Cumulative incidence of type 1 diabetes in two cohorts of children with different national gluten recommendations in infancy.

AIMS: Between 1985 and 1996, Sweden experienced an "epidemic" of celiac disease with a fourfold increase in incidence in young children. Timing and amount of gluten introduced during infancy have been thought to explain this "epidemic". We aimed to study whether the cumulative incidence of type 1 diabetes differs between children born during the "epidemic" compared to children born after. METHODS: This is a national register study in Sweden comparing the cumulative incidence of type 1 diabetes in two birth cohorts of 240 844 children 0-17 years old born 1992-1993, during the "epidemic", and 179 530 children born 1997-1998, after the "epidemic". Children diagnosed with type 1 diabetes were identified using three national registers. RESULTS: The cumulative incidence of type 1 diabetes by the age of 17 was statistically significantly higher in those born after the "epidemic" 0.77% than in those born during the "epidemic" 0.68% (p < 0.001). CONCLUSION: The incidence of type 1 diabetes is higher in those born after the epidemic compared to those born during the epidemic, which does not support the hypothesis that gluten introduction increases the incidence of T1D. Changes in gluten introduction did not halt the increased incidence of type 1 diabetes in Sweden.

The prevalence of having coeliac disease in children with type 1 diabetes was not significantly higher during the Swedish coeliac epidemic.

AIM: From 1986 to 1996, there was a four-fold increase in coeliac disease among young Swedish children, known as the Swedish coeliac epidemic. Children with type 1 diabetes have an increased risk of developing coeliac disease. We studied whether the prevalence of coeliac disease differed in children with type 1 diabetes born during and after this epidemic. METHODS: We compared national birth cohorts of 240 844 children born in 1992-1993 during the coeliac disease epidemic and 179 530 children born in 1997-1998 after the epidemic. Children diagnosed with both type 1 diabetes and coeliac disease were identified by merging information from five national registers. RESULTS: There was no statistically significant difference in the prevalence of coeliac disease among children with type 1 diabetes between the two cohorts: 176/1642 (10.7%, 95% confidence interval 9.2%-12.2%) in the cohort born during the coeliac disease epidemic versus 161/1380 (11.7%, 95% confidence interval 10.0%-13.5%) in the post-epidemic cohort. CONCLUSION: The prevalence of having both coeliac disease and type 1 diabetes was not significantly higher in children born during, than after, the Swedish coeliac epidemic. This may support a stronger genetic disposition in children who develop both conditions.