Continuous combined replacement therapy in postmenopausal women: effect on plasma lipoproteins, bone mass and the endometrium.

Objective: The purpose of this study was to examine the effects of Hormone Replacement Therapy (HRT) on plasma lipoprotein levels, bone mass and the endometrium.

Methods: Thirty healthy women were enrolled in the study for climacteric symptoms and received a combination of 17beta-estradiol and norethisterone acetate continuously for 2 years. An untreated group, consisting of 25 healthy postmenopausal women presenting the same symptoms and not willing to receive HRT, were also studied and served as controls. Plasma lipoprotein levels, bone mineral density as well as thickness of the endometrium measured by ultrasound and biopsy of the endometrium were evaluated at baseline and after 1 and 2 years. There were no differences between the two groups regarding clinical and demographic baseline data.

Results: After 2 years of HRT, total cholesterol and LDL-cholesterol levels were significantly reduced (p<0.05). Changes in serum triglyceride and HDL-cholesterol levels were not statistically significant. Levels of lipoprotein (a) showed a statistically significant decrease at 1(st) and 2(nd) year (p<0.05) in both groups while levels of ApoA1 and ApoB were significantly lower only in the HRT group compared to the baseline values. After 2 years of HRT, biomarkers of bone metabolism showed a significant decline, while endometrium was atrophic in 93.3% of the cases.

Conclusions: Hormone replacement therapy (17beta-estradiol combined with norethisterone acetate) was associated with favorable changes in the lipid status and bone metabolism. Endometrium was atrophic in most of the treated subjects.