Noncommunicable Disease Conditions and HIV in Rural and Urban South Africa: 2005-2015.

Purpose: Hypertension, obesity, hyperlipidemia, and type 2 diabetes contribute primarily to noncommunicable disease deaths and together with human immunodeficiency virus contribute largely to mortality in South Africa. Our longitudinal study provides the necessary data and insights over a 10-year period to highlight the areas where improved management is required in urban and rural localities. Methods: This study included 536 rural and 387 urban Black participants aged 32 to 93 years from the North-West province, South Africa. Disease prevalence, treatment, and control were determined in 2005 and were re-evaluated in 2015. Multiple measures analyses were used to determine the trends of blood pressure and waist circumference. Results: The initial prevalence of hypertension was 53.2%, obesity was 23.6%, hyperlipidemia was 5.1%, diabetes was 2.9%, and human immunodeficiency virus was 10.7% in 2005. By 2015, the rural population had higher rates of hypertension (63.7% versus 58.5%) and lower rates diabetes (4.3% versus 7.9%) and hyperlipidemia (6.6% versus 18.0%) with similar obesity rates (41.7% versus 42.4%). The average blood pressure levels of urban hypertensives decreased (Ptrend<.001), whereas levels were maintained in the rural group (Ptrend=.52). In both locations, treatment and control rates increased from 2005 to 2015 for all conditions (all ≥6.7%), except for diabetes in which a decrease in control was observed. Waist circumference increased (Ptrend>.001) in both sex and locality groups over the 10-year period. Conclusion: Although average blood pressure of urban hypertensive individuals decreased, urgent measures focused on early identification, treatment, and control of the respective conditions should be implemented to decrease the burden of noncommunicable diseases.

Cardiovascular Profile of South African Adults with Low-Level Viremia during Antiretroviral Therapy.

Chronic inflammation is an HIV infection feature, contributing to elevated risk of cardiovascular disease among people with HIV, which can be induced by viral replication. A proportion of antiretroviral therapy (ART) recipients fail to achieve viral suppression, despite not meeting criteria for treatment failure, so-called low-level viremia (LLV). We investigated the relationship between LLV and an array of cardiovascular measures and biomarkers. South Africans with LLV (viral load = 50−999 copies/mL) and virological suppression (viral load <50 copies/mL) were selected from the EndoAfrica study (all receiving efavirenz-based ART) for cross-sectional comparison of vascular structure and function measures, as well as 21 plasma biomarkers related to cardiovascular risk and inflammation. Associations were investigated with univariate, multivariate, and binomial logistic regression analyses (having outcome measures above (cases) or below (controls) the 75th percentile). Among 208 participants, 95 (46%) had LLV, and 113 (54%) had viral suppression. The median age was 44 years, 73% were women, and the median ART duration was 4.5 years. Cardiovascular measures and biomarker levels were similar between these two categories. Cardiovascular function and structure measures were not associated with viremia status and having LLV did not increase the odds of having outcome measures above the 75th percentile. In this study among South African ART recipients, LLV did not associate with cardiovascular risk.

Age-related differences in the vascular function and structure of South Africans living with HIV.

Background: As the life expectancy of people living with the HIV increases because of antiretroviral treatment (ART), their risk for vascular co-morbidities and early vascular ageing (EVA) also increases. Objective: We aimed to investigate whether HIV infection relates to vascular structure and function in black South African adults and whether this relationship is age dependent. Method: This cross-sectional study carried out in urban and rural areas of North West province, South Africa, included 572 age- and sex-matched people living with HIV (PLWH) and without HIV. Participants from the EndoAfrica study and PURE study were stratified according to tertiles of age. Measures of vascular structure (carotid intima-media thickness) and function (carotid-femoral pulse wave velocity, central systolic blood pressure, central pulse pressure and pulse pressure amplification) were determined. Results: Blood pressure measures were lower in PLWH compared with their controls (all P ≤ 0.001), especially in the younger and middle-aged groups (all P ≤ 0.031), whilst vascular measures did not differ (all P ≥ 0.611). In multivariate linear regression analyses, vascular measures were not associated with a HIV- positive status in either the total or any of the age groups. Conclusion: Black South Africans living with HIV have a less adverse blood pressure profile than their counterparts without HIV. The HIV-positive status was not associated with measures of vascular structure or function in any age group. The results suggest that HIV does not contribute to EVA in this population; however, further longitudinal investigation is warranted.

