Association of neutrophil-lymphocyte ratio with cardiovascular and all-cause mortality in patients receiving chronic hemodialysis: Systematic review and meta-analysis

Abstract

Background: The neutrophil-lymphocyte ratio (NLR) has been proposed as a potential prognostic marker for mortality outcomes in various conditions, yet its association with chronic hemodialysis (HD) remains underexplored. We aim to study its utility by conducting a meta-analysis of this specific population.

Aim: To determine whether elevated NLR is associated with all-cause mortality (ACM) and cardiovascular mortality (CVM) in patients undergoing chronic HD.

Methods: A comprehensive search from PubMed, Google Scholar, and Scopus identified studies showing the association between NLR and mortality outcomes in patients with chronic HD. Random-effects models with 95%CIs were employed to pool adjusted hazard ratios (aHRs), odds ratios (ORs), and I² statistics for evaluating the heterogeneity of findings. Leave-one-out sensitivity and meta-regression analyses assessed changes in overall effects and identified confounders, respectively. The Joanna Briggs Institute (JBI) tool was used to assess the quality of studies.

Results: 19 studies comprising 9047 patients with a mean age of 59.5 ± 5.86 years and a mean follow-up duration of 46.7 months were included in our study. Our meta-analysis revealed a significant association between NLR > 2.5 and increased risks of ACM (aHR: 1.25, 95%CI: 1.14-1.37, P < 0.0001) and CVM (aHR: 1.24, 95%CI: 1.02-1.49, P = 0.03). Studies reporting outcomes in OR reported similar findings for ACM (OR: 4.59, 95%CI: 1.74-12.11, P = 0.002) and CVM (OR: 1.11, 95%CI: 1.01-1.23, P = 0.03). Sensitivity analysis revealed no variations. Meta-regression revealed increasing male proportion is positively associated with ACM. Pooled area under the curve (AUC) was 0.71 (95%CI: 0.63-0.80, P < 0.0001). The JBI tool revealed high-quality studies.

Conclusion: This meta-analysis suggests that elevated NLR may serve as a useful prognostic marker for ACM and CVM in patients on chronic HD and can be useful in planning for the prevention of mortality-related strategies.

Keywords: All-cause mortality; Cardiovascular mortality; Chronic hemodialysis; Dialysis outcomes; Dialysis-associated cardiovascular disease; Hematological biomarkers; Inflammation; Inflammatory markers; Neutrophil-lymphocyte ratio.