Investigation of Metformin in Pre-Diabetes on Atherosclerotic Cardiovascular OuTcomes

Eligibility Criteria

• 1. Pre-diabetes: This condition is fulfilled by HbA1c of at least 5.7%, but less than 6.5%; or two measurements of fasting plasma glucose (on separate days) of 100-125 mg/dL; or a 2-hour plasma glucose level of 140-199 mg/dL following a 75 g glucose load oral glucose tolerance test.
• 2. Established atherosclerotic cardiovascular disease: Qualifying participants must have evidence of atherosclerotic disease in at least one of the following vascular beds: coronary, cerebrovascular, or peripheral arterial circulation.
• 1. History of myocardial infarction at least one month prior to randomization.
• 2. History of percutaneous coronary intervention or coronary artery bypass surgery at least one month prior to randomization.
• 3. Angiographic evidence of coronary stenosis of at least 50% in at least two major epicardial coronary arteries.
• 1. Documented prior ischemic stroke (at least one month prior to randomization),
• 2. Carotid artery stenosis 50% and history of transient ischemic attack or transient ischemic visual symptoms attributable to the identified lesion(s),
• 3. Asymptomatic carotid stenosis of at least 70% luminal diameter,
• 4. History of carotid revascularization (surgical or catheter-based).
• 1. History of aorto-iliac or peripheral artery intervention (surgical or catheter based) for limb ischemia, or amputation for limb ischemia,
• 2. Symptoms of intermittent claudication with ankle:brachial index less than or equal to 0.85.
• 3. Renal function: Estimated glomerular filtration rate at least 45 mL/min/1.73 m2.
• 4. Informed consent has been fully executed, and participant agrees to study procedures.
• 1. Treatment with metformin or other anti-diabetic medication within 12 months of randomization. Note: In the absence of a diagnosis of diabetes, inpatient treatment with insulin or treatment with an SGLT2 inhibitor (e.g., for heart failure) or a GLP-1 receptor agonist (e.g., for obesity) is not exclusionary.
• 2. Treatment with systemic glucocorticoids within 3 months of randomization
• 3. Fasting plasma glucose 140 mg/dL measured between screening and randomization visits, or any plasma glucose 200 mg/dL or HbA1c 7.0% measured within 12 months of randomization.
• 4. Total CO2 below the local laboratory lower limit of normal on most recent blood chemistry panel
• 5. Current treatment with cimetidine, vandetanib, or a systemic treatment with a carbonic anhydrase inhibitor.
• 6. Cirrhosis, active hepatitis, or jaundice at time of randomization, or total bilirubin \> 2 times upper limit of normal
• 7. Binge or heavy alcohol consumption within 6 months of randomization
• 8. Severe anemia (hemoglobin \< 10 g/dL)
• 9. Prior history of intolerance to metformin
• 10. Myocardial infarction, coronary revascularization procedure, or stroke within 1 month of randomization
• 11. Uncontrolled hypertension at screening assessment (systolic blood pressure 180 mm Hg or diastolic blood pressure 110 mm Hg
• 12. Acute or decompensated congestive heart failure
• 13. Expected survival less than study duration
• 14. Participants considered to be unable, unwilling, or unreliable to meet protocol requirements
• 15. Impaired decision-making capacity, defined by any history of dementia or cognitive impairment
• 16. Concurrent participation in another research study involving a randomized comparison of drug or device treatments, unless specifically excepted.
• 17. Pregnant, intent to become pregnant during the trial, or lactating
• 18. Women of childbearing potential who are not using a highly effective method of contraception