A large observational study found that adults with both prediabetes and obesity who used GLP-1 medications had lower rates of type 2 diabetes and death than patients taking metformin. The GLP-1 group had a 31% lower risk of developing diabetes and a 41% lower risk of death from any cause.
The results are scheduled to be presented this weekend at the American Heart Association’s Scientific Sessions 2026 in Chicago. They are preliminary and have not yet been fully peer reviewed.
Researchers analyzed health records for 256,492 adults, whose average age was 52. About half took a GLP-1 medication, such as semaglutide, tirzepatide, liraglutide or dulaglutide; the rest took metformin. Metformin is commonly used to treat type 2 diabetes and is sometimes prescribed to people with prediabetes to help delay or prevent the condition.
Over three years, GLP-1 use was also associated with 20% fewer strokes, 15% fewer heart attacks and 25% fewer cases of heart failure than metformin use.
Study author Vinicius de Sousa Barzon Serra, a cardiovascular medicine research fellow at Mayo Clinic in Scottsdale, Arizona, said the lower risk of death was the result that surprised him most. He had expected GLP-1 medications to have an advantage for blood sugar and diabetes risk, in part because they tend to produce greater weight loss. He also noted that the apparent benefit extended to several other health outcomes, including stroke, heart attack, heart failure and atrial fibrillation.
Nearly 40% of U.S. adults have prediabetes, according to the American Heart Association. The condition means blood sugar is higher than normal but not high enough for a diabetes diagnosis. Each year, up to 10% of people with prediabetes may go on to develop type 2 diabetes.
Much of the earlier research on GLP-1 medications has focused on people who already have diabetes, Serra said. These findings suggest the prediabetes stage may be worth studying as a point to consider treatment, rather than waiting for diabetes to develop.
The study does not show that GLP-1 medications caused the lower risks. Researchers matched participants by age, medical conditions and other characteristics, but differences between the groups may still have affected the results. The analysis also combined several GLP-1 drugs, so it could not compare their effects individually.
The researchers relied on electronic health records, which may have been incomplete or inaccurate. They also lacked information on some factors, including medication doses and whether patients took their medicines as prescribed.
Serra advised people with prediabetes and obesity to discuss treatment choices with a doctor and not to stop or change medication without medical guidance. Metformin remains a well-established, low-cost option, he said, while healthy eating, regular activity and weight management continue to be central to care. A GLP-1 medication may be an option for some people, depending on their health, other conditions, cost and access.
