Associations of Glymphatic System Function with White Matter Alterations and Cognitive Impairment in Type 2 Diabetes

Motivation: Limited understanding of brain glymphatic system function in Type 2 Diabetes (T2DM) hinders insight into its mechanisms. Goal(s): To explore brain glymphatic function using the Diffusion tensor imaging-analysis along the perivascular space (DTI-ALPS) technique, and association with white matter injury in T2DM patients. Approach: 26 T2DM patients with cognitive impairment, 25 T2DM patients with normal cognition, and 27 healthy controls were imaged at 3.0T using DTI. Results: Reduced DTI-ALPS index was observed in T2DM groups, and correlated with the whole white matter skeleton alterations (measured by increased peak width of skeletonized mean diffusivity, PSMD), also associated with cognitive decline and prolonged disease duration. Impact: This study highlights that the DTI-ALPS technique and PSMD estimates can provide valuable insights into physiological mechanisms of T2DM, especially those with cognitive impairment, and offers greater specificity in detecting glymphatic system function and global white matter changes.