Decreased prevalence of atopic diseases in children with diabetes

Objective: To test the hypothesis that atopic diseases in early life are associated with a reduced risk (protection) for the development of type 1 diabetes in childhood. Study design: European centers (n = 8) with access to population-based type 1 diabetes registries (>90% degree of ascertainment) participated in a case control study focusing on early exposures and risk factors for type 1 diabetes. Altogether data from 1028 members of a case group and 2744 members of a control group corresponding to 85.4% eligible members of the case group and 76.1% of the control group were analyzed. Information in this study was collected regarding atopic diseases (atopic eczema, allergic rhinoconjunctivitis, and asthma). Results: Atopic disease and asthma particularly are associated with significant reductions in risk of childhood type 1 diabetes. The risk reduction associated with asthma was observed reasonably consistently among the 8 study centers, which represent a wide range of diabetes incidence. Risk reductions associated with all 3 expressions of atopy were particularly marked in children whose type 1 diabetes was diagnosed in the 10- to 14-year age group. Conclusion: These findings indicate that atopic conditions may be protective against the development of type 1 diabetes and are consistent with the immunologic concept of T(H)1 (type 1 diabetes) and T(H)2 (atopy) diseases being mutually exclusive.