Bone health in transgender subjects

Abstract

Cross sex hormone therapy (CSHT) in transgender women (TW) it is an option to achieve desired secondary sexual characteristics. It is known that sex steroids play a fundamental role in the acquisition of bone mineral density during puberty, in addition to determining a different characteristic bone pattern between both biological sexes. So the impact of affirming HT on bone is it has become in subject of study. In early pubertal stages, GNRH analogs are used with a reversible effect. Although bone mineral density (BMD) seems to remain stable, when compared with a reference population of the same biological sex and age, the Z-score is lower than expected. In adults, during CSHT no decreases in BMD were reported. However, it was reported that TW prior to starting CSHT present different densitometric characteristics than cisgender men. So far, the data load for the fracture risk calculators and DXA software is based on biological sex and not gender identity.
Recently the ISCD issued its recommendations for the evaluation of bone mass in transgender subjects and in those non-conforming to gender. Although the ISCD suggests performing the evaluation only in those patients with risk factors, our group recognizes that baseline DXA, especially in TW, constitutes a useful tool to determine the initial risk of this population. Our proposal arises from our own experience and from that compiled in the international literature, where it is observed that even without starting CSHT, transgender women have lower BMD. DXA. This article reviews the available evidence regarding the effect of CSHT on health bone in transgender people.