Diabetes mellitus is one of the common comorbid conditions among adults with asthma. Recent epidemiological studies have demonstrated that the incidence of asthma in patients with type 2 diabetes is low, given metformin’s effecton improving asthma outcomes in diabetic patients. Due to the dearth of data on the efficacy of this drug in the treatment of asthma, the researchers performed a systematic review and meta-analysis in patients with concurrent asthma and diabetes. The search was done on the PubMed, Embase, and CENTRAL databases for articles published before April 2020 to look for observational studies of individuals with concurrent asthma and diabetes that compared the risk of asthma exacerbation between metformin users and nonusers.

The primary outcome was the adjusted risk of asthma exacerbation, while the secondary outcomes were the adjusted risk of asthma-related hospitalization and emergency room visits. A total of two studies were included with a total of 25,252 patients. The pooled effect size revealed that metformin use was inversely linked with risk of asthma exacerbation (OR = 0.65, 95% CI 0.28–1.48; χ2 = 5.42, P=0.02; I2 = 82%), asthma-related emergency department visits (OR = 0.81, 95% CI 0.74–0.89; χ2 = 0.36, P=0.55; I2 = 0%), and hospitalizations (OR = 0.43, 95% CI 0.14–1.29; χ2 = 4.01, P=0.05; I2 = 75%). Based on this data, it could be suggested that metformin may be a valuable therapeutic agent for reducing the risk of asthma-related emergency room visits for patients with concomitant asthma and diabetes. Besides, it may also help in decreasing the risk of asthma-related hospitalization and exacerbation.

Reference

Wen L, Zhong W, Chai Y, et al. Association of Metformin Use with Asthma Exacerbation in Patients with Concurrent Asthma and Diabetes: A Systematic Review and Meta-Analysis of Observational Studies. Can Respir J. 2020;2020:9705604.