Cognitive function and information processing in type 2 diabetes.

AIMS To determine whether uncomplicated Type 2 diabetes is associated with impairment of cognitive function and information processing ability. METHODS Thirty-eight participants with uncomplicated Type 2 diabetes and 38 non-diabetic controls were studied. The two groups were comparable for age and premorbid intellectual ability, and did not have other medical disorders likely to affect cognitive function. An extensive battery of tests was administered which assessed different levels and domains of cognitive functions including verbal and visual memory, executive function, general mental ability and efficiency of information processing. RESULTS No significant differences were found between the diabetic and control groups on any measure of cognitive function or information processing. The performance on these tests was not associated with recent glycaemic control (assessed by HbA1c). Duration of diabetes, however, correlated significantly with poorer performance on several measures of verbal memory. CONCLUSIONS The results of the present study suggest that some aspect of Type 2 diabetes (as indexed by the estimated duration of the disorder) does relate significantly to cognitive function within the group with diabetes. However, other diabetes-related factors, such as macrovascular disease, hypertension and depression, may contribute more to previously observed cognitive decrements in Type 2 diabetes.