Abstract: Objective To investigate the effects of different combinations of blood purification technologies on mineral and bone disorder (MBD) in maintenance hemodialysis (MHD) patients through observing their bone metabolism and prevalence of osteoporosis. Methods Ninety MHD patients with chronic kidney
disease (CKD) and MBD were randomly divided into three groups, HD group (hemodialysis, control group, n=30), HD+HDF group (HD and hemodiafiltration group, n=30), and HD+HP group (HD and hemoperfusion, n=30). After the treatment for six months, the changes of serum calcium (Ca), phosphorus (P), intact parathyroid hormone (iPTH), β-type I collagen carboxy-terminal peptide (β-CTX), type I procollagen amino-terminal peptide (PINP), fibroblast growth factor 23 (FGF-23), and prevalence of osteoporosis were compared in the groups and among the 3 groups to evaluate the effects of different combinations of dialysis methods on MHD patients with MBD. Results After the treatment for 6 months, serum P increased in HD group (2.64±1.04 vs. 2.21±0.55 mmol/l, t=2.047, P= 0.049 for serum P; 452.1±43.00 vs. 427.7±44.00 pg/ml, t=2.140, P=0.038 for iPTH); iPTH decreased in HD+HDF group (431.0±37.39 vs. 465.3±43.02 pg/ml, t=3.298, P=0.007); iPTH, β- CTX, PINP, and FGF-23 decreased in HD+HP group (389.1±29.89 vs. 457.4±60.01 pg/ml, t=5.598, P=0.0006 for iPTH; 2.13±1.51 vs. 2.73±1.16 ng/ml, t=2.278, P=0.031 for β-CTX; 140.76±36.13 vs. 157.92±31.16 ng/ ml, t=2.106, P=0.047 for PINP; 397.30±63.18 vs. 461.16±101.69 ng/ml, t=2.922, P=0.011 for FGF-23). After the treatment for 6 months, PINP was lower in HD+HDF group than in HD group (147.33±40.72 vs. 165.32± 43.11 ng/ml, t=1.969, P =0.048); FGF-23, serum P, β-CTX, PINP and iPTH were lower in HD+HP group than in HD group (397.30±63.18 vs. 465.38±101.36 ng/ml t=3.114, P=0.003 for FGF-23; 2.02±0.81 vs. 2.64±1.04 mmol/l, t=3.221, P=0.003 for serum P; 2.13±1.51 vs. 2.95±1.28 ng/ml, t=2.278, P=0.031 for β-CTX; 140.76±
36.13 vs. 165.32±43.11 ng/ml, t=2.339, P=0.028 for PINP; 389.1±29.89 vs. 452.1±43.0 pg/ml, t=6.661, P= 0.005 for iPTH); iPTH was lower in HD+HP group than in HD+HDF group (389.1±29.89 vs. 431.0±37.39 ng/ ml, t=7.303, P=0.000). After the treatments for 6 months, the cases of osteoporosis and bone mass reduction were increased in HD group and were decreased in HD+HDF group and HD+HP group but without statistical significances. Comparison The combined use of different hemodialysis methods has different effects on MBD in MHD patients. HD+HDF and HD+HP are better than HD, and HD+HP is the best for the improvement of MBD.

Key words: Mineral and bone disorder, Intact parathyroid hormone, β-Type I collagen carboxy-terminal peptide, Type I procollagen amino-terminal peptide, fibroblast growth factor23