Since estrogens are known to have some antiatherosclerotic properties and influence on endothelial function, including nitric oxide (NO) synthesis, the purpose of this study was to determine NOx levels after menopause and to find whether the administration of estrogen therapy restores plasma NOx levels back to normal. The study group consisted of 26 women with surgically induced menopause, mean age 50.9±2.9 years, and the controls were 40 healthy pre-menopausal women, mean age 48.3±2.3 years. Post-menopausal women were treated for four months with transdermal estradiol. Blood samples were collected for estimation of E2, FSH, NOx and lipid profile before and after therapy. Serum NOx concentration in the study group was significantly lower than in controls (P<0.01) and it increased after treatment (P<0.01) reaching the values observed in the controls. The statistical analysis showed significant correlation between NOx concentration and E2 concentration in menopausal group before (r=0.25, P<0.05) and after (r=0.46, P<0.001) treatment. TC, LDL-C, TG, and azpo-B levels were higher in postmenopausal group comparing to controls, and after estrogen therapy they decreased to the values observed in the control group. HDL-C and its subfractions were lower in postmenopausal women than in controls and they improved after hormonal therapy. The same tendency was observed concerning apo-A1. There were no correlations between NOx and lipids or apolipoproteins. We conclude that low E2 levels in postmenopausal women were associated with lower NOx levels. Estrogen therapy improves NO synthesis and relaxation of the vessels.
03 - 07 May 2008
European Society of Endocrinology