Evaluation of the glymphatic system using the DTI-ALPS index in type 2 diabetes mellitus-induced cognitive impairment.

Objectives: The objective of the study is to assess the utility of the perivascular space diffusion tensor imaging - along the perivascular space (DTI-ALPS) index in evaluating the activity of the brain glymphatic system in patients with type 2 diabetes mellitus (T2DM) and cognitive impairment.

Material and methods: This study included 40 T2DM patients with cognitive impairment and 40 healthy controls (HCs). All participants underwent DTI, and the DTI-ALPS index was calculated based on relevant DTI parameters. Statistical analyses were performed using the Statistical Package for the Social Sciences version 26.0, with significance set at P < 0.05.

Results: The DTI-ALPS index in T2DM patients with cognitive impairment were significantly lower than that of the HCs. A significant negative correlation was observed between the DTI-ALPS index and glycated hemoglobin levels, while positive correlations were found with vitamin D, Montreal Cognitive Assessment scores, and high-density lipoprotein cholesterol levels.

Conclusion: This study confirms glymphatic dysfunction in T2DM patients with cognitive impairment, as indicated by the reduced DTI-ALPS index. Furthermore, it demonstrates the feasibility of utilizing the DTI-ALPS method to assess glymphatic system activity in this patient population.