Metformin IN Asthma for Overweight and Obese Individuals (MINA)

This is a randomized, placebo-controlled, parallel-arm pilot clinical trial. Adult participants who are overweight or obese and have not well-controlled asthma despite use of an inhaled corticosteroid will be randomized to metformin, an FDA-approved medication for the treatment of type 2 diabetes mellitus, or to placebo, to be taken daily for a total duration of six months. Recruitment will occur at two sites in the United States.

Randomized participants will have regular telemedicine visits to assess side effects and adherence. Additionally, participants will have a measurement of asthma outcomes at randomization and at 3 and 6 months after randomization.

The purpose of this study is to determine feasibility to inform a future multi-center clinical trial of metformin in this population.

Inclusion criteria

• Physician-diagnosed asthma on maintenance therapy
• Not well-controlled asthma (ACT score <20, or at least one asthma exacerbation requiring corticosteroids in the prior 12 months)
• Overweight or obesity: Body mass index ≥25kg/m2
• Adult: Age ≥18

Exclusion criteria

• Currently pregnant, expect to become pregnant in the next 6 months or are currently breastfeeding
• Major cardiovascular disease: heart failure, heart attack or stroke within the last 6 months
• Other chronic lung disease, inclusive of chronic obstructive pulmonary disease, bronchiectasis, interstitial lung disease, pulmonary fibrosis
• Active smoking or former smoker with ≥20 pack-year smoking history
• Chronic kidney disease: estimated glomerular filtration rate ≤60 mL/min/1.73 m2
• Heavy alcohol use: in a typical week, 8 or more drinks for a woman or 15 or more drinks for a man
• Liver disease: elevation in aspartate aminotransferase (AST) or alanine aminotransferase (ALT) > 2x the upper limit of normal or prior diagnosis of liver disease
• Anemia: hemoglobin < 13 g/dl in males and hemoglobin < 11 g/dl in females
• Taking Glucagon Like Peptide 1(GLP-1) medications for weight loss
• Diabetes (Hemoglobin A1C ≥ 6.5% or taking metformin or other medications used to treat diabetes)
• Participation in any other clinical trial (observational studies are permitted)