Title: Changes in the glymphatic system before and after dialysis initiation in patients with end-stage kidney disease

Authros: Yoo Jin Leea*, Kang Min Parkb*, Chang Min Heoa, Sihyung Parka, Yang Wook Kima, Dongyeol Leec,

Yunmi Kimd, Joon Seok Ohe, Ho Sik Shin f and Bong Soo Parka

aDepartment of Internal Medicine, Inje University Haeundae Paik Hospital, Inje University College of Medicine, Busan, Republic of Korea;

bDepartment of Neurology, Inje University Haeundae Paik Hospital, Inje University College of Medicine, Busan, Republic of Korea;

cDepartment of Internal Medicine, Good Gangan Hospital, Busan, Republic of Korea; dDepartment of Internal Medicine, Inje University

Busan Paik Hospital, Inje University College of Medicine, Busan, Republic of Korea; eDepartment of Internal Medicine, Bong Seng

Memorial Hospital, Busan, Republic of Korea; fDepartment of Internal Medicine, Gospel Hospital, Kosin University College of Medicine,

Busan, South Korea

ABSTRACT

Introduction: The aims of this study were to evaluate 1) glymphatic system function in patients with end-stage kidney disease (ESKD) before initiating dialysis compared to healthy controls, and 2) changes in the glymphatic system function after kidney replacement therapy including dialysis in patients with ESKD using the diffusion tensor image analysis along the perivascular space (DTI-ALPS) method.

Materials and methods: This study was prospectively conducted at a single hospital. We enrolled 14 neurologically asymptomatic patients who first initiated hemodialysis or peritoneal dialysis for ESKD and 17 healthy controls. Patients had magnetic resonance imaging scans before initiating dialysis and again 3 months after initiating dialysis and the DTI-ALPS index was calculated. We compared the DTI-ALPS index before and after the initiation of dialysis and compared the DTI-ALPS index between the patients with ESKD and healthy control.

Results: There were differences in the DTI-ALPS index between ESKD patients before initiating dialysis and healthy controls (1.342 vs. 1.633, p = 0.003). DTI-ALPS index between ESKD patients before initiating dialysis and those after dialysis were not different (1.342 vs. 1.262, p = 0.386). There was a positive correlation between DTI-ALPS index and phosphate (r = 0.610, p = 0.020) in patients with ESKD.

Conclusion: We confirmed the presence of glymphatic dysfunction in patients with ESKD. However, there was no difference in the glymphatic system before and after dialysis initiation. This finding may be related to uremic toxins that are not removed by dialysis in patients with ESKD. This study can be used for the development of pathophysiology of patients with ESKD.