Gender-affirming hormone treatment: friend or foe? Long-term follow-up of 755 transgender people

Purpose: Gender-affirming hormone treatment (GAHT) is one of the main demands of transgender and gender diverse (TGD) people, who are usually categorised as transgender assigned-male-at birth (AMAB) and assigned-female-at birth (AFAB). The aim of the study is to investigate the long-term therapeutic management of GAHT, considering hormonal targets, treatment adjustments and GAHT safety. Methods: A retrospective, longitudinal, observational, multicentre clinical study was carried out. Transgender people, both AMAB and AFAB, were recruited from two Endocrinology Units in Italy (Turin and Modena) between 2005 and 2022. Each subject was managed with specific and personalized follow-up depending on the clinical practice of the Centre. All clinical data routinely collected were extracted, including anthropometric and biochemical parameters, lifestyle habits, GAHT regime, and cardiovascular events. Results: Three-hundred and two transgender AFAB and 453 transgender AMAB were included. Similar follow-up duration (p = 0.974) and visits' number (p = 0.384) were detected between groups. The transgender AFAB group reached therapeutic goals in less time (p = 0.002), fewer visits (p = 0.006) and fewer adjustments of GAHT scheme (p = 0.024). Accordingly, transgender AFAB showed a higher adherence to medical prescriptions compared to transgender AMAB people (p < 0.001). No significantly increased rate of cardiovascular events was detected in both groups. Conclusion: Our real-world clinical study shows that transgender AFAB achieve hormone target earlier and more frequently in comparison to transgender AMAB individuals. Therefore, transgender AMAB people may require more frequent check-ups in order to tailor feminizing GAHT and increase therapeutic adherence.