Hypertension Incidence and Its Risk Factors in a Longitudinal Cohort of Middle‐Aged Men and Women Living in Urban South Africa

Abstract

Hypertension is a growing burden in rapidly urbanizing settings, yet longitudinal studies on its incidence and risk factors in urban populations living in resource-constrained settings in Africa are limited. This study aimed to determine the incidence of hypertension and associated risk factors in urban middle-aged South African men and women. Longitudinal data from the Middle-Aged Soweto Cohort were collected at four time points between 2011 and 2025 and included: blood pressure, sociodemographic, anthropometry, chronic disease status, and medication use. Participants were included if they had complete data for at least two time points and were normotensive at baseline. The incidence of hypertension was estimated using survival analysis and the significant risk factors were determined using Cox proportional hazard models. Of the 679 eligible participants, there were 332 incident hypertension cases, and an overall incidence of 6.4 cases per 100 person years, with no significant difference between men and women (p = 0.0977). In multivariable analyses in the whole cohort, older age (hazard ratio [HR]: 1.15, 95% CI: 1.04-1.28) and higher BMI (HR: 1.22, 95% CI: 1.11-1.35) were associated with a higher risk of incident hypertension. In sex stratified analysis, higher BMI (p < 0.001) and alcohol consumption (p < 0.001) were associated with incident hypertension in men, while higher BMI (p = 0.002) and older age (p = 0.025) were associated with incident hypertension in women. The study identifies modifiable risk factors associated with incident hypertension in urban South African men and women. Sex-specific interventions targeting ageing adults may be beneficial in resource constrained urban settings. Clinical Trial Registration: This study is not a clinical trial and does not require registration.