The Effect of Myokines on Glucose-stimulated Insulin Secretion in Health and Obesity

Dr. Cathy Chan

Catherine Chan

The global prevalence of diabetes has been increasing due to population growth, aging, urbanization, and an increase in obesity and physical inactivity.  According to the Canadian Diabetes Association, more than 9 million Canadians live with diabetes and prediabetes.  Type 2 diabetes can be prevented and managed effectively with physical exercise.  the exercise-induced metabolic benefits are obtained partly through the release of a hormone called Irisin from skeletal muscle.  Irisin causes increased energy expenditure in adipose tissue (which serves as a fat depot) and provides an exercise-like weight loss benefit.  However, the effects of Irisin on other organs, including the pancreas, has not been studied.  The pancreas secretes insulin, which is controlled by the blood glucose level and the whole-body glucose demand.  we hypothesize that Irisin will regulate insulin secretion from the pancreatic β-cells according to the nutrient/energy demand of skeletal muscle.  Therefore, the objective of this research is to test the effect of Irisin on β-cell function.  Chronically high insulin concentrations (i.e. hyperinsulinemia) are a characteristic feature of obesity and prediabetes.  We therefore predict that Irisin will normalize insulin levels in obesity, and will prevent the progression to type 2 diabetes.  Healthy and diet-induced obese models will be utilized to conduct these experiments.  This study will help to find a novel mechanism to explain how skeletal muscle communicates with the pancreas to regulate insulin secretion, and possibly help in mapping future targets for diabetes treatment.