Background: The profound effect of a minimally-invasive procedure under general anesthesia with remifentanil contributes to suppression of hyperglycemic responses, which was formerly observed as a stress response. However, intraoperative occurrence of hypoglycemia is considered more of a concern. In addition, depending on preoperative nutritional status, critical hypoglycemia may occur during surgery. There are few reports on perioperative glucose metabolism in patients not receiving glucose infusion under anesthesia with remifentanil. The preoperative fasting period is longer in Japan and preoperative carbohydrate infusion or other pretreatment is not actively performed; thus, the preoperative nutritional status is close to that of starvation. Furthermore, the regulation of glucose metabolism under intraoperative management with potent opioids, such as remifentanil, as well as the fluctuations in metabolism due to perioperative glucose infusion, is important from the viewpoint of nutritional management.