Trends in hypertension prevalence among adults aged ≥40 years in Agincourt, South Africa (2014 - 2022)
DOI:
https://doi.org/10.7196/SAMJ.2025.v115i10.3195Keywords:
Hypertension, Prevalence, Risk factorsAbstract
Background. Hypertension is a leading cause of cardiovascular disease. There are limited longitudinal data on temporal trends in hypertension prevalence in rural South Africa (SA).
Objectives. To analyse trends in hypertension prevalence and investigate its associated factors among adults aged ≥40 years in SA.
Methods. A retrospective observational secondary quantitative analysis of a sample from the Health and Aging in Africa: A Longitudinal Study of an INDEPTH Community in South Africa (HAALSI) was conducted. Data for the HAALSI study were collected over three waves during 2014, 2018 and 2021 from the existing Agincourt Health and Socio-demographic Surveillance System (AHDSS) framework, with a total sample of 3 707 participants in the present study. Descriptive statistics were used to summarise sociodemographic data. A bivariate analysis and multivariable generalised estimating equation (GEE) model was applied to determine factors associated with hypertension prevalence, with significance set at p<0.05.
Results. The overall prevalence of hypertension declined from 58% (95% confidence interval (CI) 56.42 - 59.58) in wave 1 to 42% (95% CI 40.42 - 43.58) in wave 2, and further decreased to 30% (95% CI 28.58 - 31.42) in wave 3. Transitions between hypertensive and normotensive status were observed, with 1 018 individuals transitioning to normotensive from wave 1 to wave 2, and 1 167 individuals from wave 2 to wave 3. The GEE analysis identified significant predictors of hypertension. High body mass index (BMI) was associated with increased odds in wave 2 (adjusted odds ratio (aOR) 1.11; 95% CI 1.02 - 1.21; p=0.014). Frequent alcohol consumption increased the odds of hypertension in wave 3 (aOR 1.19; 95% CI 1.04 - 1.37; p=0.009). No formal education was associated with higher hypertension prevalence (aOR 1.07; 95% CI:1.00 - 1.14; p=0.0026). Younger age (40 - 49 years) was protective, with decreased odds of hypertension in wave 2 (aOR 0.64; 95% CI 0.48 - 0.84; p=0.014), as was employment (aOR 0.82; 95% CI 0.69 - 0.96; p=0.020) and fruit consumption in wave 3 (aOR 0.95; 95% CI 0.91 - 0.99; p=0.037).
Conclusion. The study found that the prevalence of hypertension in Agincourt decreased from 58 to 30% between waves 1 and 3. High BMI, high alcohol use frequency and no formal education were key predators of hypertension. The study highlights the need for targeted public health interventions, including regular hypertension screening, lifestyle modification and better management of associated factors. These efforts will be crucial in reducing hypertension-related morbidity and mortality in rural SA.
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