MMP-9 regulates inflammatory processes by its proteolytic activity (Manicone and Mcguire, 2008) and circulating levels of MMP-9 are increased in obesity, metabolic syndrome (MetS) and cardiovascular disease (Hopps et al., 2016; Jaoude and Koh, 2016; Ritter et al., 2017). This evidence concerns the gene MMP9 and obesity due to melanocortin 4 receptor deficiency.