Obesity, type 2 diabetes, and the metabolic syndrome. Pathophysiologic relationships and guidelines for surgical intervention

Cardiometabolic disorders are characterized by a complex pathophysiology and increased risk of mortality. Experimental evidence shows that some rearrangements of GI anatomy can directly affect glucose homeostasis, insulin sensitivity, and inflammation, supporting the idea that the GI tract is a biologically rational target for interventions aimed at correcting pathophysiologic aspects of obesity and type 2 diabetes. Recent randomized controlled trials show that GI surgery results in superior glycemic control compared with conventional medical and lifestyle approaches in patients with diabetes. Such mechanistic and clinical evidence is transforming traditional bariatric surgery, focused on weight reduction, into a new surgical discipline aimed at the improvement of metabolic regulation and reduction of cardiometabolic risk (“metabolic surgery”). Future studies designed to further elucidate the mechanisms of action of metabolic surgery can inform decisions regarding the choice of procedures for individual patients, may help optimize surgical design, and could also identify targets for novel device-based and/or pharmaceutical approaches to obesity and T2DM.