Long-term use of gonadotropin-releasing hormone analogs and hormone replacement therapy in the management of endometriosis: a randomized trial with a6-year follow-up

Objective: To identify the effects of long-term GnRH agonist use (6-24 mont hs), with and without add-back therapy, and spontaneous reversibility of bo ne mass density (BMD) up to 6 years after treatment. Design: A prospective, randomized, long-term follow-up study. Setting: Obstetrics and gynecology department in a university hospital in t he United Kingdom. Patient(s): Forty-nine symptomatic women with a laparoscopic diagnosis of e ndometriosis who had been identified for treatment with long-acting GnRH ag onist and volunteered to participate in the study. Intervention(s): Women were randomly allocated to receive hormone replaceme nt therapy (I-IRT) as a daily oral dose of estradiol, 2 mg, and norethister one acetate, 1 mg, or no treatment in addition to monthly subcutaneous impl ants of goserelin acetate for up to 7 years, until cessation of symptoms. B one mineral density (BMD) at the lumbar spine (C2-C4) and hip (Ward triangl e) was measured every 6 months. Main Outcome Measure(s): BMD changes in both groups. Result(s): 45 women were followed up for 6 years, at the end of which the g roups did not differ significantly in the reduction in mean BMD at the lumb ar spine or hip. Conclusion(s): BMD reduction occurs during long-term GnRH agonist use and i s not fully recovered by up to 6 years after treatment. Use of HRT does not affect this process. (Fertil Steril(R) 2000;74:961-8, (C) 2000 by American Society for Reproductive Medicine.)