Brain natriuretic peptide reflects volume status and influences on survival of hemodialysis patients

Abstract

Background Periodic volume accumulation is a characteristic feature of hemodialysis. Aim of the study was to investigate the relatively normal range of brain natriuretic peptide (BNP) in hemodialysis patients and to explore its role in volume management. Methods Patients on hemodialysis were enrolled. Normal range of BNP was deduced from patients with normal volume status defined by systolic blood pressure (SBP) and over hydration (OH). Hemodialysis patients were classified according to BNP expression at baseline and followed-up for 57 months. The outcome was defined as all-cause mortality, and cardiovascular disease related death. Results Pre-dialysis BNP and BCM measurement was conducted in 127 hemodialysis patients. BNP significantly correlated with OH in total patients (r = 0.255, P = 0.004). In patients with appropriate volume load, the average of BNP was 701 (± 645)pg/ml, with the 95% confidence interval (CI) of 500 ~ 902pg/ml. In patients with BNP < 902pg/ml, SBP significantly correlated with OH. Patients with BNP ≥ 902/ml showed increased risk of all-cause mortality (HR = 3.151, P < 0.001) and cardiovascular mortality (HR = 7.381, P < 0.001). Reduced BNP expression during the first year after baseline resulted in significantly decreased all-cause mortality. Conclusion Pre-dialysis measured BNP levels are associated with volume status, and normal range is from 500 to 902pg/ml. Patients with upregulated BNP expression showed increased risk of all-cause mortality and cardiovascular death. To reduce BNP expression to normal range showed protective effect on all-cause and cardiovascular mortality in long-term observation.