Comparison of two HRT regimens with bimonthly and monthly progestin administration in postmenopause

OBJECTIVES: Here we report the results of a study in which natural estrogens were given transdermally cyclically and continuously for 1 year, and a progestin of the latest generation, namely nomegestrol acetate, was given for 10 days every month and for 15 days every 2 months. METHODS: The patients were a group of 34 post-menopausal women (51-56 years), 18 of whom (group A) were treated with continuous transdermal estradiol (50 micrograms/day) and cyclic oral nomegestrol at a dose of 5 mg/day for 15 days every 2 months for 1 year. The other 16 women (group B) were treated with cyclic transdermal estradiol for 3 weeks with oral nomegestrol for 10 days (12-21)/month. Endometrial thickness was evaluated by transvaginal ultrasonography before and after treatment. At the end of treatment, an endometrial biopsy was performed. Serum total cholesterol, HDL, LDL and triglycerides were assessed at baseline and every 4 months. The characteristics of the cycle were deduced from the diary cards recorded by the women. RESULTS: No significant differences were found in the mean interval between the last dose of nomegestrol and the start of bleeding or in the duration of bleeding. The total number of days of bleeding per year was significantly lower in group A than group B (27 +/- 12 vs. 52 +/- 18; P < 0.01). Total serum cholesterol and LDL significantly decreased after 1 year of treatment in both groups, HDL-cholesterol and triglycerides were found increased at most of the time points studied. CONCLUSIONS: The present protocol involving continuous transdermal administration of estrogen combined with oral progestin every 2 months gave good control of the menstrual cycle, did not increase the risk of endometrial pathology and met with good patient compliance.