Optimal Range Of Serum Calcium,phosphorus,and Intact Parathyroid Homonein In Maintenance Hemodialysis Patients

Objective:The effective management of chronic kidney disease-mineral and bone disorder(CKD-MBD)has a great significance for improving the survival prognosis of maintenance hemodialysis(MHD)patients.To date,there have been a number of guidelines or consensus on the best survival benefits of CKD-MBD biomarkers remains controversial,such as serum calcium,serum phosphorus and intact parathyroid homone(i PTH).There are still great differences in clinical practice in different regions of the world.This paper aims to explore the optimal target level of CKD-MBD biomarkers,so as to provide more references for the management of CKD-MBD.Methods:This atricle is a retrospective cohort study.A total of 14,583 patients who received MHD and were on dialysis for more than 3 months in Shanxi Province from January 1,2012 to June 30,2020 were followed up until December 31,2020.The case data of hemodialysis(HD)patients in the first quarter were used as baseline values to explore the correlation between CKD-MBD biomarkers and all-cause mortality in MHD patients at baseline level,as well as the optimal target levels of serum calcium,serum phosphorus and i PTH in MHD patients.The following parameters were statistically analyzed:(1)Demographic data:name,sex,age at dialysis entry,date of first renal replacement therapy,date of death;(2)Related medical history:primary disease,complications,cause of death;(3)Clinical laboratory data:serum calcium,serum phosphorus,i PTH,prendialysis blood pressure,urea reduction rate(URR),urea clearance index(Kt/V),hemoglobin(Hb),serum albumin(Alb),potassium(K~+).The data came from the Chinese National Renal Data System(CNRDS).Multivariate Cox proportional hazard regression model and Kaplan-Meier method were used for survival analysis.Results:(1)From 2012 to 2020,mean age at dialysis entry of MHD patients in Shanxi Province was 55 years old,60%were male,45%had glomerular disease,28%had diabetic nephropathy,and the median dialysis age was 35 months.A total of 2147 patients died by the end of follow-up,and the first cause of death was cardiovascular events(36%).(2)In the multivariate Cox regression model,compared with patients with i PTH at 150-300pg/ml levels,Patients with low i PTH(50-150pg/ml,HR=1.42,95%CI 1.26-1.61,P<0.001)and those with high i PTH(≥600pg/ml,HR=1.33,95%CI 1.17-1.52,P<0.001)had a higher risk of death;i PTH in the range of 300-600pg/ml(HR=1.04,95%CI 0.922-1.173,P=0.524)showed no significant difference in survival of dialysis patients.When the reference level of serum calcium is 2.10-2.37mmol/L,hypocalcemia(<2.10mmol/L,HR=1.16,95%CI1.05-1.29,P=0.003)and hypercalcemia(≥2.63mmol/L,HR=2.20,95%CI 1.88-2.57,P<0.001)were associated with increased all-cause mortality.Referring to serum phosphorus levels of 1.13-1.45mmol/L,Low phosphorus levels(0.87-1.13mmol/L,HR=1.42,95%CI1.22-1.66,P<0.001)or hypophosphatemia(<0.87mmol/L,HR=1.68,95%CI 1.34-2.12,P<0.001)were associated with increased all-cause mortality.Conclusion:In this large-scale cohort study of MHD patients with CKD-MBD,combined with current domestic and international guidelines(K/DOQI,KDIGO,Blood Purification Standard Operating Procedures(SOP),etc.)for the management objectives of CKD-MBD,we demonstrated the correlation between different levels of CKD-MBD biomarkers and the death risks in MHD patients initially starting HD,while exploring the range of optimal survival benefit for each biomarker.Among them,MHD patients with hypophosphatemia had a significantly increased risk of death.There was a U-shaped correlation between serum calcium and i PTH levels and all-cause mortality of dialysis patients.Blood calcium levels in the range of 2.10-2.63mmol/L and i PTH levels in the range of 150-600pg/ml may be the best target level for MHD patients.