Long-term Hypocalcemia Relates To The Aggravation Of Left Ventricular Diastolic Function Of Peritoneal Dialysis Patients

Background:Peritoneal dialysis(PD)is one of the major renal replacement therapy.Among those complications of peritoneal dialysis,there are many researches about the disorder of calcium-phosphorus(Ca-P)metabolism and cardiovascular disease.However,the association between the disorder of calcium-phosphorus(Ca-P)metabolism and left ventricular diastolic dysfunction(LVDD)remains unclear.In this retrospective study,we included PD patients from two centers(Zhujiang Hospital of Southern Medical University and Jiangmen Central Hospital,Affiliated Jiangmen Hospital of Sun Yat-sen University),to analyze the association between disorder of calcium-phosphorus(Ca-P)metabolism and LVDD.Methods:This study consisted of PD patients from Zhujiang Hospital of Southern Medical University and Jiangmen Central Hospital,Affiliated Jiangmen Hospital of Sun Yat-sen University.Those who initiated peritoneal dialysis between July 1st,2010 to June 30th,2015,more than 18 years old,and the duration of CAPD of whom is more than 6 months were recruited and followed up through June 30th,2016.Exclusion criteria comprised:EF<40%,non-sinus rhythm,cardiomyopathy,severe valvular heart disease,transfer renal replacement therapy from hemodialysis or renal transplantation.At the time of PD initiation,general characteristics data were collected,including demographic details,etiology of end-stage renal disease(ESRD),and presence of hypertension or diabetes.All biochemical and hematological data from the time of PD initiation to the end of observation were collected.Including calcium(Ca),phosphorus(P),intact parathyroid hormone(iPTH),N-terminal proB-type natriuretic peptide(NT-proBNP)levels.In the meantime,the time-averaged level of these subjects were calculated and mentioned in the following.Echocardiography data were collected both at the time of PD initiation and at the end of observation.Patients were divided into two groups depending on the difference of the two E/A ratio(?E/A)--E/A ratio at the end of observation minus E/A ratio at the time of PD initiation:aggravation of diastolic function group(?E/A<0),non-aggravation of diastolic function group(AE/A?0).Results:This study consisted of 265 PD patients,200 from Zhujiang Hospital of Southern Medical University and 65 from Jiangmen Central Hospital.148 patients were male(55.8%)and 117 were female.The average of age was(51.07±13.78),and BMI was(23.27±2.97)kg/m2,the duration of PD was 34.71±16.45months.Etiology of ESRD:chronic glomerulonephritis in 144 patients(54.3%);diabetic nephropathy in 24 patients(9.1%);hypertensive nephrosclerosis in 32 patients(12.1%).Those parameters with p<0.05 in Student's t-test,Mann-Whitney U-test or univariate logistic regression were taken into multivariate logistic regression.Among those examined variables,only lower level of time-averaged Ca(Ca level ? 9.58 mg/dL with odds ratio = 1.939(95%CI 1.078-3.487),p = 0.027)and LVH(odds ratio =1.771(95%CI 1.054-2.974),p =0.031)were found to be predictive factors for aggravation of diastolic function.Conclusions:Long-term hypocalcemia relates to the aggravation of left ventricular diastolic function of PD patients and can be used as a useful biomarker to predicate the prognosis of PD patients.