IGF1 and Insulin resistance: The excess of insulin-like growth factor-1 (IGF-1) in acromegalic patients, ascribed to GH overexpression, seems to be involved in the onset of hyperglycemia (with a prevalence of DM ranging from 12 to 37%); it also promotes insulin resistance by lipolysis, stimulating gluconeogenesis, and blocking the signaling of insulin mediators, such as p85 alpha and insulin receptor substrate (IRS-1) [3].