Endocrine Abstracts

Background: Persons with assigned either male (AMAB) or female (AFAB) sex at birth might wish to obtain feminization or masculinization, respectively. To this purpose, hormonal treatment with sex hormones must be tailored to each subject. Several studies and the European Society of Endocrinology guidelines tried to identify the optimal hormonal treatment in both AMAB and AFAB subjects. However, the clinical management in the long term follow-up remains challenging. Many treatment adjustments and/or shifts are clinically performed to reach the therapeutic goal, i.e. phenotypic characteristics of the perceived gender, minimizing adverse events.

Aim of the study: To evaluate treatment modifications/shifts required in the long term follow-up of AMAB and AFAB subjects treated with guideline-based hormone therapy adjusted according to biochemical results.

Methods: A retrospective, longitudinal, observational clinical study was carried out at the Andrology Unit of Modena (Italy). All AMAB and AFAB subjects evaluated since 2006 were considered eligible. All clinical consultations performed until January 2022 were collected, including data regarding previous medical history, comorbidities, physical examination, blood examinations, hormonal assessment, and therapeutic choice.

Results: A total of 120 subjects were enrolled, 69 AMAB (57%) and 51 AFAB (43%). AFAB subjects were significantly older (41.1+9.1 vs 33.9+8.8 years, P<0.001) and followed-up for longer time (36.8+42.0 vs23.4+31.2 months, P<0.001) than AMAB.

In AFAB subjects, treatment modifications were performed 60 times (26.5%) during the follow-up and the dropout rate was 2.0% (1 subject). Mean testosterone serum levels during follow-up were 6.7+6.4 ng/ml. Therapy modifications were neither predicted by testosterone serum levels, nor comorbidities number, nor drug number (Cox logistic regression: 0.384, P=0.061). In AMAB group, hormonal treatment was modified 164 times (45.1%) during follow-up, with a dropout rate of 24.6% (17 subjects). Mean oestradiol serum levels at follow-up were 49.8+45.1 pg/ml. While therapy changes were not predicted by oestradiol serum levels (Cox logistic regression: 0.778, P=0.194), they resulted directly related with the number of comorbidities (Cox logistic regression: 0.585, P=0.025).

Conclusion: Our retrospective long term analysis on AFAB and AMAB subjects highlighted a comprehensive maintenance of sex hormones levels within therapeutic ranges burdened by frequent therapy modifications. These drug adjustments resulted more evident in AMAB subjects, in which treatment changes seemed related to the presence of comorbidities. Considering also the higher dropout rate compared to AFAB, AMAB subjects seem to require a more stringent clinical management during follow-up.