Predictive Validity Of Phase Angle For Protein-energy Wasting And Its Correlation With Major Adverse Cardiovascular Events In Maintenance Hemodialysis Patients

Objective:To investigate the value of bioelectrical impedance analysis-derived phase angle(PA)for predicting protein-energy wasting(PEW)in maintenance hemodialysis(MHD)patients,to explore the correlation between phase angle and major adverse cardiovascular events(MACE),and to provide a feasible and objective tool to evaluate PEW for clinical workers.Methods:A total of 121 patients who under regular maintenance hemodialysis more than three months in Blood Purification Center of Taixing People’s Hospital,Jiangsu Province between August 2020 and September 2020 were enrolled in the study.The diagnosis of PEW in patients was performed by the International Society of Renal Nutrition and Metabolism(ISRNM)criteria.Korea Inbody S10 was used to measure body composition,including phase angle,fat free mass(FFM),body fat percentage(BFP),body cell mass(BCM),extracellular water(ECW),tobal body water(TBW),extracellular water/total body water(ECW/TBW).Anthropometric measurements and serum biochemical indexes were collected during the same period,and patients were followed up for two years to record the occurrence of MACE,including angina pectoris,acute myocardial infarction,severe arrhythmia,heart failure and sudden cardiac death.The age,gender,serum albumin,phase angle and other measurements of PEW group were compared with the non-PEW group.And the phase angle of MACE group was compared with the non-MACE group.Correlations between the phase angle and different indicators were discussed by correlation analysis.Measurements that may influence PEW were included in the multivariate logistic regression analysis to identify factors affecting the nutritional status of MHD patients;the validity of phase angle for predicting PEW was explored using receiver operating characteristic curve(ROC)analysis.Results:1.A total of 121 patients were included in the study,67 patients(55.4%)were male and 54 patients(44.6%)were female.And 39(32.2%)patients were diagnosed with PEW,46(38.0%)patients had MACE during the follow-up.2.MHD patients with PEW had higher age,hypersensitivity C reactive protein,extracellular water,extracellular water/total body water;lower weight,body mass index,mid-arm circumference,mid-arm muscle circumference,hemoglobin,serum albumin,prealbumin,total cholesterol,triglyceride,creatinine,fat free mass,body cell mass,and phase angle compared with well-nourished patients(P<0.05).Phase angle was lower in MACE group than in non-MACE group(P<0.05).3.Correlation analysis showed that phase angle was positively correlated with body mass index,upper arm circumference,upper arm muscle circumference,hemoglobin,serum albumin,prealbumin,total cholesterol,triglyceride,serum creatinine,parathyroid hormone,fat free mass and body cell mass(P<0.05);PA was negatively correlated with hypersensitive C-reactive protein,extracellular water and extracellular water/total body wate(P<0.05).4.Multivariate logistic regression analysis showed that phase angle,body cell mass and extracellular water were independent predictors of PEW(P<0.05).Receiver operating characteristic curve analysis suggested that phase angle was the stronger predictor.The area under curve(AUC)of phase angle was 0.876(95%CI:0.055～0.308,P<0.01),the optimal cutoff value was 4.6o,with a sensitivity of 91.5%and specificity of 79.5%.Conclusions:(1)The incidence of PEW in MHD patients is higher.(2)The nutritional indexes are worse in the MHD patients with lower PA value,and PA has a good correlation with the indexes reflecting protein and muscle mass.(3)PA has a strong predictive validity for PEW in MHD patients with a cutoff value of 4.6o.(4)PA has a good correlation with the occurrence of MACE in MHD patients.