title: Gender identity disorders and multiple sclerosis risk: A national record-linkage study.
abstract: An altered balance of gonadal hormones in males with gender identity disorders (GIDs) may increase multiple sclerosis (MS) risk both inherently and secondary to treatment in undergoing male-to-female conversion.
  
  
  
  We investigated any association between GIDs and MS through analysis of record-linked hospital statistics.
  
  
  
  Analysis of English Hospital Episode Statistics, 1999-2012.
  
  
  
  The adjusted rate ratio (RR) of MS following GIDs in males was 6.63 (95% confidence interval (95% CI) = 1.81-17.01, p = 0.0002). The RR of MS following GIDs in females was 1.44 (95% CI = 0.47-3.37, p = 0.58).
  
  
  
  We report a strong association between GIDs and MS in male-to-females, supporting a potential role for low testosterone and/or feminising hormones on MS risk in males.
authors: Unit of Health-Care Epidemiology, Nuffield Department of Population Health, University of Oxford, Oxford, UK.
authors: Julia
authors: J
authors: Pakpoor
authors: Unit of Health-Care Epidemiology, Nuffield Department of Population Health, University of Oxford, Oxford, UK.
authors: Clare J
authors: CJ
authors: Wotton
authors: Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary, University of London, London, UK; Department of Neurology, Barts Health NHS Trust, The Royal London Hospital, London, UK.
authors: Klaus
authors: K
authors: Schmierer
authors: Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary, University of London, London, UK; Department of Neurology, Barts Health NHS Trust, The Royal London Hospital, London, UK.
authors: Gavin
authors: G
authors: Giovannoni
authors: Unit of Health-Care Epidemiology, Nuffield Department of Population Health, University of Oxford, Oxford, UK michael.goldacre@dph.ox.ac.uk.
authors: Michael J
authors: MJ
authors: Goldacre
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D015897:Comorbidity; D005260:Female; D000068116:Gender Dysphoria / Q000453:epidemiology* / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000453:epidemiology* / Q000378:metabolism; D057829:Gender-Affirming Procedures / Q000009:adverse effects*; D055815:Young Adult
keywords: Multiple sclerosis; epidemiology; risk factor; sex hormones; testosterone; transgender