title: Gender differences in paediatric patients of the swiss inflammatory bowel disease cohort study.
abstract: OBJECTIVE
  Gender differences in paediatric patients with inflammatory bowel disease (IBD) are frequently reported as a secondary outcome and the results are divergent. To assess gender differences by analysing data collected within the Swiss IBD cohort study database since 2008, related to children with IBD, using the Montreal classification for a systematic approach.
  
  
  METHODS
  Data on gender, age, anthropometrics, disease location at diagnosis, disease behaviour, and therapy of 196 patients, 105 with Crohn's disease (CD) and 91 with ulcerative or indeterminate colitis (UC/IC) were retrieved and analysed.
  
  
  RESULTS
  THE CRUDE GENDER RATIO (MALE : female) of patients with CD diagnosed at <10 years of age was 2.57, the adjusted ratio was 2.42, and in patients with UC/IC it was 0.68 and 0.64 respectively. The non-adjusted gender ratio of patients diagnosed at ≥10 years was 1.58 for CD and 0.88 for UC/IC. Boys with UC/IC diagnosed <10 years of age had a longer diagnostic delay, and in girls diagnosed with UC/IC >10 years a more important use of azathioprine was observed. No other gender difference was found after analysis of age, disease location and behaviour at diagnosis, duration of disease, familial occurrence of IBD, prevalence of extra-intestinal manifestations, complications, and requirement for surgery.
  
  
  CONCLUSIONS
  CD in children <10 years affects predominantly boys with a sex ratio of 2.57; the impact of sex-hormones on the development of CD in pre-pubertal male patients should be investigated.
authors.affiliation: Division of Gastroenterology, Department of Paediatrics, Cantons Hospital of Fribourg, Fribourg, Switzerland.
authors.forename: Denise
authors.initials: D
authors.lastname: Herzog
authors.affiliation: Division of Gastroenterology and Nutrition, University Children's Hospital Zurich, Zurich, Switzerland.
authors.forename: Patrick
authors.initials: P
authors.lastname: Buehr
authors.affiliation: Division of Gastroenterology and Nutrition, University Children's Hospital Zurich, Zurich, Switzerland.
authors.forename: Rebekka
authors.initials: R
authors.lastname: Koller
authors.affiliation: Division of Gastroenterology and Nutrition, University Children's Hospital Zurich, Zurich, Switzerland.
authors.forename: Vanessa
authors.initials: V
authors.lastname: Rueger
authors.affiliation: Division of Gastroenterology and Nutrition, University Children's Hospital Zurich, Zurich, Switzerland.
authors.forename: Klaas
authors.initials: K
authors.lastname: Heyland
authors.affiliation: Division of Gastroenterology, University Children's Hospital of Lausanne, Lausanne, Switzerland.
authors.forename: Andreas
authors.initials: A
authors.lastname: Nydegger
authors.affiliation: Division of Gastroenterology, Children's Hospital of Lucerne, Lucerne, Switzerland.
authors.forename: Johannes
authors.initials: J
authors.lastname: Spalinger
authors.affiliation: Division of Gastroenterology, University Children's Hospital of Bern, Bern, Switzerland.
authors.forename: Susanne
authors.initials: S
authors.lastname: Schibli
authors.affiliation: Division of Gastroenterology and Nutrition, University Children's Hospital Zurich, Zurich, Switzerland. ; Children's Research Center, University Children's Hospital Zurich, Zurich, Switzerland.
authors.forename: Christian P
authors.initials: CP
authors.lastname: Braegger
keywords: Gender difference; Male preponderance; Paediatric inflammatory bowel disease