title: Risk of asthma and autoimmune diseases and related conditions in patients hospitalized for obesity.
abstract: BACKGROUND
  Although there are putative mechanistic links between obesity and autoimmune diseases, obesity is not considered a risk factor for most autoimmune diseases.
  
  
  METHODS
  Using the nation-wide Hospital Discharge Register we defined a cohort of 29,665 patients hospitalized for obesity since year 1964. The patients were followed for hospitalization for any of 34 autoimmune or related conditions through year 2007. Standardized incidence ratios (SIRs) were calculated for autoimmune diseases in obese individuals compared to those who had not been hospitalized for obesity.
  
  
  RESULTS
  Among 22 immune diseases diagnosed after hospitalization for obesity and in at least 5 patients, the overall SIR was 2.05. Of the individual diseases studied, the risk of 16 was significantly increased; none displayed a decreased risk. Psoriasis (4.54) and Behçet's disease (4.49) exhibited the highest risks, followed by Hashimoto's disease/hypothyroidism (4.12) and asthma (3.39). Small but significant increases in SIRs were also noted for the common autoimmune diseases Graves's disease/hyperthyroidism (1.28) and rheumatoid arthritis (1.37).
  
  
  CONCLUSIONS
  The present population of obese individuals, subsequently diagnosed with a number of autoimmune diseases and related conditions, was hospitalized at a relatively young age. Further studies are needed to describe the morbidity in the obese population at large.
authors.affiliation: Division of Molecular Genetic Epidemiology, German Cancer Research Center, Heidelberg, Germany. k.hemminki@dkfz.de
authors.forename: Kari
authors.initials: K
authors.lastname: Hemminki
authors.forename: Xinjun
authors.initials: X
authors.lastname: Li
authors.forename: Jan
authors.initials: J
authors.lastname: Sundquist
authors.forename: Kristina
authors.initials: K
authors.lastname: Sundquist
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D001249:Asthma / Q000209:etiology*; D001327:Autoimmune Diseases / Q000209:etiology*; D002648:Child; D015331:Cohort Studies; D005260:Female; D006760:Hospitalization / Q000706:statistics & numerical data*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications* / Q000276:immunology; D010351:Patient Discharge; D012042:Registries; D012306:Risk; D012307:Risk Factors