Periop Insulin: Effects

Surgery and anesthesia lead to a metabolic stress response that causes alterations in the homeostatic mechanisms involved in glucose control. This is particularly true in patients with baseline alterations in glucose management. The stress response includes the release of epinephrine, norepinephrine, cortisol, glucagon, and growth hormone along with inhibition of insulin secretion and action. There is also a negative effect on pancreatic b-cell function causing plasma insulin levels to fall and impairment of insulin secretion in response to glucose. Both the anabolic and anti-catabolic effects of insulin may be attenuated or reversed shifting toward perioperative hypercatabolism.

Anabolic Action of Insulin

1. Stimulation of glucose uptake and glycogen storage in skeletal muscle
2. Stimulation of amino acid uptake and protein synthesis in skeletal muscle
3. Stimulation of fatty acid synthesis in the liver and storage in fat cells
4. Renal sodium absorption and intravascular volume preservation

Anti-catabolic Action

1. Inhibition of hepatic glycogen breakdown
2. Inhibition of gluconeogenesis
3. Inhibition of lipolysis
4. Inhibition of fatty acid oxidation and ketone body formation
5. Inhibition of preoteolysis and amino acid oxidation