Metabolic Bariatric Surgery Shows Greater Two-Year Weight Loss Than GLP-1 RAs

Key Takeaways:

• Metabolic bariatric surgery was associated with substantially greater and more durable weight loss over two years than treatment with GLP-1 receptor agonists in adults living with class II or III obesity.
  
• Overall health care costs over two years were lower for people who underwent surgery, largely due to the ongoing pharmacy costs associated with GLP-1 receptor agonist therapy.
  
• The findings underline the importance of multidisciplinary care, particularly for clinicians managing obesity-related conditions where sustained weight reduction is central to disease control.
  

Overview

A large retrospective, claims-based cohort study has found that metabolic bariatric surgery delivers greater long-term weight loss benefits and lower overall health care costs over two years compared with glucagon-like peptide-1 receptor agonists (GLP-1 RAs) in adults living with severe obesity. The analysis suggests that, in real-world clinical practice, surgical approaches may offer more durable outcomes than pharmacotherapy alone for this population.

Study design and data sources

This retrospective cohort study compared outcomes following metabolic bariatric surgery with those achieved using GLP-1 receptor agonist therapy for weight management. Surgical procedures included sleeve gastrectomy and gastric bypass. Pharmacological treatments included dulaglutide, exenatide, liraglutide, lixisenatide, semaglutide, and tirzepatide.

The analysis drew on data from the Highmark Health insurance claims database linked with electronic health records from the Allegheny Health Network. In total, 30,458 adults living with class II or III obesity were included. All individuals in the weight-loss analysis had a body mass index of at least 40 at the time of enrolment.

To minimise baseline differences between groups, the researchers used propensity score weighting to balance key characteristics, including body mass index, age, sex, comorbid conditions, and patterns of health care utilisation. Adjusted analyses then compared weight-loss trajectories, obesity-related comorbidities, and total health care costs over a two-year follow-up period.

Weight loss outcomes and durability

Of the total cohort, 14,101 people underwent metabolic bariatric surgery, with a mean follow-up of 34 months. A further 16,357 people were prescribed GLP-1 receptor agonists, with a mean follow-up of 32 months.

After two years, metabolic bariatric surgery was associated with markedly greater mean total weight loss than GLP-1 receptor agonist therapy, at 28.3 per cent compared with 10.3 per cent. Weight loss following surgery was also more durable. Ninety-six per cent of people in the surgical group achieved sustained weight loss of at least 10 per cent, compared with 46 per cent of those treated with GLP-1 receptor agonists.

In addition to superior weight outcomes, people who underwent metabolic surgery experienced fewer obesity-related comorbidities and lower health care utilisation across inpatient, outpatient, and emergency care settings.

Cost analysis

Over the two-year follow-up period, metabolic bariatric surgery was associated with significantly lower mean total health care costs than GLP-1 receptor agonist therapy. Average costs were reported as $51,794 for the surgical group compared with $63,483 for those receiving GLP-1 receptor agonists.

The higher costs observed in the pharmacotherapy group were largely driven by ongoing pharmacy expenses related to long-term GLP-1 receptor agonist use. While surgery involves a higher upfront cost, the findings suggest this is offset over time by reduced medication use and lower overall health care utilisation.

Study limitations

The authors note several important limitations. Weight data were available for only a small proportion of participants, comprising 9 per cent of the surgery group and 1.6 per cent of the GLP-1 receptor agonist group. This limits the generalisability of the weight-loss findings to the full cohort.

In addition, the indication for GLP-1 receptor agonist prescriptions was not always clear, meaning some individuals may have been treated primarily for diabetes rather than obesity. However, an obesity-only subgroup analysis restricted to people without a diabetes diagnosis produced similar results, supporting the robustness of the main findings.

Follow-up duration differed slightly between groups, and adherence to GLP-1 receptor agonist therapy was likely lower in this real-world setting than would be expected in a controlled clinical trial. Finally, the cost data reflect the United States health care system and may not be directly transferable to other countries or funding models.

Clinical relevance

For clinicians managing obesity-related complications, including ophthalmologists caring for people with obesity-associated eye disease such as idiopathic intracranial hypertension, these findings highlight the broader systemic benefits of durable weight reduction. Although GLP-1 receptor agonists are increasingly recommended in the management of idiopathic intracranial hypertension, the study suggests that metabolic bariatric surgery may offer greater sustained weight loss at a lower long-term cost.

The results emphasise the value of close collaboration between ophthalmology, endocrinology, and bariatric surgery teams when supporting people whose disease burden is driven by obesity. While ongoing government discussions around medication pricing may influence future cost-effectiveness analyses, the substantial differences observed in this study indicate that metabolic surgery is likely to remain a cost-effective intervention even if GLP-1 receptor agonist costs were to decrease.

Disclosures and publication details

Financial disclosures: Dr Chantal Boisvert reports a financial relationship with Viridian Therapeutics, serving as a consultant or advisor and receiving grant support.