EFFECT OF TIBOLONE ON GLUCOSE AND LIPID-METABOLISM IN POSTMENOPAUSAL WOMEN

The effect of tibolone, a new therapeutic agent for menopause, on gluc ose and lipid metabolism was investigated in 11 healthy postmenopausal women. At baseline and after 3 months of tibolone administration (2.5 mg/day), glucose metabolism was evaluated in each subject using both an oral glucose tolerance test (75 g) and the minimal model method of a frequently sampled intravenous glucose tolerance test. Frequently sa mpled intravenous glucose tolerance test allows the calculation of ins ulin sensitivity and peripheral glucose use independent of insulin. Hi gh-density lipoprotein-cholesterol, total cholesterol, apoprotein-A, a nd apoprotein-B measured in fasting conditions were not modified by ti bolone, whereas triglycerides were reduced significantly (P < 0.01). F asting levels of glucose were reduced significantly (P < 0.025), where as those of insulin, C-peptide, and the C-peptide/insulin ratio were n ot modified. Glucose, insulin, C-peptide, and the C-peptide/insulin ra tio responses to oral or iv glucose were not modified. Insulin sensiti vity was inversely correlated to body mass index, and independent on t hat body mass index was significantly enhanced (P < 0.01). Glucose uti lization independent of insulin was not modified. The present data ind icate that tibolone does not negatively influence glucose metabolism a nd may indeed improve both the peripheral tissue sensitivity to insuli n and the lipid profile.