Infections and risk of type I diabetes in childhood: a population-based case-control study.
OBJECTIVE
This study focuses on the evaluation of some infectious diseases as risk determinants of type I diabetes mellitus (DM).


METHODS
A population-based case-control study was carried out by referring to the type I DM population-based register of the Abruzzo region of Italy as it includes all type I DM cases since January 1 1990, the point at which the register became operative. The pediatric population (age: 0-14), living in the same municipalities of the cases, was selected as the control population. Data were collected through questionnaires submitted by a physician to parents of cases and controls. Conditional logistic regression models were used to evaluate association between determinants and onset of type I DM.


RESULTS
The risk of diabetes for children exposed to only one infection (morbilli, parotitis, rubella, pertussis or varicella) is not statistically significant: OR: 0.778; CI: 0.427-1.370. On the contrary, when two infections are contracted statistically significant results occur: OR: 2.375; CI: 1.149-4.914; for more than two infections values are: OR: 6.786; CI: 2.881-17.877. No substantial difference in odds ratios (ORs) after adjustment for confounding variables was found. A significant decrease in OR was noted for pertussis and MMR vaccinations, respectively: OR: 0.015; CI: 0.001-0.251; OR: 0.400; CI: 0.201-0.799.


CONCLUSIONS
Since the higher the number of contracted infections, the higher the risk of diabetes, contracted infections can be considered potential accelerating factors of clinical manifestation of type I DM. Therefore multiple exposures might speed up the onset of diabetes in children. This study suggests the utility of applying the risk model method to wider populations, especially if the geographical variability of standardised incidence rates of type I DM in pediatric age is taken into consideration.
Altobelli
Emma
E
Department of Internal Medicine and Public Health, University of L'Aquila, Italy. emmaalto@tin.it
Petrocelli
Reimondo
R
Verrotti
Alberto
A
Valenti
Marco
M
D000293:Adolescent; D016022:Case-Control Studies; D019433:Chickenpox Vaccine / Q000009:adverse effects / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D003922:Diabetes Mellitus, Type 1 / Q000453:epidemiology / Q000209:etiology* / Q000517:prevention & control*; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007558:Italy / Q000453:epidemiology; D016015:Logistic Models; D008297:Male; D022542:Measles-Mumps-Rubella Vaccine / Q000009:adverse effects / Q000627:therapeutic use; D016017:Odds Ratio; D010567:Pertussis Vaccine / Q000009:adverse effects / Q000627:therapeutic use; D012042:Registries; D018570:Risk Assessment; D012307:Risk Factors; D014611:Vaccination / Q000009:adverse effects* / Q000706:statistics & numerical data; D014777:Virus Diseases / Q000145:classification / Q000150:complications* / Q000453:epidemiology / Q000517:prevention & control; D014917:Whooping Cough / Q000150:complications* / Q000453:epidemiology / Q000517:prevention & control
D019433:Chickenpox Vaccine; D022542:Measles-Mumps-Rubella Vaccine; D010567:Pertussis Vaccine