Micronized progesterone and the lipid profile: A pilot study looking at the effects of mieronized progesterone on the lipid profile in HRT

Objective: To compare lipid and endometrial effects of continuous micronized progesterone and medroxyprogesterone acetate hormone replacement therapy (HRT) on the lipid profiles of postmenopausal women with an intact uterus. Design: This prospective, randomized, non-blinded trial was performed in a university based practice. Patients: Postmenopausal women aged 40 to 75 years with an intact uterus and no contraindication to HRT. Interventions: Patients were randomized to one of two groups: group 1 received conjugated equine estrogen (CEE), 0.625mg, plus continuous micronized progesterone, 100mg/day; group 2 received CEE, 0.625mg, plus continuous medroxyprogesterone acetate (MPA) 2.5mg/day. Statistics: Data were analyzed using the SPSS (statistical package for the social sciences; SPSS Inc., Chicago, IL) (10.0) comprehensive system for analyzing data. Main Outcome Measures: Serum lipid profiles were performed at baseline, 6 weeks, and 12 weeks; endometrial thickness was measured at baseline and 12 weeks; endometrial biopsy was performed at 12 weeks; bleeding patterns were recorded. Results: Of 12 patients recruited, 10 successfully completed the study. The difference in total cholesterol at the end of the 12-week period was not significantly different between the two treatment groups (P=0.76). Additionally, no significant change was found in triglycéride levels in either group at the end of the study (P=0.41). No significant changes in HDL levels were observed in either treatment group. Decreased LDL levels were found in both treatment groups, but this change was not significant (P=0.18). Conclusions: There appears to be no difference in the beneficial effect of HRT on the lipid profile in the two treatment groups.