GLP-1 drugs may reduce asthma flares in overweight and obese adults without diabetes, a new study finds.
Researchers analyzed three years of electronic health record and claims data from adults with asthma who were overweight or obese but did not have diabetes. Asthma flares in patients taking a GLP-1 medication were compared with those in similar patients who did not receive the drugs.
Across all weight categories examined – overweight, obese and morbidly obese – GLP-1 therapy was associated with a 12 to 15 percent reduction in asthma exacerbations. The reductions translated to about one fewer flare for every seven or eight patients over the three-year period, says Dr. Ruchi Patel, the study’s first author.
“GLP-1 receptor agonists may be associated with fewer asthma exacerbations in non-diabetic patients, pointing to a promising new direction” in asthma treatment, says Patel, a former researcher at Drexel University’s College of Medicine. The research was presented at the 2026 American Academy of Allergy, Asthma & Immunology annual meeting in Philadelphia.
GLP-1s as an Asthma Tool
The global study included 710 overweight patients with a body mass index of 25 to 29 and 1,515 obese patients (BMI 30 to 39). The third group consisted of 1,249 morbidly obese patients (BMI 40 and higher). Patient data came from the TriNetX healthcare database.
Health records showed patients were prescribed various types of GLP-1s, including semaglutide, tirzepatide and liraglutide.
The study found overweight patients had 14.6 percent fewer asthma exacerbations. Those with obesity had a 12.2 percent fewer flares. Meanwhile, those in the morbidly obese weight category had a 13.3 percent reduced risk of exacerbations.
The effect was modest compared with biologic therapies such as dupilumab or omalizumab. Those medications can reduce exacerbations by half or more, says Dr. Edward Schulman. He’s the study’s senior author and director of the Allergy, Asthma and Airway Research Center at Drexel University.
However, obesity-related asthma is often harder to control and responds less well to standard inhaled therapies. “It is associated with worse control, an increase in exacerbations, and worse outcomes,” Schulman says.
GLP-1 medications could potentially be used alongside biologics or other asthma medications to help these patients, he says.
“This work is exciting and represents, to our knowledge, the largest study of non-diabetic, obese asthmatics treated with GLP-1 agonists,” Schulman says. “Our data strongly suggest GLP-1 agents represent a new armament to reduce asthma exacerbations.”
GLP-1 Effects on Airways
GLP-1s were first approved to improve blood sugar control and regulate appetite and in people with Type 2 diabetes. They’re now widely used for weight loss. Short for glucagon-like peptide-1 receptor agonists, GLP-1s mimic the natural GLP-1 hormone to slow gastric emptying and increase feelings of satiety.
GLP-1 receptors are also present in airway smooth muscle and lung tissue, meaning the hormone may have direct effects on the cells there.
Research suggests GLP-1 activity may reduce pro-inflammatory signaling and airway inflammation. Schulman says that could lower the airway hyperresponsiveness and bronchoconstriction that’s seen with asthma.
Prior research has shown that GLP-1s can reduce asthma flares in people with obesity and Type 2 diabetes.
It is not yet clear whether the association between GLP-1 therapy and the lowered risk of asthma flares is due to weight loss, a reduction in inflammation, or both. The researchers did not have data on how much weight participants lost or whether they moved between BMI categories.
Benefit Beyond Weight Loss?
However, because the reduction in exacerbations was similar across weight groups, researchers suggest the effect on asthma flares isn’t explained by weight loss alone.
“The benefit we saw in our study was consistent across the BMI categories,” says Patel, who is currently a Rutgers University internal medicine resident. “To me, this is very suggestive that there is a weight independent, direct anti-inflammatory effect that is at play.”
Morbidly obese individuals are expected to lose more weight on a GLP-1 than someone who is in the overweight category. But researchers didn’t see a “linear” relationship between asthma flare reductions and the starting weight.
Obesity-related asthma is considered a distinct subtype of asthma. Excess fat tissue can contribute to inflammation throughout the body and metabolic dysfunction that can affect the cells of the airways. Fat around the chest and abdomen can also restrict lung expansion and make it more difficult to breathe.
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