The influence of medroxyprogesterone acetate on the effects of transdermal oestradiol replacement therapy on plasma lipids

Abstract

A prospective study was carried out on 82 healthy menopausal women to determine whether or not there is an attenuation of the cardioprotective effects of continuous transdermal oestradiol on plasma lipid and lipoprotein concentrations with the use of sequential oral medroxyprogesterone acetate. Group 1 comprised 51 hysterectomised women on transdermal oestradiol (50 mug daily). Group 2 included 31 women with an intact uterus on oestradiol (50 mug daily) and medroxyprogesterone acetate (10 mg daily for the first 12 days of each calendar month). Women maintained on 50 mug throughout 6 months (group 1: n = 29; group 2: n = 20) were reviewed for changes in plasma lipids and lipoproteins at the end of 6 months (group 1), and in the combined phase of treatment in the seventh month (group 2). In group 1, there was a reduction in the concentrations of total cholesterol (- 6.3%, P = 0.004) and LDL-cholesterol (- 6.1%, P = 0.05). In group 2, there were no significant changes in total cholesterol (- 4.8%, P = 0.23) and LDL-cholesterol (- 5.8%, P = 0.30). HDL-cholesterol levels did not change significantly with unopposed oestradiol (+ 3.8%, P = 0.30), or with additional medroxyprogesterone acetate (0%, P = 0.94). Serum triglyceride concentrations decreased significantly in both the groups (- 14.3%, P = 0.001, and- 12.8%, P = 0.006, respectively). There were no statistically significant differences in the changes in the respective plasma lipid parameters on comparing the two treatment groups ( P 0.4 for all comparisons, Student's t -tests). The plasma lipid and lipoprotein profile encountered at the end of 6 months, was also generally maintained in 24 women (group 1: n = 13; group 2: n = 11) who completed 1 year of the study. Transdermal oestradiol may be of particular clinical benefit for women with hypertriglyceridaemia. Medroxyprogesterone acetate did not exert a significantly adverse influence on plasma lipid and lipoprotein concentrations.