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

Abstract

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. for T2DM are glycated hemoglobin (A1c) <7%, low-density lipoprotein cholesterol levels <100 mg/dL and blood pressure <130-80 mmHg (3,6), and less than 20% of USA patients achieve these levels in triple target despite having the best medical treatment. Bariatric surgery was first described just for reducing weight in severely obese patients. A Swedish Obese Subjects (SOS) study, demonstrated that the surgery group arm not only had more drastic and sustainable average reduction of excess body weight but also had remarkable beneficial effects on cardiovascular risk factors, such as waist circumference, blood pressure, glucose and insulin levels, uric acid, triglyceride and HDL cholesterol levels when compared with conventionally treated patients (7-10). Even though the SOS study showed a reduction of the number of cardiovascular events and overall mortality in the surgery group (HR 0.76, CI 95%) (11,12), one of the most relevant points was the finding of absence of significant relationship between cardiovascular mortality and body mass index (BMI) (7,13).Gastrointestinal (GI) operations have demonstrated, especially those that involve food rerouting through the GI tract that are safe and provide better outcomes for weight loss and...

Remission of Type 2 Diabetes Mellitus after Bariatric Surgery: Fact or Fiction?

“…The limb carrying biliopancreatic secretions is anastomosed typically 150 cm distally to the gastro-jejunostomy. RYGB has a balanced safety-efficacy profile and is considered to be the “gold standard” in the surgical therapy of obesity and T2DM [16].…”

Pancreatic Exocrine Insufficiency after Bariatric Surgery

“…Surgery is the most effective treatment for morbid obesity in terms of sustained weight loss, improvement of comorbidities and quality of life, and in terms of the long-term reduction of overall mortality [ 1 , 19 , 20 , 21 , 22 , 23 , 24 ].…”

Metformin for the management of peri‐operative hyperglycaemia

“…A notable limitation in this trial was the inclusion of a substantial proportion of patients (45.7%) undergoing bariatric surgery. Unlike other operations, patients who undergo metabolic surgery experience a rapid improvement in glycaemic control, independently of weight loss or caloric restriction . Further, this unique patient population has several notable hormonal changes that are readily detected within 24 hours of surgery, which probably has a profound impact on peri‐operative glucose metabolism .…”

“…Unlike other operations, patients who undergo metabolic surgery experience a rapid improvement in glycaemic control, independently of weight loss or caloric restriction. [16][17][18] Further, this unique patient population has several notable hormonal changes that are readily detected within 24 hours of surgery, which probably has a profound impact on perioperative glucose metabolism. 16 Although a significant stress response was seen in patients within 2 hours of surgery, we are unaware of any corresponding studies reporting the early hormonal changes that probably occur amongst patients undergoing bariatric surgery, which would be likely to mask the benefits of metformin on peri-operative glucose concentrations.…”