Effects of Cross-Sex Hormone Therapy on BMD of Transgender People

Bone mineral density (BMD) is increased in transgender men and women following 1 year of cross-sex hormone treatment (CHT), according to research published in the Journal of Bone and Mineral Research.

Martin den Heijer, MD, PhD, of the department of internal medicine at VU Medical Center in Amsterdam, The Netherlands, and colleagues conducted a multicenter, prospective, observational study of transgender people (231 transwomen [male-to-female transgender] and 199 transmen [female-to-male transgender]) who had completed their first year of CHT. Participants were part of the European Network for Investigation of Gender Incongruence study (ENIGI; ClinicalTrials.gov Identifier: NCT01072825).

At baseline and 1 year, lumbar spine, total hip, and femoral neck BMD measurements were obtained using dual-energy x-ray absorptiometry (DXA). Mean time between DXA scans was 12 months (range: 10 to 14 months).

Following 1 year of CHT, the investigators noted increases in lumbar spine, total hip, and femoral neck BMD measurements in transwomen (+3.67%, +0.97%, and +1.86%; P <.001 for all); increases were also noted in total hip BMD measurements in transmen (+1.04%; P <.001), with a larger increase in transmen 50 years of age and older (P =.001).

In both groups, lumbar spine and total hip BMD measurements did not change based on CHT administration route (transdermal vs oral estradiol in transwomen; testosterone gel vs testosterone esters vs testosterone undecanoate in transgender men).

In transmen, a greater increase in femoral neck BMD measurement was noted among those using testosterone undecanoate.

“This study showed that after 1 year of CHT the mean BMD increased in both transwomen and transmen,” the researchers concluded. “In both transwomen and transmen, the change in BMD could not be completely explained by a change in body weight … cigarette or alcohol use, or by vitamin D supplementation.”

Reference

Wiepjes CM, Vlot MC, Klaver M, et al. Bone mineral density increases in trans persons after 1 year of hormonal treatment: a multicenter prospective observational study. J Bone Miner Res. 2017;32(6):1252-1260.