Association of neutrophil-to-lymphocyte ratio and risk of cardiovascular or all-cause mortality in chronic kidney disease: a meta-analysis.

BACKGROUND: It is currently controversial whether neutrophil-to-lymphocyte ratio (NLR) has a prognostic role in patients with chronic kidney disease (CKD). We aimed to investigate whether NLR was an independent predictor of cardiovascular or all-cause mortality in CKD patients with or without hemodialysis by performing a meta-analysis. METHODS: Pubmed, Embase, and Cochrane Library databases are systematically searched for relevant literature that investigated NLR and subsequent cardiovascular or all-cause mortality risk in CKD with or without dialysis. Pooled hazard risk (HR) with 95% confidence interval (CI) was calculated for the high vs. low NLR category. RESULTS: A total of thirteen studies enrolling 116,709 patients were identified and analyzed. In summary, high NLR was associated with an increased risk of all-cause mortality (HR 1.93, 95% CI 1.87-2.00; P < 0.00001) and cardiovascular mortality (HR 1.45, 95% CI 1.18-1.79, P < 0.001). Subgroup analysis indicated that high NLR are independently associated with all-cause mortality risk in dialysis patients (HR 1.94, 95% CI 1.87-2.01; P < 0.00001). CONCLUSIONS: This meta-analysis indicates a high NLR is related to all-cause mortality and cardiovascular mortality in patients with chronic kidney disease. Dialysis patients with high NLR are candidates at high risk of mortality to allow for earlier interventions. Further large scale and more rigorously designed studies are warranted to confirm the prognostic value of NLR in the different stages of CKD.