Effect of Metformin on Insulin Sensitivity and Pan-Arterial Vascular Function in Adults With Metabolic Syndrome

Not Applicable

Completed

• Conditions: Metabolic Syndrome; Insulin Sensitivity
• Interventions: Drug: Placebos; Drug: metformin

• Registration Number: NCT02633488
• Lead Sponsor: University of Virginia

Brief Summary

The purpose of this study is to look at how insulin (a hormone that helps the cells get energy from sugar) in our body affects blood vessels (elasticity in the bigger blood vessels and blood flow in the smaller blood vessels in the arm) and how Metformin (a drug that makes you more sensitive to insulin) affects insulin's action on the blood vessels.

Detailed Description

In our protocol, we will study vascular function using pulse wave velocity (PWV) augmentation index (AI), flow mediated dilation (FMD) and contrast enhanced ultrasound (CEU) as well as insulin sensitivity (euglycemic clamp) in 50 adults with metabolic syndrome, age 18-60 years. They will each be studied 4 times,before and after two 12-wk interventions (randomly assigned) as follows: 1) Placebos and 2) Metformin . This is a cross-over design.

Basic Information
|
Recruitment & Eligibility
|
Study & Design
|
Trial Locations

Study Timeline

• Study Start: 2014-06
• Study First Submitted: 2014-09-26
• Study First Submitted QC: 2015-12-16
• Study First Posted: 2015-12-17
• Primary Completion: 2016-07
• Study Completion: 2016-07
• Results First Submitted: 2020-02-24
• Status Verified: 2020-03
• Results First Submitted QC: 2020-03-09
• Last Update Submitted: 2020-03-09
• Results First Posted: 2020-03-23
• Last Update Posted: 2020-03-23

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 19

Inclusion Criteria

• Age 18-60

  • No smoking the past 6 months

  • Normal screening labs or no clinically significant values-except those listed below

  • Must have 3 of the following 4 characteristics established by NCEP-AHA-NHLBI

    • Males waist circumference greater than 40 inches, females greater than 35 inches
    • Blood pressure greater than 130/85 or on treatment with one or more antihypertensive agent
    • Fasting plasma triglycerides >150 or HDL <40 (males) <50 (females)
    • Fasting blood sugar >100 but <126

  • Subject may participate if on the following drugs, provided the drugs can remain at stable doses throughout the 12 week treatment interval.

    • Ace inhibitor
    • ARB
    • HMG CoA reductase inhibitor
    • Beta blocker
    • Calcium channel blockers
    • Alpha-adrenergic antagonist

Read More

Exclusion Criteria

• Smoking presently or in the past 6 months
• HbA1c ≥ 6.5
• Glucocorticoids-eg: prednisone, dexamethasone
• Any known sensitivity or intolerance to Metformin
• Any chronic GI disorders such as Irritable Bowel Syndrome or Crohns disease
• History of congestive heart failure, ischemic heart disease, severe pulmonary disease, liver or kidney disease.
• History of malignant or metabolic disorders including diabetes
• Presence of an intracardiac or intrapulmonary shunt (we will screen for this by auscultation during the physical exam by PI)
• Hypersensitivity to perflutren (contained in Definity)
• Pregnant or breastfeeding

Read More

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Placebo	Placebos	12 weeks of Placebo tablet 3 x daily
Metformin	metformin	12 weeks of Metformin tablet 850 mg 3 x daily

Primary Outcome Measures

Name	Time	Method
Flow Mediated Dilation - Endothelial Function	before and after 12 weeks on placebo or metformin	brachial artery ultrasonography % flow-mediated dilatation (FMD) for assessing endothelial function before and after an insulin clamp to assess insulin's effect on the vasculature

Trial Locations

Locations (1)

University of Virginia; 🇺🇸 Charlottesville, Virginia, United States