NCT07481942

Body Composition Assessment in Transgender Population.

Body Composition Adaptations Following Initiation of Gender-Affirming Hormone Therapy in Transgender Populations.

• Status: Completed
• Phase: —
• Study type: Observational
• Enrollment: 70 (actual)
• Sponsor: Celia Bañuls · Academic / Other
• Sex: Female
• Age: 14 Years
• Healthy volunteers: Not accepted

Summary

Gender-affirming hormone therapy (GAHT) is a fundamental component of medical transition in transgender men, promoting body composition changes that align physical characteristics with gender identity and alleviate gender dysphoria. In adults, GAHT typically involves testosterone administration, whereas adolescents may receive gonadotropin-releasing hormone agonists to suppress puberty before initiating testosterone. Despite its general safety when appropriately monitored, findings on GAHT-related changes in body composition and potential cardiovascular implications are inconsistent. Accurate assessment of skeletal muscle mass and fat redistribution is clinically relevant, as conventional anthropometric measures may fail to capture these changes. This study evaluates body composition changes after one year of testosterone therapy in transgender men using bioelectrical impedance vector analysis (BIVA), and explores the utility of muscle ultrasound as an accessible tool for monitoring skeletal muscle and potential differences among testosterone formulations.

Detailed description

Gender-affirming hormone therapy (GAHT) is a central component of medical transition in transgender men, and aims to induce body composition changes that align physical appearance with gender identity and reduce gender dysphoria. In adults, GAHT typically consists of testosterone administration, whereas, in adolescents, gonadotropin-releasing hormone agonists (GnRHa) may be used to suppress puberty before initiating testosterone. GAHT has been associated with improvements in psychological well-being, social integration, and quality of life, although evidence remains limited due to the lack of randomized clinical trials. Moreover, body composition changes have been linked to psychological health in this population. GAHT is considered safe when adequately monitored and individualized according to cardiovascular risk profile and pre-existing conditions. However, current evidence regarding its effects on body composition and potential implications for cardiovascular risk is inconsistent. Clinically, it is particularly relevant to determine the extent to which GAHT supports gains in skeletal muscle mass and fat redistribution, given their influence on body satisfaction and cardiometabolic risk. Importantly, relying on basic anthropometric measures such as body weight may lead to an underestimation of cardiovascular risk by failing to capture changes in key body compartments. Reference techniques such as DXA or magnetic resonance imaging have been used to characterize these changes, although their limited accessibility restricts their routine application in clinical follow-up. In this context, bioelectrical impedance vector analysis (BIVA) and muscle ultrasound emerge as accessible alternatives for assessing skeletal muscle mass. However, the lack of population-specific reference values may hinder interpretation, underscoring the need to develop dedicated standards and validate these methods in transgender populations. To examine the effect of one year of testosterone treatment on body composition in transgender men, different parameters will be assessed using BIVA. Additionally, the utility of muscle ultrasound as a feasible tool for monitoring skeletal muscle during masculinization will be explored, as well as if there are differences in body composition between different types of testosterone formulations.

Conditions

• Transgender

Interventions

Type	Name	Description
DRUG	gender affirming hormone therapy	Participants will be treated with testosterone according to the World Professional Association for Transgender Health (WPATH) guidelines. Pharmaceutical presentation of testosterone will be consensually chosen by participants together with their endocrinologists. This include 1,000 mg of intramuscularly administered testosterone undecanoate every 6 weeks after initiation of GAHT and then every 12 weeks (and, in case of testosterone undecanoate stock-out, with 200-250 mg of intramuscularly administered testosterone cypionate), or 50 mg/day of transdermic testosterone gel (Tgel), according to European guidelines. For adolescents, GAHT may be combined with puberty suppression using gonadotropin-releasing hormone agonist (GnRHa), when indicated, and these agents will be continued in adults if menses persisted despite testosterone escalation.

Timeline

• Start date: 2017-01-01
• Primary completion: 2024-12-31
• Completion: 2025-10-31
• First posted: 2026-03-19
• Last updated: 2026-03-23

Locations

1 site across 1 country: Spain

Regulatory

• FDA-regulated drug study