Bone mass, bone geometry, and body composition in female-to-male transsexual persons after long-term cross-sex hormonal therapy

J Clin Endocrinol Metab. 2012 Jul;97(7):2503-11. doi: 10.1210/jc.2012-1187. Epub 2012 May 7.


Context: Female-to-male transsexual persons (transsexual men) undergo extreme hormonal changes due to ovariectomy and testosterone substitution, allowing studies on sex steroid effects on bone geometry and physiology in the adult.

Objective: The objective of the study was to examine the effects of cross-gender sex steroid exposure on volumetric bone parameters in transsexual men.

Design: This was a cross-sectional study.

Setting: Participants were recruited from the Center for Sexology and Gender Problems at the Ghent University Hospital (Ghent, Belgium).

Participants: Fifty transsexual men after sex reassignment surgery with 50 age-matched control women and an additional 16 transsexual men before testosterone substitution and sex reassignment surgery with 16 control women participated in the study.

Main outcome measures: The main outcome measures were areal and volumetric bone parameters using dual-energy X-ray absorptiometry and peripheral quantitative computed tomography, body composition (dual-energy X-ray absorptiometry), sex steroids, markers of bone turnover and grip strength.

Results: Before hormonal treatment, transsexual men had similar body composition and bone geometry as female controls. The transsexual men on long-term testosterone therapy, however, demonstrated a higher lean body mass and muscle mass and a greater grip strength as well as a lower body and subcutaneous fat mass and a larger waist and smaller hip circumference compared with female controls (all P < 0.001). We observed a larger radial cortical bone size (P < 0.001) and lower cortical volumetric bone mineral density at the radius and tibia (P < 0.05) in transsexual men on testosterone therapy.

Conclusions: Transsexual men on testosterone substitution therapy present with a different body composition with more muscle mass and strength and less fat mass as well as an altered bone geometry with larger bones compared with female controls.

Publication types

  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Absorptiometry, Photon
  • Adult
  • Body Composition / physiology*
  • Bone Density / physiology*
  • Bone Development / physiology
  • Bone and Bones / anatomy & histology*
  • Bone and Bones / diagnostic imaging
  • Case-Control Studies
  • Cross-Sectional Studies
  • Female
  • Hormone Replacement Therapy* / methods
  • Humans
  • Male
  • Middle Aged
  • Organ Size
  • Sex Reassignment Procedures* / methods
  • Time Factors
  • Transsexualism / diagnostic imaging
  • Transsexualism / metabolism
  • Transsexualism / physiopathology*
  • Transsexualism / therapy*
  • Young Adult