title: Association between infectious diseases and type 1 diabetes: a case-crossover study.
abstract: BACKGROUND
  To investigate the role of infectious diseases in the development of type 1 diabetes, this study estimated the relative risks of type 1 diabetes immediately after infectious diseases.
  
  
  METHODS
  A case-crossover design was employed. Information on infectious diseases during 407 d before the onset of type 1 diabetes was collected from medical records and parents' interviews for 260 patients in Chinese type 1 diabetes registry. The frequency of infectious diseases in 42 d before the onset of type 1 diabetes was compared with either the usual frequency of infectious diseases over the past year or the actual frequency of infectious diseases in a comparable 42-d control period.
  
  
  RESULTS
  Forty-eight (18%) patients were reported to have infectious diseases during this period based on medical records and interviews with parents. The relative risk of type 1 diabetes onset was markedly elevated to 10.1 (5.6, 17.9) immediately after infectious diseases, suggesting the role of infections as a precipitator. The relative risk decreased gradually before and after 42 d and was similar between male and female patients.
  
  
  CONCLUSIONS
  The results showed that infectious diseases are associated with a large and transient increase in the risk of type 1 diabetes during 42 d after the infection.
authors.affiliation: Institute of Geriatrics and Beijing Hospital, Ministry of Health, Beijing, China.
authors.forename: Ze
authors.initials: Z
authors.lastname: Yang
authors.forename: Fan
authors.initials: F
authors.lastname: Zhou
authors.forename: Janice
authors.initials: J
authors.lastname: Dorman
authors.forename: Huijuan
authors.initials: H
authors.lastname: Wang
authors.forename: Xiaoquan
authors.initials: X
authors.lastname: Zu
authors.forename: Sati
authors.initials: S
authors.lastname: Mazumdar
authors.forename: Ronald E
authors.initials: RE
authors.lastname: LaPorte
mesh_terms: D015984:Causality; D002648:Child; D002681:China / Q000453:epidemiology; D003141:Communicable Diseases / Q000150:complications*; D018592:Cross-Over Studies; D003922:Diabetes Mellitus, Type 1 / Q000453:epidemiology / Q000209:etiology*; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D012042:Registries; D012107:Research Design; D012306:Risk