Meta-analysis finds slight IQ difference in children with type 1 diabetes versus peers

Type 1 diabetes (T1D) complications may impair cognitive development, but evidence on cognitive skills in children and adolescents with T1D is inconsistent. This study aimed to document measures and outcomes used to assess cognitive skills in children with T1D and to examine the relationship between T1D and cognitive skills. A systematic literature search was conducted across five databases to identify studies that administered cognitive assessments to children and adolescents aged ≤19 years with T1D. Study characteristics, cognitive skills assessments and outcomes and comparisons to non-T1D peers where available were synthesized on an evidence map. Random-effects meta-analysis was used to assess differences in Wechsler Full Scale Intelligence Quotient (IQ) test scores between T1D and non-T1D groups. From 2464 studies, 129 were included. Five main cognitive categories were identified, with comparisons to non-T1D peers-where available-yielding mixed results: academic performance (n=37; n=7/22 worse T1D), executive function (n=101; n=31/48 worse T1D), intelligence (n=73; n=22/37 worse T1D), language (n=30; n=7/20 worse T1D) and memory and learning (n=84; n=31/48 worse T1D). Large-scale studies (n≥1000) did not find significant differences between groups for academic performance (n=0/6 worse T1D) and language (n=0/3 worse T1D). In the meta-analysis of 16 studies (n=1594), children with T1D had slightly lower IQ scores than peers without T1D (mean difference -3.49, 95% CI (-6.16 to -0.82); p=0.010). T1D appears to be associated with slightly lower cognitive outcomes in some areas. Further research is needed to understand the impact of these findings on daily functioning and to inform screening for at-risk children.