We sought to determine whether menopausal status or postmenopausal
hypercholesterolemia affects forearm resistance artery endothelial function. We studied the forearm resistance artery endothelial function in 75 Japanese women: 25 premenopausal volunteers, 25 postmenopausal women with normal serum
low-density lipoprotein (
LDL) cholesterol concentrations, and 25 hypercholesterolemic postmenopausal women. Excluded from the study were patients with
hypertriglyceridemia,
hypertension, or diabetes, cigarette smokers. The forearm blood flow (FBF) during
reactive hyperemia and after sublingual
nitroglycerin (NTG) administration was measured by strain-gauge plethysmography. The serum concentrations of
lipoprotein (a) [Lp(a)] were significantly higher in the hypercholesterolemic postmenopausal group than in the other two groups (P<0.01). These
lipid parameters were similar between the premenopausal and postmenopausal women with normal
cholesterol. The FBF responses to
reactive hyperemia were significantly lower in the postmenopausal hypercholesterolemic women than in the other two groups (P<0.01). The
reactive hyperemia also was impaired in the postmenopausal group with normal
cholesterol as compared with the premenopausal group (P<0.01). Increases in FBF after NTG were similar between the three groups. By stepwise multivariate analysis, menopausal status and serum
LDL cholesterol was the significant predictor of forearm endothelial function. These findings suggest that
reactive hyperemia is impaired in forearm resistance arteries after menopause, especially in postmenopausal women with
hypercholesterolemia.