Vascular function and cardiovascular risk in a HIV infected and HIV free cohort of African ancestry: baseline profile, rationale and methods of the longitudinal EndoAfrica-NWU study.

BACKGROUND: People living with the Human Immunodeficiency Virus (PLHIV) have an increased susceptibility to develop non-communicable diseases such as cardiovascular disease (CVD). Infection with HIV contributes to the development of CVD independent of traditional risk factors, with endothelial dysfunction being the central physiological mechanism. While HIV-related mortality is declining due to antiretroviral treatment (ART), the number of deaths due to CVD is rising in South Africa - the country with the highest number of PLHIV and the world's largest ART programme. The EndoAfrica study was developed to determine whether HIV infection and ART are associated with cardiovascular risk markers and changes in vascular structure and function over 18 months in adults from different provinces of South Africa. This paper describes the rationale, methodology and baseline cohort profile of the EndoAfrica study conducted in the North West Province, South Africa. METHODS: In this case-control study, conducted between August 2017 and June 2018, 382 volunteers of African descent (276 women; 106 men), comprising of 278 HIV infected and 104 HIV free individuals were included. We measured health behaviours, a detailed cardiovascular profile, and performed biomarker analyses. We compared baseline characteristics, blood pressure, vascular function and biochemical markers between those infected and HIV free. RESULTS: At baseline, the HIV infected participants were older (43 vs 39 years), less were employed (21% vs 40%), less had a tertiary education (7% vs 16%) and their body mass index was lower (26 vs 29 kg/m2) than that of the HIV free participants. While the cardiovascular profile, flow-mediated dilation and pulse wave velocity did not differ, glycated haemoglobin was lower (p = 0.017) and total cholesterol, high density lipoprotein cholesterol, triglycerides, gamma-glutamyltransferase and tobacco use were higher (all p < 0.047) in PLHIV. CONCLUSION: Despite PLHIV being older, preliminary cross-sectional analysis suggests that PLHIV being treated with ART do not have poorer endothelial or vascular function compared to the HIV free participants. More detailed analyses on the baseline and follow-up data will provide further clarity regarding the cardiovascular profile of South Africans living with HIV.

Asymmetric dimethylarginine and L-homoarginine prospectively relate to carotid wall thickness in a South African cohort.

BACKGROUND AND AIMS: The L-arginine derivatives asymmetric (ADMA) and symmetric dimethylarginine (SDMA), as well as L-homoarginine may have opposing effects in the pathogenesis of atherosclerosis. We aimed to investigate (i) 5-year changes in arginine derivatives, and (ii) the association between baseline arginine derivatives and follow-up measures of carotid wall thickness in South Africans. METHODS AND RESULTS: This study included men (n = 187) and women (n = 396) who took part in the 2010 and 2015 data collections of the South African arm of the Prospective Urban and Rural Epidemiology (PURE) study. Arginine derivatives were determined in plasma with liquid chromatography-tandem mass spectrometry. Carotid intima-media thickness (cIMT) and cross-sectional wall area (CSWA) were determined with B-mode ultrasonography. RESULTS: Mean values of arginine derivatives did not change over time. In the study group, follow-up cIMT (ß = - 0.10 p = 0.018) and CSWA (ß = - 0.12; p = 0.004) inversely associated with baseline L-homoarginine, and cIMT inversely associated with ADMA (ß = - 0.09; p = 0.033). In women, CSWA inversely associated with both ADMA (ß = - 0.11; p = 0.034) and L-homoarginine (ß = - 0.11; p = 0.024). No such associations were found in men. CONCLUSION: These results suggest that higher levels of L-homoarginine may play a protective role against vascular injury and delay progression of carotid wall thickening in this cohort. The role of ADMA in atherosclerosis deserves further investigation in this population.

A comparative analysis of blood pressure in HIV-infected patients versus uninfected controls residing in Sub-Saharan Africa: a narrative review.

