Plasma NT-proBNP increases in response to LPS administration in healthy men

Circulating levels of B-type natriuretic peptide (BNP) and NH(2)-terminal-proBNP (NT-proBNP) increase in response to volume overload and help in the differential diagnosis of acute heart failure. Elevated plasma BNP levels are observed also in sepsis and do not always correspond to left ventricular dysfunction. Here, we investigated plasma NT-proBNP fluctuations in response to human bacterial endotoxinemia, an experimental model of systemic infection and inflammation. Escherichia coli endotoxin (LPS) (2 ng/kg) was administered to 10 healthy volunteers in a randomized, placebo-controlled, cross-over design. Plasma NT-proBNP, C-reactive protein (CRP), COOH terminal pro-endothelin-1 (CT-proET-1), and midregional-pro-adrenomedullin (MR-proADM) were measured at hourly intervals for 6 h. LPS administration induced a continuous increase in plasma NT-proBNP that reached peak values after 6 h (40.7 +/- 7.9 vs. 16.1 +/- 3.2 pg/ml in placebo days, mean +/- SE; P = 0.023). The profile of changes in NT-proBNP correlated to changes in body temperature (P < 0.001), heart rate (P = 0.005), CRP (P < 0.001), and CT-proET-1 (P = 0.008), but not to blood pressure values. Our results demonstrate that plasma NT-proBNP increases in a model of systemic infection/inflammation in healthy men with normal heart function. This finding emphasizes the necessity to consider concomitant infections when interpreting elevated circulating NT-proBNP concentrations.