Patients with asthma and abnormal glucose metabolism have increased asthma exacerbations, worse lung function, and higher health care utilization. Metformin, an insulin-sensitizing agent with anti-inflammatory properties, may modify these outcomes.

This study explored the association between metformin use and acute asthma exacerbations in children with asthma with elevated blood glucose or a type 2 diabetes diagnosis.

This observational study was conducted among children aged 10–17 years with asthma and evidence of type 2 diabetes, abnormal glucose, or serum glucose ≥200 mg/dL, using the Linked Network in TrinetX data. Two cohorts were constructed: a metformin treatment group and a comparison group without metformin. Groups were matched 1:1 using a propensity score algorithm on baseline characteristics. Negative binomial models were used to compare asthma-related healthcare utilizations and systemic steroid courses. Kaplan-Meier analysis using the log-rank test compared the time to-first asthma exacerbation.

After propensity score matching, there were 536 children each in the metformin user and comparison groups. Metformin use was associated with a significantly lower rate of systemic corticosteroid courses, with a 42 % reduction compared to the comparison group (IRR = 0.58; 95 % CI: 0.40–0.85; p = 0.005). There was no difference in the median time to the first occurrence of asthma hospitalizations, ER visits, or systemic steroid courses between the metformin use and comparison group.

Metformin use was associated with a significantly lower rate of systemic corticosteroid courses, although no differences were observed in acute care utilization and in time to first asthma exacerbation.