Elevated blood pressure (BP) is an important risk factor for cardiovascular disease and mortality in Sub-Saharan Africa (SSA). We reviewed the literature comparing BP in treated HIV-infected populations against untreated and/or uninfected controls from SSA. We conducted a narrative review through PubMed and EBSCO Discovery Service to determine estimates of raised BP and hypertension in HIV-infected patients versus untreated/uninfected controls (1 January 2005 to 31 July 2019 and 9 May 2020). We included 19 eligible studies that compared treated HIV-infected with untreated and/or uninfected controls. In studies comparing treated HIV-infected patients to uninfected controls, studies including 6882 (56.30%) and 21,819 (79.2%) participants reported lower BP and hypertension prevalence, respectively in HIV-infected patients; whereas studies including 753 (6.16%) and 3553 (12.9%) participants showed a higher BP and hypertension prevalence. Lastly, 4588 (37.54%) and 2180 (7.91%) participants showed no difference in BP and the prevalence of hypertension. When comparing BP of treated versus untreated HIV-infected patients, studies including 5757 (44.2%) patients reported lower BP in treated patients; while studies with 200 (1.53%) patients showed higher BP and 7073 (54.28%) showed no difference in BP. For hypertension status, studies with 4547 (74.5%) patients reported a lower prevalence of hypertension in treated patients; whereas studies with 598 (9.80%) patients showed higher prevalence; and 959 (15.7%) no difference in prevalence between treated versus untreated HIV-infected patients. In studies conducted in Sub-Saharan Africa, the majority of the findings indicate lower blood pressure and/or prevalence of hypertension in treated HIV-infected individuals compared to untreated and uninfected controls.

The metabolic syndrome and renal function in an African cohort infected with human immunodeficiency virus.

INTRODUCTION: The human immunodeficiency virus (HIV) is often accompanied by renal dysfunction. It is expected that metabolic syndrome (MetS) may exacerbate renal impairment. OBJECTIVE: We therefore determined the prevalence of MetS and the association thereof with renal function in a South African cohort infected with HIV. METHODS: We matched 114 HIV-infected (77.3% on antiretroviral therapy [ART] and 22.7% ART-naïve) and 114 HIV-uninfected individuals according to age, sex and locality. We examined cardiovascular, anthropometric and metabolic measurements and determined the MetS. Renal function was assessed using standardised procedures. RESULTS: The prevalence of MetS was lower in the HIV-infected individuals as compared to the uninfected individuals (28% vs. 44%, p = 0.013). The HIV-infected group presented with a lower body mass index (BMI) and waist circumference (WC) (all p < 0.001), as well as blood pressure (BP) (p ≤ 0.0021). The results were confirmed when comparing the HIV-infected group using ART (N = 85) and the HIV-uninfected group. When comparing the HIV-infected individuals with MetS to the HIV-uninfected individuals with MetS, no differences in BP were seen. With regard to renal function, the HIV-infected individuals with MetS (n = 32) had 43% higher urinary albumin-creatinine ratio (uACR) compared to the HIV-uninfected individuals with MetS, after adjusting for age, sex and WC (p = 0.032). None of the other renal function markers differed after adjustments for WC or BMI. CONCLUSION: The HIV-infected Africans with MetS had almost twofold higher uACR, despite the low prevalence of MetS, compared to their uninfected counterparts. The combination of HIV and MetS seemed to increase the risk for renal impairment.

Evaluating several biomarkers as predictors of aortic stiffness in young and older Africans, not consuming alcohol based on self-report.

AIMS: Black populations from sub-Saharan Africa have a high prevalence of cardiovascular disease, which places significant strain on public health systems. Aortic stiffness is a prominent risk factor for cardiovascular disease development. We reported earlier that excessive alcohol use predicts aortic stiffness. However, we require a better understanding of other biomarkers involved in stiffness development, beyond alcohol use. Therefore, we determined which biomarkers (metabolic, inflammatory, endothelial activation and oxidative stress) relate to aortic stiffness in young and older black South Africans, self-reporting no alcohol-use. METHODS: We included cross-sectional data from young (aged 24.7 ±â€¯3.24 years) black adults participating in the African Prospective study on the Early Detection and Identification of Cardiovascular Disease and Hypertension (African-PREDICT) study (N = 216), and five-year follow-up data from older (aged 61.6 ±â€¯9.77 years) black adults (N = 322) participating in the South African leg of the Prospective Urban and Rural Epidemiology study, conducted in the North West Province (PURE-SA-NWP). We excluded all participants self-reporting alcohol use. We determined biomarkers from blood samples, and measured carotid-femoral pulse wave velocity (PWV). RESULTS: Of all biomarkers investigated in multivariable-adjusted regression analyses, only plasma glucose (R2 = 0.24, ß = 0.21, p < 0.001) and glycated haemoglobin (R2 = 0.22, ß = 0.17, p = 0.002) independently predicted PWV five years later in older adults. We found no other associations in young or older black adults. CONCLUSION: Dysglycaemia independently predicted aortic stiffness after five years in older black adults. Life-course management of body weight and sugar intake are important in preventing early vascular ageing and subsequent cardiovascular disease development in Africa.

