Bone mineral density in women with endometriosis before and during ovarian suppression with gonadotropin-releasing hormone agonists or danazol

Lumbar bone mineral density (BMD) was evaluated by dual photon absorptiometry (DPA) in 38 women with laparoscopically diagnosed and staged endometriosis. DPA was performed before and at the completion of 26 weeks of treatment with either gonadotropin releasing hormone agonist (GnRHa) or danazol. Twenty-five women received GnRHa either nasally or subcutaneously and 13 women received danazol 200 mg four times daily by mouth. During treatment amenorrhea and suppressed estradiol levels were observed in all patients. Each patient took a supplement of oral calcium 1 gm daily. DPA (reproducibility +/- 1.5%) was read by a single observer unaware of the treatment assignment of the patient. The mean (+/- standard error) of the entire group prior to treatment was 98.8% +/- 0.03% of a control population of women from the same geographic area matched for race, age, and weight. At the completion of treatment, BMD was slightly decreased in the GnRHa group and marginally increased in the danazol group but neither change was significant. Women with endometriosis have lumbar BMD in the normal range and ovarian suppression with either GnRHa or danazol produces no significant change in BMD.