Wu TD, Fawzy A, Akenroye A, Keet C, Hansel NN, McCormack MC. Metformin Use and Risk of Asthma Exacerbation Among Asthma Patients with Glycemic Dysfunction.
THE JOURNAL OF ALLERGY AND CLINICAL IMMUNOLOGY-IN PRACTICE 2021;
9:4014-4020.e4. [PMID:
34293503 DOI:
10.1016/j.jaip.2021.07.007]
[Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 05/12/2021] [Accepted: 07/01/2021] [Indexed: 11/19/2022]
Abstract
BACKGROUND
Diabetes is associated with worse asthma morbidity. Metformin, which treats diabetes, may have a role among patients with asthma and glycemic dysfunction.
OBJECTIVE
To determine the association between metformin use and asthma exacerbations among patients with diabetes.
METHODS
We queried the Johns Hopkins electronic health record from April 1, 2013, to May 31, 2018. Adults with asthma and diabetes were followed from first hemoglobin A1c (HbA1c) test to an asthma-related systemic corticosteroid prescription, emergency department (ED) visit, or hospitalization. Multivariable Cox models estimated time to each outcome associated with metformin use, modeled as either time-invariant (status at HbA1c testing) or time-dependent (based on fill data). Mediation of results by HbA1c was assessed. Sensitivity analysis was performed by propensity score matching.
RESULTS
The cohort comprised 1749 adults with asthma and diabetes. Metformin use at entry was associated with a lower hazard of asthma-related ED visits (adjusted hazard ratio [aHR], 0.40; 95% CI, 0.22-0.75) but not steroid prescription (aHR, 0.89; 95% CI, 0.70-1.13) or hospitalization (aHR, 0.38; 95% CI, 0.13-1.12). HbA1c did not mediate the association with ED visits. With metformin exposure modeled as time-dependent, metformin use was additionally associated with lower hazard of asthma-related hospitalization (aHR, 0.30; 95% CI, 0.09-0.93). Results were consistent within a subcohort of 698 metformin users matched 1:1 to nonusers by propensity score.
CONCLUSIONS
Metformin use, independent of glycemic control and obesity, was associated with lower hazard of asthma-related ED visits and hospitalizations. Metformin may have benefit in patients with asthma and glycemic dysfunction.
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