The association between obesity and low natriuretic peptides is highly relevant in clinical practice for many reasons. Obese patients are virtually all breathless and do not often unveil typical heart failure signs including increased jugular venous pressure, a third heart sound, displaced apical impulse and ankle oedema. The quality of their chest x-rays and transthoracic echocardiograms, both essentials in heart failure diagnosis, are, most of the time, reduced. Therefore, it would be ideal to rely on a biomarker in these patients. However, using the standard BNP threshold of 100 ng/l, the diagnosis of acute heart failure may be missed in one in five patients with a BMI ≥35 kg/m
2 [
22]. Therefore, Daniels et al. have tried to define for each BMI groups the cut-off points corresponding to a sensitivity of 90% for diagnosing acute heart failure. They found a value of 54 ng/l in patients with a BMI of 35 kg/m
2 or more. In contrast, the cut-off point could be increased to 170 ng/l for lean subjects with a BMI <25 kg/m
2 (
table 1) [
22]. No specific cut-off value has been established for NT-proBNP in obese patients. In the inclusion criteria of a recent trial [
23], another correction of BNP/NT-proBNP cut-off values according to BMI has been proposed. It consists of a 4% reduction of the BNP (≥300 ng/l) or NT-proBNP (≥1500 ng/l) cut-off for every 1 kg/m
2 increase in BMI above a reference BMI of 20 kg/m
2. However, the clinical value of such a correction has not yet been evaluated, neither in the diagnosis nor prognosis of heart failure patients. Finally, a recent review of the ESC proposed 50% lower BNP/NT-proBNP cut-off concentrations in obese subjects, but this correction remains controversial among experts [
7].