Body composition, bone turnover, and bone mass in trans men during testosterone treatment: 1-year follow-up data from a prospective case-controlled study (ENIGI)

E Van Caenegem; K Wierckx; Y Taes; T Schreiner; S Vandewalle; K Toye; B Lapauw; J-M Kaufman; G T'Sjoen

doi:10.1530/EJE-14-0586

Body composition, bone turnover, and bone mass in trans men during testosterone treatment: 1-year follow-up data from a prospective case-controlled study (ENIGI)

Eur J Endocrinol. 2015 Feb;172(2):163-71. doi: 10.1530/EJE-14-0586.

Authors

E Van Caenegem¹, K Wierckx², Y Taes³, T Schreiner², S Vandewalle³, K Toye³, B Lapauw³, J-M Kaufman³, G T'Sjoen⁴

Affiliations

¹ Department of EndocrinologyGhent University Hospital, De Pintelaan 185, 9000 Ghent, BelgiumEuropean Network for the Investigation of Gender Incongruence (ENIGI)Ghent, BelgiumDepartment of EndocrinologyRikshospitalet, Oslo University Hospital, Sognsvannvn 20, Oslo, NorwayCenter for Sexology and Gender ProblemsGhent University Hospital, De Pintelaan 185, Ghent, Belgium Department of EndocrinologyGhent University Hospital, De Pintelaan 185, 9000 Ghent, BelgiumEuropean Network for the Investigation of Gender Incongruence (ENIGI)Ghent, BelgiumDepartment of EndocrinologyRikshospitalet, Oslo University Hospital, Sognsvannvn 20, Oslo, NorwayCenter for Sexology and Gender ProblemsGhent University Hospital, De Pintelaan 185, Ghent, Belgium eva.vancaenegem@ugent.be.
² Department of EndocrinologyGhent University Hospital, De Pintelaan 185, 9000 Ghent, BelgiumEuropean Network for the Investigation of Gender Incongruence (ENIGI)Ghent, BelgiumDepartment of EndocrinologyRikshospitalet, Oslo University Hospital, Sognsvannvn 20, Oslo, NorwayCenter for Sexology and Gender ProblemsGhent University Hospital, De Pintelaan 185, Ghent, Belgium Department of EndocrinologyGhent University Hospital, De Pintelaan 185, 9000 Ghent, BelgiumEuropean Network for the Investigation of Gender Incongruence (ENIGI)Ghent, BelgiumDepartment of EndocrinologyRikshospitalet, Oslo University Hospital, Sognsvannvn 20, Oslo, NorwayCenter for Sexology and Gender ProblemsGhent University Hospital, De Pintelaan 185, Ghent, Belgium.
³ Department of EndocrinologyGhent University Hospital, De Pintelaan 185, 9000 Ghent, BelgiumEuropean Network for the Investigation of Gender Incongruence (ENIGI)Ghent, BelgiumDepartment of EndocrinologyRikshospitalet, Oslo University Hospital, Sognsvannvn 20, Oslo, NorwayCenter for Sexology and Gender ProblemsGhent University Hospital, De Pintelaan 185, Ghent, Belgium.
⁴ Department of EndocrinologyGhent University Hospital, De Pintelaan 185, 9000 Ghent, BelgiumEuropean Network for the Investigation of Gender Incongruence (ENIGI)Ghent, BelgiumDepartment of EndocrinologyRikshospitalet, Oslo University Hospital, Sognsvannvn 20, Oslo, NorwayCenter for Sexology and Gender ProblemsGhent University Hospital, De Pintelaan 185, Ghent, Belgium Department of EndocrinologyGhent University Hospital, De Pintelaan 185, 9000 Ghent, BelgiumEuropean Network for the Investigation of Gender Incongruence (ENIGI)Ghent, BelgiumDepartment of EndocrinologyRikshospitalet, Oslo University Hospital, Sognsvannvn 20, Oslo, NorwayCenter for Sexology and Gender ProblemsGhent University Hospital, De Pintelaan 185, Ghent, Belgium Department of EndocrinologyGhent University Hospital, De Pintelaan 185, 9000 Ghent, BelgiumEuropean Network for the Investigation of Gender Incongruence (ENIGI)Ghent, BelgiumDepartment of EndocrinologyRikshospitalet, Oslo University Hospital, Sognsvannvn 20, Oslo, NorwayCenter for Sexology and Gender ProblemsGhent University Hospital, De Pintelaan 185, Ghent, Belgium.

PMID: 25550352
DOI: 10.1530/EJE-14-0586

Abstract

Purpose: To assess the evolution of body composition and bone metabolism in trans men during the first year of cross-sex hormonal therapy.

Methods: In a prospective controlled study, we included 23 trans men (female-to-male trans persons) and 23 age-matched control women. In both groups, we examined grip strength (hand dynamometer), biochemical markers of bone turnover (C-terminal telopeptides of type 1 collagen (CTX) and procollagen 1 aminoterminal propeptide (P1NP)), total body fat and lean mass, and areal bone mineral density (aBMD) by dual-X-ray absorptiometry (DXA) and fat and muscle area at the forearm and calf, bone geometry, and volumetric bone mineral density (vBMD) by peripheral quantitative computed tomography (pQCT), before treatment and after 1 year of treatment with undecanoate (1000 mg i.m./12 weeks).

Results: Before hormonal treatment, trans men had similar bone and body composition compared with control women. Testosterone treatment induced in trans men a gain in muscle mass (+10.4%) and strength and loss of fat mass (-9.7%) (all P<0.001) and increased the levels of P1NP and CTX (both P<0.01). Areal and volumetric bone parameters remained largely unchanged apart from a small increase in trabecular vBMD at the distal radius and in BMD at the total hip in trans men (P=0.036 and P=0.001 respectively). None of these changes were observed in the control group.

Conclusions: Short-term testosterone treatment in trans men increased muscle mass and bone turnover. The latter may rather reflect an anabolic effect of testosterone treatment rather than bone loss.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adolescent
Adult
Body Composition / drug effects
Body Composition / physiology*
Bone Density / drug effects
Bone Density / physiology*
Bone Remodeling / drug effects
Bone Remodeling / physiology*
Case-Control Studies
Female
Follow-Up Studies
Humans
Male
Middle Aged
Muscle Strength / drug effects
Muscle Strength / physiology
Prospective Studies
Testosterone / administration & dosage*
Transgender Persons*
Treatment Outcome
Young Adult

Substances

Testosterone