NPPB and obesity due to melanocortin 4 receptor deficiency: Obesity affects as many as half of HFpEF patients and is linked to a decrease in NT-proBNP production, with levels approximately 30-50% lower than those in non-obese individuals experiencing similar cardiac stress [14]. In these cases, a "normal" NT-proBNP does not rule out HFpEF; clinicians should depend more on clinical suspicion and imaging, or use lower cut-offs.