Diabetes drugs associated with a lower rate of asthma attacks
The associations between asthma and metformin and glucagon-like peptide-1 receptor agonists were found regardless of glycemic control, weight, or asthma type.
Patients who take metformin had lower risk of asthma attacks and those who also took glucagon-like peptide-1 (GLP-1) receptor agonists had additional reductions in risk, a study found.
To determine if any diabetic medications were associated with a reduced risk of asthma attacks, researchers conducted a self-controlled case series and population-based cohort study using U.K. data on patients with asthma from 2004 to 2020. They looked at metformin as a primary exposure and then as secondary exposures, GLP-1 receptor agonists, dipeptidyl peptidase-4 inhibitors, sulfonylureas, sodium-glucose cotransporter-2 inhibitors, and insulin. The primary outcome was first asthma exacerbation (defined as a short course of oral corticosteroids, unscheduled asthma-related hospital attendance, or death) during 12 months of follow-up.
A total of 4,278 patients (61.2% women; mean age, 52.9 years) were included in the case series. In the cohort study, which used inverse probability of treatment weighting, there were 8,424 patients (55.7% women; mean ages, 61.6 years and 59.7 years in the unexposed and exposed cohorts, respectively). Results were published by JAMA Internal Medicine on Nov. 18.
Metformin was associated with fewer asthma attacks with both statistical approaches (incidence rate ratio [IRR], 0.68 [95% CI, 0.62 to 0.75] in the case series; hazard ratio, 0.76 [95% CI, 0.67 to 0.85] in the cohort study). Negative control analyses did not find evidence of significant bias. HbA1c levels, body mass index (BMI), blood eosinophil cell counts, and asthma severity did not affect the association. The only add-on antidiabetic medications to have an additive association were GLP-1 receptor agonists (IRR, 0.60 [95% CI, 0.49 to 0.73] in the case series).
The mechanisms for the association of metformin and GLP-1 receptor agonists with reduced asthma attacks do not seem to be glycemic control or weight loss, the study authors said. It's also significant that the effects occurred across types of asthma, they added. “These findings suggest potential for repurposing antidiabetic drugs to much-needed alternative treatments for asthma,” the authors wrote, calling for additional research.