Browsing by Author "Mashele, Nyiko"

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    Cardiovascular risk and endothelial function in people living with HIV/AIDS: design of the multi-site, longitudinal EndoAfrica study in the Western Cape Province of South Africa
    (BioMed Central, 2017-01-07) Strijdom, Hans; De Boever, Patrick; Walzl, Gerhard; Essop, M. Faadiel; Nawrot, Tim S.; Webster, Ingrid; Westcott, Corli; Mashele, Nyiko; Everson, Frans; Malherbe, Stephanus T.; Stanley, Kim; Kessler, Harald H.; Stelzl, Evelyn; Goswami, Nandu
    Background: There is growing evidence of an interaction between HIV-infection, anti-retroviral therapy (ART) and cardiovascular diseases (CVD). Epidemiological studies in Europe and North America have been observing a shift towards an increased incidence of coronary heart disease and acute myocardial infarctions in HIV-infected populations compared to the general population even after adjusting for traditional cardiovascular risk factors. Despite South Africa (and sub-Saharan Africa, SSA) being regarded as the epicentre of the global HIV epidemic, very little is known about the prevalence of cardiovascular risk factors and precursors of vascular disease in HIV-infected populations in this region. The knowledge gap is further widened by the paucity of data from prospective studies. We present the rationale, objectives and key methodological features of the EndoAfrica study, which aims to determine whether HIVinfection and ART are associated with altered cardiovascular risk and changes in vascular endothelial structure and function in adults living in the Western Cape Province of South Africa. Methods: In this longitudinal study, comprehensive cardiovascular assessments of HIV-negative and HIV-positive (with and without ART) study participants are performed by clinical and biochemical screening for traditional cardiovascular risk factors and biomarkers of CVD. Vascular and endothelial function is determined by brachial artery flow-mediated dilatation (FMD), carotid-intima-thickness (IMT) measurements and quantitative retinal blood vessel analyses, complemented by vascular endothelial biomarker assays. Finally, we aim to statistically determine whether HIVinfection and/or ART are associated with increased cardiovascular risk and vascular endothelial dysfunction, and determine whether there is progression/regression in these endpoints 18 months after the baseline assessments. Discussion: The EndoAfrica study provides a unique opportunity to recruit a cohort of HIV-infected patients and HIVnegative controls who will be comprehensively and longitudinally assessed for cardiovascular risk and disease profile with vascular endothelial function as a potentially important intermediate cardiovascular phenotype. To our knowledge, it is the first time that such a systematic study has been established in the context of SSA and South Africa.
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    Personal NO2 and volatile organic compounds exposure levels are associated with markers of cardiovascular risk in women in the Cape Town region of South Africa
    (MDPI, 2019) Everson, Frans; De Boever, Patrick; Nawrot, Tim S.; Goswami, Nandu; Mthethwa, Mashudu; Webster, Ingrid; Martens, Dries S.; Mashele, Nyiko; Charania, Sana; Kamau, Festus; Strijdom, Hans
    ENGLISH ABSTRACT: Exposure to ambient NO2 and benzene, toluene ethyl-benzene and m+p- and o-xylenes (BTEX) is associated with adverse cardiovascular effects, but limited information is available on the effects of personal exposure to these compounds in South African populations. This 6-month follow-up study aims to determine 7-day personal ambient NO2 and BTEX exposure levels via compact passive diffusion samplers in female participants from Cape Town, and investigate whether exposure levels are associated with cardiovascular risk markers. Overall, the measured air pollutant exposure levels were lower compared to international standards. NO2 was positively associated with systolic and diastolic blood pressure (SBP and DBP), and inversely associated with the central retinal venular equivalent (CRVE) and mean baseline brachial artery diameter. o-xylene was associated with DBP and benzene was strongly associated with carotid intima media thickness (cIMT). Our findings showed that personal air pollution exposure, even at relatively low levels, was associated with several markers of cardiovascular risk in women residing in the Cape Town region.