Continuous versus cyclical transdermal oestrogen replacement therapy in postmenopausal women: effects on lipoprotein(a) and nitric oxide levels

The purpose of our study was to compare the effects of cyclical versus cont inuous transdermal oestrogen replacement therapy on lipoprotein (a) (Lp(a)) and nitric oxide levels. The patients were randomly assigned into two grou ps. The first group received transdermal 17-beta oestradiol 50 mug/day for 21 days and the second group the same treatment on a continuous basis. Medr oxyprogesterone acetate (10 mg/day orally) was added between the 14th and 2 5th days to each group. Lipoprotein (a) and nitric oxide levels were measur ed before the study and after six months. These values were compared using the Wilcoxon rank test within the groups and the unpaired t-test between th e groups. Lipoprotein (a) levels decreased significantly in each group at t he sixth month (p < 0.05). When compared between the groups, the decrease o f lipoprotein (a) levels in the second group was more prominent at the sixt h month (p < 0.05). Nitric oxide levels increased in each group after six m onths (p < 0.05). No difference in nitric oxide levels was observed between the groups before and after the therapy (p > 0,05). Continuous transdermal estradiol had a better effect on lipoprotein (a) levels than cyclical ther apy The seven day pause in the 21-day administration did not affect nitric oxide levels negatively after six months.