INS and metabolic syndrome: Vaspin was found to be mainly expressed in visceral adipose tissue of Otsuka Long-Evans Tokushima fatty (OLETF) rats (Hida et al., 2000, 2005), an animal model of T2DM characterized by abdominal obesity, insulin resistance, hypertension, and dyslipidemia (Kawano et al., 1992), with higher plasma levels at age 30 weeks, concomitantly with peak of insulin concentrations.