The role of stress, sleep, and depression in obesity-related Type 2 Diabetes

Type 2 diabetes mellitus (T2DM) affects a large population worldwide. T2DM is a complex heterogeneous group of metabolic disorders including hyperglycemia and impaired insulin action and/or insulin secretion. T2DM causes dysfunctions in multiple organs or tissues. Current theories of T2DM include a defect in insulin-mediated glucose uptake in muscle, a dysfunction of the pancreatic β-cells, a disruption of secretory function of adipocytes, and an impaired insulin action in the liver. There is increasing scientific evidence regarding the role of obesity and overweight in type 1 diabetes. Weight gain may be considered as a complication of insulin treatment but also reveals significant pathophysiological impact on various stages of the disease. Depression and stress also plays an important role in the pathogenesis and treatment of obesity and type 2 diabetes (T2D). However, its relevance is frequently unrecognized by clinicians and researchers. The purpose of this review is to present a critical analysis of the evidence linking depression and metabolic disorders and to highlight the practical implications of this complex relationship. Evidence obtained from epidemiological, basic, clinical and controlled studies demonstrate that the association goes beyond a random phenomenon. In this review we also highlight evidence that supports the hypothesis that reduced sleep duration may be part of the behavioral modifications that played a role in the development of the current epidemic of obesity and diabetes