title: Cortical and trabecular bone mineral density in transsexuals after long-term cross-sex hormonal treatment: a cross-sectional study.
abstract: The aim of this study was to explore the effect of long-term cross-sex hormonal treatment on cortical and trabecular bone mineral density and main biochemical parameters of bone metabolism in transsexuals. Twenty-four male-to-female (M-F) transsexuals and 15 female-to-male (F-M) transsexuals treated with either an antiandrogen in combination with an estrogen or parenteral testosterone were included in this cross-sectional study. BMD was measured by DXA at distal tibial diaphysis (TDIA) and epiphysis (TEPI), lumbar spine (LS), total hip (HIP) and subregions, and whole body (WB) and Z-scores determined for both the genetic and the phenotypic gender. Biochemical parameters of bone turnover, insulin-like growth factor-1 (IGF-1) and sex hormone levels were measured in all patients. M-F transsexuals were significantly older, taller and heavier than F-M transsexuals. They were treated by cross-sex hormones during a median of 12.5 years before inclusion. As compared with female age-matched controls, they showed a significantly higher median Z-score at TDIA and WB (1.7+/-1.0 and 1.8+/-1.1, P < 0.01) only. Based on the WHO definition, five (who did not comply with cross-sex hormone therapy) had osteoporosis. F-M transsexuals were treated by cross-sex hormones during a median of 7.6 years. They had significantly higher median Z-scores at TEPI, TDIA and WB compared with female age-matched controls (+0.9+/-0.2 SD, +1.0+/-0.4 SD and +1.4+/-0.3 SD, respectively, P < 0.0001 for all) and reached normal male levels except at TEPI. They had significantly higher testosterone and IGF-1 levels (p < 0.001) than M-F transsexuals. We conclude that in M-F transsexuals, BMD is preserved over a median of 12.5 years under antiandrogen and estrogen combination therapy, while in F-M transsexuals BMD is preserved or, at sites rich in cortical bone, is increased to normal male levels under a median of 7.6 years of androgen treatment in this cross sectional study. IGF-1 could play a role in the mediation of the effect of androgens on bone in F-M transsexuals.
authors.affiliation: Osteoporosis Unit, University Hospital of Berne, CH-3010 Berne, Switzerland.
authors.forename: Adrian G
authors.initials: AG
authors.lastname: Ruetsche
authors.forename: Renato
authors.initials: R
authors.lastname: Kneubuehl
authors.forename: Martin H
authors.initials: MH
authors.lastname: Birkhaeuser
authors.forename: Kurt
authors.initials: K
authors.lastname: Lippuner
mesh_terms: D015502:Absorptiometry, Photon; D000328:Adult; D000726:Androgen Antagonists / Q000008:administration & dosage; D015519:Bone Density / Q000187:drug effects; D003430:Cross-Sectional Studies; D004967:Estrogens / Q000008:administration & dosage / Q000097:blood; D005260:Female; D020249:Hormone Replacement Therapy / Q000009:adverse effects*; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000032:analysis; D008159:Lumbar Vertebrae / Q000503:physiopathology; D008297:Male; D010024:Osteoporosis / Q000097:blood / Q000139:chemically induced*; D010384:Pelvic Bones / Q000503:physiopathology; D013739:Testosterone / Q000008:administration & dosage / Q000097:blood; D013977:Tibia / Q000503:physiopathology; D013997:Time Factors; D014189:Transsexualism / Q000097:blood / Q000503:physiopathology*
chemical_list: D000726:Androgen Antagonists; D004967:Estrogens; D013739:Testosterone; D007334:Insulin-Like Growth Factor I