Celiac disease and risk of subsequent type 1 diabetes: a general population cohort study of children and adolescents.

OBJECTIVE Earlier studies suggest that children with type 1 diabetes are more likely to have a subsequent diagnosis of celiac disease. However, research is sparse on the risk of subsequent type 1 diabetes in individuals with celiac disease. We sought to determine the risk of subsequent type 1 diabetes diagnosed before the age of 20 years in children and adolescents with celiac disease in a national, general population-based cohort. RESEARCH DESIGN AND METHODS We identified 9,243 children with a diagnosis of celiac disease in the Swedish national inpatient register between 1964 and 2003. We then identified five reference individuals matched at time of diagnosis for age, calendar year, sex, and county (n = 45,680). Only individuals with >1 year of follow-up after study entry (diagnosis of celiac disease) were included in the analyses. RESULTS Celiac disease was associated with a statistically significantly increased risk of subsequent type 1 diabetes before age 20 years (hazard ratio 2.4 [95% CI 1.9-3.0], P < 0.001). This risk increase was seen regardless of whether celiac disease was first diagnosed between 0 and 2 (2.2 [1.7-2.9], P < 0.001) or 3 and 20 (3.4 [1.9-6.1], P < 0.001) years of age. Individuals with prior celiac disease were also at increased risk of ketoacidosis or diabetic coma before the age of 20 years (2.3 [1.4-3.9], P = 0.001). CONCLUSIONS Children with celiac disease are at increased risk of subsequent type 1 diabetes. This risk increase is low considering that 95% of individuals with celiac disease are HLA-DQ2 positive.