Effect of transdermal estradiol therapy on bone mineral density of amenorrheic athletes.

BACKGROUND: The effects of transdermal estradiol treatment (HT) in amenorrheic athletes (AA) with low body weight (BW) and low bone mineral density (BMD) are unknown. PURPOSE: To investigate whether HT increases BMD in AA and to compare the results with levels in AA who have recovered spontaneous menstruation (SM). METHODS: Female athletes (n=151) were recruited at the Japan Institute of Sports Sciences and the University of Tokyo. All participants were divided into four groups: an AA group (untreated group) (n=36), an HT group (n=55), a SM group (n=21), and an eumenorrheic athletes (EA) group (n=39). Height, body weight, blood tests and dual-energy X-ray absorptiometry were measured at baseline and after 12 months. The HT group was treated daily for 12 months with transdermal estrogen therapy. In addition, participants received oral progestin for 7 days once every 3 months. RESULTS: After 12 months, BMD in the AA group was significantly lower than at baseline; however, BMD in the other three groups was significantly higher than at baseline. The ratio of the change in BMD values before and after 12 months was -1.6+/-3.2% for the AA group, 5.3+/-8.7% for the HT group, 11.1+/-8.9% for the SM group, and 2.3+/-5.7% for the EA group. The rate of change in BMD values in the SM group was greater than that in the HT group. CONCLUSION: HT increased BMD in AA and the increase in those with SM was greater than that in those treated with HT.