Differential Effect of GLP-1 Receptor Agonists and SGLT2 Inhibitors on Lower-Extremity Amputation Outcomes in Type 2 Diabetes: A Nationwide Retrospective Cohort Study.

Abstract

Objective: To compare the risk of lower-extremity amputations (LEAs) between new users of glucagon-like peptide 1 receptor agonists (GLP-1RAs) versus sodium-glucose cotransporter 2 inhibitors (SGLT2is).

Research design and methods: This retrospective cohort study used TriNetX, a federated electronic health records network, including adults with type 2 diabetes who initiated GLP-1RAs or SGLT2is between May 2013 and March 2025. Propensity score matching (1:1) was used to balance demographics, comorbidities, medications, and laboratory values. Major (above-ankle) amputation-free survival was evaluated using Kaplan-Meier curves, while risks of major and minor LEAs, diabetic foot ulcers (DFUs), and mortality were estimated using hazard ratios (HRs) with 95% confidence intervals (CIs).

Results: The matched cohorts included 180,740 GLP-1RA and 180,740 SGLT2i recipients. At 3 years, the GLP-1RA cohort was associated with greater major amputation-free survival (99.69% vs. 99.64%, P = 0.001) compared with the SGLT2i cohort. Additionally, GLP-1RA treatment was associated with a lower risk of major LEAs (HR 0.77 [95% CI 0.66, 0.90]), minor LEAs (HR 0.73 [95% CI 0.63, 0.84]), DFUs (HR 0.92 [95% CI 0.87, 0.96]), and mortality (HR 0.66 [95% CI 0.63, 0.69]). Risk reduction for major LEA remained significant in individuals with peripheral artery disease (HR 0.68 [95% CI 0.56, 0.82]) and DFUs (HR 0.70 [95% CI 0.58, 0.84]).

Conclusions: GLP-1RA treatment was associated with greater major amputation-free survival compared with SGLT2i in people with type 2 diabetes, particularly in high-risk subgroups. Prospective studies are needed to confirm findings and inform selection of glucose-lowering therapies for people at risk for diabetes-related amputations.