Endocrine Abstracts

JOINT3301

Introduction and Objective: Individuals experiencing gender incongruence with their sex assigned at birth may seek gender-affirming hormone therapy (GAHT) to align their gender expression with their identity. GAHT is known to induce changes in body composition, and advanced morphofunctional assessment techniques could serve as valuable tools for evaluating these modifications. This study aims to analyze the morphofunctional characteristics of this population before the initiation of hormone therapy.

Materials and Methods: A descriptive observational study was conducted on individuals aged ≥18 years seeking GAHT at the Transgender Healthcare Unit (UAPT) of Hospital Universitario Clínico San Cecilio in Granada. Anthropometric variables, muscle strength (handgrip dynamometry), bioelectrical impedance parameters—including metabolically active cellular mass (BCM) and total body water (TBW)—as well as muscle and abdominal ultrasound measurements, were assessed.

Results: The study included 14 trans men and 7 trans women, with mean ages of 20.93 ± 3.36 and 22.85 ± 4.8 years, respectively, and BMI values of 23.83 ± 7.38 kg/m² vs. 22.51 ± 6.11 kg/m². Handgrip strength was higher in trans women (26.57 ± 10.32 kg vs. 25.02 ± 7.13 kg; P > 0.05). This finding aligns with a trend toward statistical significance in Y-axis thickness (1.79 ± 0.53 cm vs. 1.41 ± 0.32 cm, P = 0.054) and rectus femoris muscle area (5.87 ± 2.53 cm² vs. 3.84 ± 1.03 cm²), as measured by ultrasound. These parameters correlate with total muscle mass and strength. Statistically significant differences were observed in BCM (x̅;: 32.87 ± 7.34 kg/m² vs. 24.03 ± 4.28 kg/m², P < 0.05) and TBW (x̅;: 43.62 ± 9.9 kg/m² vs. 31.38 ± 4.03 kg/m², P < 0.05), both higher in trans women. No significant differences were found in abdominal ultrasound measurements of superficial adipose tissue (0.57 ± 0.39 cm vs. 0.52 ± 0.45 cm, P = 0.807) or preperitoneal adipose tissue (0.57 ± 0.48 cm vs. 0.55 ± 0.29 cm, P = 0.868).

Conclusions: This study provides novel insights into the application of advanced morphofunctional assessment techniques for characterizing body composition and muscle strength changes in transgender individuals before GAHT. These findings establish a baseline for future research into the physiological effects of hormone therapy.