Elevated urinary albumin excretion is associated with impaired arterial dilatory capacity in clinically healthy subjects.

BACKGROUND Elevated urinary albumin excretion (UAE) predicts atherosclerotic cardiovascular disease. It is hypothesized that elevated UAE is associated with a generalized vascular dysfunction. This study tested this hypothesis for conduit arteries. METHODS AND RESULTS Clinically healthy subjects were selected: 19 with UAE >90th percentile in the background population (6.6 microgram/min<UAE<150 microgram/min) and 41 with normoalbuminuria (UAE <6.6 microgram/min). External ultrasound was used to measure the dilatory response of the brachial artery to postischemic increased blood flow (endothelium-dependent, flow-associated dilation) and to nitroglycerin (endothelium-independent, nitroglycerin-induced dilation). Plasma concentrations of the endothelial markers nitrate/nitrite, thrombomodulin, and von Willebrand factor antigen were also measured. Both flow-associated and nitroglycerin-induced dilations were significantly impaired in subjects with elevated UAE as compared with normoalbuminuric control subjects: 102.0+/-1.0% (mean+/-SEM) versus 104.3+/-0.6% (P<0.05) and 120.1+/-1.5% versus 123.8+/-1.0% (P<0.05). No differences in the plasma concentrations of endothelial markers were found. Conclusions-Slightly elevated UAE is associated with impaired conduit arterial dilatory capacity in clinically healthy subjects, and this impairment may be explained by a reduced dilatory response to nitric oxide of both endogenous and exogenous origin. Impaired arterial dilatory capacity may contribute to the increased cardiovascular risk in subjects with elevated UAE.