ABSTRACT

Glutamine affects not only insulin secretion, but also insulin action, including reducing insulin resistance and improving glycemic control in certain physiological conditions. This chapter outlines the action of insulin, identifies metabolic states associated with positive effects of glutamine supplementation, summarizes findings from studies of the effects of glutamine supplementation on insulin action and glycemic control and discusses possible mechanisms by which glutamine affects insulin secretion and action. Glutamine stimulates pancreatic release of glucagon in healthy and diabetic subjects. An interesting study used liquid chromatography/mass spectrometry to profile plasma metabolites from subjects enrolled in the Framingham Heart Study and the Malmo Diet and Cancer Study to link metabolic pathways with cardiometabolic risk factors. They found that metabolic risk factors, including high plasma insulin levels and insulin resistance, were strongly associated with high circulating glutamate compared to glutamine. The researchers conducted diet intervention studies to test the effect of glutamine on glucose tolerance.