Aldosterone and alterations of hypertension-related vascular function in African Americans

TA Kotchen, JM Kotchen, CE Grim… - American journal of …, 2009 - academic.oup.com
TA Kotchen, JM Kotchen, CE Grim, S Krishnaswami, S Kidambi
American journal of hypertension, 2009academic.oup.com
Abstract Background African Americans have a high prevalence of hypertension and
hypertension-related vascular disease. We previously reported that plasma aldosterone
concentrations are relatively high in hypertensive African Americans. This study evaluates
the hypothesis that hypertension and hypertension-related alterations of peripheral vascular
and renal vascular function are associated with aldosterone. Methods Twenty four-hour
blood pressures, cardiac output, renal blood flow (RBF), plasma renin activity (PRA), and …
Background
African Americans have a high prevalence of hypertension and hypertension-related vascular disease. We previously reported that plasma aldosterone concentrations are relatively high in hypertensive African Americans. This study evaluates the hypothesis that hypertension and hypertension-related alterations of peripheral vascular and renal vascular function are associated with aldosterone.
Methods
Twenty four-hour blood pressures, cardiac output, renal blood flow (RBF), plasma renin activity (PRA), and plasma aldosterone were measured in hypertensive and normotensive African Americans. Hemodynamic measurements were repeated in response to graded infusions of norepinephrine (NE).
Results
Ambulatory blood pressures in hypertensives and normotensives were 142 ± 1/86 ± 1 and 117 ± 1/70 ± 1 mm Hg, respectively. Cardiac index (CI) was lower (P < 0.01), peripheral vascular resistance was higher (P < 0.0001), arterial compliance was lower (P < 0.0001), RBF was lower (P = 0.04), and renal vascular resistance (RVR) was higher (P < 0.0001) in the hypertensives. Overall, blood pressures were positively correlated with peripheral vascular resistance (P < 0.0001) and inversely correlated with vascular compliance (P < 0.0001). In response to NE, hypertensives had greater increases of systolic blood pressure (P < 0.004) and pulse pressure (P < 0.005). PRA was lower (P < 0.0001) and plasma aldosterone was higher (P < 0.0001) in the hypertensives. Overall, blood pressures and pulse pressure were correlated with aldosterone (P ≤ 0.01). Vascular compliance, RVR, and the increment of RVR in response to NE were also correlated with aldosterone (P ≤ 0.03).
Conclusions
Aldosterone may contribute to hypertension and to hypertension-related alterations of peripheral vascular and renal vascular function in African Americans.
American Journal of Hypertension 2009; doi:10.1038/ajh.2008.327
Oxford University Press