BNP: Fluid overload marker in HD patients
In incident HD patients, the level of brain natriuretic peptide (BNP) is related to fluid excess and cardiac status, and a BNP decrease in the first months of hemodialysis is related to the correction of fluid excess.
BNP should therefore be seen as an important tool to evaluate hydration status correction after HD onset, conclude French researchers in the present study (Chazot C et al, Brain Natriuretic Peptide Is a Marker of Fluid Overload in Incident Hemodialysis Patients. Cardiorenal Med. 2017;7:218-226).
The authors noted the monthly BNP during the first 6 months of hemodialysis (HD) therapy of 236 incident patients and analyzed its relationship with fluid removal and cardiac history (CH). Pre- and postdialysis blood pressure as well as postdialysis body weight were also noted every month.
At HD initiation, the median BNP was 593 pg/mL, showing a significant difference between CH- and CH+ patients (291 vs. 731 pg/mL, p < 0.0001); patients in the higher BNP tertile showed significantly higher mortality rates. BNP dropped sharply between M1 and M2 and then plateaued. The BNP change between M1 and M2 and between M1 and M6 showed a significant correlation with the initial fluid removal, while the BNP change between M1 and M2 was significantly and independently related to fluid removal. In addition, the authors were able to demonstrate that the BNP level at M6 was also related to patient survival.
BNP level is related to fluid excess and cardiac status, a BNP drop in the first months of HD is related to fluid excess correction.
Link to the study: https://www.karger.com/Article/Abstract/471815