3-year comparative analysis of bariatric surgery versus GLP-1 RA therapy (including tirzepatide) in a predominantly Medicare/Medicaid patient cohort with diabetes, examining long-term outcomes including weight loss, diabetes remission, cardiovascular events, and complications. Addresses the long-term comparative effectiveness question in public payer patients who represent the highest-burden obesity and diabetes population. Provides long-term payer-relevant comparative evidence for the bariatric surgery versus GLP-1 RA decision—informing Medicare and Medicaid coverage policy for populations where drug affordability and surgical access both present barriers to optimal obesity-diabetes management.
Abstract
BACKGROUND: Bariatric surgery has long been established as an effective treatment option for obesity and diabetes [Kalainov et al. in J Am Acad Orthop Surg [32(10):427-438, 2025] and Ogden et al. in JAMA 311(8):806-806, 2025. 10.1001/jama.2014.732]. Recently, GLP-1 Receptor Agonists' (GLP-1RAs) use has expanded as an alternative therapy for weight loss and diabetes management. While GLP1RAs are known to be safe and effective, few have compared long term outcomes of GLP-1RAs versus the "gold standard" of bariatric surgery among Medicare/Medicaid patients, who make up the largest payer group in the U.S. [Kalainov et al. in J Am Acad Orthop Surg [32(10):427-438, 2025].
METHODS: This was a retrospective, multicenter study of obese, type-2 diabetic patients (T2D) ≥ 18 years old, who initiated weekly injectable semaglutide or tirzepatide or underwent bariatric surgery between January 1st, 2018 to July 31st, 2024. Patients with a baseline BMI ≤ 35, those with prior GLP1-RA use, or any prior bariatric procedure were excluded from analysis. The primary outcome of interest was % total body weight loss 3 months to 3 years post intervention among bariatrics surgery patients vs. GLP1-RA patients (any GLP1-RA prescription and 12 months continuous GLP1-RA prescription).
RESULTS: 7667 patients were included for analysis (7200 GLP1-RA, 467 bariatric surgery). Bariatric surgery patients were younger (median (IQR): 43 (34, 53) vs. 65 (54, 72); p < 0.001) and more likely to be female (67.5% vs. 60.8%; p < 0.01) and Hispanic (58.7% vs. 19.4%; p < 0.001) while GLP1-RA users were more likely to be white (58.5% vs. 10.7%; p < 0.001). In models adjusting for demographic and clinical characteristics, bariatric surgery was associated with a 22.9% total weight loss 3 years following surgery compared to 2.3% for patients with any GLP1-RA use, and 15.9% vs 2.4% for patients with 12 months consecutive GLP1-RA use (22.9 [21.0-24.8] vs 2.3 [0.5-4.1], 15.9 [6.9-24.9] vs. 2.4 [6.7-11.5].
CONCLUSIONS: Among obese, T2D, publicly insured patients, bariatric surgery was associated with greater weight loss than GLP1-RAs at all measured periods from 3 months to 3 years post op.