News & Updates

Los Angeles—It’s been a decades-long effort to have bariatric surgery accepted as a safe, effective treatment for people who are morbidly obese.

Now, a new study presented at ObesityWeek 2015 suggests that bariatric procedures also should be considered a safe, effective treatment for people who have type 2 diabetes and are overweight or mildly obese.

“A two-hour operation and a two-day hospital stay has the potential to resolve or improve what is a chronic, progressive and dangerous disease,” said John M. Morton, MD, immediate past president of the American Society for Metabolic and Bariatric Surgery, and chief of bariatric and minimally invasive surgery at Stanford University School of Medicine, in California, who was not involved in the study.

“The risk–benefit profile that has emerged for bariatric surgery in people with type 2 diabetes and low body mass index [BMI] is very favorable and should be considered as a treatment option in carefully selected patients.” The Cleveland Clinic researchers who conducted the study say it is the largest published series of bariatric surgery in patients with type 2 diabetes and a BMI of 35 kg/m2 or less.

They evaluated 1,003 patients from North America with a BMI between 25 and 35 kg/m2. The average BMI in the study cohort was 33.5 kg/m2. Forty percent of patients were taking insulin injections and 60% were on oral medications for their diabetes before surgery. Analysis showed that bariatric surgery was associated with a low rate of complications and mortality in these lower BMI patients. The 30-day postoperative mortality rate was 0.2% and the cumulative rate of postoperative adverse events was 4%; 1.6% of patients required reoperation within 30 days. The procedures averaged 110 minutes, and patients were discharged from the hospital within two days.

“We are seeing significant improvement or remission of type 2 diabetes in most lower-BMI patients,” said lead investigator Ali Aminian, MD, laparoscopic and bariatric surgeon at the Cleveland Clinic Digestive Disease Institute, in Ohio. “Currently, evidence suggests that baseline BMI is unrelated to diabetes remission following bariatric and metabolic surgery.

“Our data, which is from a large sample size, shows a modest early morbidity and low mortality following bariatric surgery in nonseverely obese patients. These data are important because most patients with diabetes fall into this BMI category.”

The study, which used data from the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP), lacks long-term follow-up—which is key to assessing the long-term durability of results in these patients. The ACS-NSQIP collects data on more than 150 variables, including preoperative details and 30-day postoperative mortality and morbidity outcomes, on patients undergoing major surgical procedures in the United States. It does not capture adverse events beyond 30 days after surgery, which can lead to inderestimation
of real risks.

Other small series looked at the effects of bariatric surgery in patients with type 2 diabetes who are overweight and mildly obese, but had not been large enough to examine safety.

Despite growing evidence to support bariatric surgery in this population, only a few private insurance carriers provide bariatric coverage for people with a BMI below 35 kg/m2. The existing cutoff of a BMI of 35 kg/m2 for insurance coverage was arbitrarily established nearly 20 years ago, Dr. Aminian said.

“Over the last quarter century, however, the field has significantly evolved with introduction of new, less invasive surgical approaches and surgical procedures, which have led to improvements in the safety profile of surgery and can potentially expand the indications for surgery.”

There are still many unanswered questions about bariatric surgery as a treatment for type 2 diabetes, he added. Although studies have confirmed that surgery can control blood glucose concentrations and cardiovascular risk factors in low-BMI patients, the long-term effects of gastrointestinal surgical procedures on diabetes outcomes, such as retinopathy, nephropathy and cardiovascular events, are not known. Several randomized controlled trials are currently underway to address these concerns.