FLuctuATion Reduction With inSULin and Glp-1 Added togetheR (FLAT-SUGAR)

Inclusion Criteria:

1. T2DM for >12 months defined according to current ADA criteria
2. C-peptide >0.5 ng/mL-after informed consent has been signed, samples will be drawn fasting and sent to a central lab
3. Participants must be on insulin therapy. Diabetes, Blood Pressure & Lipid therapy must be stable (in both dose and agent) for ≥3 months (dose of any 1 drug has not changed by more than 2-fold, & new agents not been added within the previous 3 months)
4. HbA1c 7.5-8.5% for enrollment

5. Age at enrollment (screening): 40-75 years (inclusive) when there is a history of cardiovascular disease (defined in 'a'), or 55 to 75 years (inclusive) when there is not a history of cardiovascular disease but 2 or more risk factors (with or without treatment) are present (defined in 'b')

   a) Established cardiovascular disease defined as presence of one of the following: i. Previous myocardial infarction (MI). (most recent must be > 3 months prior enrollment) ii. Previous stroke. (most recent must be >3 months prior enrollment) iii. History of coronary revascularization (e.g., coronary artery bypass graft surgery, stent placement, percutaneous transluminal coronary angioplasty, or laser atherectomy)(most recent must be > 3 months prior enrollment) iv. History of carotid or peripheral revascularization (e.g., carotid endarterectomy, lower extremity atherosclerotic disease atherectomy, repair of abdominal aortic aneurysm, femoral or popliteal bypass). (most recent must be >3 months prior enrollment) v. Angina with either ischemic changes on a resting ECG, or ECG changes on a graded exercise test (GXT), or positive cardiac imaging study vi. Ankle/brachial index <0.9 vii. LVH with strain by ECG or ECHO viii. >50% stenosis of a coronary, carotid, renal or lower extremity artery. ix. Urine albumin to urine creatinine ratio of >30 mg albumin/g creatinine in 2 samples, separated by at least 7 days, within past 12 months) [Target of 50% of study cohort] or b) Increased CVD risk defined as presence of 2 or more of the following: i. Untreated LDL-C >130 mg/dL or on lipid treatment ii. Low HDL-C (<40 mg/dL for men and <50 mg/dL for women) iii. Untreated systolic BP >140 mm Hg, or on antihypertensive treatment iv. Current cigarette smoking v. Body mass index 25-45 (Asian populations 23-45) kg/m2

6. No expectation that participant will move out of clinical center area during the next 8 months, unless move will be to an area served by another trial center
7. Ability to speak & read English

Exclusion Criteria:

1. The presence of a physical disability, significant medical or psychiatric disorder; substance abuse or use of a medication that in the judgment of the investigator will affect the use of CGM, wearing of the sensors, Holter or Telemetry monitor, complex medication regimen, or completion of any aspect of the protocol
2. Cannot have had any cardiovascular event or interventional procedure, (MI, Stroke or revascularization) or been hospitalized for unstable angina within the last 3 months
3. Inability or unwillingness to discontinue use of acetaminophen products during CGM use
4. Inability or unwillingness to discontinue use of all other diabetes agents other than insulin & metformin during trial (including insulin pump participants who will need to convert to BBI)
5. Intolerance of metformin dose <500 mg/day
6. Inability or unwillingness to perform blood glucose testing a minimum of 3 times/per day
7. Creatinine level ≥1.5 for males or 1.4 for females
8. ALT level ≥ 3 times upper limit of normal
9. Current symptomatic heart failure, history of NYHA Class III or IV congestive heart failure at any time, or ejection fraction (by any method) < 25%
10. Inpatient psychiatric treatment in the past 6 months
11. Currently participating in an intervention trial
12. Chronic inflammatory diseases, such as collagen vascular diseases or inflammatory bowel disease
13. History of pancreatitis
14. BMI >45kg/m2
15. For females, pregnant or intending to become pregnant during the next 7 months