Effects of transdermal and oral estrogen replacement on lipids and glucose metabolism in postmenopausal women with type 2 diabetes mellitus

Abstract

Objective: To compare the effects of oral and transdermal estrogen replacement on lipid and glucose metabolism in postmenopausal women with diabetes mellitus type 2. Design and methods: In an open, randomized, cross-over study, 21 diabetic postmenopausal women were treated with transdermal 17β-estradiol 50 μg or oral conjugated equine estrogens (CEE) 0.625 mg daily, both associated with 300 mg/day of oral micronized progesterone for 12 days monthly during 6 months each. After a 12-h overnight fasting period, blood glucose, insulin, glycosylated hemoglobin (HbA1c) and lipoprotein profile were evaluated, at baseline and after 6 months of each schedule of hormone replacement therapy (HRT). Insulin sensitivity was determined by homeostasis model assessment (HOMA). Results: HRT had no negative influence on glucose metabolism. After 6 months of CEE treatment, there was a significant increase in high-density lipoprotein (HDL) cholesterol, but also in triglycerides, of 9.0% and 20.7%, respectively (p = 0.04). The levels of total cholesterol and low-density lipoprotein (LDL) cholesterol were unaffected. Transdermal estradiol did not affect the lipid profile. Conclusions: Hormone replacement therapy with either oral or transdermal estrogen plus micronized progesterone has no harmful influence on glucose metabolism in type 2 diabetic postmenopausal women; whether the increase in HDL cholesterol, but also in triglyceride levels, makes oral CEE the better choice remains an open question.