Estrogen therapy effects on different vasoactive factors in recent postmenopausal healthy women

Background To evaluate whether the route of estrogen therapy (ET) may affect the levels of different vasoactive factors in healthy recent post-menopausal women. Methods We conducted a cross-over study in 20 healthy nonsmoking women in recent postmenopause (1.8 ± 0.1 years). Women received either 1-month oral-ET (O-ET, 2 mg oral micronized 17β estradiol daily) or transdermal-ET regimen (T-ET, 17β estradiol 1.5 mg gel daily) with a 1-month wash-out interval. Blood pressure, plasma levels of endothelin-1 (ET), 6-ketoPGF1a (6-ketoPG, prostacyclin metabolite), nitrite/nitrate (NOx), epinephrine (E) and norepinephrine (NE) and lipid profile were measured at baseline and after each treatment. Results Both regimens significantly reduced E (p < 0.01) and NE levels (p < 0.05). O-ET reduced low-density lipoproteins (LDL) levels (p < 0.05) and increased NOx values (p < 0.01). Neither regimen caused significant changes of ET or 6-ketoPG. Conclusions Our results, obtained in healthy women in recent menopause, indicate that the ratio between vasodilator (NOx and prostacyclin) and vasoconstrictor (ET) bioavailability shifted towards the previous ones after O-ET, while it remained unchanged after T-ET; moreover, catecholamines levels were reduced by both treatments already from 1 month of therapy. These changes might represent very early beneficial effects evoked by ET on the cardiovascular system.