title: 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).
abstract: OBJECTIVE
  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.
authors.affiliation: 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.
authors.forename: E
authors.initials: E
authors.lastname: Van Caenegem
authors.affiliation: 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.
authors.forename: K
authors.initials: K
authors.lastname: Wierckx
authors.affiliation: 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.
authors.forename: Y
authors.initials: Y
authors.lastname: Taes
authors.affiliation: 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.
authors.forename: T
authors.initials: T
authors.lastname: Schreiner
authors.affiliation: 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.
authors.forename: S
authors.initials: S
authors.lastname: Vandewalle
authors.affiliation: 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.
authors.forename: K
authors.initials: K
authors.lastname: Toye
authors.affiliation: 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.
authors.forename: B
authors.initials: B
authors.lastname: Lapauw
authors.affiliation: 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.
authors.forename: J-M
authors.initials: JM
authors.lastname: Kaufman
authors.affiliation: 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.
authors.forename: G
authors.initials: G
authors.lastname: T'Sjoen
mesh_terms: D000293:Adolescent; D000328:Adult; D001823:Body Composition / Q000187:drug effects / Q000502:physiology*; D015519:Bone Density / Q000187:drug effects / Q000502:physiology*; D016723:Bone Remodeling / Q000187:drug effects / Q000502:physiology*; D016022:Case-Control Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D053580:Muscle Strength / Q000187:drug effects / Q000502:physiology; D011446:Prospective Studies; D013739:Testosterone / Q000008:administration & dosage*; D063106:Transgender Persons; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D013739:Testosterone