Effect of maintenance dialysis periods on CKD-MBD in peritoneal dialysis patients

Abstract

Objectives To investigate the bone metabolic biomarkers of peritoneal dialysis and to study the effect of maintenance dialysis periods on chronic kidney disease-mineral and bone disorder(CKD-MBD) in peritoneal dialysis.Methods We observed the change of bone metabolic biochemical markers:serum calcium and phosphorus,intact parathyroid hormone (iPTH),25-hydroxy vitamin D3 [25 (OH) D3)] and bone alkaline phosphatase (BALP) in the participants,which contained 60 peritoneal dialysis patients and 30 healthy controls.Furthermore,the peritoneal dialysis patients were grouped into A (maintenance dialysis periods ＜ 24 months) and B (maintenance dialysis periods ≥24 months).Results Compared to the healthy control,the level of serum calcium went down,while serum phosphate went up obviously (P 1.40 ± 0.29mmol/L vs 1.75 ± 0.57mmoL/L; Ca 2.33 ± 0.19mmol/l 2.02 ± 0.2mmol/l,P ＜ 0.01),at the same time,the level of iPTH,25 (OH) D3 and BALP showed obviously change in iPTH,25 (OH) D3 and BALP [iPTH 436.41 ± 368.28pg/ml vs 53.31 ± 23.71pg/ml; 25 (OH)D3 199.28 ± 139.52ng/ml vs 36.04 ±14.17ng/ml; BALP 80.24 ± 39.41ng/ml vs 173.76 ±52.38ng/ml,P ＜0.01].The rate was nearly 100％ that at least one of bone metabolic biochemical markers was abnormal.Compared to the healthy control,the level of serum calcium and phosphate changed obviously in group A and B.While the level of serum calcium and phosphate did not show difference obviously in group A and B (P ＞ 0.05).Compared to the healthy control,the level of iPTH raised (iPTH 53.31 ± 23.71pg/ml vs 596.57 ±449.91pg/ml & 276.25 ± 148.23pg/ml,P ＜ 0.05),25 (OH) D3 declined [25 (OH) D3:173.76 ± 52.38ng/ml vs 58.99 ± 25.79ng/ml & 101.48 ± 39.67ng/ml,P ＜0.05] in group A and B,while BALP went up (BALP:36.04 ± 14.18ng/ml vs 264.58 ± 114.24ng/ml) in group A.Compared to the level of iPTH,25 (OH)D3,BALP in group A,in group B,iPTH increased significantly,although the concentration of 25 (OH)D3 and BALP dropped obviously (BALP:133.97 ± 133.90ng/ml vs 264.58 ± 114.24ng/ml,P ＜ 0.05).Conclusions CKD-MBD was widespread in peritoneal dialysis patients.The bone turnover type may be converted by the peritoneal dialysis time going on.Due to the difficulty of bone biopsy,the dynamic monitoring of bone metabolic biomarkers was necessary to explicit the bone turnover type.Therapies tailored particularly to different turnover bone should be taken appropriately in peritoneal dialysis. Key words: Peritoneal Dialysis; Alkaline Phosphatase