One-year changes in body composition and phase angle during feminizing gender-affirming hormone therapy: a longitudinal and comparative study


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Avcı S., Kara Z., DURCAN E., Polat Korkmaz Ö., KIMIAEI A., Safaei S., ...Daha Fazla

Frontiers in Endocrinology, cilt.17, 2026 (SCI-Expanded, Scopus) identifier identifier identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 17
  • Basım Tarihi: 2026
  • Doi Numarası: 10.3389/fendo.2026.1694472
  • Dergi Adı: Frontiers in Endocrinology
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, BIOSIS, EMBASE, MEDLINE, Directory of Open Access Journals
  • Anahtar Kelimeler: assigned male at birth, body composition, gender dysphoria, gender-affirming hormone therapy, metabolic changes, phase angle
  • Açık Arşiv Koleksiyonu: AVESİS Açık Erişim Koleksiyonu
  • Hatay Mustafa Kemal Üniversitesi Adresli: Evet

Özet

Background: Gender dysphoria (GD) refers to the clinically significant distress or discomfort that may arise from a marked incongruence between an individual’s gender identity and the sex assigned at birth, involving primary and/or secondary sex characteristics and social roles. Gender-affirming hormone therapy (GAHT) aims to alleviate this distress by aligning secondary sex characteristics with gender identity and improving psychological well-being. This study examined the effects of GAHT on metabolic and body composition changes in assigned male at birth (AMAB) individuals. Methods: This single-center longitudinal study (2019–2022) followed 20 GAHT-naïve AMAB individuals with gender dysphoria, reassessed after 12 months of GAHT, with 24 cisgender women serving as a reference group. GAHT included estradiol with cyproterone acetate or spironolactone. Outcomes included bioelectrical impedance analysis (BIA)-derived phase angle (PhA) and body cell mass, as well as handgrip strength and gait speed. Results: After 12 months of GAHT, AMAB participants receiving hormone therapy showed significant reductions in fat-free mass (49.9 [39.4–54.6] kg, p = 0.01), fat-free mass index (FFMI) (18.4 [16.5–19.4] kg/m², p = 0.04), body cell mass (25.7 [20.6–29.3] kg, p = 0.04), and phase angle (6.9 [6.0–7.6], p = 0.04). Fat mass increased from 10.6 [8.9–13.8] to 12.9 [10.8–16.1] kg, although this change did not reach statistical significance (p = 0.07). Grip strength showed a non-significant decline (32.5 ± 6.6 kg, p = 0.20), while gait speed remained stable (1.52 [1.30–1.80] m/s, p = 0.60). Despite these changes, lean mass indices and phase angle remained higher than in cisgender women at follow-up (all p < 0.001). Hormonal and metabolic markers remained stable over the one-year follow-up. Conclusion: During the first year of GAHT, AMAB participants exhibited notable physiological changes, including decreases in fat-free mass (FFM) and phase angle. Because phase angle is an indicator of cellular integrity and muscle quality, its decline during GAHT warrants careful monitoring in future long-term studies. These findings underscore the importance of comprehensive body composition assessments in AMAB individuals receiving feminizing GAHT. Further studies with longer follow-up periods and larger cohorts are needed to elucidate the long-term clinical significance of these changes.