Hemodialysis and its effects on glymphatic system function in end-stage kidney disease patients

The glymphatic system, responsible for clearing metabolic waste from the brain, may be affected in patients with end-stage kidney disease (ESKD), potentially impacting brain health. This study investigates the effects of hemodialysis on glymphatic function in ESKD patients.

This prospective study enrolled ESKD patients along with age- and sex-matched healthy controls (HCs). Each ESKD patient underwent magnetic resonance imaging (MRI) scans before and after a single hemodialysis session to obtain diffusion tensor imaging (DTI) data. HCs underwent a single MRI scan. The analysis along the perivascular space (ALPS) index was calculated using DTI-ALPS to indirectly assess changes in glymphatic system function pre- and post-hemodialysis in ESKD patients and to compare pre-hemodialysis with HCs. Additionally, correlations between the ALPS index and clinical indicators were assessed to explore potential links between glymphatic and kidney function.

A total of 25 ESKD patients (mean age 49.80±13.01 years; 14 males) and 27 HCs (mean age 48.67±10.16 years; 12 males) were analyzed. After hemodialysis, ESKD patients showed increased calcium (2.09±0.28 vs. 2.20±0.20 mmol/L, P=0.003) and estimated glomerular filtration rate (eGFR; 5.83±2.20 vs. 12.93±3.94 mL/min/1.73 m², P<0.001), with reductions in blood urea nitrogen (BUN) (23.07±9.06 vs. 7.33±3.35 mmol/L, P<0.001), creatinine (1,036.65±241.42 vs. 414.75±109.83 µmol/L, P<0.001), and potassium (4.83±0.89 vs. 3.63±0.56 mmol/L, P=0.001). The ALPS index in ESKD patients was significantly lower than that in HCs (1.379±0.154 vs. 1.469±0.090, P=0.023). However, there was no significant change in the ALPS index of ESKD patients after a single hemodialysis session (1.379±0.154 vs. 1.387±0.143, P=0.493). A positive correlation was observed between ALPS index and prealbumin levels (r=0.663, P=0.002).

ESKD patients exhibited a significantly lower ALPS index compared with HCs, indicating altered perivascular diffusion patterns. No significant changes in the ALPS index were detected after a single hemodialysis session. As the ALPS index is an indirect marker, further research is needed to clarify its relationship with glymphatic function in kidney disease.