Impact of GLP-1 Receptor Agonists on the Risk of Additional Lumbar Fusion Surgery Within One Year Following TLIF in Patients with Type 2 Diabetes

Introduction: Glucagon-like peptide-1 receptor agonists(GLP-1 RAs)—including semaglutide, tirzepatide, and liraglutide—are commonly used for glycemic control and weight management in patients with type 2 diabetes(T2DM). While these medications provide metabolic benefits, their effects on bone health and spinal fusion outcomes are not well understood. This study evaluates the association between specific GLP-1 RAs and the incidence of all-cause need for additional lumbar fusion surgery within one year following transforaminal lumbar interbody fusion(TLIF) in patients with T2DM.

Methods: Using a national claims database, we identified patients with T2DM who underwent short-segment(≤3-level) TLIFs. Patients were categorized based on exposure to GLP-1 RAs (semaglutide, tirzepatide, or liraglutide) and further stratified by duration of use( < 9 months vs. ≥9 months). Exact 2:1 matching was performed based on demographics and comorbidities. Multivariate logistic regression analyses were conducted to compare the incidence of all-cause additional lumbar fusion surgery within one-year post-TLIF.

Results: After matching, 2,294 patients were included: 911 in the GLP-1 RA–exposed group(728 on semaglutide, 107 on tirzepatide, 155 on liraglutide) and 1,383 in the non-exposed group. The overall incidence of additional lumbar fusion surgery was significantly higher in the GLP-1 RA–exposed group compared to the non-exposed group (p < 0.001). Multivariate logistic regression revealed that liraglutide (odds ratio [OR]=2.11; 95% confidence interval[CI]:1.04–4.11; p=0.032) and semaglutide (OR=2.30; 95% CI: 1.06–5.07; p = 0.035) were independently associated with increased odds of requiring additional lumbar fusion surgery. Short-term semaglutide use ( < 9 months) was associated with decreased odds of additional surgery (OR=0.45; 95% CI:0.27–0.74; p=0.002). Tirzepatide did not show a statistically significant association with the need for additional surgery (OR=1.74; 95% CI: 0.78–3.60; p=0.153).

Conclusion : Liraglutide and semaglutide use are independently associated with an increased risk of requiring all-cause additional lumbar fusion surgery within one year following TLIF in patients with T2DM. The risk appears to be influenced by the duration of semaglutide use, with shorter durations associated with lower risk.