EFFECTS OF ORAL AND TRANSDERMAL HORMONE REPLACEMENT THERAPY ON LIPOPROTEIN(A) AND LIPIDS - A RANDOMIZED CONTROLLED TRIAL

Objective: Our purpose was to compare the effect of oral and transderm al hormone replacement therapy on lipoprotein(a) and other plasma lipi ds in healthy postmenopausal women. Design: A total of 120 postmenopau sal women were enrolled in a prospective randomized controlled study, and allocated either to transdermal 17 beta-estradiol (50 mu g/day) or to oral conjugated estrogen (0.625 mg/day), Forty-one age-matched wom en wee used as the reference group, Plasma lipids and lipoproteins wer e determined every 3 months and differences were sought by statistical analysis. Results: Plasma Lipoprotein(a) dropped after 3 months of tr eatment either with transdermal estradiol (p < 0.01) or oral estrogen (p < 0.01). Lipoprotein(a) was reduced by 12% and 22%, respectively. N o further decreases were seen later on. Plasma total and low-density l ipoprotein (LDL) cholesterol concentrations were decreased significant ly with both treatments after 3 months of therapy. No difference was s een in the lowering effect on lipoprotein(a), LDL and total cholestero l concentrations between regimens, Plasma high-density lipoprotein (HD L) cholesterol and triglyceride concentrations increased throughout th e study only in patients treated with oral estrogen, Conclusions: Thes e data demonstrate that hormone replacement therapy reduces the concen tration of lipoprotein(a) when given both orally and transdermally. Th e lowering effect is achieved quickly because the maximal effect is ob served after 3 months of therapy. (Menopause 1998;5:157-162, (C) 1998, The North American Menopause Society.).