ESPE Abstracts

Background: The rapidly increasing T1D incidence in European children suggests the recent emergence or extension of predisposing E factors, or the decrease of protective E factors acting during pregnancy, infancy or early childhood. E research has preferentially focused on specific candidate factors, such as hygiene hypothesis, enteroviruses, alimentation, in cohort or case-control studies. The risk of bias is a major concern in E studies.

Objectives: To compare retrospectively T1D and controls for markers of E exposures recalled from the period preceding diagnosis.

Method: ISIS-Diab is a large multicenter cohort of T1D children, who were asked to find controls among their healthy friends. An original 846-item questionnaire was first designed to characterize pregnancy, infancy and childhood E makers. Analyses were done using two complementary methods i) matching 428 patients and 567 controls with Cochran–Mantel–Haenszel (CMH) (binary responses) or conditional logistic regression (ordinal responses) and ii) propensity score method (out-of-bag estimate of the random forest, stratification, then CMH test between the question of interest and disease status) to control for bias in 1127 patients and 642 controls.

Results: Strong associations for both categories of analyses were found. Their relationship with outdoor activities, dental hygiene, specific nutrients, infectious events will be discussed.

Conclusion: This study opens a few original directions for E research in T1D.