Hypertension in white South African miners.

A study was undertaken to determine the prevalence of hypertension among white South African miners, examine risk factors for hypertension, identify adverse outcomes of hypertension, and evaluate the extent and efficacy of treatment for hypertension. A total of 11686 miners was assessed. The prevalence of hypertension was comparable to that in three occupational groups in the USA and probably comparable to a group of urban males in Durban, although differences in methods did not allow precise comparison with this population. Obesity was an important risk factor. Electrocardiographic abnormalities, especially premature ventricular contractions, right and left bundle-branch block and myocardial infarction, were associated with elevated first recorded blood pressure. Of the 468 miners in the cross-sectional study who stated that they were taking antihypertensive medication, only 30% had diastolic blood pressures lower than 90 mmHg.