Effects of hormone therapy on the endometrium in postmenopausal women: a one year randomized trial of low dose oral estradiol in association with a levonorgestrel-releasing intrauterine system or drospirenone

Abstract

OBJECTIVES: to compare the endometrial effects and uterine bleeding patterns associated with treatment using (1) levonorgestrel-releasing intrauterine system (LNG-IUS) and estradiol (1 mg/day, p.o.) or (2) orally administered drospirenone (2 mg/day) andestradiol (1 mg/day). METHODS: thirty-four patients (aged 52.53 ± 4.44 in the LNG-IUS group and 53.15 ± 4.018 in the DRSP group) were randomized. The severity of menopausal symptoms was evaluated using the Kupperman index every three months. Transvaginal ultrasound, hysteroscopy and histological evaluation were repeated after 12 months. During this period, patients kept menstrual calendars. All categorical variables were described as percentages. Variables were tested for normal distribution and Student's t test was applied for independent samples and ANOVA forrepeated measures when appropriate. Data were considered to be significant when p<0.05. RESULTS: slight vaginal bleeding was reported in the first month of treatment by 53.3% of patients from the LNG-IUS/estradiol group compared with 7.7% of patients from the drospirenone/estradiol group. There were no differences in endometrial thickness between the two groups throughout the study period. End-of-study histological findings showed atrophic endometrium in 53.3% of patients in the LNG-IUS/estradiol group compared with 76.9% of patients in the drospirenone/estradiol group. CONCLUSIONS: our results suggest good endometrial protection with both HT regimens.