Transdermal HRT and Doppler findings in normotensive and hypertensive postmenopausal patients

To evaluate the effects of transdermal hormone replacement therapy (HRT) on plasma viscosity, serum levels of thromboxane B2 (TXB2) and vascular impedance in the uterine, bladder wall, internal carotid and ophthalmic arteries in normotensive and hypertensive postmenopausal patients.

Thirty postmenopausal patients underwent continuous estradiol transdermal supplementation at a dose of 50 microg/day and 12-day courses of medroxyprogesterone acetate 10 mg/day every 2 months. The women were divided into two groups according to their blood pressure: normotensive women (Group 1, n=14) and hypertensive subjects (Group 2, n=16). Before starting HRT and after 6 months of therapy, the patients underwent: transvaginal ultrasonographic examination of the pelvic organs; Doppler examination of the blood flow velocities in the uterine, bladder wall, internal carotid and ophthalmic arteries; and analysis of plasma viscosity and plasma TXB2.

After 6 months of HRT plasma viscosity had decreased in both groups (mean reduction in Group 1, (14+/-1)%, P=0.005; mean reduction in Group 2, (10+/-1)%, P=0.005) as had the TXB2 levels (mean reduction in Group 1, (93+/-2)%, P<0.001; mean reduction in Group 2, (92+/-3)%, P<0.001). The mean percentage reduction in plasma viscosity was smaller in hypertensive women than in normotensive women (P<0.05). There was also a significant reduction in vascular impedance in the uterine artery (mean reduction in Group 1, (16+/-1)%, P=0.005; mean reduction in Group 2, (19+/-1)%, P=0.005), the bladder wall arteries (mean reduction in Group 1, (23+/-2)%, P=0.005; mean reduction in Group 2, (18+/-1)%, P=0.005), the internal carotid artery (mean reduction in Group 1, (25+/-1)%, P=0.005; mean reduction in Group 2, (26+/-1)%, P=0.005) and the ophthalmic artery (mean reduction in Group 1, (24+/-2)%, P=0.005; mean reduction in Group 2, (16+/-1)%, P=0.005). The percentage reduction in vascular impedance did not differ significantly between the two groups.

Our results show that transdermal HRT is effective in reducing plasma viscosity, TXB2 levels and vascular impedance in the peripheral and central vessels both in normotensive and hypertensive postmenopausal patients.