The relationship between serum level of N-terminal pro-B-type natriuretic peptide and nutritional status, and inflammation in chronic hemodialysis patients

Background: N-terminal proB-type natriuretic peptide (NT-pro BNP), a biomarker of heart failure, is involved in regulation of the body fluid homeostasis and vascular tone. The purpose of this study was to investigate the relationship between serum level of NT-pro BNP and nutritional status, inflammation and hydration in patients on maintenance hemodialysis (HD). Materials and methods: The study involved 97 HD patients (mean age: 65.3 +/- 13.9 years, H D duration: 36.3 +/- 43.5 months). Blood tests comprised the measurements of serum levels of NT-pro BNP, interleukin-6 (IL-6), human lsoluble tumor necrosis factor receptor I (s TNF RI), hemoglobin (Hb), albumin (alb) and urea. Furthermore, normalized protein catabolic rate (n PCR), body mass index (BMI), mean arterial blood pressure (MAP), adequacy of HD (Kt/V), and interdialytic body weight gain (IBWG) were calculated. In addition, NT-pro BNP was measured in a healthy control group (CG; n = 24, mean age 49.5 +/- 15.0 years). Hydration status was determined by bioimpedance analysis (BIA). Results: Irrespective of gender, NT-pro BNP levels were markedly elevated in I-ID patients compared with CG (15879.2 +/- 14033.3 pg/ml vs. 73.45 +/- 23.56 pg/ml; p < 0.00001). NT-pro BNP was unrelated to any measures of body fluid compartments. Multivariate regression analysis revealed that only four parameters (nPCR, Hb, MAP, and total time on HD) influenced serum NT-pro BNP levels. Conclusion: While there was only moderate direct association of NT-pro BNP with hydration status, it was elevated in patients with intensive catabolism, severe anemia, higher MAP and longer total duration of HD.