Modifiable risk factors including smoking, waist circumference, and alcohol intake significantly predicted the development of hypertension in 24% of Black South Africans with optimal baseline BP.
Cohort (n=1,994)
Yes
Do modifiable behavioral risk factors predict the 5-year development of hypertension in Black South Africans with optimal baseline blood pressure?
Modifiable lifestyle factors, including alcohol intake (indicated by γ-glutamyltransferase) and central obesity, are significant drivers of the rapid conversion from optimal blood pressure to hypertension in Black South Africans.
BACKGROUND: Longitudinal cohort studies in sub-Saharan Africa are urgently needed to understand cardiovascular disease development. We, therefore, explored health behaviours and conventional risk factors of African individuals with optimal blood pressure (BP) (≤ 120/80 mm Hg), and their 5-year prediction for the development of hypertension. METHODS: The Prospective Urban Rural Epidemiology study in the North West Province, South Africa, started in 2005 and included African volunteers (n = 1994; aged > 30 years) from a sample of 6000 randomly selected households in rural and urban areas. RESULTS: At baseline, 48% of the participants were hypertensive (≥ 140/90 mmHg). Those with optimal BP (n = 478) were followed at a success rate of 70% for 5 years (213 normotensive, 68 hypertensive, 57 deceased). Africans that became hypertensive smoked more than the normotensive individuals (68.2% vs 49.8%), and they also had a greater waist circumference ratio of geometric means of 0.94 cm (95% CI: 0.86-0.99) and greater amount of γ-glutamyltransferase 0.74 U/l (95% CI: 0.62-0.88) at baseline. The 5-year change in BP was independently explained by baseline γ-glutamyltransferase R(2) = 0.23, β = 0.13 U/l (95% CI: 0.01-0.19). Alcohol intake also predicted central systolic BP and carotid cross-sectional wall area (CSWA) at follow-up. Waist circumference was another predictor of BP changes β = 0.18 cm (95% CI: 0.05-0.24) and CSWA. HIV infection was inversely associated with increased BP. CONCLUSIONS: During the 5 years, 24% of Africans with optimal BP developed hypertension. The surge in hypertension in Africa is largely explained by modifiable risk factors. Public health strategies should focus aggressively on lifestyle to prevent a catastrophic burden on the national health system.
Schutte et al. (Mon,) conducted a cohort in optimal blood pressure (n=1,994). Modifiable risk factors (smoking, waist circumference, alcohol intake) was evaluated on development of hypertension. Modifiable risk factors including smoking, waist circumference, and alcohol intake significantly predicted the development of hypertension in 24% of Black South Africans with optimal baseline BP.