Skeletal Health and Bone Marrow Composition Among Youth

Children and adolescents experiencing gender dysphoria feel increased distress with the onset of puberty. Gender clinics treat these young adolescents by "blocking" puberty using gonadotropin-releasing hormone (GnRH) agonist medications. This has the possibility of impacting bone development as sex steroids are important to bone mass development. In this multi-site study, the investigators will examine bone marrow composition (by MRI) in 40 transgender youth and bone density and body composition before/after pubertal blockade compared to healthy participants.

The investigators propose to identify the effects of pubertal blockade on bone density and size in pediatric transgender individuals. Information is limited regarding bone health and metabolism for this group, and especially for children who are transgender. Further, the team's expertise in magnetic resonance imaging (MRI), magnetic resonance spectroscopy (MRS), dual-energy x-ray absorptiometry (DXA), and peripheral quantitative computed tomography (pQCT), examining the natal female skeleton in previous NIH funded studies, and extensive clinical expertise, provide an ideal foundation to apply this protocol to examine transgender female and transgender male skeleton. Findings from this study will allow us to identify potential preventative strategies to counter the long-term effects of puberty blockade such as osteoporosis and raise awareness of this medical consequence to medical care providers of transgender patients. The proposed project seeks to answer the clinically relevant question of how bone marrow composition relates to body composition, and its relation to both bone density and skeletal strength, in transgender patients who are undergoing puberty blockade, the first phase of therapy preceding gender-affirming hormone therapy.