Brain Natriuretic Peptide Is a Marker of Fluid Overload in Incident Hemodialysis Patients

Abstract

Background/Aims: Brain natriuretic peptide (BNP) is secreted by cardiomyocytes under stretch condition. High blood levels are associated with decreased patient survival in heart failure patients and in hemodialysis (HD) patients. We report the monthly BNP change in the first months of HD therapy in incident patients and its relationship with fluid removal and cardiac history (CH). Methods: All patients starting HD therapy in our unit from May 2008 to December 2012 were retrospectively analyzed. Every month (M1 to M6), BNP was assessed before a midweek dialysis session. CH, monthly pre- and postdialysis blood pressure, and postdialysis body weight were collected. Results: A total of 236 patients were included in the analysis. The median BNP at HD start was 593 (175-1,433) pg/mL, with a significant difference between CH- and CH+ patients (291 vs. 731 pg/mL, p < 0.0001). Mortality was significantly higher in patients in the higher BNP tertile. BNP decreased significantly between M1 and M2 and then plateaued. The BNP change between M1 and M2 and between M1 and M6 was significantly correlated with the initial fluid removal. Applying stepwise multiple regression, the BNP change between M1 and M2 was significantly and independently related to fluid removal. The BNP level at M6 was also related to patient survival. Conclusions: We confirm that in incident HD patients, BNP level is related to fluid excess and cardiac status. The BNP decrease in the first months of HD therapy is related to fluid excess correction. BNP appears as an important tool to evaluate hydration status correction after HD onset.

Brain natriuretic peptide reflects individual variation in hydration status in hemodialysis patients

“…Because BNP and bioimpedance parameters have been found to remain relatively stable within individuals over time, measurement of BNP may be better applied in the dialysis population using a relative‐change strategy rather than by comparing absolute values to a reference interval or threshold value . The results of our study support these findings, as our main finding was that the variation in BNP reflected the variation in ROH in repeated measurements, and the between‐individuals variation of BNP in relation to overhydration was larger than the within‐individual variation.…”

“…After calculating the area under the receiver operating characteristic curve in order to try and find the best cutoff threshold values of BNP for overhydration, Lee and Tapolyai have suggested a value of 500 pg/mL to differentiate between hemodialysis patients with or without volume overload. BNP concentrations have been found to vary considerably across the dialysis population, but when BNP is already elevated (due to biological variation or pathophysiological processes), fluctuations in hydration status presumably account for some of the variance …”

Decreasing hospitalizations in patients on hemodialysis: Time for a paradigm shift

“…Some concern exists regarding the ill effects (heart, brain) of the hypotension accompanying DW probing; alternative methods of DW determination (eg, bioimpedence) may replace probing. Blood pressure control, specifically pulse pressure, without medication is one of the best markers of survival in patients on dialysis, and the literature endorses continuous assessment and maintenance of accurate EDW with strategies like DW probing, as a way to decrease antihypertensive pill burden and adverse cardiovascular outcomes . Thus, fluid overload is common in patients on hemodialysis, is related to inability to recognize or achieve accurate DWs, and is the leading cause of hospitalizations.…”

“…Relative IDWG greater than 4% of body weight is associated with hospitalizations, and IDWG >5.7% of body weight is associated with mortality . Excessive IDWG prevents achievement of EDW in a fixed dialysis schedule because of hypotension and cramping, which in and of themselves are associated with increased mortality when they occur …”

End-Stage Kidney Patients Require Hemodialysis Therapy Full Start

“…In our unit, where we have maintained a specific focus on fluid balance for more than 4 decades, the initial dehydration in the first 2 months of HD therapy is on average a decrease of -5.0 ± 4.5% from the initial body weight [36]. This fluid removal is related to the rapid decline of brain natriuretic peptide [37] and long-term decrease of predialysis systolic blood pressure [36]. In our practice, we have never prioritized the preservation of RRF/UO because of fear to persistent fluid overload.…”