Diabetes and obesity

Abstract

The prevalence of obesity and diabetes has reached epidemic proportions worldwide and contributes to premature mortality. Obesity is an abnormal or excessive fat accumulation and is defined by a body mass index ≥30 kg/m2. Obesity increases the risk for metabolic and cardiovascular diseases, musculoskeletal disorders, some types of cancer, pulmonary diseases, and psychological diseases. A doubling of the obesity prevalence since the 1980s may be caused by a globally increased intake of energy-dense foods with a parallel decrease in daily physical activity due to the increasingly sedentary nature of many forms of work, changing modes of transportation, and increasing urbanization. Obesity represents the strongest modifiable risk factor for type 2 diabetes (T2D). Obesity and T2D may develop on a common genetic risk background. Mechanisms linking obesity to T2D include abdominal fat distribution, adipose tissue dysfunction, and inflammation characterized by the secretion of a diabetogenic adipokine pattern which contributes to impaired insulin action in skeletal muscle, liver, brain, and other organs. In patients with obesity and T2D, therapeutic weight reduction leads to improvements of all metabolic disturbances including beneficial effects on insulin sensitivity, lipid metabolism, liver fat, and chronic inflammation. Weight loss could be achieved by caloric restriction combined with increased physical activity and behavior training in the context of multimodal interventions. Pharmacotherapies may support additional weight loss, and for patients with overweight- or obesity-associated T2D antihyperglycemic treatment strategies which promote weight loss should be preferred. However, bariatric surgery is the approach with the best long-term efficacy to treat morbid obesity and may lead to significant improvements on obesity comorbidities including a high remission rate of T2D.