Hypertension incidence among middle-aged and older adults: findings from a 5-year prospective study in rural South Africa, 2010-2015

BMJ Open. 2021 Dec 7;11(12):e049621. doi: 10.1136/bmjopen-2021-049621.


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.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • HIV Infections* / epidemiology
  • Humans
  • Hypertension* / epidemiology
  • Incidence
  • Longitudinal Studies
  • Middle Aged
  • Prospective Studies
  • Risk Factors
  • Rural Population
  • South Africa / epidemiology