Adequate reduction degree of pituitary gonadotropin levels in the clinical management of short-term hormone replacement therapy of women with menopausal symptoms.

The purpose of this study was to clarify the adequate reduction rate of pituitary gonadotropins in ideal clinical management of shortterm hormone replacement therapy (ST-HRT) in postmenopausal women with undefined symptoms. Subjects included a total 324 postmenopausal patients between 48 and 61 years of age who visited the Department of Obstetrics and Gynecology at Osaka Medical College Hospital for the consult of menopausal symptoms. Administration of conjugated equine estrogen (0.625 mg/day) and progestin (2.5 mg/day) in the patients for 8 weeks. HRT was markedly effective in 28.7% of cases, effective in 40.7%, fairly effective in 21.9%, and ineffective in 8.6% of cases. The plasma concentration of FSH and LH after administration decreased significantly (P < 0.001) by 58.1% and 59.9% for markedly effective cases, and by 31.0% and 36.1% for effective cases. On the other hand, decreases in FSH and LH concentration were 14.1% and 1.3% for the fairly effective and 8.5% and -5.1% for ineffective cases, demonstrating a significantly greater decrease in plasma FSH and LH levels in the markedly effective and effective cases than those in ineffective cases (P < 0.001). There were significant differences in the reduction rates of plasma FSH and LH levels between in cases showing (59.9% and 53.2%) and not showing the side effects (24.8% and 25.9%), respectively (P < 0.0001). In conclusion, efficacy of ST-HRT was significantly correlated to the degree of decrease in plasma FSH and LH levels in patients with undefined symptoms. In addition, efficacy appeared to be correlated to the incidence of side effects. The degree of reduction of FSH (24.8-31.0%) and LH (25.9-36.1%) from the baseline may possibly be used as the suitable therapeutic window for hormone levels during HRT. The present results suggest that plasma gonadotropin levels could be a useful indicator for the management of patients undergoing short-term HRT for women with menopausal symptoms.