GLP-1 before surgery was linked to 11% lower odds of major heart complications and 8% lower odds of infections in a study of more than 2 million U.S. patients, according to a News-Medical summary published Oct. 19 of an American Society of Anesthesiologists release. The finding is an association, not proof that the drugs caused the benefit. Here is what the data show, what they do not, and what to ask your surgical team. This is general information, not medical advice.
What the GLP-1 before surgery study found
Researchers studying GLP-1 before surgery presented the work at ANESTHESIOLOGY 2026, the annual meeting of the American Society of Anesthesiologists. The summary does not say the findings have been peer reviewed, so treat them as a conference presentation for now.
The lead author is Josephine Tolan, MD, an anesthesiologist at the Center for Outcomes Research at UTHealth Houston (McGovern Medical School). Her team looked at patients who were taking GLP-1 medications before an operation and compared them with similar patients who were not.
Here are the two headline results, as reported:
- Heart and stroke events: 11% lower odds of major cardiovascular complications, defined as heart attack, heart injury, stroke or death.
- Infections: 8% lower odds of infections, including surgical site infections, urinary tract infections, pneumonia and sepsis.
KFF Health News also mentioned the study in its Oct. 19 morning briefing, noting that patients taking GLP-1 drugs before elective surgery had fewer serious cardiovascular complications and postoperative infections.
Who was studied
The analysis used Epic Cosmos, a de-identified electronic health record database that covers more than 1,700 hospitals and 40,000 clinics. It was a retrospective observational analysis, which means the researchers looked back at records rather than assigning patients to a treatment.
The group included U.S. adults aged 18 and older who had elective surgery lasting more than 60 minutes and stayed in the hospital at least 24 hours. The records ran from January 2016 to December 2024.
In all, the study covered 2,028,601 patients. Of those, 145,610 (about 7%) were taking GLP-1 medications. The GLP-1 users were matched with similar non-users, although the summary does not describe the matching method.
What are GLP-1 medications?
GLP-1 receptor agonists are a class of drugs that mimic a gut hormone involved in blood sugar control and appetite. Semaglutide is one well-known example. They are widely used for type 2 diabetes and for weight loss.
That background matters for GLP-1 before surgery research. People who take these drugs often differ from people who do not, in weight, blood sugar and overall health management. Those differences can affect surgical outcomes on their own.
If you want to understand how another diabetes-related approach compares, see our report on the high-fiber diet versus metformin trial.
Odds, risk and what “11% lower” really means
The study reports lower odds, not lower risk. The two are related but not identical. Risk is the share of people who have an event. Odds compare the chance an event happens with the chance it does not.
When an event is fairly rare, the two numbers are close. When it is common, odds can sound like a bigger change than the actual difference in risk.
The summary does not give event counts, confidence intervals or p-values. So we cannot say how many fewer complications 11% or 8% would mean for 100 patients. Without those numbers, it is hard to judge how large or how certain the effect is.
An example of why this matters: a drop in odds from a small baseline might mean only a handful of avoided complications per thousand operations. Readers should wait for the full data before drawing conclusions about their own procedure.
Why an observational study cannot prove cause
The authors themselves say the work “does not prove cause and effect.” That is the key limit of any study that looks back at records.
In a randomized trial, chance decides who gets the treatment, which balances out hidden differences. In an observational study, patients choose or are prescribed a drug for reasons that may also shape their outcomes.
Matching helps in GLP-1 before surgery research, but it can only account for the factors a researcher measures. Other factors may explain the lower complication rates. For example, people on GLP-1 drugs may have had closer medical follow-up, or healthier habits that did not show up in the records.
In other words, GLP-1 before surgery may be a marker of something else, or it may truly help. This study cannot tell us which. Dr. Tolan put it plainly: “These results are encouraging, but we need more research.”
The safety question: stomach emptying and anesthesia
Alongside any good news about GLP-1 before surgery, there is a safety topic that anesthesia teams have discussed for some time. GLP-1 drugs can slow how fast the stomach empties. If food or liquid stays in the stomach during anesthesia, there is a risk it could be inhaled into the lungs, which is called aspiration.
Anesthesia societies have issued guidance on this concern in the past. The study summary does not address it, and we are not reporting any new recommendation here.
The practical point is simple. Do not stop, start or change a medication on your own because of this study. Follow your surgical team’s specific instructions on when to pause or continue a GLP-1 drug and how to fast before the procedure. Those instructions can vary by drug, dose and type of surgery.
For the official voice of the specialty, the American Society of Anesthesiologists publishes patient and clinician resources.
Questions to ask your surgical team about GLP-1 before surgery
If you take a GLP-1 medication and have an operation coming up, bring a short list to your pre-op visit. A good checklist for GLP-1 before surgery includes:
- List every medication. Tell the team the exact drug, dose and how often you take it, including injections and pills.
- Ask for written instructions. What should you do with your GLP-1 dose in the days before surgery? Get the answer in writing.
- Confirm fasting rules. Ask whether your usual food and drink cutoff times change because of your medication.
- Mention stomach symptoms. Nausea, bloating, vomiting or feeling full for long periods are worth reporting.
- Discuss your blood sugar plan. If you take the drug for diabetes, ask how your glucose will be managed around the operation.
- Ask about restarting. When can you resume the drug after surgery, and who will tell you?
These questions are general. Your own team knows your health history and the details of your procedure.
What we still do not know
Several gaps remain in the GLP-1 before surgery evidence, and we want to be clear about them:
- The findings were presented at a meeting, and the summary does not state that they were peer reviewed.
- The matching method was not described.
- No event counts, confidence intervals or p-values were provided in the summary.
- The study did not report which GLP-1 drug, dose or duration of use mattered most.
- The data cover elective surgeries lasting over an hour with a hospital stay of at least 24 hours, so the results may not apply to shorter or emergency procedures.
Until the full paper appears, the safest reading is that the signal is interesting and worth testing in better-designed studies. It is not a reason to change treatment.
Healthy habits that support recovery
Whether or not GLP-1 before surgery applies to you, some basics help most patients heading into an operation. Staying active, sleeping well and managing chronic conditions all matter, and your team can tailor the advice.
Our coverage of steps per day for heart health and a study on small daily changes and heart benefit offers practical ideas for building heart-friendly routines. Ask your surgeon how much activity is safe before and after your procedure.
The bottom line on GLP-1 before surgery
A very large database study found that GLP-1 before surgery was associated with 11% lower odds of major cardiovascular complications and 8% lower odds of infections. The authors caution that it does not prove cause and effect, and the lead author called for more research.
Your takeaway: if surgery is on your calendar, make a complete medication list, ask the questions above and follow your team’s written instructions on your GLP-1 drug. Bookmark USA One News for updates when the full results are published.
