Prenatal and early life factors and type 1 diabetes.

Background: The prevalence of type 1 diabetes is increasing worldwide, suggesting that unknown environmental factors are becoming increasingly important in its pathogenesis.

Aim: The aim of the study was to investigate the possible role of a number of prenatal and perinatal factors in the aetiology of type 1 diabetes.

Methods: Mothers of patients diagnosed with type 1 diabetes (cases) and mothers of children born on the same day and of the same sex as type 1 diabetes patients (controls) were interviewed on a number of prenatal and perinatal factors of interest.

Results: Hand washing prior to eating, frequency of bathing and total stress score were found to be positively associated with the development of type 1 diabetes on univariate analyses. Hand-washing prior to eating and frequency of house cleaning were independently associated with an increased risk of type 1 diabetes, whilst getting dirty was associated with a reduced risk in multivariate analyses. There was no association of type 1 diabetes to removing of outdoor shoes indoors or to the age of first attendance to school or pre-school. There were also no significant associations to parental smoking, parental age, birth order, infant feeding, antibiotic use, mode of delivery or birth weight.

Conclusion: Our data suggest that factors that affect the skin or gut microbiome might be more important than infections or factors affecting the microbiome at other sites.