Type-2 diabetes and cognitive function in a non-demented population

Objectives - To study if type-2 (non-insulin-dependent) diabetes mellitus (NIDDM) is associated with cognitive dysfunction independently of clinically diagnosed dementia in an elderly population. Material and methods - Cognitive function was investigated with a brief neuropsychological test battery in a non-demented elderly population consisting of 183 NIDDM (World Health Organization, 1985) patients and 732 non-diabetic subjects. Results - Patients with NIDDM were impaired in the Trail-Making Test parts A and C, which may be a reflection of mildly affected frontal lobe/executive functions. Women with NIDDM performed better than non-diabetic subjects in the Mini-Mental State Examination. Conclusions - We conclude that NIDDM per se is not associated with impaired memory in the elderly, and the minor defects observed in tests of frontal lobe/executive functions are unlikely to affect daily living. In the non-demented population aged 69-78 years, NIDDM does not carry a significant risk of cognitive dysfunction, when compared to the non-diabetic subjects.