More Evidence Metabolic Surgery Superior to Drug Treatment in Patients With Obesity

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CONTACT: Zach Gross, 212-266-0063

CHICAGO, IL, June 20, 2019 – Metabolic or bariatric surgery was significantly more effective than medical management in treating type 2 diabetes in patients with milder forms of obesity, according to new research presented here at an American Society for Metabolic and Bariatric Surgery (ASMBS) national clinical symposium on obesity prevention, treatment and research.

In a systematic review and meta-analysis of 28 studies that included patients with a body mass index (BMI) between 30 and 35 and diagnosed diabetes, George Washington University researchers found metabolic surgery was superior to medical management in reducing HbA1c, fasting plasma glucose (FPG) levels and BMI in the vast majority of patients. In the 15 studies with one-year follow up, HbA1c levels were on average more than 1 percent lower, FPG was 26.62 mg/dL less and BMI decreased by 3.49 points more than patients treated with drug therapy.

“This study suggests metabolic surgery should not be reserved for those with more severe obesity and type 2 diabetes,” said Kyra Folkert, one of the researchers from The George Washington University in Washington, DC. “Metabolic surgery appears to be more effective in resolving or improving diabetes in lower BMI patients than medical management.”

Most bariatric surgery is performed on patients with a BMI of 35 or greater, but in 2018, the ASMBS issued a position statement noting that in the last five years, “there is mounting evidence to support surgical treatment of obesity in patients with class I obesity (BMI 30-35).” According to the ASMBS, the evidence demonstrates “a marked and durable improvement in co-morbid conditions, especially type 2 diabetes, as well as significant weight loss compared with medical therapy in patients with class I obesity.” The Centers for Disease Control and Prevention (CDC) estimates more than 100 million U.S. adults are currently living with diabetes or prediabetes.

“Current nonsurgical treatments for class I obesity are often ineffective at achieving major, long-term weight reduction and resolution of obesity-related diseases,” said Eric J. DeMaria, MD, president of the ASMBS and professor and chief, Division of General/Bariatric Surgery, Brody School of Medicine at East Carolina University in Greenville, NC, who was not involved in the study. “The existing BMI inclusion criterion of ≥35 kg/m2 as a prerequisite for bariatric and metabolic surgery was established more than a quarter century ago. There is no current evidence that justifies patients with class I obesity being excluded from this life-saving surgical treatment. Access to bariatric and metabolic surgery should not be denied solely based on an outdated threshold.”

In a Joint Statement and Clinical Guidelines first issued in 2016 and updated this year, 45 international professional organizations, including the American Diabetes Association, as well as diabetes clinicians and researchers, recommended metabolic or bariatric surgery be considered as a treatment option for certain categories of people with diabetes, including people with mild obesity who fail to respond to conventional treatment.

The Guidelines authors wrote, “Despite continuing advances in diabetes pharmacotherapy, fewer than half of adults with type 2 diabetes mellitus (T2D) attain therapeutic goals designed to reduce long-term risks of complications, especially for glycemic control, and lifestyle interventions are disappointing in the long term.” Metabolic surgery, however, has been shown to “improve glucose homeostasis more effectively than any known pharmaceutical or behavioral approach.”

These conclusions are based on a large body of evidence including 11 randomized clinical trials showing that in most cases surgery can either achieve diabetes remission or maintain adequate glycemic control despite major reduction in medication usage.

Head-to-head studies show bariatric or metabolic surgery is superior to nonsurgical treatment including drug therapy and intensive lifestyle intervention in producing long-term diabetes remission with 25 to 50 percent more surgery patients maintaining glycemic control without medication for up to five years.2,3

Metabolic/bariatric surgery has been shown to be the most effective and long-lasting treatment for severe obesity and many related conditions and results in significant weight loss.4 The Agency for Healthcare Research and Quality (AHRQ) reported significant improvements in the safety of metabolic/bariatric surgery due in large part to improved laparoscopic techniques.5 The risk of death is about 0.1 percent6 and the overall likelihood of major complications is about 4 percent.7 According to a study from the Cleveland Clinic’s Bariatric and Metabolic Institute, laparoscopic bariatric surgery has complication and mortality rates comparable to some of the safest and most commonly performed surgeries in the U.S., including gallbladder surgery, appendectomy and knee replacement.8

Obesity is associated with increased risk of developing more than 40 other diseases and health conditions including type 2 diabetes and coronary heart disease.9 The CDC reports that in 2015-2016, the prevalence of obesity in the U.S. was 39.8 percent in adults and 18.5 percent in youths, the highest in American history.10 The ASMBS estimates about 24 million have severe obesity, which for adults means a body mass index (BMI) of 35 or more with an obesity-related condition like diabetes or a BMI of 40 or more. In 2017, 228,000 bariatric procedures were performed in the U.S., which is about 1 percent of the population eligible for surgery based on BMI.

About the ASMBS
The ASMBS is the largest organization for bariatric surgeons in the nation. It is a non-profit organization that works to advance the art and science of bariatric surgery and is committed to educating medical professionals and the lay public about bariatric surgery as an option for the treatment of severe obesity, as well as the associated risks and benefits. It encourages its members to investigate and discover new advances in bariatric surgery, while maintaining a steady exchange of experiences and ideas that may lead to improved surgical outcomes for patients with severe obesity. For more information, visit

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