Cognitive function in patients with type 2 diabetes mellitus

Patients with type 2 (non-insulin dependent) diabetes mellitus may express moderate degrees of cognitive impairment. The aim of this study was to further characterise these cognitive deficits. Cognitive functions were assessed in 13 patients and 16 controls, matched for age, sex, education and occupational level. In addition, a neurological examination was performed. The performance of diabetic patients was impaired on the neuropsychological examination, in particular in tasks assessing learning and memory. Attention, motor planning and reaction time appeared to be unaffected. Symptoms and/or signs of distal symmetric polyneuropathy were detected in 31% and 46% of the diabetic patients, respectively. The observed deficits are in line with previous neuropsychological studies in type 2 diabetic patients, showing deficits in learning and memory and complex information processing. The fact that these cognitive impairments are reported consistently stresses the need to obtain further insights into pathogenic mechanisms, in order to be able to take adequate preventive measures.