A health profile associated with excessive alcohol use independently predicts aortic stiffness over 10 years in black South Africans.

OBJECTIVE: Black populations exhibit higher arterial stiffness than whites and suffer a disproportionate burden of cardiovascular disease. It is therefore important to identify modifiable health behaviours predicting large artery stiffness in blacks. We examined whether traditional cardiovascular risk factors and health behaviours of black South Africans predict large artery stiffness 10 years later. METHODS: We included 650 HIV-free participants (32.8% men) and collected data in rural and urban areas of the North West Province in 2005 and 2015. We collected questionnaire data, anthropometry, blood pressure and determined cardiometabolic and inflammatory markers from blood samples. We measured carotid-femoral pulse wave velocity (PWV) at follow-up. RESULTS: A total of 25.3% of our population, aged 65 ±â€Š9.57 years, had a PWV exceeding 10 m/s. In multivariable-adjusted regression analyses, the strongest predictors of PWV were mean arterial pressure, age and heart rate (all P < 0.024). Urban locality (R = 0.31, ß = 0.12, P = 0.001), self-reported alcohol use (ß = 0.11, P = 0.018) and plasma glucose (ß = 0.08 P = 0.023) associated positively with PWV at follow-up. We found a negative association between PWV and BMI (ß = -0.15, P = 0.001), and no associations with sex, smoking, inflammatory markers, lipids, liver enzymes or antihypertensive medication. When replacing self-reported alcohol with gamma-glutamyltransferase, the latter associated positively with PWV (ß = 0.09, P = 0.023). CONCLUSION: A health profile associated with excessive alcohol use, including an urban setting, elevated plasma glucose and lower BMI predicts large artery stiffness independently of age and blood pressure in black South Africans over 10 years. This observation prompts urgent public health strategies to target alcohol overuse.

Monocyte Chemoattractant Protein-1 and Large Artery Structure and Function in Young Individuals: The African-PREDICT Study.

To better understand hypertension development, the authors determined whether monocyte chemoattractant protein-1 (MCP-1) is associated with arterial stiffness (pulse wave velocity [PWV]) and carotid intima-media wall thickness (cIMT) in a young apparently healthy black and white population (N=403, aged 20-30 years). Carotid-femoral PWV, central systolic blood pressure, and cIMT were measured, and MCP-1, reactive oxygen species, inflammatory markers (interleukin 6, tumor necrosis factor α), and endothelial activation (intercellular adhesion molecule, vascular cell adhesion molecule) were determined from blood samples. Although carotid-femoral PWV and cIMT were similar between blacks and whites, black men and women showed higher central systolic blood pressure, MCP-1, and reactive oxygen species than whites (all P<.05). In addition, black women had higher brachial blood pressure and interleukin 6 (all P<.001). A consistent positive association only in black women between cIMT and MCP-1 in multiple regression analyses was found (R²=0.151, ß=0.248; P=.021). In this model, cIMT was also independently associated with vascular cell adhesion molecule (ß=0.251; P=.022). The authors found elevated central systolic blood pressure and MCP-1 in young blacks, where cIMT was independently associated with MCP-1 in black women.

Large artery stiffness is associated with gamma-glutamyltransferase in young, healthy adults: The African-PREDICT study.

