Obesity drugs help patients lose weight regained years after bariatric surgery

Anti-obesity medications, including semaglutide (Ozempic and Wegovy), can effectively help patients manage weight regained after bariatric surgery, a study led by UT Southwestern Medical Center researchers shows. The research is published in the journal Obesity.

"There was very little published data on how to treat post-bariatric surgery weight gain," said Jaime Almandoz, M.D., Associate Professor of Internal Medicine in the Division of Endocrinology at UTSW and the study's senior author. "Our research found that newer anti-obesity medications are effective for treating weight regain and optimizing body weight after bariatric surgery. Our study also found that weight management medication regimens containing semaglutide worked better than those containing liraglutide, even when the dose of semaglutide was lower than what is currently approved to treat obesity."

More than 40% of adults in the United States have obesity, according to the Centers for Disease Control and Prevention, and many patients choose to undergo bariatric surgery as part of their treatment. However, regaining weight after the surgery is common and can exacerbate obesity-related conditions such as Type 2 diabetes and fatty liver disease.

In recent years, two anti-obesity medications have been approved by the Food and Drug Administration: semaglutide (Wegovy), which is given as a weekly injection, and liraglutide (Saxenda), a daily injection. Both belong to the same drug class—glucagon-like peptide-1 (GLP-1) receptor agonists—and work by controlling appetite and satiety. Previous work by Dr. Almandoz and colleagues suggested that this class of drugs could be more effective than other drugs, or even lifestyle modification, in treating post-bariatric surgery weight regain. However, the two drugs had not been directly compared in this context.

The new study analyzed health records for 207 adults who previously had bariatric surgery and were then treated for obesity at UTSW's Weight Wellness Program between 2015 and 2021. Nearly 90% of the patients were women, and the average age was 55. About 46% were non-Hispanic white, nearly 35% were non-Hispanic Black, and about 11% were Hispanic. These patients were, on average, eight years out from surgery and had regained more than 40% of the weight they lost after their bariatric procedures. Data were analyzed from patients who were prescribed weight management regimens containing either semaglutide or liraglutide for at least three months.

Twelve months later, those taking semaglutide had lost an average of 12.9% of their body weight, while those taking liraglutide had lost an average of 8.8%, the study showed. People in the semaglutide group were more than twice as likely to have lost at least 10% of their body weight. The results with semaglutide remained unchanged when factoring in age, sex, or the type of bariatric surgery, according to the study.

"Our results support the real-world effectiveness of GLP-1 receptor agonists for treating post-bariatric weight recurrence and suggest that semaglutide is superior to liraglutide," Dr. Almandoz said. He noted that the results could help inform the use of these drugs in optimizing body weight after bariatric surgery.

Other UTSW researchers who contributed to this study are Jeffrey N. Schellinger, RD, registered dietitian nutritionist in the Division of Endocrinology, and Ildiko Lingvay, M.D., Professor of Internal Medicine in the Division of Endocrinology.