Blood pressure, antihypertensive therapy and risk for renal injury in African-Americans.

Abstract

African-Americans are more likely than Caucasians to develop hypertension-related end-stage renal disease. Elevations in blood pressure levels clearly potentiate pre-existing renal disease and also contribute to kidney injury independently of other primary renal diseases in this cohort. Until recently, data relevant to a full examination of the issue of blood pressure levels and end-stage renal disease in African-Americans have largely been from post-hoc analyses of clinical trials or from small, prospective, short-term studies. The most recent United States Renal Data Systems data show hypertension as the primary cause of end-stage renal disease in African-Americans until 1997, diabetes now being the most prevalent etiology. Data from post-hoc analyses of the Modification of Diet in Renal Disease study demonstrated that African-Americans with a mean arterial pressure above 98 mmHg had a higher risk of end-stage renal disease than Caucasians. The African-American Study of Kidney Disease tested the hypothesis that a blood pressure well below the usual recommended level will further reduce renal disease progression in African-Americans. The study concluded that a blood pressure lower than that needed to reduce cardiovascular events, as defined by the Sixth Joint National Committee Report on the Detection, Evaluation and Treatment of High Blood Pressure, i.e. 135-140/80-85 mmHg, will not further slow renal disease progression in African-Americans with hypertensive nephrosclerosis. Moreover, a regimen of blood pressure lowering anchored on angiotensin-converting enzyme inhibitors, antihypertensive agents that are touted as ineffective in African-Americans, was more effective than one based on either beta-blockers or dihydropyridine calcium-channel blockers in slowing the progression of renal injury. Systolic blood pressure reduction in the range 130-139 mmHg is appropriate to reduce risk of nephropathy progression and cardiovascular risk in African-Americans with hypertensive nephrosclerosis. Moreover, a regimen that is initiated with an angiotensin-converting enzyme inhibitor should be the antihypertensive treatment of choice in African-Americans with kidney disease.