Effects of hormone replacement therapy on glucose metabolism

To evaluate the relationship between hormone replacement therapy and glucose metabolism, and the possible role played by the administration route.

Prospective randomized study.

Eighty-four patients in either surgical or spontaneous menopause were randomly allocated into four groups: 15 patients in surgical menopause were treated with estrogens alone administered transdermically (17 beta-estradiol, 50 micrograms/day); 15 patients in surgical menopause were treated with oral conjugated equine estrogens (0.625 mg/day); 18 patients in spontaneous menopause were treated with transdermic estrogens plus oral progestagen (17 beta-estradiol 50 micrograms/day, acetate medroxyprogestogen 10 mg/day for 12 days per month); 16 patients in spontaneous menopause were treated with oral conjugated equine estrogens (0.625 mg/day) plus oral progestagen (10 mg/day for 12 days per month). Twenty patients not given any medication represented the control group. Before starting the trial and after six months of therapy, glucose and insulin levels before and after an oral glucose loading test were evaluated. Data analysis was performed by means of Student's "t"-test, ANOVA was used to compare mean levels between the groups. Significance was set at p < 0.005.

Dosages made after 6 months of therapy showed comparable basal glucose levels in all the studied group, while basal insuline levels in patients taking estrogen alone were lower (76.88 +/- 23.66 vs 95.91 +/- 24.57 in group 1, 80 +/- 13.34 vs 96.91 +/- 18.97 in group 2) than pretreatment values. No significant difference in glucose levels was found after glucose load in the four groups. CONCLUSION. Women treated with estrogen alone have a tendency to a lower insulin response, which could indicate a greater insulin sensitivity. This effect seems to be more evident in transdermic administration than with oral administration. The addition of progestagen seems to wane the increase in insulin sensitivity induced by estrogens.