Study to compare bariatric surgery vs. medical therapy in obese patients with diabetes

Researchers at New York-Presbyterian Hospital/Weill Cornell Medical Center are planning a clinical trial to determine whether bariatric surgery can control diabetes as well as or better than medical treatment. This is the first study of its kind open to overweight or mildly obese patients, according to a press release.

“Having a potentially effective surgical option against diabetes does not mean that surgery is the best choice for every diabetic patient,” Francesco Rubino, MD, chief of the gastrointestinal metabolic surgery program at New York-Presbyterian Hospital/Weill Cornell Medical Center and associate professor of surgery at Weill Cornell Medical College, said in the release. “We need rigorous, comparative clinical trials, like this one, in order to better understand when to prioritize surgery and when to recommend traditional medical treatment.”

The study will enroll 50 patients with type 2 diabetes and a BMI of 26 to 35. Patients will be randomly assigned to Roux-en-Y gastric bypass or traditional medical therapy and lifestyle modification, including counseling on diet and exercise.

The researchers will measure gut hormone responses to meal stimulation when an equivalent amount of weight loss has been achieved in both surgically and conventionally treated patients. With this design, they aim to uncover endocrine effects specific to gastric bypass surgery beyond those associated with nonsurgical weight loss.

“Understanding how gastric bypass surgery functions may help us learn how diabetes works,” Rubino said. “This knowledge has the potential to lead to the development of new minimally invasive procedures, device interventions and better pharmaceutical treatments.”

According to Rubino, patients in both arms should reap medical advantages due to the rigorous therapy being used in the medical treatment arm. However, patients in the therapy arm will have the option to receive free surgery at study completion or earlier if their diabetes remains poorly controlled after medical and lifestyle therapy. Rubino and colleagues also said they hope that their study will help identify better criteria than BMI for surgical candidate selection.

“Using strictly BMI-based criteria may be practical, but it is medically inappropriate because, on its own, BMI does not accurately define the severity of diabetes or identify patients who are best suited to benefit from a surgical approach,” Rubino said. “New criteria would not only help patients and clinicians, but also payers.”

Currently, insurance companies do not cover bariatric surgery in patients with a BMI of less than 35. The current study is supported by a research grant from Covidien, which will cover the cost of surgery for patients enrolled.

Previous research has demonstrated that bariatric surgery is a safe and effective way to treat type 2 diabetes in severely obese people. Surgery has been shown to improve or normalize blood glucose levels, reduce or eliminate the need for medication and lower the risk for diabetes-related death. Based on these results, the American Diabetes Association has suggested that studies of bariatric surgery in patients with BMI of less than 35 are a priority for diabetes research.

Rubino said he hopes that the current study will be a template for larger, international studies.

“We intend this study to serve as a core protocol for similar randomized clinical trials independently run at other institutions as part of a worldwide consortium coordinated through the Diabetes Surgery Center at New York-Presbyterian/Weill Cornell,” he said. “The consortium will provide a larger pool of patients allowing researchers to better evaluate the impact of surgery on various health measures, including cardiovascular risk and life expectancy.”

Disclosure: Dr. Rubino reports no relevant financial disclosures.

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