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Weight loss surgery is seen as an important tool in the management of type 2 diabetes. Halfpoint Images/Getty Images
  • Researchers report that bariatric weight-loss surgery provides more long-term benefits for managing type 2 diabetes than lifestyle changes.
  • They said that bariatric surgery also improves cholesterol and triglyceride levels more effectively than medical or lifestyle modifications.
  • Currently, people with body mass index readings of under 35 do not qualify for the surgery under most health insurance company guidelines.

Bariatric surgery provides more benefits than lifestyle changes in managing type 2 diabetes, according to a study completed at the University of Pittsburgh School of Medicine and published today in the journal JAMA.

As part of the research, participants with type 2 diabetes and obesity enrolled in one of four randomized clinical trials completed between May 2007 and August 2013.

The participants underwent bariatric surgery or completed a medical and lifestyle program based on established interventions known to reduce diabetes risk.

Interventions included physical activity, nutrition tracking, enhanced engagement with a healthcare team, stress management, support groups, and medication. The trials occurred before the availability of GLP-1 receptor agonist medications such as Ozempic for diabetes management and weight loss.

The researchers followed most of the participants for 12 years.

The researchers reported that bariatric surgery improved cholesterol and triglyceride levels more effectively than medical or lifestyle modifications. High cholesterol levels are a risk factor for heart disease.

Participants who had the surgery also consistently had lower HbA1c levels, indicating better blood sugar control, at every follow-up point, despite starting the study with higher baseline levels.

The findings also included:

  • At the seven-year follow-up, 18% of participants achieved diabetes remission, compared to 6% in the medical and lifestyle groups.
  • At the 12-year follow-up, participants who had surgery achieved an average of 19% weight loss, compared to slightly less than 11% in the medical and lifestyle intervention group.
  • Anemia, fractures, and adverse gastrointestinal symptoms, such as nausea and abdominal pain, were more common in those who received bariatric surgery.

Participants who did not achieve diabetic remission still had better blood sugar control and used less diabetes medication than those who underwent lifestyle changes, the researchers noted.

“In my practice, I have seen patients who have weight loss surgery be able to discontinue their diabetes, high blood pressure, and lipid-lowering medications,” said Dr. Mir Ali, a bariatric surgeon and medical director of MemorialCare Surgical Weight Loss Center at Orange Coast Medical Center in California who was not involved in the study.

The confirmation from the study results that bariatric surgery is more effective than lifestyle interventions was not surprising to Dr. Anita Courcoulas, the chief of the Section of Minimally Invasive Bariatric and General Surgery at the University of Pittsburgh School of Medicine and one of the authors of the study.

What is new/novel is that this is the largest study of its type and the length of follow up of 7 to 12 years is the longest,” she told Medical News Today. “As well, this study includes 37 percent of participants with BMI (body mass index) less than 35 with class 1 obesity and also finds long-term superiority of surgery over medical/lifestyle treatment in this subset. These findings combined with existing evidence lend very strong support for the use of bariatric surgery to treat type 2 diabetes in people who cannot achieve glycemic control by non-surgical means.”

Dr. Eliud Sifonte, an endocrinologist at NYU Langone Medical Associates — West Palm Beach and Delray Beach in Florida who was not involved in the study, agreed.

“This study confirms previously known findings showing the benefits of bariatric surgery in those with metabolic diseases like diabetes and the efficacy of early interventions in the progress of a diabetic,” he told Medical News Today. “It also confirms the weight-centered approach to treatment of metabolic derangements as compared to the traditional glucose-centric approach.”

“I believe this confirmation could be key to helping some patients make the decision to undergo bariatric surgery particularly since it presents the possibility of remission, which is something many people with new onset diabetes are interested in,” Sifonte added. “In my practice I typically discuss bariatric surgery with those patients who have a history of obesity with metabolic complications regardless of the typical threshold.”

The researchers reported that the study’s results were consistent across weight class groups, indicating that surgery was equally beneficial for people with body mass indexes (BMI) below and above 35 kg/m2.

Typically, physicians do not recommend surgery for people below the 35 BMI level.

“BMI is not an ideal marker of metabolic disease,” said Dr. Mitchell Roslin, the chief of bariatric surgery at Northwell Lenox Hill Hospital in New York who was not involved in the study. “In fact, even high sugar misses a lot of people. All the big killers in the West are linked to metabolic disease. This includes heart disease, cancer, and neurological degenerative diseases.”

“Bariatric surgery that provides a long-lasting control mechanism that better matches the brain and GI tract, reduced hunger and prolonging satiety, is the best and perhaps only treatment to provide long-term control of metabolic syndrome,” Roslin told Medical News Today. “While obesity makes metabolic [disease] more common, there are many with smaller BMI who have metabolic disease. Additionally, as people age, metabolic disease increases.”

“Thus, [I have] no reluctance to offer bariatric surgery to low BMI patients with metabolic syndrome,” he added. “Like any therapy, [some] things will be prevented and others, more likely. The advantage is a lower risk of heart disease and cancer and [but] an increased risk of osteoporosis and anemia. In my mind, this risk can be mitigated with follow-up after surgery, diet, and exercise.”

The researchers did not find differences in mortality or major cardiovascular events in different weight class groups.

In many cases, the final word on having bariatric surgery is not with the doctor or the patient.

“The decision is up to their health insurance company,” Mir told Medical News Today. “Many times, the insurance companies are quite strict with approvals. People with a BMI of under 35 often do not get approved. Sometimes, if there are other health conditions, such as diabetes, we can ask them to approve payment. More often, they deny the claim.”

Ali said he has been working with other physicians to try to get the insurance companies to lower the BMI threshold for weight loss surgery, but so far has not had any luck.