Neutrophil/lymphocyte ratio as a predictor of cardiovascular events in incident dialysis patients: a Japanese prospective cohort study

Background: Previous studies have suggested that high neutrophil/lymphocyte ratios are related to worse outcome in patients with cardiovascular diseases. Patients with end-stage renal disease, especially those with inflammation, are at an increased risk of premature mortality, primarily because of cardiovascular disease. We aimed to clarify if high neutrophil/lymphocyte ratio is associated with increasing cardiovascular events in Japanese patients with end-stage renal disease. Methods: We enrolled 86 incident Japanese dialysis patients (58 men, age 58 ± 11 years) in a prospective cohort study. The median follow-up was for 38.7 months. The association between neutrophil/lymphocyte ratio at the start of dialysis therapy and clinical biomarkers was investigated. Relative risks and cumulative cardiovascular disease events were calculated. Results: The median neutrophil/lymphocyte ratio reported was 3.72. The duration from the start of the dialysis therapy to the first cardiovascular disease event was significantly shorter as a neutrophil/lymphocyte ratio increased (log-rank test, P = 0.003). The relative risk of cardiovascular disease events in patients with neutrophil/lymphocyte ratio > median to cardiovascular events in patients with the ratio < median as a reference was 3.02 (95 % CI 1.32–8.00) in a Cox proportional hazard model. The cumulative cardiovascular disease events during the observational period was higher in patients with neutrophil/lymphocyte ratio > median (23.0 events 100 person-years) than in patients with the ratio < median (6.8 events 100 person-years). Conclusions: A higher neutrophil/lymphocyte ratio is associated with increased risk of cardiovascular disease events and is a stronger predictor of future events.