Comparison of control status and influencing factors of serum calcium, phosphorous and parathyroid hormone between peritoneal and hemodialysis patients

Objective To compare the control status and influencing factors of serum calcium,phosphorus and parathyroid hormone in peritoneal versus hemodialysis patients.Methods A single-center cross-sectional observational study was performed.A total of 448 patients on stable maintenance dialysis for over 3 months were recruited from March 2013 to March 2015.The sociodemographic profiles,biochemical parameters and dialysis related parameters were collected for comparing the target-attaining rates of calcium,phosphorus and iPTH and analyzing the influencing factors between peritoneal and hemodialysis patients.Results There were 355 continuous ambulatory peritoneal dialysis(CAPD) patients with an average age of 52 years and a median vintage of 17 months.And there were 93 intermittent hemodialysis(IHD) patients with an average age of 52 years and a median vintage of 21 months.Among CAPD patients,there were 182 males(51.5%) and 76 cases(21.4%) had a diagnosis of diabetic kidney disease.In IHD patients,55(59.1%) were males and 18(19.3%) diabetic kidney disease.The target-attaining rates of serum calcium,serum phosphate and iPTH were not statistically different between two groups(serum calcium:65.7% vs 65.6%,P=0.99;serum phosphate:53.2% vs 33.3%,P=0.31;iPTH:47.3% vs 53.8%,P=0.30).The incidence of hypocalcemia was significantly higher in IHD group than that in CAPD group(17.2% vs 2.8%,P<0.01) and hyperphosphatemia occurred more frequently in IHD group(9.1% vs 43.1%,P<0.01).And the incidence of hypercalcemia was higher in CAPD group than that in IHD group(31.5% vs 17.2%,P<0.01).Comparisons of risk factors for calcium,phosphorus and iPTH failure in different groups:For CAPD patients,advanced age and longer dialysis vintage were the independent risk factors for non-targeting of serum level of calcium.Taking no phosphate binder and impaired residual renal function were independently associated with non-targeting of serum phosphate level.Advanced age,longer dialysis vintage and a higher level of serum phosphate were the independent risk factors of non-targeting of iPTH level.For IHD patients,a higher level of iPTH was an independent risk factor for non-targeting of serum level of calcium.A higher level of iPTH and taking no phosphate binder were the independently associated with targeting of serum level of phosphate.A higher level of serum phosphate and a lower level of hemoglobin were the independent risk factors for non-targeting of iPTH level.Conclusion The incidence of hypocalcemia and hyperphosphatemia were significantly higher and the incidence of hypercalcemia was lower in IHD group than in CAPD group.Regular monitoring may facilitate controlling abnormal calcium-phosphorous metabolism and boost quality-of-life through protecting residual renal function,reducing serum phosphorus level,enhancing hemoglobin level and rationalizing phosphorus binder.