Pubertal Suppression, Bone Mass, and Body Composition in Youth With Gender Dysphoria.

Background And Objectives: Puberty onset and development contribute substantially to adolescents' bone mass and body composition. Our objective with this study was to examine the effects of gonadotropin-releasing hormone agonists (GnRHa) on these puberty-induced changes among youth with gender dysphoria (GD).

Methods: Medical records of the endocrine diversity clinic in an academic children's hospital were reviewed for youth with GD seen from January 2006 to April 2017 with at least 1 baseline dual-energy radiograph absorptiometry measurement.

Results: At baseline, transgender females had lower lumbar spine (LS) and left total hip (LTH) areal bone mineral density (aBMD) and LS bone mineral apparent density (BMAD) scores. Only 44.7% of transgender youth were vitamin D sufficient. Baseline vitamin D status was associated with LS, LTH aBMD, and LS BMAD scores. Post-GnRHa assessments revealed a significant drop in LS and LTH aBMD scores (transgender males and transgender females) without fractures and LS BMAD (transgender males), an increase in gynoid (fat percentage), and android (fat percentage) (transgender males and transgender females), and no changes in BMI score.

Conclusions: GnRHa monotherapy negatively affected bone mineral density of youth with GD without evidence of fractures or changes in BMI score. Transgender youth body fat redistribution (android versus gynoid) were in keeping with their affirmed gender. The majority of transgender youth had vitamin D insufficiency or deficiency with baseline status associated with bone mineral density. Vitamin D supplementation should be considered for all youth with GD.