IGF1 and obesity due to melanocortin 4 receptor deficiency: The mechanism underlying this association is not completely understood, but obesity-induced insulin resistance, adipokine levels and obesity-related inflammation are all important factors (Sandhu et al, 2002; Giovannucci, 2007; Birmingham et al, 2009; Gonullu et al, 2009), implicating insulin resistance and alterations in the insulin – insulin-like growth factor-1 (IGF-1) axis as the main driving forces (Komninou et al, 2003; Giovannucci, 2007).