The Vascular Effects of Exenatide Versus Metformin in Patients With Pre-Diabetes

Study Overview
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Brief Summary
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The purpose of this study is to compare the effects of exenatide versus metformin on vascular health with chronic (3-month) therapy and during a 2-hour period following a meal in patients with pre-diabetes. It is predicted that exenatide will improve vascular health to a greater degree compared to metformin.

Official Title
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The Chronic and Acute Postprandial Vascular Effects of Exenatide vs. Metformin in Abdominally Obese Patients With Impaired Glucose Tolerance

Conditions
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Impaired Glucose Tolerance

Intervention / Treatment
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* Drug: Exenatide
* Drug: Metformin


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Greater than or equal to 18 years old Impaired glucose tolerance: 2-hr oral glucose tolerance test (OGTT) plasma glucose >140 mg/dL OR impaired fasting glucose: fasting glucose > or = 100 mg/dL OR elevated glycosylated hemoglobin: Hemoglobin A1c > or = 5.7% Abdominal obesity: waist circumference >102 cm (men) and >88 cm (women) Stable cardiovascular medication regimen (or other medications known to affect endothelial function) at least 1 month prior to enrollment and throughout the study Exclusion Criteria: Type 2 diabetes Current use of glycemic control medications within one month of randomization Fasting glucose >126 mg/dL Current use of weight loss medication Previous weight loss surgery History of severe gastrointestinal disease Standard clinical contraindications to exenatide or metformin therapy Unstable angina Heart failure Stroke or coronary artery bypass graft within 3 months of screening Women who are currently pregnant or planning to become pregnant Breastfeeding women Clinically significant liver disease Creatinine > 1.5 mg/dL Hepatic function greater than 3 times upper limit of normal Patients who are mentally incompetent and cannot sign a Patient Informed Consent

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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No

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Exenatide<br>Subjects were randomlly assigned to treatment arm: Exenatide 10 mcg twice daily vs. Metformin 500 mg twice daily. | Drug: Exenatide<br>* exenatide 10 mcg twice daily<br>|
| Active Comparator: Metformin<br>Subjects were randomlly assigned to treatment arm: Exenatide 10 mcg twice daily vs. Metformin 500 mg twice daily. | Drug: Metformin<br>* metformin 500 twice daily<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Change in Reactive Hyperemic Index Over the 3-month Treatment Period | Change in reactive hyperemic index over the 3-month treatment period, which is a measure of endothelial (inner lining of blood vessels) function. This is measured as a ratio of post-occlusion blood flow volume versus baseline blood flow volume in fingertips. Higher ratio values are considered indicative of better arterial health. | Change from baseline to 3 months |