The characteristic of cognitive function in Type 2 diabetes mellitus

Aim: To identify characteristics of neuropsychological function among elderly individuals with Type 2 diabetes mellitus with mild cognitive impairment (T2DM-MCI) and evaluate domain-specific effects of T2DM on cognition. Methods: This was a cross-sectional study conducted in Tianjin, China. MCI subjects (n = 246) and controls were identified in elderly individuals with diabetes, and groups were matched in a 1: 1 ratio for sex, age and educational level. Cognitive function was assessed using WAIS-III (block design, digit span), Trail Making Test A, Trail Making Test B, WMS-III (word list learning, logical memory), verbal fluency and MMSE. We used multivariable logistic regression to find diabetic factors associated with MCI. Results: The mean MMSE score was 22.73 +/- 2.32 in subjects with T2DM-MCI, versus 26.71 +/- 2.43 in subjects cognitive normal (P < 0.001). Executive and visuospatial functions were more impaired in individuals with T2DM-MCI than in those without, as assessed using block design (P < 0.001), digit span test (P < 0.001), and Trails B (P < 0.001). For memory, subjects with T2DM-MCI did worse than those cognitive normal on the word learning list delayed recall (P = 0.015). Diabetic-related factors such as longer duration of T2DM, higher HbA1c, insulin treatment was associated with a lower level of cognitive functioning using MMSE, block design, delayed recall and Trails B test. Conclusions: T2DM should be considered a risk factor for MCI. This risk may be associated with duration of diabetes, use of glucose-lowering medications, degree of glucose control. To decrease risk of MCI, it is important to monitor glucose control and adjust medications appropriately in elderly patients. (C) 2015 Elsevier Ireland Ltd. All rights reserved.