Impact of six months of GnRH agonist therapy for endometriosis. Is there an age-related effect on bone mineral density?

ABSTRACT

OBJECTIVE: To determine if there is an age-related effect on bone mineral density (BMD) loss with GnRH agonist treatment of endometriosis and, in particular, whether the impact of this therapy in terms of BMD loss is different if it is used at an age prior to attainment of peak BMD than after attaining it. STUDY DESIGN: Data from a randomized, double-placebo-controlled clinical trial comparing efficacy and safety of two GnRH agonists, without add-back, for the treatment of endometriosis, were analyzed. RESULTS: No significant age-related effect was detected for either GnRH agonist on absolute BMD loss with a single, six-month course. However, in women at an age prior to peak BMD, prevention of the natural increase in BMD with these drugs may prevent women from attaining their peak BMD and thus increase their risk of osteoporosis in later life. CONCLUSION: GnRH agonists should be used with caution and perhaps only with strategies designed to minimize the impact on BMD in women prior to attainment of peak BMD.