Reacción a "Reactions: study looks at bone health in transgender youth on blockers and hormones"

This is a retrospective study of bone mineral density in transgender people treated first with puberty blockers and then with gender-affirming hormone treatment. They measure mineralisation by dual-energy X-ray absorptiometry. The group conducting the study belongs to the clinic of the University of Amsterdam, which introduced puberty blocker treatment in the 1980s and is a leader in the study of the subject. They have a database dating back to 1972 (the Amsterdam Cohort of Gender Dysphoria). 

This type of retrospective study, in which participants are extracted from the database and re-examined, is very difficult to conduct. The number of participants is small (25 transgender women and 50 transgender men). The authors acknowledge the limitations of the work and that they were unable to stratify the results with respect to the number of years receiving blocker treatment. 

With respect to the measure used, the results are to be expected: hormone treatment affects transgender women and not transgender men. This is true for other clinical measures. 

The interest of the paper lies in the fact that it provides data on the sequence: blocker treatment-gender affirming hormone treatment. There are very few papers in the scientific literature that address the adverse effects of these treatments, so the paper, with its limitations, has relevance.