings for the cohort were 133.66 (SD: 19.9) and 78.07 mmHg (SD: 11.6), respectively. Mean LDL-cholesterol was 2.6 mmol/L (SD: 0.9). 26.2% reached HbA1c of ≤7%, 45.8% reached ≤130/80 mm Hg blood pressure targets, 53.8% reached LDL-C of ≤2.5mmol/L and all 3 were reached by 7.5% of the cohort. TC ≤4.5 mmol/L was reached by 53.8%, 60.2% reached TG ≤1.7mmol/L, 58.6% males and 52.8% females reached HDL-C targets of ≥1.0 mmol/L and ≥1.2 mmol/L, respectively. There were 17.9% of patients with CVD reaching targets of LDL-C ≤1.8 mmol/L whilst 16.4% of patients with nephropathy reaching targets of ≤120/70 mm Hg. Almost half (48.2%) were not receiving lipid-lowering therapy, yet would be deemed eligible for therapy. Blood pressure targets may have been better reached with appropriate dosage reductions in addition to the introduction of further antihypertensive combination therapy. CVD was present in 15.5%. Conclusions: T2DM patients are at high-risk for CVD. Many trials have demonstrated the benefits of targeting CVD risk factors (HbA1c, blood pressure, serum lipids) in T2DM. Less than 10% of CVD risk factor targets were reached by the study cohort despite treatment guideline recommendations. The data from the study suggests poor control of modifiable cardiovascular risk factors and significant under treatment of T2DM in clinical practice. Whether improvement lies in the form of therapeutic titration adjustment or an increase in patient education, there needs to be a more aggressive multi-factorial therapeutic approach to treating this high risk group of patients in order to reduce overall morbidity, mortality and improve patient outcomes.Item Scintigraphic assessment of cardiovascular diseases in asymptomatic diabetic black patients(2012-01-10) Vangu, Mboyo Di Tamba Heb'En WillyThe association between diabetes and coronary artery disease (CAD) has been recognized as a major public health problem in the developed world. While there is an increased prevalence of silent myocardial ischaemia among asymptomatic individuals with diabetes, diabetic individuals with CAD in their larger number are usually asymptomatic, and when they present with signs of disease, there is extensive and severe CAD. It should be noted that amongst black South African, ischemic heart disease (IHD) remains rare, and there is little data linking diabetes mellitus with IHD. However, contrary to early reports that have suggested a low prevalence of CAD in black population in Africa, many studies have indicated a rapid change on the spectrum of CAD in numerous parts of the African continent. Despite the emerging report of high prevalence of risk factors there are only limited data investigating prevalence of CAD in black African with diabetes. The purpose of this thesis was to use myocardial perfusion imaging (MPI) at rest and after stress testing to detect CAD in a group of asymptomatic black patients suffering from diabetes and therefore assess the prevalence of CAD; to assess the changes in myocardial perfusion in asymptomatic diabetic black individuals and compare the differences seen in myocardial perfusion changes between the asymptomatic diabetic black and, the asymptomatic diabetic white and Indian individuals; to include data from symptomatic diabetic patients who were referred for MPI as part of their routine clinical management for possible comparison Consecutive 94 asymptomatic diabetic black patients and 50 asymptomatic diabetic white and Indian patients were recruited from the outpatient diabetic clinic of the Johannesburg hospital. Data from 90 subjects forming a group of symptomatic diabetic patients, 45 blacks and 45 whites and Indians referred for MPI as part of their clinical management were also analyzed. A two-day protocol for SPECT MPI was used in all participants: on the first day the stress testing MPI while the rest MPI was consistently done on the second day. Both exercise and pharmacologic stress testing were used. Technetium-99m methoxy-isobutylisonitrile (MIBI) was used as the myocardial perfusion radiopharmaceutical. Myocardial perfusion was assessed by means of semi-quantitative scoring system to measure the extent and severity of perfusion abnormality. Visual inspection of the reconstructed SPECT MPI images was carried out to assess perfusion deficit where there was a doubt on the extent and severity of perfusion abnormality. The QPS/QGS software allows obtaining resting and post stress left ventricular ejection fraction (LVEF). The means and percentages on study variables were obtained. The Spearmen correlation coefficient was used to calculate correlations between variables. The Kruskal-Wallis test was used to assess differences between black diabetic and white or Indian diabetic patients and Wilcoxon scores (rank sum) two-sided were used to measure differences within these racial groups. There were 123 females (52.6%) and 111 males (47.4%) in total. From the recruited participants, 53 (56.4%) asymptomatic females and 41 (43.6%) asymptomatic males were blacks whereas 24 (48%) asymptomatic females and 26 (52%) asymptomatic males were whites or Indians. The symptomatic group was comprised of 26 (57.8%) female and 19 (42.2%) male black patients and 20 (44.5%) female and 25 (55.5%) male white or Indian patients. Asymptomatic diabetic black participants were younger than the participants from the asymptomatic diabetic white and Indian group with a mean age of 60 (SD±7.2) years Vs 64 (SD±7.7) [p=0.003]. Fourteen percent of asymptomatic black participants had evidence of ischaemia by showing improvement of perfusion on stress testing versus twenty eight percent of white and Indian asymptomatic participants (p=0.62). Perfusion defects that did not change from rest to post stress testing MPI (fixed defects) were also noted in 20% of asymptomatic black and 26% of asymptomatic white and Indian diabetic participants. These fixed perfusion defects are indicative of previous myocardial infarctions and therefore suggestive of CAD. No significant difference was noted on the changes of perfusion that could account either for ischaemia or infract between asymptomatic diabetic black participants and their white and Indian counterparts (p=0.47). The difference on the improvement of perfusion from rest to post-stress MPIs or reversibility of perfusion to suggest only the presence of ischaemia did not also show a significant difference between these two racial groups (p=0.62). Our data demonstrated a high prevalence of CAD in asymptomatic diabetic black participants similar to other racial groups. Our study has demonstrated evidence to recommend screening of asymptomatic diabetic black individuals in equal manner than other races for the detection of CAD. More importantly, stress MPI should be routinely used as a noninvasive investigation in our environment and be utilized more actively in the management of all asymptomatic diabetic patients.