GHRL and Insulin resistance: Accordingly, the tight relationship between ghrelin and insulin also relies in the general assumption that insulin elicits a negative action on both plasma acylated- and unacylated-ghrelin concentration (Saad et al., 2002; McLaughlin et al., 2004), while administration of acylated-ghrelin results in insulin resistance (Gauna and van der Lely, 2005).