Association between infectious diseases and type 1 diabetes: a case-crossover study.
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.
Yang
Ze
Z
Institute of Geriatrics and Beijing Hospital, Ministry of Health, Beijing, China.
Zhou
Fan
F
Dorman
Janice
J
Wang
Huijuan
H
Zu
Xiaoquan
X
Mazumdar
Sati
S
LaPorte
Ronald E
RE
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