Hypertension in a rural South African white population and the effect of antihypertensive treatment on the risk of coronary heart disease.

The association between hypertension and coronary risk factors and the effect of antihypertensive treatment on coronary risk were investigated in rural South African whites aged 15-64 years. Almost 25% of men (range 1.9-46.6%) and almost 27% of women (2.1-56.2%) were hypertensive or being treated for hypertension; the prevalence increased with age, particularly among women. Only 25.8% of male and 43.4% of female hypertensives were being treated, and of these only 38% had controlled blood pressure. Hypertension was associated with a high serum total cholesterol level, a low high-density lipoprotein cholesterol level, a high body mass index, a high uric acid level, a high prevalence of coronary heart disease and, in men, high alcohol consumption. Treated hypertensives had a greater risk of coronary heart disease than untreated hypertensives. Men on beta-blockers had significantly lower high-density lipoprotein cholesterol levels than men not on treatment, while uric acid levels in both men and women on diuretics were higher than those of untreated hypertensives. Hypertension in the study population appears to be inadequately treated, and antihypertensive medication may impact adversely on metabolic risk factors. The goal of antihypertensive therapy should be a net reduction of coronary heart disease risk.