PP.03.10: PREVALENCE OF MASKED HYPERTENSION IN A BI-ETHNIC AFRICAN POPULATION, AND ITS ASSOCIATION WITH HAEMODYNAMIC AND BIOCHEMICAL MARKERS OF CARDIOVASCULAR RISK. (June 2015) - Thompson, J.E.S.
Abstract : Objective: The current study aimed to determine the prevalence of masked hypertension (i.e. normotensive office blood pressure [BP] and hypertensive ambulatory BP) in a young, bi-ethnic South African population who were recruited on to the AFRICAN-PREDICT study based on normotensive office BP readings. Design and method: The first baseline phase of the AFRICAN-PREDICT study recruited 352 participants from within the North-West province, South Africa (54% white, 40% male). Study eligibility criteria were; 20 to 30 years of age, normal office BP, not on BP medication, black or white South African, HIV-negative, and apparently healthy. Measurements included 24hour ambulatory BP monitoring (ABPM) (Cardio-Xplore), aortic pulse wave velocity (aPWV) and augmentation index (AIx) (SphygmoCor-XCEL), peripheral BP (DINAMAP) and the Godin exercise questionnaire. Further to this, fasted venous blood samples were collected for biochemical analyses. Results: By office and ABPM BP, n = 290 (82%) were normotensive (NT), and n = 62 (18%) had masked hypertension (MHT). The MHT group had significantly higher clinic and ABPM (24hour, day and night) BPs, aPWV, I-CAM, MCP-1, and insulin levels, compared to NT. There were no differences in cotinine or exercise levels. Figure. No caption available. Conclusions: These data, obtained from a cohort recruited on the basis of their normotensive office BP, highlight the high prevalence of masked hypertension among young South Africans. Masked hypertension further demonstrated increased CV risk via unfavourably increased haemodynamic and biochemical markers. This group would have been missed without measurement of ambulatory BP and therefore unaware of the lifestyle or pharmaceutical changes required. As well as the important public health message, these data highlight the importance of using sensitive markers of BP in research if recruiting based on BP status.