Neurocognitive Outcomes in Young Adults With Early-Onset Type 1 Diabetes

OBJECTIVE-The aim of this study was to reexamine the neurocognitive function of a cohort of young adults with early-onset type 1 diabetes and compare their cognitive function to a matched control group. We also examined whether cognitive function was related to prospectively obtained severe hypoglycemia history, long-term glycemic control, or severe diabetic ketoacidosis. RESEARCH DESIGN AND METHODS-Testing included Wechsler Intelligence Scale for Children and Adults, Wechsler Memory Scale, Cattell Culture Fair Intelligence Test (CCFIT), Wisconsin Card Sorting Test (WCST), youth and adult self-report, and Beck Depression Inventory. We tested 34 control subjects (mean +/- SE, age 19.5 +/- 0.5 years) and 33 type 1 diabetic subjects (age 19.3 +/- 0.5 years, age at type 1 diabetes onset 3.3 +/- 0.3 years, AlC from diagnosis 8.7 +/- 0.1%, and diabetes duration 16.0 +/- 0.5 years). RESULTS-There was no difference in full-scale IQ scores in type 1 diabetic and control subjects (100.7 +/- 2.0 vs. 102.5 +/- 1.4). There was no difference between groups in memory subtests or in reporting of emotional and behavioral difficulties. The type 1 diabetes group scored lower on the CCFIT for fluid intelligence compared with control subjects (P = 0.028) and also scored lower on WCST with more perseverative errors (P = 0.002) and fewer categories completed (P = 0.022). CONCLUSIONS-These data suggest no difference in general intellectual ability, memory, and emotional difficulties in our cohort of young adults with early-onset type 1 diabetes compared with control subjects and no deterioration over time. There were, however, findings to suggest subtle changes leading to poorer performance on complex tasks of executive function.