Peritoneal Dialysis Shows Cognitive Benefits Over Hemodialysis in CKD: Study
UK: A recent meta-analysis of 26 studies has revealed that peritoneal dialysis may better preserve cognitive function—especially executive function and memory—and may lower dementia risk compared with hemodialysis in patients with chronic kidney disease (CKD).
The research, published in Clinical and Experimental Nephrology, offers fresh insight into how dialysis modality may influence cognitive health in individuals with CKD.
Led by Ali Malik and colleagues from King’s College London, the analysis highlights meaningful differences between peritoneal dialysis (PD) and hemodialysis (HD), suggesting that PD may confer cognitive advantages in several domains.
Cognitive impairment is increasingly recognized as a major comorbidity among people with CKD, yet until now, evidence comparing the cognitive effects of the two main dialysis modalities has been inconsistent.
To clarify these associations, the researchers systematically searched multiple major databases for cohort studies published between January 2000 and January 2025. Their protocol was prospectively registered on PROSPERO, and the included studies were assessed using ROBINS-I for risk of bias and the GRADE framework for quality of evidence.
Key Findings:
- Out of 1489 screened articles, 26 studies qualified for inclusion, covering a total of 326,216 patients.
- The meta-analysis showed a significant difference in cognitive outcomes between the two dialysis modalities.
- Peritoneal dialysis was linked to better overall cognitive performance (SMD −0.46).
- Patients on peritoneal dialysis also had a notably lower odds of developing dementia (OR 1.68).
- Subgroup analyses indicated that peritoneal dialysis offered advantages, particularly in executive function, verbal memory, and overall cognitive stability.
The authors note that these findings strengthen the argument for incorporating cognitive considerations into dialysis modality decision-making, especially for patients who may already be at higher risk of neurocognitive decline. They also emphasised that while quantitative evidence supports PD’s advantage, qualitative patterns across studies further highlight its potential to maintain cognitive function.
However, the review has notable limitations. With no randomized controlled trials available, the evidence is largely observational and susceptible to confounding and selection bias. Variations in cognitive assessment tools, dialysis duration, and non-standardized testing protocols make comparisons across studies challenging. Most research also captures only short-term cognitive outcomes, leaving long-term trajectories unclear. Important secondary factors such as quality of life, mood symptoms, and caregiver burden were rarely assessed, despite their relevance to cognitive health.
The authors call for high-quality, multicentre randomized controlled trials incorporating standardized cognitive assessments and neuroimaging to explore the mechanistic underpinnings of cognitive decline in dialysis patients. They also recommend future research that considers long-term outcomes and patient-centered measures such as autonomy, mental health, and overall quality of life.
Overall, the findings reinforce the complex relationship between dialysis modality and cognitive outcomes in CKD, while suggesting that peritoneal dialysis may offer selective cognitive benefits. As clinicians counsel patients and tailor renal replacement strategies, these insights may play an increasingly important role in shared decision-making.
Reference:
Malik, A., Mansour, H.R.K., Kundur, S.P. et al. Dialysis modality and cognitive outcomes in chronic kidney disease: a systematic review and meta-analysis. Clin Exp Nephrol (2025). https://doi.org/10.1007/s10157-025-02798-2
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