A comparative study of two levonorgestrel-containing hormone replacement therapy regimens on efficacy and tolerability variables

Abstract

Objective: To compare the effect of two sequential hormone replacement regimens differing in the dose of levonorgestrel on climacteric symptoms, bleeding pattern and lipid metabolism in postmenopausal women. Study design: In a multicentre, randomized, double-blind, active-treatment-controlled study, 210 postmenopausal women were assessed at the end of treatment cycles 3 and 6. The high-levonorgestrel group was treated with 2 mg estradiol valerate (days 1–21) sequentially combined with 0.25 mg levonorgestrel (days 12–21). The low-levonorgestrel group received the same estrogen regimen (2 mg estradiol valerate, days 1–21), but levonorgestrel was administered sequentially in a dose of 0.15 mg during the last 12 days of the cycle (days 10–21). Statistical analysis by Student's t-test for dependent variables (measured values versus baseline) and independent variables (differences between groups), and the composite t-test method for comparison of both regimens with respect to efficacy, was performed. Results: Both groups were statistically comparable. The trial was completed by 137 subjects. Protocol violations occurred in 38 cases. Thirty-five subjects dropped out during the study, 21 of them because of adverse events. Both treatments were equally effective in the treatment of climacteric complaints. There were no clinically significant changes in body weight, blood pressure, haematological tests, and parameters of clinical chemistry. There was a tendency towards a reduction in bleeding intensity in both groups in the second half of the treatment period. The treatment for six cycles with both regimens significantly ( P<0.05) decreased plasma concentrations of triglycerides (significant in the low-levonorgestrel group only), high-density lipoprotein cholesterol, high-density lipoprotein-3-cholesterol, lipoprotein(a) and apolipoprotein A1. In parallel, the serum concentration of total cholesterol increased significantly in both treatment groups, whereas low-density lipoprotein cholesterol increased significantly in the high-levonorgestrel group only. The changes in high-density lipoprotein-2-cholesterol, and apolipoprotein B did not reach statistical significance. Conclusions: It can be concluded that both sequential combined oral hormone replacement therapy (HRT) regimens were equivalent with respect to efficacy and tolerability in the treatment of women with climacteric complaints. The preparation with the lower dose of progestin showed a tendency towards a less unfavourable influence on the lipid profile.