Aims/hypothesis: The role of infections in the aetiology of Type I diabetes is controversial. Certain enteroviral infections might be involved in triggering the beta-cell destruction but insufficient exposure to early infections might increase the risk. We studied how the number of infections experienced during several periods from birth to onset influence diabetes risk.
Methods: The study group came from the five largest Lithuanian cities: 124 patients, selected from the 0-14 years-of-age childhood diabetes register and 372 population-based control subjects matched with them for age group and sex. Information about infections and duration of breastfeeding was collected from health care booklets, other data from a mailed questionnaire, returned by 94.4% of patients and 72.6 % of control subjects.
Results: One or more infections experienced during the first half year of life tended to reduce diabetes risk. Crude odds ratios (95% confidence intervals) in the 0-14, 0-4 and 5-14 years-of-age groups were 0.66 (0.42-1.04), 1.06 (0.48-2.36) and 0.52 (0.30-0.90) respectively. Adjustment for the duration of breastfeeding, number of people in the household, duration of mother's education and birth order of the index child made little difference. Odds ratios (95 % confidence intervals) in the 0-14, 0-4 and 5-14 years-of-age groups were 0.60 (0.37-0.98), 0.94 (0.40-2.20) and 0.47 (0.26-0.87), respectively. The number of infections recorded during the last pre-onset year or from birth to onset did not influence diabetes risk.
Conclusion/interpretation: Exposure to infections early in life could decrease diabetes risk, particularly for children diagnosed after the age of 4 years.