Increased arterial stiffness is linked to cardiovascular disease development, particularly in black populations. Since detrimental health behaviors in young adults may affect arterial stiffness, we determined whether arterial stiffness associates with specific health behaviors, and whether it is more pronounced in young healthy black compared to white adults. We included 373 participants (49% black, 42% men) aged 20-30 years. Mean arterial pressure was higher for blacks than whites (P < .001), but carotid-femoral pulse wave velocity was similar (6.37 vs. 6.36 m/s; P = .89) after adjustment for mean arterial pressure. The black group had higher gamma-glutamyltransferase (GGT) (P < .001), cotinine, reactive oxygen species, interleukin-6, and monocyte-chemoattractant protein-1 (all P ≤ .017). Pulse wave velocity related positively and independently to GGT in both groups before and after multiple adjustments (both ß = 0.15; P ≤ .049). Blacks had an unfavorable vascular profile and higher GGT, possibly indicating a higher vulnerability to cardiovascular disease development, including changes in arterial stiffness. However, this observation needs confirmation.

Soluble urokinase plasminogen activator receptor as a prognostic marker of all-cause and cardiovascular mortality in a black population.

BACKGROUND: Elevated inflammatory markers such as C-reactive protein (CRP) and interleukin-6 (IL-6) are well-known risk factors for cardiovascular mortality. The less familiar marker, soluble urokinase plasminogen activator receptor (suPAR), is known to predict cancer, infections and all-cause mortality. We determined whether suPAR, CRP and IL-6 are predictive of both all-cause and cardiovascular mortality in a black population, highly burdened by cardiovascular disease and HIV infection. METHODS: We included 1425 black South Africans, of which 208 died within five years after baseline data collection. EDTA plasma biomarker levels were determined, while all-cause and cardiovascular mortality were used as endpoints. RESULTS: At baseline suPAR, CRP and IL-6 were higher in non-survivors than in survivors (P<0.001). SuPAR (HR 1.27, 95% CI 1.09-1.48), IL-6 (HR 1.49, 95% CI 1.24-1.78) and CRP (HR 1.39, 95% CI 1.17-1.65) predicted all-cause mortality, while only suPAR (HR 1.40, 95% CI 1.04-1.87) and IL-6 (HR 1.61, 95% CI 1.10-2.35) predicted cardiovascular mortality. The prognostic value of suPAR was independent of IL-6 and CRP (P≤0.015). CONCLUSION: SuPAR predicted both all-cause and cardiovascular mortality, independent of traditional risk factors, HIV and other inflammatory markers, underlining the prognostic value of suPAR in a black population.

Cornell product relates to albuminuria in hypertensive black adults independently of blood pressure: the SABPA study.

Evidence of the relationship between left ventricular hypertrophy and urinary albumin excretion is contradictory and limited in black adults in whom hypertensive heart disease is common. We aimed to investigate the relationship between subclinical left ventricular hypertrophy and albuminuria in non-diabetic hypertensive blacks. Urinary albumin-to-creatinine ratio (UACR) was determined from 8-hour overnight urine collection. We recorded ambulatory blood pressure and 12-lead electrocardiogram during a typical working day. Cornell product (P = .002), UACR (P = .042), 24-hour systolic pressure (P < .0001), and 24-hour pulse pressure (P < .0001) were higher in the hypertensive group. Cornell product was associated with UACR in single (r = 0.25; P = .012), partial (P trend = .002), and multiple regression (ß = 0.326; P = .0005) analyses in the hypertensive group only, even below the threshold for microalbuminuria and independent of 24-hour systolic pressure. Urinary albumin excretion is associated with subclinical left ventricular hypertrophy in non-diabetic hypertensive blacks and may be a useful marker of early cardiovascular disease in blacks.

Psychological distress and the development of hypertension over 5 years in black South Africans.

Alarming increases in the incidence of hypertension in many low- and middle-income countries are related to alcohol overuse. It is unclear whether alcohol overuse is a symptom of psychological distress. The authors assessed psychological distress in Africans and its relationship with a 5-year change in blood pressure (BP), independent of alcohol intake. The authors followed 107 Africans with optimal BP (≤120/80 mm Hg) (aged 35-75 years) over 5 years. Alcohol intake (self-report and serum γ-glutamyl transferase) and nonspecific psychological distress (Kessler Screening Scale for Psychological Distress [K6]) were assessed. The K6 predicted hypertension development (P=.019), and its individual component "nervous" increased a participant's risk two-fold to become hypertensive (hazard ratio, 2.00 [1.23-3.26]). By entering K6 and γ-glutamyl transferase into multivariable-adjusted regression models for change in systolic BP, both were independently associated with change in systolic BP. Psychological distress and scoring high on being nervous predicted the development of hypertension over 5 years, independent of alcohol intake.

