Effect of different hormone replacement therapy regimens on circadian blood pressure profile and active renin in postmenopausal women.

Hormone replacement therapy (HRT) was considered as main prevention of cardiovascular disease (CVD) in postmenopausal women. Mechanisms of vasoprotective effect of this treatment are complex. However, recent data give rise to some uncertainties about HRT benefits and risks. Little is known about the effects of oral and transdermal HRT regimens on the renin-angiotensin-aldosterone system (RAS) and blood pressure (BP). This 3-month study comprised 28 menopausal women (age range 45-55 years) divided into two groups: Group 1: 12 normotensive women with natural occurrence of menopause receiving oral treatment with Climen (Schering) containing estradiol valerate and cyproterone acetate; Group 2: 16 normotensive women with surgically induced menopause receiving transdermal application of Climara (Schering) containing 17beta-estradiol. There were no significant differences in office BP before and after treatment with Climara or Climen. However, ambulatory monitoring showed a significant fall in systolic BP (day-time, night-time and total 24-h) when estradiol alone was used. A similar trend towards lower values of systolic BP that was significant only for the night-time BP was observed after treatment with Climen. There were no significant changes in diastolic BP after both treatment regimens. Heart rate (day-time and 24-h) was significantly lower after transdermal estradiol treatment. There was no significant change in active renin after both treatment regimens. The present study showed that both treatment regimens resulted in lower ambulatory BP in normotensive postmenopausal women with more notable reduction in night-time BP. Increase in nocturnal dipping may account in part for the beneficial cardiovascular effects of HRT including decreased end-organ damage.