ABSTRACT
Glutamine is a conditionally essential amino acid that helps maintain the cellular oxidation-reduction state, immune and gut barrier function, nitrogen transport, protein synthesis, glucose metabolism, and insulin sensitivity following stress. Glutamine also influences glycemic control during critical illness. Stress-induced insulin resistance (IR) correlates with the severity of illness and mortality independent of blood glucose levels. Insulin resistance may be altered by several factors including nutritional provision, glycemic control, adiponectin, and infection. Glutamine has been shown to reduce IR following severe illness, and thus, it may improve outcomes via the mechanism. The evidence relating to glutamine supplementation has spanned more than 20 years of research and thousands of patients, but without a clear understanding about the risks and benefits of glutamine supplementation in critical illness. The chapter summarizes basic and clinical research related to glutamine’s role in critical illness.
