MBS achieves greater weight loss with lower ongoing cost vs GLP-1s

Metabolic bariatric surgery (MBS) achieves greater weight loss and lower ongoing cost compared to the glucagon-like peptide-1 receptor agonists (GLP-1 RAs), according to a study authored by Highmark Health researchers. The study reported that bariatric surgery was significantly associated with greater weight loss while saving approximately $11,689 in ongoing costs over two years.

"This real-world study provides evidence on the long-term effectiveness and cost-efficiency of bariatric surgery compared to weight management medication for severe obesity," said Dr Tyson Barrett, Highmark Health Research Institute. "Our findings highlight the potential for bariatric surgery to offer a more durable and economically sound solution for this patient population."  

In the US, obesity rates continue to rise, affecting over 40 percent of adults.

Meanwhile, the surging demand for GLP-1s is a significant cost driver for the nation's health carriers and employer-based health insurance plans. From 2019 to 2024, the number of people prescribed GLP-1 medications for weight management purposes – as opposed to diabetes management – has skyrocketed by nearly 600 percent. The drugs have shown promise for weight loss, but also require ongoing adherence, the cost of which compounds over time. 

The study specifically looked at the costs and clinical side effects of surgery vs. GLP-1s for managing class II and class III obesity, as well as weight loss outcomes for those with class III obesity. According to the Center for Disease Control and Prevention (CDC), adults ages 20 or older with a body mass index (BMI) of 35 to 39.9 are considered to have class II obesity, while a BMI of 40 or greater indicates class III, or severe, obesity.

This retrospective study, which examined data from Highmark Health Plan insurance claims and Allegheny Health Network (AHN) medical records, included 30,458 patients treated between 2018 and 2023. The research compared the health care costs and clinical outcomes of patients who underwent metabolic bariatric surgery (MBS), such as a sleeve gastrectomy or gastric bypass, with those who received GLP-1 RAs (dulaglutide, exenatide, liraglutide, lixisenatide, semaglutide or tirzepatide) for obesity management.   

In total, 14,101 patients received MBS (mean [SD] follow-up, 34 [16] months) and 16,357 patients received GLP-1 RAs (mean [SD] follow-up, 32 [17] months). After propensity score weighting, baseline characteristics were comparable. The mean (SE) total costs over two years were $63,483 ($1563) for GLP-1 RAs and $51,794 ($1724) for MBS (p<0.001). The main driver of this difference was higher sustained pharmacy costs in the GLP-1 RA group throughout year two of follow-up.

Comparing weight loss data of 257 patients using GLP-1 RAs and 1291 patients who underwent MBS, total weight loss was greater for the MBS group (mean [SE], 28.3% [0.3%]) than the GLP-1 RA group (mean [SE], 10.3% [0.5%]) (p<0.001).

Over two years, bariatric surgery resulted in approximately 18 percent lower costs compared to medications, mostly because of sustained high pharmacy costs associated with medication use. This translates to an average cost savings of nearly $12,000 per patient.  

Greater Weight Loss with MBS: In patients with a BMI of 40 or higher, bariatric surgery led to nearly three times as much weight loss compared to medications. On average, patients lost about 28 percent of their weight with surgery, compared to about 10 percent with medications.  

On average, patients who underwent bariatric surgery had 25 percent fewer inpatient stays and 38 percent fewer emergency room visits. MBS was also associated with a lower incidence of obesity-related comorbidities, such as hyperlipidaemia and sleep apnoea, compared to medication use.  

The findings are in line with other recent studies on the topic but those studies have largely been forward-looking and have used predictive modelling. The Highmark Health study is among the first to use historical claims and clinical data, made possible through Highmark Health's unique payor/provider integrated model.  

"With projections indicating that 50 percent of the adult U.S. population will have obesity by 2030, it's vital for physicians to have comprehensive data to inform their treatment decisions," said Dr George Eid, chair of the AHN Bariatric and Metabolic Institute. "This study should serve as a data point to help physicians make individualised care choices, optimising each patient's weight management journey."  

The findings were reported in the paper, ‘Obesity Treatment With Bariatric Surgery vs GLP-1 Receptor Agonists’, published in JAMA Surgery. To access this paper, please click here