The Relationship Between Red Blood Cell Distribution Width And Prognosis In Peritoneal Dialysis Patients

ObjectiveTo analyse the relationship between red cell distribution width(RDW)and all-cause mortality as well as cardiovascular(CVD)death in continuous ambulatory peritoneal dialysis(CAPD)patients;To explore the role of RDW on the evaluation of prognosis of peritoneal dialysis(PD)patients.MethodA retrospective cohort study was designed.Patients on stable CAPD treatment more than 3 months in PD center of General Hospital of Ningxia Medical University from January2007 to December 2016 were enrolled.We collected the informations of the participants on their social-demographic condition,biochemical items,body mass index,residual renal function,dialysis adequacyand the outcomes.At least 3 records of RDW re-measurements every 1-3 months after initiation of dialysis were collected.The slope of RDW were calculated by the regression coefficients of the RDW to each patient,by which all the patients were divided into the RDW-increased group and the RDW-decreased group.The clinical characteristics of the two groups were compared.The end points were set as all-cause mortality and CVD death.The Kaplan-Meier method and univariate and multivariate Cox regression model were used to explore the association of RDW change with patient survival.Results(1)A total of 462 patients were enrolled,including 242 males(52.4%).The average agewas 51.89±14.08 years and median vintage was 32.28(17.67,51.36)months.As for the primary disease,227(49.1%)cases were primary glomerular disease,114(24.7%)cases were diabetes kidney diseaseand 96(20.8%)cases were hypertension nephropathy.(2)The baseline comparisons:The baseline RDW was 13.7%(13.1%,14.7%).Compared with RDW-decreased group,RDW-increasedpatients had higher proportion of diabetes mellitus and higher Charlson comorbidity index(CCI),while lower total KT / V and RDW value(p< 0.05).(3)The end point events: After a median follow-up of 32.28(17.67,51.36)months,180(38.96%)cases of 462 patients died.The primary cause of death was CVD death in 48(26.67%)cases.Kaplan-Meier survival analysis showed that the all-cause mortality(Log Rank=24.233,p=0.000;Breslow=18.976,p=0.000)and CVD death(Log Rank=15.621,p=0.000;Breslow=9.346,p=0.002)was significantly higher in RDW-increased group than than the RDW-decreased group.(4)Cox hazard ratio model analysis:after adjusted for the confounders,the rising RDW was the independent risk factor of all-cause mortality in the multivariate Cox regression model.The hazard ratio of all-cause mortality of patients with RDW-increased were 1.81 times(HR 1.81,95%CI 1.20-2.71,p=0.004)over that of the patients with RDW-decreased risk of death.ConclusionsThe study demenstrated that the increasing RDW was independently associated with the increased hazard ratio of all-cause mortality in PD patients.This association was more significant after adjusted for the confounders such as the age,gender,albumin level,etc..The results predicted that the rising RDW may be a useful predictor of adverse outcome in PD patients.