Clinical features affecting the results of estrogen replacement therapy on bone density in Japanese postmenopausal...

Although estrogen replacement therapy (ERT) has been established as an effective treatment for postmenopausal bone loss, the clinical features which predict the effects of ERT have not been well investigated in Japanese postmenopausal women. We analyzed the role of physical factors influencing the effect of ERT on vertebral bone mineral density (BMD) in 94 Japanese postmenopausal women treated for 2 years or longer. The increase in BMD with ERT is 17.6 +/- 27.6 mg/cm(2)/year (mean +/- SD) during the first 2 years. Rates of BMD change were negatively correlated with the estimated initial BMD, and positively correlated with age and years since menopause, while no correlation was noted with the body mass index by a simple correlation analysis. The relationships between BMD change and estimated initial BMD or age also held in a multiple regression analysis. The estimated initial BMD and age together accounted for 34.4% of the BMD change during ERT. Furthermore, there were very few (2.4%) nonresponders with a negative linear regression slope of BMD in the osteoporosis and osteopenia group, although 32.7% of the normal initial BMD group were nonresponders. These results suggest that the initial BMD and age are potent predictive factors of the ERT effect on BMD change in Japanese postmenopausal women.