Renal and systemic hemodynamics in black versus white hypertensives.

In this study we examined whether race per se effected markers of early target organ damage in a population of white (n = 40) and black (n = 20) hypertensive patients in which as well casual as ambulatory blood pressure (BP) measurements were performed. We assessed renal and systemic hemodynamics by measuring mean arterial pressure invasively, renal blood flow (RBF) by 131-I-para-aminohippuric acid clearance and cardiac output (CO) by the indocyanine dye dilution technique. Left ventricular (LV) structure was determined by 2-dimensional guided M-mode echocardiography. No significant difference in 24-h ambulatory BP values (average diastolic BP 90 ± 7 vs 89 ± 10 mmHg, average systolic BP 139 ± 9 vs 136 ± 16 mmHg [black vs white]), RBF, renal vascular resistance (RVR) and LV mass were found between the two racial populations. Despite an initial tendency for a higher total peripheral resistance (TPR) and a lower CO in the black hypertensives when compared to the white hypertensives, no significant difference could be obtained with regard to TPR and CO after performing a covariance analysis taking into account 24-h systolic and diastolic BP and sex. Results: We conclude that even with the use of 24-hour ambulatory BP as the most valid tool to determine the hemodynamic load in hypertension no differences in early target organ damage can be found between black and white patients with mild essential hypertension.