Renal Vasculature in Essential Hypertension: Racial Differences

Abstract

To explain the greater morbidity from essential hypertension in the black as compared with the white race, the intrarenal vasculature of 27 patients with hypertension (19 white and 8 black) was evaluated. All patients had mild-to-moderate hypertension (mean arterial pressure, 110-125 mm Hg), normal renal function and minimal target-organ demage. All patients had selective renal angiograms, which were evaluated for arterial nephrosclerosis. Renal blood flow was estimated by the clearance of paraaminohippurate. Patient age, blood pressure and plasma renin activity did not differ between the 2 races. Black hypertensives had significantly (P < 0.01) more severe nephrosclerosis than white patients. Renal blood flow was lower (P < 0.05) in black patients (390 .+-. 35 ml/min .cntdot. m2 body surface area) than white patients (473 .+-. 19 ml/min .cntdot. m2 body surface area). These findings may help to explain racial differences in morbidity and mortality from essential hypertension.