Effect of Half-dose and Standard-dose Conjugated Equine Estrogens Combined with Natural Progesterone or Dydrogesterone on Components of Metabolic Syndrome in Healthy Postmenopausal Women: A Randomized Controlled Trial

BACKGROUND: Menopausal hormone therapy (MHT) has been proven to have beneficial effects on several components of metabolic syndrome. However, the effects vary according to different regimens, dosages, and duration of MHT. The aim of the study was to evaluate the effect of standard-dose 0.625 mg conjugated equine estrogen (CEE) and half-dose 0.3 mg CEE daily with different progestogens in a continuous sequential regimen on postmenopausal metabolic parameters in generally healthy postmenopausal women. METHODS: A prospective, open-label, randomized controlled clinical trial was conducted between February 2014 and December 2015. Totally 123 Chinese postmenopausal women with climacteric symptoms were included in this study and were randomly assigned to three groups: Group A received CEE 0.3 mg/micronized progesterone (MP) 100 mg daily; Group B received CEE 0.625 mg/MP 100 mg daily; and Group C received CEE 0.625 mg/dydrogesterone 10 mg daily. Drugs were given in a continuous sequential pattern. The duration of treatment was 12 months. Clinical, anthropometrical, and metabolic variables were measured. Data were analyzed according to intention-to-treat analysis, using Student's t-test and analysis of variance. RESULTS: A total of 107 participants completed the 12-month follow-up and were included in the data analysis. At 12 months of treatment, high-density lipoprotein cholesterol and apolipoprotein A significantly increased, and low-density lipoprotein cholesterol, fasting glucose, and glycosylated hemoglobin significantly decreased in Groups B and C, compared with baseline (all P < 0.05). Among the three groups, only Group C showed significantly increased triglycerides compared with baseline (1.61 ± 0.80 mmol/L vs. 1.21 ± 0.52 mmol/L, P = 0.026). Each group showed a neutral effect on total cholesterol, lipoprotein A, apolipoprotein B, and fasting insulin levels. No cardiovascular and venous thromboembolic events occurred in the three groups. CONCLUSIONS: Among Chinese postmenopausal women, half-dose CEE was not sufficient to induce a favorable lipid and carbohydrate profile compared with standard-dose CEE. Adding natural MP may counterbalance the TG-increasing effect of CEE. TRIAL REGISTRATION: ClinicalTrials.gov, NCT01698164; https://clinicaltrials.gov/ct2/show/NCT01698164?term=NCT01698164&rank=1.