Asymmetric Dimethylarginine, Blood Pressure, and Renal Perfusion in Elderly Subjects

Abstract

Background— Reduced availability of nitric oxide (NO) is thought to contribute to the age-associated increase of renovascular tone and blood pressure. We assessed blood concentrations of the endogenous NO synthase inhibitor asymmetric dimethylarginine (ADMA) as well as renal hemodynamics, comparing young (n=24, 13 men, 25±1 years) and elderly (n=24, 13 men, 69±2 years) healthy subjects and elderly subjects with essential hypertension (n=24, 13 men, 70±2 years). Methods and Results— Plasma ADMA concentration and renovascular resistance (RVR) were significantly higher ( P P 2 ) than in young healthy subjects (1.30±0.11, 77±3, 654±18). Both ADMA levels and RVR were higher and ERPF lower in the hypertensive elderly subjects (3.53±0.23, 163±11, 427±19; P P r ² =0.80) and RVR ( P r ² =0.86). In addition, ADMA ( P P r ² =0.67) to the level of blood pressure. Conclusions— These results are compatible with the notion that accumulation of the endogenous NO synthase inhibitor ADMA in senescent individuals is involved in the decrease of renal perfusion and increase of blood pressure.