GLP-1s’ Preoperative Use Requires Safety Considerations

Preoperative glucagon-like peptide-1 (GLP-1) receptor agonist therapy did not increase perioperative risks in individuals with obesity or overweight, indicating their potential in effective, scalable, and applicable preoperative strategies for weight management, according to a recent study published in eClinical Medicine.¹ However, guidelines suggest that surgical teams follow safety precautions to reduce complication risks in these patients.

GLP-1 use in theory should decrease preoperative risks more prevalent among those with obesity; however, safety considerations are still necessary. | Image Credit: © Anatta Tan - stock.adobe.com

As obesity remains a global epidemic, GLP-1s might help to mitigate the risk associated with obesity and overweight in surgical patients, as it pertains to both their preoperative and long-term health. Cardiovascular disease and type 2 diabetes are more likely among individuals with obesity or overweight, as are metabolic dysfunction, chronic inflammation, and impaired immune responses. However, the recent trend in GLP-1 uptake as a pharmacological intervention has begun to transform obesity and overweight management, including for patients who require surgeries. As traditional nonsurgical weight loss interventions, like lifestyle modifications, have shown variable success in preparing patients for surgery, there is a clinical need for scalable preoperative strategies to mitigate surgical risks in patients with obesity or overweight. These risks include anesthetic complications, delayed wound healing, increased infection rates, and prolonged hospital stays.

The American Society of Anesthesiologists (ASA) updated its guideline regarding preoperative use of GLP-1s in October 2024.² The guidelines encourage patients to wait until after the escalation phase (increase in dosage) for elective surgeries to minimize the risk of complications and allow for any gastrointestinal (GI) adverse effects to cease. For patients on a higher dose, it is recommended to follow a liquid diet for 24 hours before their procedure, as these patients are more likely to have elevated GI adverse effects. Ultimately, the ASA recommendations encourage patients to consult their health care team to make the best decision for them; preoperative strategies depending on a patient’s risk level can include a liquid diet to minimize the risk of delayed stomach emptying, adjusting anesthesia to reduce aspiration risk, and a point-of-care ultrasound to determine the contents of a patient’s stomach.

This study, however, is the first systematic review and meta-analysis to compare and assess outstanding evidence on preoperative risk and safety in patients taking GLP-1s.¹ The review included 21 studies with 97,059 patients—all of which met the criteria for evaluation of GLP-1 receptor agonists in adult surgical patients, assessed weight reduction and metabolic outcomes, and were randomized controlled trials, cohort studies, or case-control studies. Postoperative complications were considered up to 90 days post-surgery when evaluating preoperative safety. Only 31.9% (n = 30,981) received a preoperative GLP-1, and the most common medications used—reported in 16 studies—were liraglutide and semaglutide. The most common surgery type—reported in 11 studies—was bariatric.

Twelve out of the 18 studies reported postoperative complications, and although the pooled odds ratio suggested a potential protective effect (OR, 0.78; 95% CI, 0.59-1.05), the complications were rated as very low. Additionally, only 10 studies reported preoperative weight loss with reductions of up to 16.7 kg over 6 months, and 11 studies reported adverse events; the most prevalent were hypoglycemia, nausea, headache, gastroesophageal reflux, constipation, diarrhea, vomiting, dizziness, and residual gastric content.¹

“With the rapidly rising prevalence of obesity around the world, particularly in surgical patients, identifying effective interventions to promote weight loss before surgery allows improved perioperative outcomes and long-term health,” the study authors concluded.

The limitations of this study included high heterogeneity (I² = 73%), indicating significant variation among study designs, patient populations, outcome measures, and safety reporting, making it difficult to perform direct comparisons and draw conclusions. Furthermore, there were no standardized protocols for how GLP-1s were used, and the majority of studies did not specify whether they were continued or stopped before surgery.

While GLP-1s may support clinically meaningful weight loss, the authors write, their risks, safety, and complications in the preoperative setting remain targets for future research, as the certainty of current evidence is low.

Reference

1. Kamarajah SK, Gudiozzi N, Findlay JM, Lee MJ, Pinkney T, Markar SR. Evaluation of safety of preoperative GLP-1 receptor agonists in patients undergoing elective surgery: a systematic review, meta-analysis, and meta-regression. eClinicalMedicine. Published online August 12, 2025. doi:10.1016/j.eclinm.2025.103408

2. Most patients can continue diabetes and weight loss GLP-1 drugs before surgery; those at highest risk for GI problems should follow a liquid diet before the procedure. News release. American Society of Anesthesiologists. October 29, 2024. Accessed August 14, 2025. https://www.asahq.org/about-asa/newsroom/news-releases/2024/10/new-multi-society-glp-1-guidance