Will New Obesity Drugs Make Bariatric Surgery Obsolete?

MADRID — In spirited presentations at the European Association for the Study of Diabetes (EASD) 2024 Annual Meeting, Louis J. Aronne, MD, of Weill Cornell Medicine in New York City, made a compelling case that the next generation of obesity medications will make bariatric surgery obsolete, and Francesco Rubino, MD, of King’s College London, London, England, made an equally compelling case that they will not.

In fact, Rubino predicted that “metabolic” surgery — new nomenclature reflecting the power of surgery to reduce not only obesity, but also other metabolic conditions, over the long term — will continue and could even increase in years to come.

‘Medical Treatment Will Dominate’

“Obesity treatment is the superhero of treating metabolic disease because it can defeat all of the bad guys at once, not just one, like the other treatments,” Aronne told meeting attendees. “If you treat somebody’s cholesterol, you’re just treating their cholesterol, and you may actually increase their risk of developing type 2 diabetes (T2D). You treat their blood pressure, you don’t treat their glucose and you don’t treat their lipids — the list goes on and on and on. But by treating obesity, if you can get enough weight loss, you can get all those things at once.”

He pointed to the SELECT trial, which showed that treating obesity with a glucagon-like peptide 1 receptor agonist reduced major adverse cardiovascular events as well as death from any cause, results in line with those from other modes of treatment for cardiovascular disease (CVD) or lipid lowering, he said. “But we get much more with these drugs, including positive effects on heart failure, chronic kidney disease, and a 73% reduction in T2D. So, we’re now on the verge of a major change in the way we manage metabolic disease.”

Aronne drew a parallel between treating obesity and the historic way of treating hypertension. Years ago, he said, “we waited too long to treat people. We waited until they had severe hypertension that in many cases was irreversible. What would you prefer to do now for obesity — have the patient lose weight with a medicine that is proven to reduce complications or wait until they develop diabetes, high blood pressure, heart disease and then have them undergo surgery to treat that?”

Looking ahead, “the trend could be to treat obesity before it gets out of hand,” he suggested. Treatment might start in people with a body mass index (BMI) of 27, who would be treated to a target BMI of 25. “That’s only a 10% or so change, but our goal would be to keep them in the normal range so they never go above that target. In fact, I think we’re going to be looking at people with severe obesity in a few years and saying, ‘I can’t believe someone didn’t treat that guy earlier.’ What’s going to happen to bariatric surgery if no one gets to a higher weight?”

The plethora of current weight-loss drugs and the large group on the horizon mean that if someone doesn’t respond to one drug, there will be plenty of other choices, Aronne continued. People will be referred for surgery, but possibly only after they’ve not responded to medical treatment — or just the opposite. “In the United States, it’s much cheaper to have surgery, and I bet the insurance companies are going to make people have surgery before they can get the medicines,” he acknowledged.

A recent report from Morgan Stanley suggests that the global market for the newer weight-loss drugs could increase by 15-fold over the next 5 years as their benefits expand beyond weight loss and that as much as 9% of the US population will be taking the drugs by 2035, Aronne said, adding that he thinks 9% is an underestimate. By contrast, the number of patients treated by his team’s surgical program is down about 20%.

“I think it’s very clear that medical treatment is going to dominate,” he concluded. “But, it’s also possible that surgery could go up because so many people are going to be coming for medical therapy that we may wind up referring more for surgical therapy.”

‘Surgery Is Saving Lives’

Rubino is convinced that anti-obesity drugs will not make surgery obsolete, “but it will not be business as usual,” he told meeting attendees. “In fact, I think these drugs will expedite a process that is already ongoing — a transformation of bariatric into metabolic surgery.”

“Bariatric surgery will go down in history as one of the biggest missed opportunities that we, as medical professionals, have seen over the past many years,” he said. “It has been shown beyond any doubt to reduce all-cause mortality — in other words, it saves lives,” and it’s also cost effective and improves quality of life. Yet, fewer than 1% of people globally who meet the criteria actually get the surgery.

Many clinicians don’t inform patients about the treatment and don’t refer them for it, he said. “That would be equivalent to having surgery for CVD, cancer, or other important diseases available but not being accessed as they should be.”

A big reason for the dearth of procedures is that people have unrealistic expectations about diet and exercise interventions for weight loss, he said. His team’s survey, presented last year at the 26th World Congress of the International Federation for the Surgery of Obesity and Metabolic Disorders, showed that 43% of respondents believed diet and exercise was the best treatment for severe obesity (BMI > 35 kg/m²). A more recent survey asked which among several choices was the most effective weight-loss intervention, and again a large proportion “believed wrongly that diet and exercise is most effective — more so than drugs or surgery — despite plenty of evidence that this is not the case.”

In this context, he said, “any surgery, no matter how safe or effective, would never be very popular.” If obesity is viewed as a modifiable risk factor, patients may say they’ll think about it for 6 months. In contrast, “Nobody will tell you ‘I will think about it’ if you tell them they need gallbladder surgery to get rid of gallstone pain.”

Although drugs are available to treat obesity, none of them are curative, and if they’re stopped, the weight comes back, Rubino pointed out. “Efficacy of drugs is measured in weeks or months, whereas efficacy of surgery is measured in decades of durability — in the case of bariatric surgery, 10-20 years. That’s why bariatric surgery will remain an option,” he said. “It’s not just preventing disease, it’s resolving ongoing disease.”

Furthermore, bariatric surgery is showing value for people with established T2D, whereas in the past, it was mainly considered to be a weight-loss intervention for younger, healthier patients, he said. “In my practice, we’re operating more often in people with T2D, even those at higher risk for anesthesia and surgery — eg, patients with heart failure, chronic kidney disease, on dialysis — and we’re still able to maintain the same safety with minimally invasive laparoscopic surgery that we had with healthier patients.”

A vote held at the end of the session revealed that the audience was split about half and half in favor of drugs making bariatric surgery obsolete or not.

“I think we may have to duke it out now,” Aronne quipped.

Aronne disclosed being a consultant, speaker, and advisor for and receiving research support from Altimmune, Amgen, AstraZeneca, Eli Lilly and Company, Intellihealth, Janssen, Novo Nordisk, Pfizer, Senda, UnitedHealth Group, Versanis, and others; he has ownership interests in ERX, Intellihealth, Jamieson, Kallyope, Skye Bioscience, Veru, and others; and he is on the board of directors of ERX, Jamieson Wellness, and Intellihealth/FlyteHealth.

Rubino disclosed receiving research and educational grants from Novo Nordisk, Ethicon, and Medtronic; he is on the scientific advisory board/Data Safety Advisory Board for Keyron, Morphic Medical, and GT Metabolic Solutions; he receives speaking honoraria from Medtronic, Ethicon, Novo Nordisk, and Eli Lilly and Company; and he is president of the nonprofit Metabolic Health Institute.

Marilynn Larkin, MA, is an award-winning medical writer and editor whose work has appeared in numerous publications, including Medscape Medical News and its sister publication MDedge, The Lancet (where she was a contributing editor), and Reuters Health.