Association between monocyte to lymphocyte ratio and mortality in patients with continuous ambulatory peritoneal dialysis / 中华肾脏病杂志

ABSTRACT

Objective:To investigate the association of monocyte to lymphocyte ratio (MLR) with all-cause mortality and cardiovascular disease (CVD) mortality in patients with continuous ambulatory peritoneal dialysis (CAPD).Methods:It was a retrospective cohort study. The clinical data of 495 incident CAPD patients in the First Affiliated Hospital of Zhengzhou University from January 1, 2013 to December 31, 2019 were retrospectively analyzed. The optimal cut-off value of baseline MLR was determined by the receiver operating characteristic (ROC) curve for predicting all-cause death in the first year of CAPD, and then the patients were divided into high MLR group and low MLR group. The differences of clinical data and laboratory tests were compared between the two groups. The endpoint events were death (all-cause death and CVD death), conversion to hemodialysis, conversion to kidney transplantation, or follow-up until March 31, 2020. The survival curve was drawn by the Kaplan-Meier method, and the Log-rank test was used to compare the survival difference between the two groups. A Cox regression model was established to analyze the relevant factors of all-cause mortality and CVD mortality in CAPD patients.Results:The study included 495 patients, with age of (43.79±12.16) years and 308 (62.22%) males. The median age of dialysis was 17(10, 30) months. By the end of follow-up, 61(12.32%) of 495 patients had died, 51(10.51%) had been converted to hemodialysis, and 28(5.66%) had been converted to kidney transplantation. Of the 61 patients who died, 36(59.02%) died of cardiovascular events. ROC curve analysis results showed that the optimal cut-off value was 38.24%, so there were 246 cases in the high MLR group (MLR>38.24%) and 249 cases in the low MLR group (MLR≤38.24%). The all-cause mortality rates were 6.83% in the low MLR group and 17.89% in the high MLR group, and the CVD mortality rates were 3.21% in the low MLR group and 11.38% in the high MLR group, respectively. The Kaplan-Meier survival curve showed that the survival rate of the low MLR group was significantly higher than that of the high MLR group (all-cause mortality, Log-rank χ2=18.369, P<0.001; CVD mortality, Log-rank χ2=16.142, P<0.001). Using all-cause death as the end event, the 1-year, 3-year and 5-year cumulative survival rates were 99.5%, 89.4% and 79.9%, respectively, with a median survival time of 64 months in the low MLR group. The 1-year, 3-year and 5-year cumulative survival rates were 95.0%, 68.3% and 49.6%, respectively, with a median survival time of 54 months in the high MLR group. Using CVD death as the end event, the 1-year, 3-year and 5-year cumulative survival rates were 99.5%, 95.2% and 91.2%, respectively, with a median survival time of 69 months in the low MLR group. The 1-year, 3-year, and 5-year cumulative survival rates were 97.8%, 78.6%, and 60.8%, respectively, with a median survival time of 60 months in the high MLR group. Multivariate Cox regression analysis showed that MLR was independently associated with all-cause mortality ( HR=2.744, 95% CI 1.484-5.075, P=0.001) and CVD death ( HR=3.249, 95% CI 1.418- 7.443, P=0.005) in CAPD patients. According to the competing risk model analysis, MLR was still independently associated with all-cause mortality and CVD mortality in CAPD patients. Conclusion:MLR is associated with all-cause mortality and CVD mortality in CAPD patients, and can be used as a valuable indicator for judging the prognosis of CAPD patients.