Intellectual deficits associated with early onset of insulin-dependent diabetes mellitus in children.

Twenty-seven children with early-onset (less than 4 yr) diabetes (EOD), 24 children with late-onset (greater than 4 yr) diabetes (LOD), and 30 sibling controls were compared in their performance on tests of intellectual functioning and school achievement. The results indicated that children with EOD, particularly girls, scored lower than the other groups of diabetic children and siblings on tests of visuospatial (P less than .05) but not verbal ability. Many of the girls with EOD were also having difficulty at school, and several were receiving special education. Children with EOD had more hypoglycemic convulsions than those with LOD. Both convulsions and age of onset were associated with poorer performance on spatial tasks. Girls with EOD had lower spatial test scores regardless of convulsion history, whereas boys with EOD scored lower only if they had had a convulsion.