Background: The influence of hormone replacement therapy on plasma lipid levels is a well-known fact. The effect depends on the therapy mode and on the way of the drug administration. The aim of the study was to compare effects of two different types of HRT on plasma lipid levels.
Methods and results: During two-year prospective study plasma lipid levels were assayed in two groups of menopausal women. Group A (n = 37) was treated with transdermal 17-beta estradiol, 0.05 mg per day. Group B (n = 44) was treated with 2 mg of estradiol valerate and 0.150 mg of levonorgestrel administrated orally for 21 and 12 days, respectively, in the 28-day treatment cycles. Changes of the total cholesterol level as well as LDL-cholesterol level in both groups were not significantly different in spite of the adjusting to basal levels of total cholesterol or basal levels of the body mass index (BMI). Levels of triglycerides decreased significantly (p = 0.014) in both groups with no difference between the groups. The increase of HDL-cholesterol levels was significantly higher in group A (p = 0.034). This difference remained significant (p = 0.044) after adjusting to basal levels of HDL-cholesterol and BMI. While the BMI in group A slightly decreased (0.3%), BMI in group B increased by 0.66%. The difference was significant (p < 0.001) even after adjusting to the basal level of BMI values.
Conclusions: Presented data indicated that the impact of HRT on plasma lipid levels was only moderate, regardless the route of administration. We consider the influence of HRT on lipids to be mild, individual and only slightly beneficial from the point of the lipid spectrum.