Risk factors and coronary heart disease in Durban blacks--the missing links.

Coronary heart disease (CHD) is still relatively uncommon in the black population of South Africa. We embarked on a study to determine the prevalence of risk factors leading to CHD in the black population of Durban. The study sample was selected from patients attending a dental clinic at a hospital. A total of 458 patients (age range 16-69 years) was studied. The prevalence of CHD was 2.4%. The percentage prevalences of selected risk factors were: hypertension (blood pressure > or = 140 mmHg systolic and/or > or = 90 mmHg diastolic) 28% (31.9% for males, 25.4% for females); protective levels of high-density lipoprotein/total cholesterol > or = 20%, 81.3%; diabetes mellitus 4.9% for males, 2.9% for females; smoking > or = 10 cigarettes per day 28.1% for males, 3.4% for females; obesity 3.7% for males 22.6% for females. We found the Minnesota Coding System for electrocardiographic changes of CHD and the Rose questionnaire to be unreliable for eliciting CHD in blacks. Hypercholesterolaemia is less common, and this may explain the low incidence of CHD in blacks. Epidemics of CHD as seen in Indian, coloured and white South Africans can still be prevented in the black population, but preventive measures must be instituted rapidly.