INS and diabetes mellitus: Diabetes mellitus (DM) is a systemic metabolic disease characterized by the impaired production and secretion of insulin due to the destruction of pancreatic beta cells by autoimmune mechanisms (type I diabetes mellitus) or the failure of the cells of the body to adequately respond to insulin, which is mediated by cellular resistance to insulin action on glucose uptake in various tissues, especially the skeletal muscles and adipose tissue (type II diabetes mellitus).