BDKRB1 and obesity due to melanocortin 4 receptor deficiency: SIRT1 levels strongly negatively correlate with the amount of visceral fat (Mariani et al., 2018) B1R in adipocytes regulates glucose tolerance and predisposition to obesity (Mori et al., 2012) and B1R knockout mice have been shown to be resistant to obesity induced by a high-fat diet (Morais et al., 2015).