Elevated neutrophil to lymphocyte ratio predicts overall and cardiovascular mortality in maintenance peritoneal dialysis patients.

Background: Neutrophil to lymphocyte ratio (NLR) is widely used as a marker of inflammation and an indicator of cardiovascular outcomes in patients with coronary artery disease. However, its prognostic value in peritoneal dialysis (PD) patients is still unknown.

Methods: We studied 138 newly started PD patients and 60 healthy controls at the First Affiliated Hospital of Sun Yat-Sen University, Guangzhou, China. Baseline NLR as well as demographic, clinical, and biochemical parameters were recorded. All patients were followed up until March 2011 to evaluate mortality as the primary outcome. Overall and cardiovascular disease-free survival rates were compared according to NLR level. Multivariate analysis was performed to assess the prognostic value of NLR.

Results: Baseline NLR levels (mean 3.5 ± 1.6) were significantly increased in PD patients compared to healthy controls (mean 1.5 ± 0.5; P < 0.001). Patients with higher NLR had a higher mortality rate compared with patients with lower NLR (51.5% vs 22.9%; P = 0.006). The 1-year and 3-year overall survival rates were 86.6% and 65.9% for patients with higher NLR compared with 97% and 85.1% for patients with lower NLR (P = 0.006). Patients with higher NLR also showed a higher cardiovascular mortality rate, compared with patients with lower NLR (38% vs 7.6%; P = 0.003). The 1-year and 3-year cardiovascular event-free survival rates were 90.7% and 81.9% for patients with higher NLR, compared with 98.6% and 95.1% for patients with lower NLR. Multivariate analysis showed high NLR value was an independent risk factor for all-cause and cardiovascular mortality.

Conclusion: Neutrophil to lymphocyte ratio is a strong predictor for overall and cardiovascular mortality in PD patients.