New data on measures of bone health in trans people taking hormone therapy

If you’ve spent just about any time being exposed to what the general public believes about transgender medicine, you’ve likely had the misfortune of encountering the belief that cross-sex hormone therapy is harmful or deadly to us in several respects. From heart disease to stroke risk, from cancer (any or all, apparently) to suicide (based on a misread Swedish study), widespread fear of the dangers that must surely accompany chemicals and artificial hormones is marshaled in the service of the certainty that medically transitioning – “unnatural” as it is – must ultimately be bad for you.

Of course, we’ve spent plenty of time explaining that transition is not an unalloyed bad, and provides extensive benefits in terms of improved mental health and overall quality of life. And a recent multicenter study, part of the European Network for Investigation of Gender Incongruence (ENIGI) initiative, provides additional information on one of the most frequent targets of misguided concern: our bone health.

While previous studies of the effect of cross-sex hormones on transgender bone health have largely focused on bone mineral density, Vlot et al. (2019) examined bone turnover markers in trans women and trans men before and after one year of HRT. Bone turnover markers are implicated in bone health due to the ongoing process of bone remodeling, in which bone is created and resorbed. In osteoporosis, lowered bone density and accompanying increased fracture risk can be due to imbalances in this process, with increase in bone resorption and/or decrease in bone formation, indicated by variations in bone turnover markers.

In the present study, participants showed an increase in bone mineral density after a year of treatment, but variations in bone turnover markers among subgroups: trans women and older trans men exhibited a decrease in bone turnover markers, while younger trans men showed an increase. The authors note that this may be attributable to the development of greater muscle mass in younger trans men as a result of testosterone treatment: “As muscle mass increased in trans men, which is resembled by an increase in creatinine after 1 year of HT, mechanical loading on bones increased, which possibly explains the increase in bone formation markers.” ■