Rayner B.,E13 Groote Schuur Hospital |
Ramesar R.,University of Cape Town |
Steyn K.,Biostatistics Unit |
Steyn K.,University of Cape Town |
And 3 more authors.
Journal of Human Hypertension | Year: 2012
Dopamine via G-protein-coupled receptor kinase 4 (GRK-4) regulates sodium (Na) balance in the proximal tubule of the kidney. Single-nucleotide polymorphisms of GRK-4 have been linked to impaired natriuresis and salt-sensitive hypertension. The purpose of this report was to determine the effect of GRK-4 gene polymorphisms on the blood pressure (BP) responses to dietary intervention. Black subjects aged 50-75 years with mild-to-moderate hypertension were randomised to an 8-week dietary intervention (n40) or standard diet (n40). BP was measured at baseline and at 8 weeks using 24-h ambulatory BP. All subjects underwent DNA analysis for the R65L and A142V polymorphisms. Data were analysed using generalised linear models. For the whole group, between-diet differences in mean 24-h ambulatory systolic BP was 4.53 mm Hg (95% confidence interval 9.05 to 0.01, P0.05). In the intervention arm, the combined CC and CT group of the A142V showed a significant reduction in both systolic and diastolic ambulatory BP (10 mm Hg, P0.023 and 6.5 mm Hg, P0.01, respectively), whereas the TT group demonstrated no reduction. Similarly, the combined GG and GT groups of the R65L showed a significant reduction in ambulatory BP (10.6 mm Hg for systolic, P0.004 and 5.8 mm Hg for diastolic, P0.006). There was no response in the TT group. GRK-4 polymorphisms predict BP response to dietary modification in Black subjects with mild-to-moderate hypertension. These data may provide at least one among a range of clinical tools to target selected hypertensives to dietary intervention. © 2012 Macmillan Publishers Limited All rights reserved.
Nel D.,University of Cape Town |
Rayner B.,E13 Groote Schuur Hospital
Vascular Disease Management | Year: 2011
The burden of HIV infection, particularly in Sub-Saharan Africa, is well documented. The consequences are far-reaching and go beyond those of opportunistic infection and malignancy and into the realm of chronic diseases of lifestyle, with an increasing risk of cardiovascular disease in HIV-positive individuals. In this report we explore the case of a young black female with HIV who was referred with severe early-onset hypertension and was found, on further investigation, to have unilateral renal artery stenosis and bilateral renal artery aneurysms. We will also look at the clinicopathological entity of large- and medium-vessel vasculopathy associated with HIV.