Effect of Glymphatic System Function on Cognitive Function in Patients with CKD

Background: The aim of this study was to investigate the effects of glymphatic system function on cognitive function in patients with chronic kidney disease (CKD). Methods: We prospectively enrolled the patients with CKD and healthy controls. We divided the patients with CKD into two groups according to their cognitive function. All of them underwent brain magnetic resonance imaging, which included diffusion tensor imaging (DTI). We calculated the diffusion tensor image analysis along the perivascular space index (DTI-ALPS index) based on the DTI which was the marker for glymphatic system function (Fig1). We compared the DTI-ALPS index between the groups. Results: DTI-ALPS index in patients with CKD was lower than that in healthy controls (1.436 vs. 1.632, p<0.001). In addition, there were significant differences of the DTI-ALPS index between CKD patients with and without CI. DTI-ALPS index in CKD patients with CI was lower than that in those without CI (1.338 vs. 1.494, p=0.031, Fig 2). Furthermore, DTI-ALPS index was negatively correlated with age (r=-0.326, p=0.014) in the patients with CKD. Conclusion: This study observed that the DTI-ALPS index was lower in patients with CKD, suggesting glymphatic system dysfunction in patients with CKD. Moreover, within the CKD patient group, those with CI had lower DTI-ALPS index compared to those without CI, indicating a potential link between glymphatic system dysfunction and CI. These findings suggest that glymphatic system dysfunction may contribute to CI in patients with CKD.Figure 1. Calculation of the DTI-ALPS indexFigure 2. Differences of the DTI-ALPS index between the groups