Peritoneal Dialysis Linked To Improved Cognitive Function In CKD

New research suggests peritoneal dialysis (PD) may be associated with improved cognitive outcomes compared to hemodialysis (HD) in patients with chronic kidney disease (CKD).

Findings regarding these select domains include executive function, memory, processing speed, and long-term cognitive integrity and highlight the further need to individualize dialysis modality decisions based on cognitive risk profiles and standardize research in this patient population.1

“To the best of our knowledge, this systematic review and meta-analysis provides the most comprehensive and up-to-date synthesis of evidence regarding cognitive outcomes associated with HD and PD in patients with CKD,” wrote study investigator Ali Malik, a medical student at King’s College London, and colleagues.1

Cognitive impairment is a significant comorbidity associated with CKD and dialysis modalities, affecting between 33-46% of patients. Cognitive impairment affects patient executive functioning, memory, attention, visuospatial skills, quality of life, and increases the risk of progression towards dementia. Previous literature has reported conflicting findings on which dialysis modality can more effectively preserve cognitive function.2

To evaluate this further, Malik and colleagues conducted a systematic review and meta-analysis of studies with cognitive outcome reporting and direct comparisons between HD and PD. They determined the primary outcomes as cognitive function, measured by results from neuropsychological assessments, available neuroimaging findings, and psychological or psychiatric evaluations, and dementia incidence.1

Investigators selected 26 eligible cohort studies that enrolled 326,216 adult patients ≥ 18 years of age with CKD, receiving either HD or PD.1

Based on the 4 cognitive domains tested by studies, they conducted subgroup meta-analysis. These domains include global cognitive function, executive function, processing speed, and memory scores compared between PD and HD. The pooled analysis demonstrated benefits from PD by the majority of factors assessed, including executive function (Standardized Mean Difference [SMD], − 0.39; 95% Confidence Interval [CI], − 0.61 to − 0.16; P = .0008; Heterogeneity [I2], 31%), global cognitive function (SMD, − 0.46; 95% CI, − 0.62 to − 0.29; P < .00001; I2, 49%), lowered risk of incidence of dementia (Odds Ratio [OR], 1.68; 95% CI, 1.25 to 2.25; P = .0006; I2, 94%), increased processing speed (SMD, − 0.28; 95% CI − 0.47 to − 0.08; P = .005; I2, 0%), and memory scores (SMD, − 0.35; 95% CI, − 0.62 to − 0.06; P = .01; I2 = 0%). Additionally, multiple studies reported enhanced autonomy and slower trajectories of cognitive decline in patients undergoing PD.1

From these findings, investigators suggest an association between the continuous toxin clearance, stable hemodynamic profiles, and improved preservation of residual renal function in patients receiving PD as potential sources for these perceived cognitive benefits.1

Despite this, investigators noted a significant number of studies with no statistically significant differences between PD and HD. As a result, Malik and colleagues emphasize the potential that these cognitive outcomes could be substantially influenced by patient-specific factors such as age, dialysis duration, and comorbidities.1

“Clinically, our findings highlight potential cognitive benefits associated with PD, supporting its consideration, particularly among ESRD patients at elevated risk for cognitive decline,” investigators concluded. “Nevertheless, selecting dialysis modalities must remain individualised, carefully weighing cognitive considerations alongside patient-specific medical, psychosocial, and logistical factors.”1

References

1. Malik A, Mansour HRK, Kundur SP, Hunjan A, Zaheer R. Dialysis modality and cognitive outcomes in chronic kidney disease: a systematic review and meta-analysis. Clinical and Experimental Nephrology. Published online December 1, 2025. doi:https://doi.org/10.1007/s10157-025-02798-2

2. Dhakal A, Bobrin BD. Cognitive Deficits. StatPearls. Published 2023. https://www.ncbi.nlm.nih.gov/books/NBK559052/

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