Vascular Endothelial Dysfunction with Age is Related to Increased Sympathetic Nervous System Activity in Women, but Not Men

Abstract

We tested the hypothesis that vascular endothelial dysfunction (impaired endothelium‐dependent dilation, EDD) with aging is related to increases in sympathetic nervous system (SNS) activity. In 314 healthy adults aged 18 to 79 years, age was inversely related to EDD (brachial artery flow‐mediated dilation, FMD) (r=−0.30, P<0.001) and positively related to plasma norepinephrine concentrations (PNE) (r=0.49, P<0.001). Brachial FMD was inversely related to PNE in the overall group (r=−0.25, P<0.001), as well as in men only (n=187) and women only (n=127). After controlling for age (multiple regression analysis), brachial FMD remained related to PNE in women (r=−0.24, P<0.01), but not men (r=−0.03, P=0.68). PNE independently predicted FMD in women after further adjustment for conventional risk factors for cardiovascular disease. Indeed, PNE was the strongest independent predictor of FMD in women (r=−0.25, P<0.01). Endothelium‐independent dilation (EID, sublingual nitroglycerin), a measure of vascular smooth muscle sensitivity to nitric oxide, was positively related to PNE in men (P<0.05), but not women (P=0.49). EID did not account for the lack of an independent relation between FMD and PNE in men. These findings suggest that increased SNS activity may play an important role in modulating EDD with aging in women, but not men.Supported by NIH AG013038, AG015897, AG031617, AG00279, RR025780, AHA 0715735Z