The Correlation Study Of Fluid Overload With Pulmonary Arterial Hypertension In Peritoneal Dialysis Patients

BackgroundPeritoneal dialysis(PD)is one of the most important renal replacement therapies in patients with end-stage renal disease.Cardiovascular disease is the main cause of death in patients undergoing PD.Pulmonary arterial hypertension(PAH)is a common cardiovascular complication characterized by increased pulmonary artery pressure and pulmonary vascular resistance,which may be linked to right heart failure or sudden death in PD patients.PAH is prevalent in PD patients,which adversely affects the quality of life and prognosis of patients.However,the mechanism of PAH in PD patients was not fully understood.Fluid overload(FO)is not only a common complication in PD patients,but also a risk factor for cardiovascular complications.This study aims to explore the risk factors of PAH in PD patients and verify whether FO is an independent risk factor of PAH in PD patients.MethodsThis study enrolled 84 PD patients who were regularly followed up in the Department of Nephrology of the First Affiliated Hospital of Anhui Medical University from September 2020 to May 2022.Demographic characteristics,clinical data and laboratory indicators of patients were collected by consulting medical records,face-to-face interviews and blood samples.The peritoneal equilibration test(PET)was performed on the admission day to assess the adequacy of PD therapy.The body composition analysis(BCA)was used to assess the fluid status of patients.Over-hydration(OH)/extracellular water(ECW)ratio was used as the indicator of fluid overload(FO).FO was defined as OH/ECW≥15%.Pulmonary artery systolic pressure(PASP)was measured by echocardiography.PASP≥35mm Hg was used as the diagnostic standard of PAH.According to the level of PASP,PD patients were divided into PAH group and non-PAH group.and comparisons of all parameters were conducted between the two groups.Pearson and Spearman rank correlation analysis was used to explore the correlation between clinical parameters with PASP and OH/ECW respectively.Multivariable binary-logistic regression analysis was used to identify the independent risk factors of PAH.Receiver operator characteristic curve(ROC)and area under the curve(AUC)were conducted to evaluate the diagnostic efficacy of OH/ECW for PAH.ResultsThis study enrolled 84 PD patients.There were 29(34.5%)males and 55(65.5%)females.The average age was(50.50±10.88)years,and the median dialysis duration was[26.0(12.3,52.0)]months.The median estimated glomerular filtration rate(e GFR)was[4.0(3.0,5.0)]m L/min/1.73m~2.Among all patients,67(79.8%)had hypertension,8(9.5%)had diabetes,and 22(26.2%)had fluid overload.There were 31(36.9%)in the PAH group and 53(63.1%)in the non-PAH group.The results of the comparison between two groups and the risk factor analyses were listed below:1.The general characteristics:the age of the PAH group was higher than the non-PAH group,and the difference was statistically significant(P<0.05).There was no significant difference between the two groups in gender,dialysis duration and other general characteristics.2.Laboratory parameters:Compared with the non-PAH group,PAH group had higher percentage of eosinophils and lower white blood cell count.The difference was statistically significant(P<0.05).3.BCA parameters:OH,OH/ECW,ECW,and total body water(TBW)in the PAH group was significantly higher than the non-PAH group(P<0.05).4.Echocardiographic parameters:The left atrial diameter and cardiac stroke volume in the PAH group were significantly higher than the non-PAH group(P<0.05).5.PET parameters:The 4h dialysate/0h dialysate glucose in the PAH group was significantly lower than the non-PAH group(P<0.05),and the 4h dialysate/plasma creatinine was significantly higher than the non-PAH group(P<0.05).6.Correlation analysis of clinical parameters with PASP and OH/ECW:Age was positively correlated with PASP(r=0.242,P=0.027),and OH was positively correlated with PASP(r=0.285,P=0.009).OH/ECW was positively correlated with PASP(r=0.216,P=0.047),ECW was positively correlated with PASP(r=0.382,P<0.001),and TBW was positively correlated with PASP(r=0.269,P=0.013).The white blood cell count was negatively correlated with PASP(r=-0.266,P=0.014).The left atrial diameter was positively correlated with PASP(r=0.360,P=0.001),and the cardiac stroke volume was positively correlated with PASP(r=0.334,P=0.003).Glucose in 4h dialysate/0h dialysate was negatively correlated with OH/ECW(r=-0.300,P=0.009),and cardiac stroke volume was positively correlated with OH/ECW(r=0.267,P=0.017).7.The risk factors analyses of PAH:After adjusting for confounding factors,the results showed that older age(OR=1.057,95%CI:1.06～1.011,P=0.028),increased percentage of eosinophils(OR=1.252,95%CI:1.042～1.504,P=0.016),and OH/ECW≥15%(OR=3.755,95%CI:1.217～11.586,P=0.021)were independent risk factors for PAH in PD patients.8.The diagnostic value of OH/ECW for PAH:The ROC curve showed that the AUC of OH/ECW for predicting PAH was 0.736[95%CI(0.624～0.849)].The sensitivity was 67%,and the specificity was 74%(P<0.001),which has a good diagnostic efficacy in the diagnosis of PAH.Conclusion1.In this study,26.2%PD patients had FO.2.The prevalence of PAH in PD patients was 36.9%,most of which occurred in elderly patients(51.7%).3.The occurrence of PAH in PD patients had no significant association with their kidney disease etiology,dialysis duration,and residual kidney function.The elderly age,increased eosinophil percentage and FO were independent risk factors for PAH in PD patients.FO had a good diagnostic value for PAH,suggesting that PD patients with these risk factors should be screened for PAH by echocardiography to receive early intervention in order to improve prognosis.