Vascular effects of estrogen and vitamin E therapies in postmenopausal women.
BACKGROUND
Estrogen and vitamin E therapies have been suggested to reduce cardiovascular risk, but comparison of the vascular effects of these therapies to determine mechanisms of potential benefit has not been performed in postmenopausal women.


RESULTS
In a double-blind, 3-period crossover study, we randomly assigned 28 healthy postmenopausal women to conjugated equine estrogens (CE) 0. 625 mg/d, vitamin E 800 IU/d, and their combination, with measurements 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 ANOVA). Brachial artery flow-mediated dilation improved on all therapies (all P<0.001 versus pretreatment values) and to a similar degree (P=0.267 by ANOVA). No therapy improved the dilator response to nitroglycerin. CE lowered 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 effect 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 lowered or showed a trend for lowering plasma levels of plasminogen activator inhibitor type-1 (P=0.069 by ANOVA).


CONCLUSIONS
Estrogen and vitamin E therapies similarly improved arterial endothelium-dependent vasodilator responsiveness consistent with increased nitric oxide in healthy postmenopausal women, despite divergent effects on atherogenic lipoproteins. However, only estrogen reduced markers of vascular disease.
Koh
K K
KK
Cardiology Branch and Office of Biostatistics Research, National Heart, Lung, and Blood Institute, and Clinical Pathology Department, Clinical Center, National Institutes of Health, Bethesda, MD, USA.
Blum
A
A
Hathaway
L
L
Mincemoyer
R
R
Csako
G
G
Waclawiw
M A
MA
Panza
J A
JA
Cannon
R O
RO
D000704:Analysis of Variance; D002318:Cardiovascular Diseases / Q000517:prevention & control*; D018592:Cross-Over Studies; D004311:Double-Blind Method; D004958:Estradiol / Q000627:therapeutic use*; D004970:Estrone / Q000627:therapeutic use*; D005260:Female; D005342:Fibrinolysis / Q000187:drug effects; D006706:Homeostasis; D006801:Humans; D007249:Inflammation / Q000188:drug therapy; D050356:Lipid Metabolism; D008875:Middle Aged; D009569:Nitric Oxide / Q000502:physiology; D017698:Postmenopause; D014665:Vasodilator Agents / Q000627:therapeutic use*; D014810:Vitamin E / Q000627:therapeutic use*
D014665:Vasodilator Agents; D014810:Vitamin E; D004970:Estrone; D009569:Nitric Oxide; D004958:Estradiol