Long-term effects of low-dose 17beta-estradiol plus dydrogesterone on 24-h ambulatory blood pressure in healthy postmenopausal women: a 1-year, randomized, prospective study.

The aim of the present 12-month, randomized, prospective controlled study was to investigate the long-term effects of low-dose oral hormone replacement therapy (HRT) on 24-h blood pressure in healthy, normotensive postmenopausal women. A total of 80 postmenopausal women received either 1 mg micronized 17beta-estradiol daily, sequentially combined with 10 mg dydrogesterone for 14 days of each 28-day cycle (n = 44), or no treatment (n = 36). Ambulatory blood pressure was recorded for a 24-h period at baseline and after 12 months. After 12 months, mean 24-h systolic ambulatory blood pressure fell significantly in the HRT group (-5.4 mmHg; p < 0.01). The difference between the values in the HRT and control groups after 12 months was significant (p < 0.01). Mean 24-h heart rate also fell significantly with HRT (-4.9 beats/min; p < 0.05), and the value was significantly lower than in the control group (p < 0.05). Mean daytime systolic blood pressure fell significantly in the HRT group (-6.6 mmHg; p < 0.001), and the value was significantly lower than in the control group (p < 0.05). There were no significant changes in blood pressure in the control group. In conclusion, sequential low-dose oral HRT with 17beta-estradiol/dydrogesterone caused a significant decrease in 24-h and daytime systolic ambulatory blood pressure in normotensive postmenopausal women.