Anesthesiology analysis finds no increased aspiration risk with preoperative GLP-1 use

A new observational study published in the journal Anesthesiology found that people with type 2 diabetes who were taking a GLP-1 receptor agonist before surgery did not have a higher risk of aspiration than patients taking other diabetes drugs — and had lower short-term death rates than patients on metformin or DPP-4 inhibitors ^[1][2].

The analysis was posted online ahead of print on August 12, 2026 ^[1]. It used electronic health record data from the TriNetX Research Network covering surgeries between June 1, 2013, and June 1, 2023 — deliberately ending before the American Society of Anesthesiologists issued its 2023 guidance telling clinicians to hold GLP-1 medicines before procedures ^[1][2]. That timing matters: it means the patients in this dataset were largely still taking their medication as usual going into surgery.

What the study measured

Researchers looked at adults with type 2 diabetes who underwent surgery with anesthesia. They matched GLP-1 users 1:1 with users of three comparison drug classes — metformin, SGLT2 inhibitors, and DPP-4 inhibitors — using propensity scores that accounted for surgery type, patient characteristics, diabetes lab markers, and risk factors for problems after surgery ^[1][2]. Patients in each group were not also taking the comparison drug ^[1].

The outcomes tracked within 14 days of surgery were death, aspiration pneumonitis, bacterial pneumonia, emergency intubation, acute kidney injury, stroke, heart attack, and a combined measure of major adverse cardiovascular events (death, heart attack, or stroke) ^[1][2].

The numbers

Compared with metformin users, GLP-1 users had lower 14-day mortality: 0.98% versus 2.20%, a risk ratio of 0.44 (95% confidence interval 0.31 to 0.64, adjusted P = 0.0002) ^[1][2].

Compared with DPP-4 inhibitor users, GLP-1 users also had lower mortality — 1.84% versus 2.89%, risk ratio 0.63 (0.45 to 0.89, adjusted P = 0.04) — and less bacterial pneumonia, 0.85% versus 1.80%, risk ratio 0.47 (0.29 to 0.76, adjusted P = 0.02) ^[1][2].

Against SGLT2 inhibitors, the difference in major adverse cardiovascular events was described by the authors as a numerical difference only: 3.86% versus 5.03%, risk ratio 0.77 (0.60 to 0.98), with an adjusted P value of 0.13 — meaning it did not hold up after accounting for multiple comparisons ^[1][2].

On the question that has driven the most anxiety in operating rooms, the authors concluded there was "no increased aspiration risk compared to any other drug class" ^[1][2]. The abstract does not report the specific aspiration pneumonitis event rates or the total number of patients studied, so those figures are not yet known from the available material.

Why it matters for patients

GLP-1 medicines slow how fast the stomach empties. That raised a concern that food or liquid left in the stomach could come up and enter the lungs during anesthesia, which led the ASA in 2023 to advise holding these drugs before procedures ^[1]. In practice, that guidance has meant canceled or delayed surgeries and skipped doses for some people taking semaglutide (Ozempic, Wegovy, Rybelsus) or tirzepatide (Mounjaro, Zepbound).

This study is one data point suggesting the aspiration signal may be smaller than feared, at least in patients with type 2 diabetes. But it is an observational analysis of records, not a randomized trial. People prescribed GLP-1 drugs may differ from people prescribed metformin or DPP-4 inhibitors in ways the matching could not fully capture, so the lower death rates should not be read as proof that the drugs caused the benefit. The authors themselves wrote that "confirmation in prospective studies is needed to guide evidence-based management strategies" ^[1][2].

Several things the abstract does not address: it covers people with type 2 diabetes, not people using these drugs only for weight loss; it does not break results out by individual drug or dose; and it does not say how long before surgery patients last took a dose or how long they fasted ^[1][2].

What happens next

The paper was published ahead of print on August 12, 2026, and the authors report no conflicts of interest ^[1][2]. Whether professional societies revisit their preoperative guidance in light of this and similar data is not addressed in the study. Decisions about medications before a scheduled procedure are made between a patient and their surgical and anesthesia team.