NPPB and obesity due to melanocortin 4 receptor deficiency: This—together with the observation that levels of BNP or the inactive fragment of its pro-hormone (N-terminal fragment of pro-BNP [NT-pro-BNP]) are consistently decreased in individuals with obesity, insulin resistance, and type 2 diabetes (T2D) in cross-sectional studies—raises the possibility of a role of BNP in the aetiology of metabolic disease [3],[4].