Type 2 diabetes mellitus (T2DM) is associated with a twofold increased risk of dementia and can affect many cognitive abilities, but its underlying cause is still unclear. In this study, we used a combination of a battery of neuropsychological tests and diffusion tensor images (DTI) to explore how T2DM impacts white matter (WM) integrity and cognition in 38 T2DM patients and 34 age-, gender- and education-matched normal controls. A battery of neuropsychological tests was used to assess a wide range of cognitive functions. Tract-based spatial statistics (TBSS) combined with ROI-wise analysis of mean values of DTI metrics in ROIs was utilized to compare group differences of DTI metrics on WM skeletons to identify severely disrupted WM tracts in T2DM. We found that T2DM patients showed (1) various cognitive impairments, including executive function, spatial processing, attention and working memory deficits; (2) widespread WM disruptions, especially in the whole corpus callosum, the left anterior limb of the internal capsule and external capsule; and (3) a positive correlation between executive function and WM integrity in ALIC.L and EC.L. In conclusion, T2DM patients show various cognitive impairments and widespread WM integrity disruptions, which we attribute by demyelination. Moreover, executive dysfunction closely correlates with WM abnormalities.
* These authors contributed equally to the manuscript.
- Received February 27, 2014.
- Accepted May 22, 2014.
- © 2014 by the American Diabetes Association.
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