White Matter Microstructural Change Contributes to Worse Cognitive Function in Patients With Type 2 Diabetes

Area of Science:

• Neuroimaging
• Neurology
• Endocrinology

Background:

• Type 2 diabetes mellitus (T2DM) significantly increases dementia risk, particularly in individuals with mild cognitive impairment (MCI).
• Understanding white matter (WM) microstructural changes in T2DM patients is crucial for elucidating T2DM-related cognitive impairment.

Purpose of the Study:

• To investigate white matter (WM) microstructural differences between T2DM patients with amnesic MCI (T2DM-aMCI) and T2DM patients with normal cognition (T2DM-NC).
• To explore the relationship between WM integrity and cognitive performance in T2DM patients.
• To identify specific WM tracts affected in T2DM-aMCI and their association with cognitive deficits.

Main Methods:

• Diffusion tensor imaging (DTI) and T1-weighted MRI scans were performed on 36 T2DM-aMCI patients, 40 T2DM-NC patients, and 40 healthy controls (HC).
• Comprehensive cognitive assessments were conducted for all participants.
• Intergroup comparisons of WM integrity and correlations with cognitive functions were analyzed.

Main Results:

• T2DM-NC patients and HC individuals showed no significant differences in WM integrity.
• T2DM-aMCI patients exhibited disrupted integrity in multiple WM tracts compared to HC and T2DM-NC groups.
• Damage in the right inferior fronto-occipital and inferior longitudinal fasciculi correlated significantly with episodic memory and attention deficits in T2DM patients.

Conclusions:

• Extensive white matter degeneration is present in T2DM-aMCI patients, affecting cognitive functions.
• No significant white matter damage was observed in T2DM patients with normal cognition.
• Cognitive impairment in T2DM-aMCI is linked to microstructural damage in specific WM tracts and associated cortical degeneration.