Association of Dynamic Changes in the Neutrophil-to-Lymphocyte Ratio with Mortality in Patients on Maintenance Hemodialysis: A Retrospective Cohort Study

Introduction: Chronic inflammation is a major contributor to excess mortality in patients on maintenance hemodialysis (HD). Although elevated baseline neutrophil-to-lymphocyte ratio (NLR) has been associated with adverse outcomes, the prognostic significance of longitudinal changes in NLR (ΔNLR) remains unclear. Therefore, we investigated whether dynamic changes in NLR provide incremental prognostic information in HD patients. Materials and Methods: In this retrospective cohort study, 64 HD patients were screened. After excluding patients who died before the 12-month reassessment or had incomplete laboratory data, 59 patients were included in the final analysis. ΔNLR was defined as the difference between 12-month and baseline NLR values. The primary endpoint was all-cause mortality during a 24-month follow-up. Kaplan–Meier analysis was performed using categorical ΔNLR (≤ 0 vs > 0), and Cox proportional hazards models were used to evaluate the association between continuous ΔNLR and mortality. Results: During follow-up, 12 patients (20.3%) died. Kaplan–Meier analysis did not demonstrate significant survival differences between ΔNLR categories (log-rank p = 0.312). However, ΔNLR analyzed as a continuous variable was significantly associated with mortality in univariable (HR 1.78, 95% CI 1.31– 2.41, p < 0.001) and multivariable analyses. Conclusion: Dynamic increases in NLR were associated with mortality when analyzed as a continuous variable in patients on maintenance HD. These findings suggest that longitudinal assessment of NLR may provide clinically relevant prognostic information beyond single time-point measurements. Keywords: biomarker, chronic kidney disease, hemodialysis, mortality, neutrophil-to-lymphocyte ratio