Most studies show that blacks have higher blood pressures than whites, and that hypertension-related mortality is significantly greater. Significant pathophysiological differences are present, on the average, between blacks and whites. Blacks tend to have higher blood volume, lower plasma renin activity, and lower kallikrein excretion.
While there may be black-white differences of genetic origin affecting the prevalence of hypertension, at least part of blood pressure difference between black and white is probably of environmental origin.
If socio-economic differences are taken into account, there is no difference between black and white in compliance. Antihypertensive therapy markedly reduces mortality in blacks as well as whites.