Postoperative insulin resistance (PIR) is a central feature of postoperative metabolism response to surgical injury, resulting in decreased insulin-stimulated glucose uptake in skeletal muscle and adipose tissue, increased glucose release and hyperglycaemia. The PIR is most pronounced on the day after surgery and lasts for about 3 weeks after uncomplicated elective open abdominal operations, and has been considered as a factor of clinical importance for the postoperative patient. Recent evidences have elucidated the toxicity of hyperglycemia and suggest a causal relation between PIR and complications in the postoperative state and the degree of PIR has been considered as an independent factor determining the length of postoperative hospital stay.