White matter microstructural alterations associated with type-2 diabetes mellitus and mild cognitive impairment.

Diabetes is one of the main risk factors for developing amnesic mild cognitive impairment and Alzheimer's disease. Several studies have found differences between the microstructural abnormalities that appear in the brains of patients with type 2 diabetes and amnesic mild cognitive impairment (T2DM-aMCI). To compare the microstructural differences between the brains of subjects with T2DM-aMCI and the brains of healthy controls. In addition, to correlate the cognitive decline of subjects with T2DM-aMCI with microstructural alterations. A cross-sectional study was conducted with a sample size of 54 patients. The participants were divided into two groups: T2DM-aMCI and healthy controls. All the participants underwent a wide range of neuropsychological tests assessing different cognitive domains. 47 subjects had MRI session. An exploratory analysis showed that the T2DM-aMCI group had a reduced fractional anisotropy in the white matter compared to the healthy controls group (p < 0.15). The most affected areas were the body of the corpus callosum and the right and left superior corona radiata. T2DM-aMCI had significant positive correlations (p < 0.05) between cerebral regions and Mini Mental State Examination, Montreal Cognitive Assessment, Rey Auditory Verbal Learning Test immediate recall and recognition, Verbal Fluency Test total words and animals. Persons with T2DM-aMCI showed less cerebral white matter integrity in different brain areas when compared to healthy controls. Positive correlations between white matter microstructural alterations and functional cognition (general cognition, memory and language) in T2DM-aMCI group were found.