GLP-1s linked to fewer asthma attacks and COPD flare-ups, but experts flag study limits

UK-based researchers have found that people with airway diseases, such as asthma and chronic obstructive pulmonary disease (COPD), who were prescribed a GLP-1 medication had fewer asthma attacks and COPD flare-ups compared to other people with the same diseases prescribed the diabetes medication sulfonylureas. 

Study lead Chloe Bloom, a clinical associate professor in Respiratory Epidemiology at the National Heart & Lung Institute, Imperial College London, UK, says: “GLP-1 receptor agonists are widely used to treat type 2 diabetes and obesity. Previous research suggests that they may have anti-inflammatory effects and may improve lung-related outcomes. However, asthma and COPD outcomes have not been included as outcomes in GLP-1 drug trials.” 

“We wanted to use real-world health records to investigate whether people with asthma or COPD who started GLP-1 receptor agonists had fewer acute respiratory attacks.”

The research has not yet been published, but the results were presented at the ongoing European Respiratory Society (ERS) Congress in Barcelona, Spain (Sep 5–9).

GLP-1 and respiratory health

Bloom says that the effect was strongest with semaglutide, especially in people with asthma, where the drug appears to be associated with nearly 40% reduction in asthma attacks and 20% reduction in COPD flare-ups.

People with airway diseases who also have diabetes or obesity, and therefore are eligible for GLP-1 medications, may benefit from these treatments, as the study results indicate respiratory benefits, she argues.

Bloom argues that based on the findings, people who are eligible for GLP-1 medications and have airway diseases may benefit from the drug.“The findings from this study are encouraging, but they should not change treatment decisions on their own. People with asthma or COPD should not start GLP-1s specifically for their lung condition outside current prescribing guidance. While the findings suggest that some people taking GLP-1 receptor agonists may experience fewer respiratory attacks, this needs confirmation in clinical trials,” notes Bloom. 

Meanwhile, the study has sparked reactions from independent experts who were not involved in the study. They caution that it cannot determine cause and effect, being an observational study.

Dr. Marie Spreckley, researcher on the Prevention of Diabetes and Related Metabolic Disorders at the University of Cambridge, UK, comments that the study’s accompanying news release makes a causal claim that is not supported by the research. Its title reports “semaglutide can reduce asthma attacks.”

“The study identifies an association between semaglutide use and a lower hazard of airway exacerbations, but it cannot establish that semaglutide caused this difference. A more accurate title would be ‘Semaglutide use associated with fewer asthma attacks.’”

Spreckley says that the most defensible conclusion is that semaglutide use was associated with a lower hazard of airway exacerbations in this dataset, particularly among people with asthma. 

“It is too early to state that semaglutide reduces or prevents asthma attacks. People should not seek semaglutide specifically for asthma or change their existing asthma treatment because of these findings. Randomized trials are needed to determine whether semaglutide provides a genuine respiratory benefit.” 

Need for clinical trials

The research has also been welcomed by other independent experts due to its importance and relevance to fill a needed research gap.

Dr. Alexander Mathioudakis, chair of the European Respiratory Society’s Group on Airway Pharmacology and Treatment and senior lecturer in Respiratory Medicine at the University of Manchester, UK, says: “This is one of the largest real-world studies to investigate GLP-1 receptor agonists and airways disease, and one of the first to examine whether effects differ between individual GLP-1 receptor agonists.”

Spreckley stresses that the findings cannot automatically be generalized to people using semaglutide solely for weight management.“The study highlights the need to consider metabolic health as part of respiratory care. It also supports the case for including respiratory outcomes, such as asthma attacks and COPD exacerbations, in future trials of metabolic therapies.”

He stresses that there is a need for clinical trials that include respiratory outcomes, such as asthma attacks, COPD exacerbations, lung function, symptoms, and quality of life, to determine whether metabolic treatments could become part of a broader, more personalized approach to managing airway disease.

Spreckley agrees that this is a large and potentially important real-world study that adds to growing evidence of an association between GLP-1 use and better respiratory outcomes. 

“The new-user, active-comparator design is a strength, and the researchers appear to have adjusted for several important factors, including body mass index, smoking, disease severity, eosinophil levels, and comorbidities,” she says.

However, she stresses that all participants were receiving treatment for type 2 diabetes, so the findings cannot automatically be generalized to people using semaglutide solely for weight management. 

“The authors’ analysis according to weight loss is interesting, but it does not prove that the association is independent of weight loss or establish another biological mechanism,” Spreckley concludes.