Aldosterone and aldosterone: renin ratio associations with insulin resistance and blood pressure in African Americans.

African Americans have more hypertension and hypertension-related morbidity than whites. Aldosterone, in presence of a high salt intake, contributes to hypertension and tissue injury. Inappropriately elevated aldosterone levels could explain this racial disparity. Our study was conducted to determine if aldosterone is associated with elevated blood pressure (BP) or insulin resistance, independent of obesity. A study was conducted on 483 young adult African Americans without cardiovascular or renal disease. Measurements included anthropometrics, BP, lipids, glucose, insulin, aldosterone, and renin. Urine sodium and potassium estimated sodium intake. The cohort was stratified by tertiles of aldosterone and tertiles of aldosterone/renin ratio (ARR). Average urine sodium/potassium ratio was >3.0 in all groups. Insulin resistance, estimated by homeostasis model, was lowest in the low aldosterone group (geometric mean 1.5 [0.6, 2.2]) compared with the high aldosterone group (1.7 [0.9, 2.7], P < .01). Adjusted analyses detected a significant association of aldosterone with insulin resistance, independent of other variables. BP was significantly higher in the high ARR group compared with low and mid ARR groups (P < .01). The significant association of ARR with BP with high dietary sodium suggests that insufficiently suppressed aldosterone may contribute to BP sensitivity to sodium in African Americans.
(© 2012 American Society of Hypertension. Published by Elsevier Inc. All rights reserved.)