Bone Mineral Density Increases in Trans Persons After 1 Year of Hormonal Treatment: A Multicenter Prospective Observational Study

Abstract

Sex steroids are important determinants of bone acquisition and bone homeostasis. Cross-sex hormonal treatment (CHT) in transgender persons can affect bone mineral density (BMD). The aim of this study was to investigate in a prospective observational multicenter study the first-year effects of CHT on BMD in transgender persons. A total of 231 transwomen and 199 transmen were included who completed the first year of CHT. Transwomen were treated with cyproterone acetate and oral or transdermal estradiol; transmen received transdermal or intramuscular testosterone. A dual-energy X-ray absorptiometry (DXA) was performed to measure lumbar spine (LS), total hip (TH), and femoral neck (FN) BMD before and after 1 year of CHT. In transwomen, an increase in LS (+3.67%, 95% confidence interval [CI] 3.20 to 4.13%, p < 0.001), TH (+0.97%, 95% CI 0.62 to 1.31%, p < 0.001), and FN (+1.86%, 95% CI 1.41 to 2.31%, p < 0.001) BMD was found. In transmen, TH BMD increased after 1 year of CHT (+1.04%, 95% CI 0.64 to 1.44%, p < 0.001). No changes were observed in FN BMD (-0.46%, 95% CI -1.07 to 0.16%, p = 0.144). The increase in LS BMD was larger in transmen aged ≥50 years (+4.32%, 95% CI 2.28 to 6.36%, p = 0.001) compared with transmen aged <50 years (+0.68%, 95% CI 0.19 to 1.17%, p = 0.007). In conclusion, BMD increased in transgender persons after 1 year of CHT. In transmen of postmenopausal age, the LS BMD increased more than in younger transmen, which may lead to the hypothesis that the increase in BMD in transmen is the result of the aromatization of testosterone to estradiol. © 2017 American Society for Bone and Mineral Research.

Bone Safety During the First Ten Years of Gender-Affirming Hormonal Treatment in Transwomen and Transmen

“…In transwomen, no differences in change in LS BMD between age groups were present, whereas in transmen LS BMD increased more in the oldest age group (≥40 years) compared with younger age groups. This finding was also described in a prospective 1‐year follow‐up study . In the current study, we found that the increase continued after 1 year.…”

“…Gender‐affirming hormonal treatment (HT) in transgender people influences bone metabolism. After 1 year of HT the BMD increases in transwomen (male‐to‐female transgender people), whereas in transmen (female‐to‐male transgender people) a maintenance or increase in BMD is described. More specifically, a larger increase in BMD was found in postmenopausal transmen with estrogen deficiency prior to HT compared with premenopausal transmen with normal estradiol concentrations.…”

“…More specifically, a larger increase in BMD was found in postmenopausal transmen with estrogen deficiency prior to HT compared with premenopausal transmen with normal estradiol concentrations. This suggests that the increase in BMD in transmen is mainly caused by the aromatization of testosterone into estradiol, therefore increasing the estradiol concentrations, instead of the direct effects of testosterone …”

Fracture Risk in Trans Women and Trans Men Using Long-Term Gender-Affirming Hormonal Treatment: A Nationwide Cohort Study

“…Earlier studies found either a maintenance (16)(17)(18)(19)(20) or increase (16)(17)(18)(21)(22)(23)(24)(25)(26) in BMD in both adult trans women and trans men after short-term HT. Earlier studies found either a maintenance (16)(17)(18)(19)(20) or increase (16)(17)(18)(21)(22)(23)(24)(25)(26) in BMD in both adult trans women and trans men after short-term HT.…”

Impact of cross‐sex hormone therapy on bone mineral density and body composition in transwomen

“…Sex steroids are important determinants of bone acquisition and bone homeostasis. In men, testosterone stimulates the process of periosteal apposition during puberty, producing a greater cortical bone size and wider bones as compared to women . Male to female transsexual individuals (transwomen) undergo oestrogen therapy associated or not with anti‐androgens, reducing endogenous testosterone and inducing feminization.…”