Obesity is on the rise worldwide and it’s a risk factor for systemic hypertension, hyperlipidemia, diabetes mellitus, and left ventricular hypertrophy, all of which are conditions associated with an increased prevalence of heart failure.  However, the applications of BNP and NT-proBNP as biomarkers in obese patients are limited, as the relationship between their levels and myocardial stiffness is complex.  An Editorial appearing in the September 2019 issue of Clinical Chemistry examines the interrelationship between obesity and BNP and NT-proBNP measurements.