A high burden of hypertension in the urban black population of Cape Town: the cardiovascular risk in Black South Africans (CRIBSA) study

Abstract

Objective To determine the prevalence, associations and management of hypertension in the 25-74-year-old urban black population of Cape Town and examine the change between 1990 and 2008/09 in 25-64-year-olds. METHODS: In 2008/09, a representative cross-sectional sample, stratified for age and sex, was randomly selected from the same townships sampled in 1990. Cardiovascular disease risk factors were determined by administered questionnaires, clinical measurements and fasting biochemical analyses. Logistic regression models evaluated the associations with hypertension. RESULTS: There were 1099 participants, 392 men and 707 women (response rate 86%) in 2008/09. Age-standardised hypertension prevalence was 38.9% (95% confidence interval (CI): 35.6-42.3) with similar rates in men and women. Among 25-64-year-olds, hypertension prevalence was significantly higher in 2008/09 (35.6%, 95% CI: 32.3-39.0) than in 1990 (21.6%, 95% CI: 18.6-24.9). In 2008/09, hypertension odds increased with older age, family history of hypertension, higher body mass index, problematic alcohol intake, physical inactivity and urbanisation. Among hypertensive participants, significantly more women than men were detected (69.5% vs. 32.7%), treated (55.7% vs. 21.9%) and controlled (32.4% vs. 10.4%) in 2008/09. There were minimal changes from 1990 except for improved control in 25-64-year-old women (1990∶14.1% vs. 2008/09∶31.5%). CONCLUSIONS: The high and rising hypertension burden in this population, its association with modifiable risk factors and the sub-optimal care provided highlight the urgent need to prioritise hypertension management. Innovative solutions with efficient and cost-effective healthcare delivery as well as population-based strategies are required.