Interaction between dietary iron intake and genetically determined iron overload: risk of islet autoimmunity and progression to type 1 diabetes in the TEDDY study
To examine if iron intake and genetically determined iron overload interact in predisposing to the development of childhood islet autoimmunity (IA) and type 1 diabetes (T1D).
Research Design and Methods
In “The Environmental Determinants of Diabetes in the Young” (TEDDY) study, 7,770 genetically high-risk children were followed from birth until the development of IA and progression to T1D. Exposures included energy-adjusted iron intake in the first 3 years of life and a genetic risk score (GRS) for increased circulating iron.
We found a U-shaped association between iron intake and risk of GADA as first autoantibody. In subjects with GRS>=2 iron risk alleles, high iron intake was associated with increased risk of IA with insulin as first autoantibody [adjusted hazard ratio (HR, 95% CI): 1.71 (1.14; 2.58), as compared to moderate iron intake.
Iron intake may alter the risk of islet autoimmunity in children with high-risk HLA haplogenotypes.