Large Records Study Finds GLP-1 Drugs Cut Diabetes Risk More Than Metformin in Prediabetes Patients

A large observational study presented this week at the American Heart Association's Scientific Sessions 2026 in Chicago found that adults with prediabetes and obesity who took GLP-1 receptor agonists were significantly less likely to develop type 2 diabetes than those on metformin, the drug that's held that standard-of-care spot for decades.

The numbers are hard to ignore. According to data reported by Cardiovascular Business and Reuters Health, researchers reviewed electronic health records from 256,492 adults with prediabetes and obesity. Roughly half were taking GLP-1 medications, specifically semaglutide, tirzepatide, liraglutide, or dulaglutide. The other half were on metformin.

Compared to the metformin group, GLP-1 users had a 1.5 times higher chance of returning their blood sugar to normal levels, a 31% lower risk of progressing to type 2 diabetes, and a 41% lower risk of death from any cause.

The cardiovascular signal was just as striking. As reported in a Reuters Health Rounds newsletter, GLP-1 medications were associated with 15% fewer heart attacks, 20% fewer strokes, 25% fewer cases of heart failure, and 8% fewer cases of atrial fibrillation.

The study was led by Dr. Vinicius de Sousa Barzon Serra, an endocrinologist at Mayo Clinic in Scottsdale, Arizona. In a statement reviewed by Reuters, Serra said the findings may add to the case for considering GLP-1 medications earlier for certain patients, rather than waiting until they develop type 2 diabetes.

Before this gets framed as the end of metformin, there are real limits here. This was an observational study of medical records, not a randomized controlled trial. It shows association, not causation. The GLP-1 drugs were also grouped together as a class rather than evaluated separately, which matters because semaglutide and tirzepatide are not the same molecule and don't carry the same risk or cost profile. And it was presented as a conference abstract, meaning it hasn't yet been through peer review.

The weight-loss mechanism is likely doing a lot of the work. Dr. Robert Eckel, a past president of the American Heart Association who wasn't involved in the study, said in a statement that the benefits are probably related to weight loss, which is well established as a driver of diabetes prevention.

Clinicians commenting for Healthline pushed back gently, noting that patients with prediabetes are often asymptomatic. Someone who doesn't feel sick may be reluctant to take a drug that carries real side effects, including nausea, vomiting, and the cost burden that metformin, cheap and generic, simply doesn't.

That's the gap the numbers don't close. Metformin is still inexpensive, widely available, and has decades of safety data behind it. GLP-1s work, often dramatically, in people who can get them and tolerate them. What the health system hasn't sorted out is how to get the right drug to the right patient without routing the access question entirely through ability to pay.

AHA Scientific Sessions 2026 runs through November 9. The study's full manuscript has not yet been published.

Sources cited:
- Cardiovascular Business (https://cardiovascularbusiness.com/topics/clinical/heart-health/glp-1-drugs/glp-1-drugs-outperform-metformin-patients-prediabetes)
- Reuters / Health Rounds (via 933TheDrive syndication) (https://www.933thedrive.com/2026/11/04/glp-1-drugs-help-control-prediabetes-better-than-current-standard-medicine/)
- Healthline Health News (https://www.healthline.com/health-news/glp-1s-lower-diabetes-heart-risks-better-than-standard-prevention)
- American Heart Association / NewMediaWire press release (https://www.financialcontent.com/article/newmediawire-2026-11-2-glp-1-meds-linked-to-lower-diabetes-heart-risks-than-standard-diabetes-prevention-med)