Associations of suPAR with lifestyle and cardiometabolic risk factors.

BACKGROUND: Soluble urokinase plasminogen activator receptor (suPAR), a novel indicator of low-grade inflammation, is associated with cardiovascular disease and mortality in the general population, while an unhealthy lifestyle influences inflammatory status. We aimed to explore the relationship of suPAR with lifestyle and cardiometabolic risk factors in a black South African population. DESIGN: This cross-sectional study includes 1068 men and women (56·4 ± 10·1 years) from the North West province who took part in the South African leg of the Prospective Urban and Rural Epidemiology (PURE) study in 2010. Captured data included a detailed lifestyle profile (tobacco use, alcohol consumption, physical activity, psychological and dietary intake status), biochemical analyses (suPAR, C-reactive protein (CRP), glucose and lipids), as well as cardiovascular and anthropometric measurements. RESULTS: In exploratory analyses, we observed positive relationships between suPAR and lifestyle factors, such as tobacco use (P-trend < 0·001), both alcohol consumption (P-trend = 0·001) and γ-glutamyl transferase (GGT) (P-trend < 0·001) and unemployment (P-trend = 0·002). suPAR and CRP correlated significantly (r = 0·23; P < 0·001). These relationships were confirmed in multiple regression analyses as suPAR independently associated with tobacco use (ß = 0·13; P < 0·001), GGT (ß = 0·24; P < 0·001) and unemployment (ß = 0·07; P = 0·039). suPAR did not associate with the cardiometabolic factors glucose, lipids, blood pressure or measures of adiposity. CONCLUSION: suPAR was independently associated with unhealthy lifestyle behaviours, but not with cardiometabolic risk factors suggesting that suPAR, as known predictor of cardiovascular disease and mortality, is augmented by modifiable cardiovascular risk factors. These findings emphasise the need for a healthy lifestyle to decrease the burden of cardiovascular disease in Africans.

Urinary albumin excretion from spot urine samples predict all-cause and stroke mortality in Africans.

BACKGROUND: Increased urinary albumin excretion reflects general vascular damage and predicts adverse cardiovascular and renal outcomes. Albuminuria can be determined from easily collected spot urine samples, especially in low-resource settings. However, no prognostic evidence exists for Africans. METHODS: We followed clinical outcomes in 1,061 randomly selected non diabetic, human immunodeficiency virus (HIV)-negative Africans (mean age: 51.5 years; 62.0% women). Baseline urinary albumin-to-creatinine ratio was assessed from spot urine samples. RESULTS: Over a median follow-up of 4.52 years, 132 deaths occurred, of which 47 were cardiovascular related. The urinary albumin-to-creatinine ratio averaged 6.1 µg/mg (5th to 95th percentile interval; 1.2-70.0). In multivariable-adjusted analyses, urinary albumin excretion predicted all-cause mortality (hazard ratio (HR), 1.26; 95% confidence interval (CI), 1.07-1.48; P = 0.006), and a tendency existed for cardiovascular mortality (HR, 1.26; 95% CI, 0.97-1.63; P = 0.087), which seemed to be driven by fatal stroke (HR, 1.72; 95% CI, 1.17-2.54; P = 0.006) rather than cardiac mortality (HR, 0.67; 95% CI, 0.41-1.07; P = 0.094). The predictive value remained in 528 hypertensives for both all-cause (HR, 1.38; 95% CI, 1.13-1.69; P = 0.001) and cardiovascular (HR, 1.45; 95% CI, 1.07-1.96; P = 0.017) mortality, again driven by stroke. Our findings also remained significant after we excluded participants with macroalbuminuria, those on antihypertensive treatment, as well as participants who died within 1 year after enrollment. CONCLUSION: In nondiabetic HIV-negative Africans, albuminuria predicts all-cause and stroke mortality.

End-organ damage in urbanized Africans with low plasma renin levels: the SABPA study.

