An umbrella term for a number of surgical procedures that improve blood glucose control in people with type 2 diabetes who are obese. Types of metabolic surgery include adjustable gastric banding, Roux-en-Y gastric bypass, biliopancreatic diversion and sleeve gastrectomy.
In adjustable gastric banding, the upper part of the stomach is surrounded by an inflatable silicon ring that restricts the movement of food. In Roux-en-Y gastric bypass, a surgical stapler is used to create a small pouch in the stomach, which is then surgically attached directly to the middle of the small intestine. In biliopancreatic diversion and sleeve gastrectomy, the reduced stomach is surgically attached to the end-portion of the small intestine. These procedures have two things in common: they decrease the absorption of calories by the gastrointestinal tract and promote weight loss. However, researchers are studying other — and perhaps even more powerful — effects such as changes in food metabolism by bile acids, changes in the hormones in the gut that regulate food metabolism and changes in the types of bacteria that live in the gastrointestinal tract.
Many randomized clinical trials have shown that these types of surgical procedures achieve better blood glucose control and a decrease in cardiovascular risk factors in obese type 2 diabetic patients compared with various medical and lifestyle interventions. A joint statement issued by international diabetes organizations in 2016 recommended that metabolic surgery be included among treatments for patients with type 2 diabetes and obesity.