Association of neutrophil-lymphocyte ratio with all-cause and cardiovascular mortality in peritoneal dialysis patients: A systematic review and meta-analysis

BACKGROUND The neutrophil-to-lymphocyte ratio (NLR) is a novel inflammatory marker predicting cardiovascular mortality (CVM) and all-cause mortality (ACM). AIM To investigate the association between the NLR and CVM and ACM in patients with peritoneal dialysis (PD). METHODS We reviewed articles from PubMed, Google Scholar, and Scopus until May 2024 for the association of ACM and CVM in patients with NLR following PD. We used a fixed effects model and I 2 statistics to pool hazard ratio (HR) and measure heterogeneity. Leave-one-out sensitivity analysis assessed the robustness of our study. Multivariate meta-regression (MMR) was utilized to identify influencing confounding factors. Joanna Briggs Institute (JBI) tool was used for quality assessment. RESULTS Out of 160 articles screened, seven studies from 2011 to 2024 with 4350 patients, a mean age of 49.9 years ± 15 years, and a median follow-up of 4 years were included. We found that higher NLR (> 3) was significantly associated with ACM [adjusted HR (aHR): 1.18, 95%CI: 1.03-1.36, P = 0.016]. However, there was no significant association of NLR (> 3) with CVM (aHR: 1.16, 95%CI: 0.68-1.98, P = 0.59) in patients following PD. Sensitivity analysis showed no variations. JBI tool revealed low bias among the studies. MMR revealed a significant relationship between age and ACM (coefficient: 0.14, P = 0.04). CONCLUSION Our meta-analysis identifies a significant association between NLR (> 3) and ACM outcome, which can help prevent deaths in the elderly and optimize resource use. Caution is needed when predicting mortality in this group as age significantly confounds ACM in patients undergoing PD.