Changes in bone mineral content following hormone treatment for endometriosis

The effects of danazol and buserelin on the bone mineral content (BMC) of 19 Japanese women with endometriosis were studied. Subjects received 24-week courses of oral danazol (400 mg/day) or intranasal buserelin (900 micrograms/day). Trabecular BMC of the 3rd lumbar vertebra (L3) was monitored by computerized tomography scans pretreatment, at the end of treatment and 6 months post-treatment. In the buserelin group there was a significant decrease in BMC (10-25.4%, P < 0.01) which was not fully reversed 6 months after therapy, and increased parameters of bone resorption. In the danazol group, there was a slight gain in BMC despite a decrease in serum estrogen. Danazol and buserelin have similar success in the treatment of endometriosis, but the decrease in BMC at L3 suggests that cumulative bone loss may follow repeated buserelin therapy.