Metabolic surgery: gastric bypass for the treatment of type 2 diabetes mellitus.

Type 2 diabetes mellitus (T2DM) is one of the largest health emergencies of the 21st century given the worldwide increase of obesity during the last decades and its close association. T2DM is an inherited, polygenic and chronic disease caused by the interaction between several genetic variants in genes and the environment. The continuous search for new and more effective tools to achieve appropriate glycemic control became imperative in order to reduce long-term complications and mortality rates related to T2DM. Treatment options includes lifestyle modifications and several pharmacotherapies as first step in the therapeutical algorithm, but high corps of evidence have shown that gastrointestinal (GI) operations, especially those that involve food rerouting through the GI tract, are safe interventions and achieve superior outcomes for improvement in glucose metabolism when comparing with optimal medical and lifestyle changes. GI Surgery, specially Roux-en-Y gastric bypass (RYGB), is currently the most accepted surgical procedure to treat T2DM, and has also demonstrated to reduce significantly other cardiovascular risk factors (lipids and blood pressure control) when compared with optimal medical treatment, with good long-term effects on cardiovascular risks and mortality. Although the most effective technique in achieving diabetes remission is biliopancreatic diversion, the effectiveness-adverse effects balance is superior for RYGB. For these reasons, metabolic surgery (which was defined as "the operative manipulation of a normal organ or organ system to achieve a biological result for a potential health gain") has been considered and accepted as a new step in the therapeutic algorithm for T2DM when optimal lifestyle and medical interventions don't achieve optimal glycemic goals.