INTRAUTERINE ADMINISTRATION OF LEVONORGESTREL IN 2 LOW-DOSES IN HRT -A RANDOMIZED CLINICAL-TRIAL DURING ONE-YEAR - EFFECTS ON LIPID AND LIPOPROTEIN METABOLISM

Objective: To investigate the effects on lipid and lipoprotein metabol ism of two doses (5- or 10 mu g/24 h) of levonorgestrel released from an intrauterine device (IUD) in combination with orally administered e stradiol (2 mg estradiol valerate) in perimenopausal women. Design: A I-year prospective randomized single blind clinical trial. Setting: De partment of Obstetrics and Gynaecology, Ostra Hospital, Goteborg, Swed en. Subjects: Fifty-one perimenopausal women with climacteric symptoms . Outcome measures: Cholesterol in serum and in lipoprotein fractions; high-density lipoprotein (HDL), low-density lipoprotein (LDL), Trigly cerides in serum and in very low-density lipoprotein, Results: In both treatment groups significant elevations in HDL-cholesterol of similar magnitude were observed after 1 month and these changes were maintain ed during the 12 month observation period. In both treatment groups an initial significant decrease of LDL-cholesterol was observed and the decrement was maintained after 12 months. Serum levels of cholesterol decreased significantly in both groups after I month and were maintain ed after 12 months in the levonorgestrel-IUD (LNG-IUD) 5 mu g group, H owever, the initial reduction of serum cholesterol in the LNG-IUD 10 p g group did not differ from baseline after 12 months. Serum triglyceri de levels fluctuated during the observation period. No significant cha nges occurred. Conclusion: Continuous combined HRT with intrauterine a dministration of levonorgestrel, 5- or 10 mu g/24 h, in perimenopausal women was observed to increase HDL-cholesterol and to decrease LDL-ch olesterol compared with pretreatment values. The low doses of levonorg estrel did not reverse the beneficial effects on lipid metabolism usua lly seen after estradiol administration.