Abstract: Objective To explore the diagnostic value of N-terminal pro- brain natriuretic peptide (NTproBNP) change rate in the estimation of volume load and ultrafiltration volume in maintenance hemodialysis (MHD) patients through the analyses of the correlation among NT-proBNP change rate, serum NT-proBNP concentration, blood pressure and water content in the body. Method The change rate of serum NT-proBNP concentration before and after a dialysis session was calculated in 103 maintenance hemodialysis (MHD) patients. These patients were then divided into 2 groups based on the median value of the change rate. NT-proBNP
concentration before dialysis, blood pressure, total body water (TWB), extracellular water (ECW), intracellular water (ICW) and serum were compared between the 2 groups. Result ① Serum NT-proBNP concentration decreased significantly after dialysis as compared with the value before dialysis (P=0.001). ② The decrease rate of serum NT-proBNP was less than zero in 32.1% patients, and was more than zero in 67.9% patients. ③ The change rate of NT-proBNP was negatively correlated with the blood pressure at the 2nd hour of a dialysis session (r=-0.198, P=0.045), and was positively correlated with the blood pressure differences between pre- dialysis and at the 2nd hour of a dialysis session (r=0.265, P=0.007). Patients in the group with more NT-proBNP change rate had lower blood pressure at the 2nd (t=2.466, P=0.015) and 3rd hour (t=2.113, P=0.037) in a dialysis session than those in the group with less NT-proBNP change rate. ④ Patients in the group with more NT-proBNP change rate had lower TBW (t=2.579, P=0.012), ECW(t=2.297, P=0.006), ICW (t=2.126, P=0.036) and NT-proBNP (z=1.829, P=0.002) than those in the group with less NT-proBNP change rate. Conclusion Serum NT-proBNP change rate is a useful marker for the determination of volume load and the evaluation of water retention clearance in a defined period of time in MHD patients.

Key words: Hemodialysis, N-terminal pro brain natriuretic peptide, variation rate, Blood pressure, Multi-frequency bioimpedance analysis