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 17beta estradiol daily) or transdermal-ET regimen (T-ET, 17beta 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 (p0.01) and NE levels (p0.05). O-ET reduced low-density lipoproteins (LDL) levels (p0.05) and increased NOx values (p0.01). 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.