A study describing bone mass development (BMD) in adolescents with gender dysphoria showed that treatment with gonadotropin-releasing hormone analogues (GnRHa) decreased bone mineral apparent density (BMAD), according to an article published in the Journal of Clinical Endocrinology & Metabolism.
The prospective observational study characterised the course of bone mineral density (BMD) during two years of treatment with GnRHa and three years of subsequent gender-affirming hormone treatment, with measurements at yearly intervals.
The analysis included 51 transgirls and 70 transboys receiving GnRHa and 36 transgirls and 42 transboys receiving GnRHa and gender-affirming hormones. The main outcomes studied were BMAD, sex-specific BMAD Z-scores, and serum bone markers. All groups had BMAD values within the normal range at the start of GnRHa treatment.
During the two-year treatment with GnRHa, BMAD stabilised or decreased slightly, whereas Z-scores decreased in all groups. During the three years of combined administration of GnRHa and gender-affirming hormones, researchers found a significant increase of BMAD. Z-scores normalised in transboys but remained below zero in transgirls. In transgirls and early pubertal transboys, all bone markers decreased during GnRHa treatment.
The consequences of lower BMD for long term bone health in these individuals remains unclear, the authors say.