Cognitive functions and glycemic control in children and adolescents with type 1 diabetes

The relationship between metabolic control and cognitive function in adolescents with type 1 diabetes (DM type 1) is not clear. We compared the quality of glycemic control (GC) and cognitive measures in adolescents with DM type 1 to find out if the quality of diabetes management is related to cognitive impairment.

We assessed executive functions (EFs) and other neuropsychological and psychosocial variables in 70 adolescent patients with DM type 1 and 20 age-matched controls. Patients were divided into two groups according to their last hemoglobin A1c (HbA1c): acceptable (HbA1c 5.9-8.0%, mean 6.9%, 36 patients, mean age 14 years) and non-optimal (HbA1c 8.2-11.6%, mean 9.3%, 34 patients, mean age 15.6 years).

We found impaired EFs, mainly problems of concept formation (p=0.038), cognitive flexibility (p=0.011) and anticipation (p=0.000), in the patients with DM type 1. Both groups did not differ in intelligence, most assessed EFs and adjustment to chronic illness (Youth Self-Report; YSR). Younger patients (<15 years) were cognitively less flexible. GC was worse in older patients and in patients with longer duration of the disease. We also found significant differences between patients with diabetes and controls concerning somatic complaints, internalizing problems (Child Behavior Checklist; CBCL) and social activity (CBCL and YSR).

DM type 1 is associated with cognitive deficits in adolescents independent of the quality of metabolic control and the duration of the disease. These deficits are probably related to the disease, especially in patients with early-onset diabetes.