Combined Predictive Value of Neutrophil-to-lymphocyte Ratio and C-reactive Protein-to-albumin Ratio for All-cause Mortality Risk in Patients with Maintenance Hemodialysis: Cohort Study Followed for 5 Years

Background Neutrophil-to-lymphocyte ratio (NLR) has been shown to have significant predictive value for all-cause mortality risk in patients with maintenance hemodialysis (MHD) in previous studies, however, whether C-reactive protein-to-albumin ratio (CAR) and the combination of NLR and CAR can enhance the predictive value for all-cause mortality risk in patients with MHD has not been investigated. Objective To investigate the combined predictive value of NLR and CAR for all-cause mortality of MHD patients, and to provide evidence for improving the quality of life of MHD patients. Methods The case data of 175 MHD patients in the Blood Purification Center of Hainan General Hospital in January 2017 were included, the deadline was December 31, 2021, with the outcome of all-cause death. Receiver operating characteristic (ROC) curves were plotted for the predictive value of NLR+CAR, NLR, and CAR for the risk of all-cause death in MHD patients. Kaplan-Meier survival curve was used to compare the cumulative survival rate between the two groups. Cox regression analysis was used to analyze the independent risk factors of 5-year all-cause death in MHD patients. Results The area under the ROC curve (AUC) of NLR for predicting the risk of all-cause death in MHD patients was 0.743 (95%CI=0.669-0.817, P<0.001). The AUC of CAR for predicting the risk of all-cause death in MHD patients was 0.710 (95%CI=0.627-0.794, P<0.001). The AUC of NLR+CAR for predicting the risk of all-cause death in MHD patients was 0.799 (95%CI=0.732-0.867, P<0.001). Kaplan-Meier survival curve analysis showed that patients with NLR>4.93 had lower cumulative survival than patients with NLR ≤4.93 (χ2=32.753, P<0.001). The patients with CAR>0.795 had a lower cumulative survival than patients with CAR≤0.795 (χ2=38.091, P<0.001). According to the results of the multiple Cox regression equation, dialysis age (HR=0.984, 95%CI=0.976-0.992), ferritin (HR=0.984, 95%CI=0.976-0.992), 25- (OH) D (HR=0.964, 95%CI=0.941-0.987) and triglyceride (HR=0.984, 95%CI=0.976-0.992) were protective factors for all-cause mortality in 5-year MHD patients; NLR>4.93 (HR=2.071, 95%CI=1.226-3.499) and CAR>0.795 (HR=1.903, 95%CI=1.155-3.136) were independent risk factors for all-cause death in 5-year MHD patients (P<0.05) . Conclusion Compared with NLR or CAR alone, the combination of NLR and CAR can better predict the risk of all-cause mortality in MHD patients. Increased NLR and CAR were independent risk factors for all-cause mortality in 5-year MHD patients.