Objectives: There is a scarcity of longitudinal cohort studies in sub-Saharan Africa to understand the epidemiology of cardiovascular disease as a basis for intervention. We estimated incident hypertension and associated sociodemographic, health and behavioural risk factors in a population aged 40 years and older over a 5-year period.
Design: We assessed the association between incident hypertension and sociodemographic, health and behavioural factors using Poisson regression. We adjusted for non-response in 2015 using inverse probability sampling weights from a logistic regression including sex and age at baseline.
Setting: Rural South Africa.
Participants: We used a population-based cohort of normotensive adults in 2010 who were aged 40 years and older at retest in 2015.
Results: Of 676 individuals completing baseline and 5-year follow-up, there were 193 incident cases of hypertension. The overall hypertension incidence rate was 8.374/100 person-years. In multivariable analyses, those who became hypertensive were more likely to be older, have a high waist circumference (incidence rate ratio (IRR): 1.557, 95% CI: 1.074 to 2.259) and be employed (IRR: 1.579, 95% CI: 1.071 to 2.329) at baseline. Being HIV positive and not on antiretroviral therapy at baseline was associated with lower risk of incident hypertension.
Conclusions: Over a 5-year period, 29% of respondents developed hypertension. Given the high burden of hypertension in South Africa, continued longitudinal follow-up is needed to understand the complex interplay of non-communicable and infectious diseases and their underlying and modifiable risk factors to inform public health prevention strategies and programmes.
Keywords: South Africa; cohort; hypertension; incidence; rural population.
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