The effect of 1% glucose loading on metabolism in the elderly patients during remifentanil-induced anesthesia: a randomized controlled trial

Background: Previous studies showed that remifentanil-induced anesthesia can inhibit surgical stress response in non-diabetic adult patients and that low-dose glucose loading during anesthesia may attenuate fat catabolism. However, little is known about the influence of glucose loading on metabolism in elderly patients, whose condition may be influenced by decreased basal metabolism and increased insulin resistance. We hypothesized that, in elderly patients, intraoperative low glucose infusion may attenuate the catabolism of fat without causing harmful hyperglycemia during remifentanil-induced anesthesia. Methods: Elderly, non-diabetic patients scheduled to undergo elective surgery were enrolled and randomized to receive no glucose (0G group) or low-dose glucose infusion (0.1 g/kg/hr. for 1 h followed by 0.05 g/kg/hr. for 1 h; LG group) during surgery. Glucose, adrenocorticotropic hormone (ACTH), 3-methylhistidine (3-MH), insulin, cortisol, free fatty acid (FFA), creatinine (Cr), and ketone body levels were measured pre-anesthesia, 1 h post-glucose infusion, at the end of surgery, and on the following morning. Results: A total of 31 patients (aged 75-85) were included (0G, n = 16; LG, n = 15). ACTH levels during anesthesia decreased significantly in both groups. In the LG group, glucose levels increased significantly after glucose loading but hyperglycemia was not observed. During surgery, ketone bodies and FFA were significantly lower in the LG group than the 0G group. There were no significant differences in insulin, Cr, 3-MH, and 3-MH/Cr between the two groups. Conclusion: Remifentanil-induced anesthesia inhibited surgical stress response in elderly patients. Intraoperative low-dose glucose infusion attenuated catabolism of fat without inducing hyperglycemia.