Anesthesiologists have been wary of GLP-1 medications for several years, largely because of what the drugs do to the stomach. They slow stomach emptying, raising concerns about what might happen during anesthesia. Now, an unexpected finding is adding another layer to that conversation.
A new study involving more than 2 million surgical patients found that people taking GLP-1 medications had lower odds of serious heart complications and infections afterward than comparable patients who weren’t taking them.
The findings, presented October 18 at the ANESTHESIOLOGY 2026 annual meeting in San Diego, raise an interesting possibility for medications already widely used to treat diabetes and obesity. For patients approaching surgery, that sounds encouraging.
Two Million Patients, One Narrow Slice of Surgery
Before the percentages mean anything, it helps to know who was in the data.
Josephine Tolan, M.D., an anesthesiologist at McGovern Medical School at UTHealth Houston, led the analysis using Epic Cosmos, a database of de-identified electronic health records.
The researchers examined U.S. adults who underwent elective surgery between January 2016 and December 2024. Procedures had to last longer than 60 minutes and require at least 24 hours in the hospital afterward.
That produced 2,028,601 patients, including 145,610 taking GLP-1 medications, roughly 7% of the total.
After matching users with similar nonusers, the team found 11% lower odds of major cardiovascular complications and 8% lower odds of postoperative infections among people taking the drugs. The cardiovascular category included heart attacks, heart injury, strokes and deaths. Infections included surgical site infections, urinary tract infections, pneumonia and sepsis.
These were combined outcomes, so the percentages cannot be applied to individual complications. Emergency operations, shorter procedures and same-day discharges were also excluded.
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What 11% Lower Odds Looks Like in Real Numbers
The headline percentages come from very low starting rates.
The more focused comparison included 114,249 GLP-1 users and 360,168 nonusers, matched on demographics, medical conditions, and surgery type. Researchers also adjusted for diabetes and previous use of opioids and NSAID painkillers.
In that comparison, major cardiovascular complications occurred in 1.0% of GLP-1 users versus 1.1% of nonusers. Postoperative infections affected 4.9% and 5.3%, respectively.
Those rounded figures translate to approximately one fewer cardiovascular event and four fewer infections per 1,000 patients. It’s a considerably smaller difference than the headline percentages might initially suggest.
Jessica Duncan, M.D., an obesity-medicine physician and chief medical officer at Ivím Health, offered some perspective in comments published by Newsweek.
“For an individual patient, that may be a small benefit, but across the millions of surgeries performed each year, it could be clinically relevant,” she said.
Why Nobody Can Say the Drugs Caused It
Patients were not randomly assigned to take GLP-1 medications. As a result, differences between users and nonusers could have influenced the results, even after statistical matching.
The researchers identified several possible explanations. GLP-1 medications can support weight loss, improve blood pressure and blood sugar control, and reduce inflammation. They may also protect heart muscle during periods of physical stress.
For infections, better glucose control is another possibility because elevated blood sugar can weaken the body’s ability to fight infection.
None of these explanations was established as the cause of the observed differences.
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Tolan acknowledged that uncertainty: “These results are encouraging, but we need more research to determine if the medications themselves are driving these benefits and how best to manage them before and after surgery.”
The meeting announcement also did not identify the individual GLP-1 medications studied or distinguish patients using them for diabetes from those taking them for weight loss.
The Safety Question This Study Skipped
Anesthesia teams have different concerns about these drugs, and this analysis didn’t measure them.
The study did not report pulmonary aspiration, which occurs when stomach contents enter the lungs under anesthesia. It also did not establish whether patients stopped taking their medication before surgery or when their last doses occurred.
That distinction matters because doctors cannot tell whether the association reflects medication use around surgery or changes resulting from longer-term treatment.
Meanwhile, a separate UK study published in September examined 47,039 patients across 119 hospitals. Regurgitation or aspiration occurred in 19 of 1,348 GLP-1 users (about 1 in 71), compared with 57 of 45,691 nonusers (about 1 in 802).
However, the combined outcome requires careful interpretation. Only two GLP-1 users experienced pulmonary aspiration itself. Most events involved regurgitation, with many occurring as patients emerged from anesthesia.
The UK study could not establish that the medications caused those events. Nor does it contradict the Houston findings, since the investigations examined different complications in different populations.
Surgery Advice Was Already Changing
Hospitals had been loosening the old stop-the-drug rule before this study arrived.
In 2023, the American Society of Anesthesiologists advised withholding daily GLP-1 doses on the day of surgery and weekly doses for a week beforehand.
By October 2024, multisociety guidance had shifted toward allowing most patients to continue treatment, with additional precautions for those at greater risk of delayed stomach emptying.
These precautions can include a liquid-only diet for 24 hours before surgery, adjustments to anesthesia plans, and ultrasound examinations to check stomach contents. Clinicians must also consider the consequences of withholding medication, particularly elevated blood sugar in patients with diabetes.
The American College of Surgeons has highlighted another concern: reported protein, iron, and vitamin D deficiencies, as well as muscle loss, among GLP-1 users. Unlike bariatric surgery, GLP-1 treatment lacks comparable formal nutritional monitoring protocols.
For now, the October findings do not support starting, stopping, or continuing GLP-1 medication specifically to improve surgical outcomes.
Patients facing an operation should discuss their medication schedule with their surgeon, anesthesiologist, and prescribing clinician rather than changing doses independently.
Have you had surgery while taking a GLP-1 medication, and what did your care team tell you to do with your doses?
