Race and hypertension. What is clinically relevant?

Hypertension, once considered rare in Africa, occurs frequently in most Black populations outside of the continent as well as within more urban areas of Africa. The frequency of hypertension in Black citizens of the US is among the highest in the world. Pathophysiological mechanisms suggest the frequency of salt-sensitive blood pressure is more common in Black patients. More Black than White patients initially present with volume expansion. However, in Black patients there appears to be no significant relationship between plasma renin activity, plasma volume and blood pressure. The syndrome of insulin resistance has also been reported in African Americans. Future studies should address this issue, both because it relates to identifying individuals at risk for development of high blood pressure and because it has implications for initial selection of antihypertensive therapy. Hypertensive kidney disease is prevalent in Black people. Lowering the blood pressure with diuretic-based therapies has not been shown to delay or prevent the loss of kidney function in patients with this condition, suggesting that this treatment approach may not be optimal. Lifestyle modifications remain the initial therapeutic regimen. Because diuretics and beta-blockers have been shown to reduce cardiovascular morbidity and mortality in controlled clinical trials, they are preferred therapies. The Hypertension Detection and Follow-up Program showed significant reductions in morbidity and mortality in Black patients using primarily diuretic-based therapies. However, controversy persists regarding use of diuretics since some investigators believe that greater reductions in overall cardiovascular risk may be achieved in Black patients using other agents. These agents may eventually be able to exert a beneficial cardiovascular effect in addition to and independent of their blood pressure-lowering effect. Long term data documenting reduced morbidity and mortality rates with other agents are needed for all populations, particularly in Black hypertensive patients.