What is the clinical evidence from this study?

Study design: Cohort. Population: Hypertension (n=679). Intervention: Risk factors (age, BMI, alcohol consumption). Primary outcome: Incidence of hypertension (HR 1.22, 95% CI 1.11-1.35).

What does this research mean for the field?

In an urban South African cohort, the incidence of hypertension is 6.4 cases per 100 person-years, with older age and higher BMI significantly increasing the risk. Novelty: ClaimNovelty.CONFIRMATORY. Consensus alignment: ConsensusAlignment.NEUTRAL.

May 16, 2026Open Access

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

Key Result

In an urban South African cohort, the incidence of hypertension was 6.4 cases per 100 person-years, with older age (HR 1.15) and higher BMI (HR 1.22) significantly increasing the risk.

Key Points

The study aims 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.
Survival analysis estimated the incidence of hypertension with 679 eligible participants, 332 cases documented.
Cox proportional hazard models identified significant risk factors for hypertension, including age and BMI.
6.4 cases of hypertension per 100 person years were observed overall, with no significant difference between genders (p=0.0977).
Older age (HR: 1.15, 95% CI: 1.04–1.28) and higher BMI (HR: 1.22, 95% CI: 1.11–1.35) were linked to increased hypertension risk.
In men, higher BMI and alcohol consumption were risk factors (both p<0.001), while in women, higher BMI and older age were linked (p=0.002 and p=0.025 respectively).

Study Design

Type

Cohort (n=679)

Structured PICO

What is the incidence of hypertension and its associated risk factors in urban middle-aged South African men and women?

Population

679 middle-aged men and women living in urban South Africa (Middle-Aged Soweto Cohort), normotensive at baseline.

Outcome

Incidence of hypertension

In urban middle-aged South Africans, the incidence of hypertension is high (6.4 per 100 person-years), driven primarily by modifiable risk factors such as higher BMI and alcohol consumption.

Main Result

Effect estimate: HR 1.22 (95% CI 1.11-1.35)

Abstract

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.