Effects of transdermal estrogen replacement therapy on plasma levels of nitric oxide and plasma lipids in postmenopausal women.

Objective: Our purpose was to assess the effects of transdermal estrogen replacement therapy (TERT) on plasma levels of nitric oxide (NO) and plasma lipids in postmenopausal women.

Materials And Methods: The study designed as a randomized, double-blind, placebo-controlled trial, involved 43 postmenopausal healthy women who had previously undergone hysterectomy. Women received either transdermal 100 microg 17beta-estradiol (Climara forte TTS) or placebo once a week for 3 months. Plasma levels of NO metabolites, estradiol (E2), total cholesterol (TC), triglicerides (TG), low-density lipoproteins (LDL), high-density lipoproteins (HDL), HDL2 and HDL3 were measured in blood samples of all women which were collected before, after 24 h and after 3 months of therapy.

Results: We found significantly increased NO levels 24 h after therapy in TERT group. Moreover significantly higher NO levels were determined at 3rd month of therapy. Serum HDL and HDL2 levels of ERT group were significantly increased at 3rd month of therapy. Alteration of serum levels of HDL3, LDL and TC were not significantly different in groups. TG levels were significantly decreased in TERT group.

Discussion: NO-related mechanism may help to explain the cardio-protective effect of TERT in the postmenopausal period. TERT seems to have favorable effects on plasma lipids in surgical menopausal women.