Brain natriuretic peptide as a potential novel marker of salt-sensitivity in chronic kidney disease patients without cardiac dysfunction

Background/Aim: Fluid volume overload occurs in chronic kidney disease (CKD), leading to the compensatory release of natriuretic peptides. However, the elevated cardiac peptides may also be associated with malnutrition as well as volume overload. Methods: Body fluid composition was measured in 147 patients with CKD between 2009 and 2015, and its relationship to brain natriuretic peptide (BNP) levels was examined. Body fluid composition was separated into three components: (a) a water-free mass consisting of muscle, fat, and minerals; (b) intracellular water (ICW) content, and (c) extracellular water (ECW) content. Excess fluid mass was calculated using Chamney's formula. Results: The measured BNP levels in the tertile groups were 10.9 ± 5.4, 36.3 ± 12.5, and 393 ± 542 pg/ml, respectively. Patients in a higher log-transformed BNP level tertile were more likely to be older, to have a higher frequency of cardiac comorbidities, pulse pressure, C-reactive protein levels, and proteinuria, and to have lower serum sodium, kidney function, and serum albumin (p < 0.05). In body fluid composition, decreased body mass was significantly associated with the ECW-to-ICW ratio in relation to the downward ICW slope (r = -0.235, p = 0.004) and was strongly correlated with excess fluid mass (r = -0.701, p < 0.001). The ECW-to-ICW ratio and excess fluid mass was independently associated with the BNP levels. Conclusion: Fluid volume imbalance between intra- and extracellular water regulated by decreased cell mass was independently associated with BNP levels, which may explain the reserve capacity for fluid accumulation in patients with CKD.

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Prognostic Significance of Asymptomatic Brain Natriuretic Peptide Elevation at Nephrology Referral in Patients with Chronic Kidney Disease

American Journal of Nephrology ◽

10.1159/000492724 ◽

2018 ◽

Vol 48 (3) ◽

pp. 205-213 ◽

Cited By ~ 3

Author(s):

Terumasa Hayashi ◽

Keiko Yasuda ◽

Tomonori Kimura ◽

Koichi Sasaki ◽

Karin Shimada ◽

...

Keyword(s):

Chronic Kidney Disease ◽

Kidney Disease ◽

Sudden Death ◽

Brain Natriuretic Peptide ◽

Natriuretic Peptide ◽

Prognostic Significance ◽

Roc Curves ◽

Cox Models ◽

End Point ◽

Asymptomatic Elevation

Background: It is unclear whether asymptomatic elevation of brain natriuretic peptide (BNP) is associated with cardiovascular events (CVEs) or heart failure (HF) in predialysis chronic kidney disease (CKD) patients. Methods: We measured BNP in 482 asymptomatic predialysis patients with CKD stages 2–5 at nephrology referral between August 2004 and October 2010, and followed them prospectively to investigate the prognostic significance of BNP using Cox models and receiver operating characteristic (ROC) analyses. The primary composite end point was the time to death or the first nonfatal CVEs. Secondary end points included CVEs including sudden death, HF and all-cause death. Results: The median age was 67 years (male, 67.4%; diabetic nephropathy, 33.4%), and estimated glomerular filtration rate was 20.1 mL/min/1.73 m2. The primary end point occurred in 92 patients. CVEs including sudden death, HF and all-cause death occurred in 66, 35, and 54 patients, respectively during a median follow-up period of 37.7 months. Multivariate analyses showed that BNP level was significantly associated with the primary end point (hazard ratio [HR] 1.241; 95% CI 1.020–1.511; p = 0.031), CVEs (HR 1.337; 95% CI 1.067–1.675; p = 0.012) and HF (HR 1.489; 95% CI 1.059–2.091; p = 0.022), but not associated with all-cause death (HR 1.081; 95% CI 0.829–1.410; p = 0.565). The ROC curves showed that the optimal predictive BNP levels for the primary end point, CVEs and HF were 92.5, 127.0, and 274.6 (pg/mL) respectively. Conclusion: Asymptomatic elevation of BNP is strongly predictive for CVEs and HF, which might help to integrate cardio-renal risk stratification in predialysis CKD patients.

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