Bariatric surgery continues to play a major role in obesity management despite the emergence of potent new weight-loss medications, according to two experts who spoke at an Endocrine Society science writers briefing.
“Bariatric surgery is safe, effective, and unfortunately underutilized for treating obesity and its complications,” said Jaime Almandoz, MD, medical director of the Weight Wellness Program at the University of Texas Southwestern Medical Center, Dallas.
Added Almandoz, who is triple board-certified in internal medicine, endocrinology, and obesity medicine, “Sometimes this gets presented in a linear fashion. ‘We’ll try lifestyle first and if that doesn’t work, we’ll try medications and if that doesn’t work, we’ll try surgery.’ But sometimes we might need to go straight to surgery instead of going through medications first, because it may be the most effective and evidence-based treatment for the person in the office in front of you.”
Moreover, he pointed out that currently, Medicare and many private insurers don’t cover antiobesity medications but do cover bariatric surgery.
Indeed, Srividya Kidambi, MD, professor and chief of endocrinology and molecular medicine at the Medical College of Wisconsin/Froedtert Hospital, Milwaukee, Wisconsin, said there are certain types of patients for whom she might consider bariatric surgery first. One would be a person with a body mass index (BMI) greater than 40 kg/m2 or with a BMI greater than 35 kg/m2 and severe comorbidities.
Another, she said, would be young, relatively healthy people with obesity who have no comorbid conditions. “We know that if we stop the medication, the weight comes back. So, if I see a 20- to 25-year-old, am I really to commit them to lifelong therapy, or is bariatric surgery a better option in these cases? These drugs have not been around that long…so I tend to recommend bariatric surgery in some patients.”
During the recent briefing, Almandoz summarized the evidence base for the benefits of bariatric surgery beyond weight loss, which include remission of type 2 diabetes and fatty liver disease, reduction of the risks of cardiovascular disease and cancer, and increased life expectancy.
“Everyone seems to be talking about GLP-1s for facilitating weight loss and treating obesity…. What I want to do is provide a counterpoint to accessible therapies that are covered by more insurance plans and that may, in fact, have a better evidence base for treating obesity and its related complications,” he said in his introduction.
Bariatric surgery has been used for decades, and many centers of excellence perform it, with greatly reduced complication rates seen today than in the past. “It’s comparable to having a gallbladder surgery in terms of perioperative risk,” he noted.
Medicare and private insurers generally cover bariatric surgery for people with BMI greater than 40 kg/m2 or 35–39 kg/m2 and at least one weight-related comorbidity, including type 2 diabetes, obstructive sleep apnea, hypertension, atherosclerotic disease, hyperlipidemia, and fatty liver disease.
Data suggest that weight reduction of about 3% can lead to meaningful reductions in blood glucose and triglyceride levels, but weight loss of 15% or greater is associated with reductions in cardiovascular events and type 2 diabetes remission. Lifestyle modification typically produces about 5% weight loss, compared to 20% to 35% with bariatric surgery with sleeve gastrectomy or gastric bypass.
Older weight loss medications produced weight loss of 5% to 10%; only the newer medications, semaglutide 2.4 mg and tirzepatide, come close to that. Weight loss with semaglutide is about 15%, while tirzepatide can produce weight loss of up to 22%. But, there are still issues with affordability, access, and lack of coverage, Almandoz noted.
One recent randomized trial of more than 400 individuals showed that bariatric surgery was more effective than lifestyle and medical therapies for treating metabolic-associated steatohepatitis (MASH) without worsening of fibrosis.
Another showed that the surgery was associated with fewer major adverse liver outcomes among people who already had MASH. That same study showed a 70% reduction in cardiovascular events with bariatric surgery.
For patients with type 2 diabetes, numerous trials have demonstrated long-term remission and reduced A1c at 5 years and 10 years post surgery, along with reductions in microvascular and macrovascular complications.
Other data suggest that a shorter history of type 2 diabetes is among the factors predicting remission with bariatric surgery. “Oftentimes, both patients and providers will wait until the diabetes is quite advanced before they even have the conversation about weight loss or even bariatric surgery. This suggests that if we intervene earlier in the course of disease, when it is less severe and less advanced, we have a higher rate of causing remission in the diabetes,” Almandoz said.
The American Diabetes Association’s Standards of Care incorporate bariatric surgery as either “recommended” or “may be considered” to treat type 2 diabetes, depending on BMI level, for those who don’t achieve durable weight loss with nonsurgical methods, he noted.
A retrospective cohort study showed significant reductions in cardiovascular outcomes with bariatric surgery among people with baseline cardiovascular disease. “This is not just about bariatric surgery to cause weight loss. This is about the multitude of effects that happen when we treat obesity as a disease with highly effective therapies such as surgery,” he said.
Even cancer risk and cancer-related mortality were significantly reduced with bariatric surgery, another study found.
And in the long-term Swedish Obese Subjects Study, among people with obesity, bariatric surgery was associated with a 3-year increase in life expectancy compared with not undergoing surgery.
However, Almandoz also pointed out that some patients may benefit from both weight-loss medication and bariatric surgery. “Once someone has undergone pharmacotherapy, there may still be a role for bariatric procedures in helping to optimize body weight and control body weight long term. And likewise for those who have undergone bariatric surgery, there’s also a role for pharmacotherapy in terms of treating insufficient weight loss or weight recurrence after bariatric surgery…. So I think there’s clearly a role for integration of therapies.”
Almandoz serves as consultant/advisory board member for Novo Nordisk, Boehringer Ingelheim, and Eli Lilly. Kidambi is director of TOPS Center for Metabolic Research Supported by TOPS Inc and is medical editor of TOPS Magazine, for which her institution receives an honorarium.
Miriam E. Tucker is a freelance journalist based in the Washington DC area. She is a regular contributor to Medscape, with other work appearing in the Washington Post, NPR’s Shots blog, and Diabetes Forecast magazine. She is on X (formerly Twitter) @MiriamETucker.
