Effect of Antiandrogen Treatment on Bone Density and Bone Geometry in Adolescents with Polycystic Ovary Syndrome

Study Objectives: To determine the impact of antiandrogen treatment on bone density and geometry. Design: Prospective cohort investigation. Setting: Academic research institute. Participants: 38 (age 14.96 +/- 1.42 yr) subjects with PCOS. Interventions: Treated with metformin (n = 17) or metformin and antiandrogen (n = 21). Main Outcome Measure: Bone density and geometry parameters at baseline and after a mean duration of 1.92 +/- 0.88 years using peripheral quantitative computed tomography of the forearm. Results: At baseline, z-scores for trabecular (0.53 +/- 1.02) and cortical BMD (0.79 +/- 1.55) as well as total (0.62 +/- 1.07) and medullary cross sectional area (CSA) (0.79 +/- 1.29) were elevated. Cortical CSA (-0.01 +/- 1.10) and bone strength strain index (SSI) z-scores (-0.01 +/- 1.10) were normal. Muscle CSA z-score (0.12 +/- 1.70) was normal, but grip strength (-1.60 +/- 1.15) was significantly reduced. There were no significant changes within and between the two treatment options in respect to bone density and bone geometry parameters. With antiandrogen treatment, free androgen index (FAI) was significantly lower and grip strength further decreased (P < .001). Conclusions: No significant changes in bone mineral density and geometry parameters took place in PCOS women irrespective of treatment followed over a time of almost two years. General muscle weakness expressed as low grip strength may influence further bone development in PCOS.