Research from Australia indicates that common diabetes drugs called GLP-1 receptor agonists could improve lung capacity and metabolic outcomes in adults with cystic fibrosis-related diabetes, though larger studies are needed.
GLP-1 receptor agonist medicines, which are already widely used for diabetes and weight management, may also improve lung function in adults with cystic fibrosis-related diabetes, according to Australian researchers whose findings were published in Diabetes, Obesity and Metabolism. The study, while small and exploratory, adds to a growing body of work suggesting these drugs may have benefits beyond glucose control in people with cystic fibrosis.
The research team reviewed records from a single centre covering 230 adults with cystic fibrosis treated between 2021 and 2024, and identified 10 patients receiving a GLP-1 receptor agonist alongside insulin, the standard treatment for cystic fibrosis-related diabetes. They compared them with 15 similar patients treated with insulin alone. The groups were matched for age and use of the highly effective cystic fibrosis modulator Trikafta, though the GLP-1 group had higher body weight and body mass index at the start of the analysis, a difference the authors said could have affected the outcome.
After a year on treatment, the patients taking a GLP-1 receptor agonist showed significant improvements in two measures of lung capacity. Median forced expiratory volume in one second, or FEV1, rose by 170 millilitres, while forced vital capacity, or FVC, increased by 100 millilitres. In practical terms, that amounted to a 6% gain in predicted FEV1 and a 3% rise in predicted FVC. The researchers said the improvement in FEV1 was greater than the change in FVC, which suggests that weight loss alone may not explain the result and that other factors, including better blood sugar control, reduced inflammation or a direct effect on the lungs, could be involved.
The same group also recorded better diabetes outcomes. Average long-term blood sugar, measured by HbA1c, fell by 1.9 percentage points in the GLP-1 group, while it did not change meaningfully in the comparison group. Time spent in the target glucose range improved, daily insulin needs dropped by 11 units, and participants spent less time below target blood sugar levels. Weight also fell by a median of 4.1 kilograms in the GLP-1 group, whereas it increased in the control group. Semaglutide was the most common drug used, with fewer patients receiving dulaglutide or liraglutide.
The findings fit with earlier signs that GLP-1 drugs may be useful in cystic fibrosis, a disease in which damaged or absent CFTR activity causes progressive lung damage and often leads to diabetes as well. A review in Diabetes Therapy in July 2026 said the medicines may offer extra advantages in cystic fibrosis beyond insulin alone, while a case report in Diabetes Technology & Therapeutics and other recent studies have pointed to possible gains in glucose control, body weight and pulmonary function. Still, the Australian authors cautioned that their data were retrospective and that differences between groups at baseline may have influenced the results. They said larger, controlled trials are needed before any conclusions can be drawn about routine use.
Disclaimer: This content is for informational purposes only and is not intended to be a substitute for professional medical judgment, advice, diagnosis, or treatment.
