Cross-sex pattern of bone mineral density in early onset gender identity disorder

Horm Behav. 2007 Sep;52(3):334-43. doi: 10.1016/j.yhbeh.2007.05.012. Epub 2007 Jun 2.


Hormonally controlled differences in bone mineral density (BMD) between males and females are well studied. The effects of cross-sex hormones on bone metabolism in patients with early onset gender identity disorder (EO-GID), however, are unclear. We examined BMD, total body fat (TBF) and total lean body mass (TLBM) in patients prior to initiation of sex hormone treatment and during treatment at months 3 and 12. The study included 33 EO-GID patients who were approved for sex reassignment and a control group of 122 healthy Norwegians (males, n=77; females, n=45). Male patients (n=12) received an oral dose of 50 mug ethinylestradiol daily for the first 3 months and 100 mug daily thereafter. Female patients (n=21) received 250 mg testosterone enantate intramuscularly every third week. BMD, TBF and TLBM were estimated using dual energy X-ray absorptiometry (DXA). In male patients, the DXA measurements except TBF were significantly lower compared to their same-sex control group at baseline and did not change during treatment. In female patients, the DXA measurements were slightly higher than in same-sex controls at baseline and also remained unchanged during treatment. In conclusion, this study reports that body composition and bone density of EO-GID patients show less pronounced sex differences compared to controls and that bone density was unaffected by cross-sex hormone treatment.

Publication types

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

MeSH terms

  • Absorptiometry, Photon
  • Adult
  • Age Factors
  • Body Composition / drug effects
  • Bone Density / drug effects*
  • Bone and Bones / diagnostic imaging
  • Bone and Bones / drug effects
  • Bone and Bones / metabolism
  • Ethinyl Estradiol / therapeutic use*
  • Female
  • Follow-Up Studies
  • Gender Identity*
  • Gonadal Steroid Hormones / therapeutic use
  • Humans
  • Male
  • Middle Aged
  • Sex Characteristics
  • Statistics, Nonparametric
  • Testosterone / analogs & derivatives*
  • Testosterone / therapeutic use
  • Transsexualism / drug therapy*
  • Transsexualism / metabolism


  • Gonadal Steroid Hormones
  • Testosterone
  • Ethinyl Estradiol
  • testosterone enanthate