INCREASED BRAIN NATRIURETIC PEPTIDE AND ATRIAL-NATRIURETIC-PEPTIDE PLASMA-CONCENTRATIONS IN DIALYSIS-DEPENDENT CHRONIC-RENAL-FAILURE AND IN PATIENTS WITH ELEVATED LEFT-VENTRICULAR FILLING PRESSURE

Brain natriuretic peptide (BNP) and atrial natriuretic peptide (ANP) plasma concentrations were measured in patients with dialysis-dependent chronic renal failure and in patients with coronary artery disease exhibiting normal or elevated left ventricular end-diastolic pressure (LVEDP) (n = 30 each). Blood samples were obtained from the arterial line of the arteriovenous shunt before, 2 h after the beginning of, and at the end of hemodialysis in patients with chronic renal failure. In patients with coronary artery disease arterial blood samples were collected during cardiac catheterization. BNP and ANP concentrations were determined by radioimmunoassay after Sep Pak C,, extraction. BNP and ANP concentrations decreased significantly (P < 0.001) during hemodialysis (BNP: 192.1 +/- 24.9, 178.6 +/- 23.0, 167.2 +/- 21.8 pg/ml; ANP: 240.2 +/- 28.7, 166.7 +/- 21.3, 133.0 +/- 15.5 pg/ml). The decrease in BNP plasma concentrations, however, was less marked than that in ANP plasma levels (BNP 13.5 +/- 1.8%, ANP 40.2 +/- 3.5%; P < 0.001). Plasma BNP and ANP concentrations were 10.7 +/- 1.0 and 60.3 +/- 4.0 pg/ml in patients with normal LVEDP and 31.7 +/- 3.6 and 118.3 +/- 9.4 pg/ml in patients with elevated LVEDP. These data demonstrate that BNP and ANP levels are strongly elevated in patients with dialysis-dependent chronic renal failure compared to patients with normal LVEDP (BNP 15.6-fold, ANP 2.2-fold, after hemodialysis; P < 0.001) or elevated LVEDP (BNP 6.1-fold, ANP 2.0-fold, before hemodialysis; P < 0.001), and that the elevation in BNP concentrations was more pronounced than that in ANP plasma concentrations. The present results provide support that other factors than volume overload, for example, decreased renal clearance, are also involved in the elevation in BNP and ANP plasma levels in chronic renal failure. The stronger elevation in BNP concentrations in patients with chronic renal failure and in patients with elevated LVEDP and the less pronounced decrease during hemodialysis suggest a different regulation of BNP and ANP plasma concentrations.