The purpose of this study was to evaluate whether active renin concentration is associated with markers of end-organ damage in urbanized Africans. This study forms part of the Sympathetic Activity and Ambulatory Blood Pressure in Africans (SABPA) study. For this study, 81 men and 74 women were divided into low- and high-renin groups. Ambulatory blood pressure measurements were conducted. A resting 12-lead ECG was determined in order to determine the gender-specific Cornell voltage. Cardiovascular variables were continuously recorded with the Finometer. Carotid-dorsalis pedis pulse wave velocity was obtained with the Complior acquisition system. The carotid intima-media thickness (CIMT) was obtained with the SonoSite MicroMaxx. Blood samples were collected; serum and plasma were stored at -80 °C for analysis. Anthropometric measurements were taken using standard methods. A general health questionnaire was also completed. The urinary creatinine was determined with a calorimetric method and albumin with a turbidimetric method. The serum sodium and potassium were determined by making use of the Konelab TM 20i Sequential Multiple Analyzer Computer (SMAC). The concentration of active renin in the plasma was analyzed by making use of a high-sensitivity radio-immunometric assay. A negative association (r=-0.29, p<0.01) exists between renal function (ACR) and plasma renin in the low-renin group (<6.18 pg/mL), which was not observed in Africans with high-renin levels. It seems evident that low renin in black South Africans may result in sub-clinical renal damage and impaired vascular function in a group of urbanized black South Africans.

Cardiometabolic changes in treated versus never treated HIV-infected black South Africans: the PURE study.

BACKGROUND: The use of antiretroviral treatment is known to be accompanied by several negative health outcomes and may negatively affect a country such as South Africa, which is the most burdened by the human immunodeficiency virus (HIV) in the world. We aimed to determine whether receiving antiretroviral treatment changes the cardiometabolic profile of HIV-infected South Africans. METHODS: In this sub-study, embedded in the Prospective Urban and Rural Epidemiology (PURE) study, we compared the cardiometabolic profile in a cohort of 66 treated and 71 never treated HIV-infected participants from the North-West province, South Africa. By using standard techniques, these participants' cardiometabolic, biochemical and lifestyle variables were assessed in 2005 and 2010, respectively. RESULTS: The treated group showed a higher percentage change in pulse pressure (13.3%; p = 0.004), systolic blood pressure (4.5%; p = 0.029) and CD4 cell count (9.2%; p = 0.009) levels over five years. During follow-up (2010), lipid variables were worse in the treated group. Further, antiretroviral treatment was associated with the percentage change in pulse pressure (R(2) = 0.24; ß = 0.19; p = 0.020). CONCLUSIONS: We concluded that Africans receiving antiretroviral treatment had a greater increase in pulse pressure and systolic blood pressure, as well as an unfavourable lipid profile when compared to never treated participants. Whether, in the long term, antiretroviral treatment will lead to increased arterial stiffness and/or accelerated atherosclerosis among this HIV-infected African population remains to be seen.

Exploring the link between cardiovascular reactivity and end-organ damage in African and Caucasian men: the SABPA study.

BACKGROUND: Heart failure in the African population is reaching alarming levels. Increased afterload as a result of increased vasoconstriction during stress may lead to impaired ventricular function and stroke volume (SV) as well as vascular hypertrophy. In this study, we challenged the cardiovascular system in order to evaluate the possible contribution of indicators of α-adrenergic vasoconstriction (i.e., vascular resistance and SV reactivity) on left ventricular mass and carotid intima-media thickness (CIMT) in African and Caucasian men. METHODS: We evaluated 101 African and 101 Caucasian male schoolteachers. Ambulatory blood pressure measurements were taken. Total peripheral resistance, Windkessel compliance and SV, and resting and reactivity values were obtained using a Finometer device while the Stroop color word conflict test was being applied. The electrocardiogram was recorded to obtain the Cornell product as indication of left ventricular mass. The CIMT was measured and the cross-sectional wall area (CSWA) calculated. RESULTS: African men showed higher total vascular resistance resting values as well as higher positive reactivity values compared with Caucasian men. The SV decreased significantly during stress in African men while resting blood pressure and the Cornell product value increased. SV showed a consistent association with left ventricular mass (ß = -0.21; P = 0.04) and CSWA (ß = -0.24; P = 0.01) in single and multiple regression analyses. No such associations were evident in the Caucasian men. CONCLUSIONS: African men showed a suppressed SV, possibly as a result of an increased ventricular afterload leading to end-organ damage.