Impact of medical treatment of endometriosis on bone mass.

A review of studies examining the effect of medical therapy of endometriosis on bone mass and potential approaches to preventing bone loss was undertaken. Studies specifically examining bone density in women with endometriosis treated medically were used. Reports on effects of oral contraceptives and progestins on bone mass were derived from women using them for contraception. Oral contraceptives and medroxyprogesterone acetate apparently did not adversely affect bone mass. While initial studies with dual-photon absorptiometry were unable to detect appreciable bone loss with gonadotropin-releasing hormone agonist, subsequent studies have invariably found significant bone loss beginning as early as 3 months of treatment. Quantitated computerized tomography always shows significant trabecular bone loss of the vertebrae and hip with gonadotropin-releasing hormone agonist. Depot preparations appear to produce more marked loss than daily injections of intranasal spray. Recent studies indicate recovery of bone loss may take longer than 6 months or even 1 year after discontinuation of therapy with considerable individual variation. Danazol produced bone gain. Bone loss with gonadotropin-releasing hormone agonists could be prevented or attenuated with progestins, and this is worthy of further studies. Impact of medical therapy on bone mass should be a practical consideration in the selection of patients, in repeat medical therapy for recurrence of endometriosis, and in formulation of medical therapy so as to attenuate or overcome such silent adverse effects.