Amino acid infusion during anesthesia attenuates the surgery induced decline in IGF-1 and diminishes the "diabetes of injury".

Background: Surgery, commonly performed after an overnight fast, causes a postoperative decline in the anabolic and glucose lowering insulin-like growth factor-1 (IGF-1). Clinical fasting studies have exhibited a positive correlation between IGF-1 and nitrogen balance during different conditions. A perioperative amino acid infusion changes nitrogen balance and might thereby influence serum IGF-1. We hypothesized that amino acid infusion would enhance IGF-1 and thereby might influence glucose homeostasis after surgery. In this study we examined two different regimes of perioperative amino acids infusion.

Methods: 24 females scheduled for abdominal hysterectomy were randomized into three groups; Ringer's solution infusion throughout anesthesia (Group B), amino acid infusion throughout anesthesia (Group C) and amino acid infusion 1 hour before anesthesia and during 1.5 hrs of surgery (Group D). Six female volunteers, who were not operated, but received the same amino acids infusion after fasting, served as controls (Group A). Fasting levels of IGF-1, Insulin-like growth factor binding protein-1 (IGFBP-1), insulin and P-glucose were studied prior to, and four days following, operation. Homeostasis model assessment (HOMA) was used as an index of insulin resistance. Non-parametric statistical methods were used.

Results: During the study the Ringer-group exhibited a decrease in IGF-1 and an increase in insulin and plasma glucose after surgery. Within the other groups there were no significant alterations over time after surgery, with the exception of a postoperative decrease in IGF-1 in group D. Group C had higher IGF-1 levels compared to group B on all days. Also, group D had higher IGF-1 levels than group B on day 2-4. From baseline to the first postoperative day there was a significant increase in HOMA and IGFBP-1 in groups B and C. These changes were not found in group D, in which insulin, glucose, HOMA and IGFBP-1 did not change. Amino acid infusion to the volunteers did not affect any of the variables studied.

Conclusion: Amino acid infusion during surgery attenuates the decrease in IGF-1 and diminishes the "diabetes of injury".