Vascular effects of estrogen and vitamin E therapies in postmenopausal women

Background-Estrogen and vitamin E therapies have been suggested to reduce c ardiovascular risk, but comparison of the vascular effects of these therapi es to determine mechanisms of potential benefit has not been performed in p ostmenopausal women. Methods and Results-In a double-blind, 3-period crossover study, We randoml y assigned 28 healthy postmenopausal women to conjugated equine estrogens ( CE) 0.625 mg/d, vitamin: E 800 IU/d, and their combination, with measuremen ts made before and after each 6-week treatment period. The ratio: of LDL to HDL cholesterol and lipoprotein(a) decreased on therapies including CE but increased on vitamin E alone (P < 0.001 and P = 0.002, respectively, by AN OVA). Brachial artery flow-mediated dilation improved on all therapies (all P < 0.001 versus pretreatment values) and to a similar degree (P = 0.267 b y ANOVA). No therapy improved the dilator response to nitroglycerin. CE low ered serum levels of cell adhesion molecules E-selectin, ICAM-1, and VCAM-1 (all P < 0.05 versus pretreatment values). Vitamin E had no: significant e ffect on levels of these markers of inflammation (P < 0.001 by ANOVA for E- selectin). CE alone or Combined with vitamin E but not vitamin E alone lowe red or showed a trend for lowering plasma levels of plasminogen activator i nhibitor type-1 (P = 0.069 by ANOVA). Conclusions-Estrogen and vitamin E therapies similarly improved arterial en dothelium-dependent vasodilator responsiveness consistent with increased ni tric oxide in healthy postmenopausal women, despite divergent effects on at herogenic lipoproteins. However, only estrogen reduced markers of vascular disease.