Cardiovascular Effects of Metformin on Obesity

Study Overview
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Brief Summary
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It has been shown that asymptomatic obese adolescents can demonstrate abnormal regional myocardial contraction, with preserved global cardiac function. Metformin has been shown to decrease cardiovascular mortality in patients with type 2 diabetes and insulin resistance, but the mechanism of cardiovascular protection is unknown. The purpose of this study is to evaluate the reversibility of subclinical cardiovascular abnormalities in obese adolescents with insulin resistance after a six-month course of Metformin. The investigators hypothesized that the beneficial effects of Metformin will be progressive and sustained after six months of therapy.

Official Title
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Cardiovascular Effects of Metformin on Obesity With Subclinical Myocardial Dysfunction

Conditions
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Insulin Resistance

Intervention / Treatment
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* Drug: Metformin


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Adolescents 12 to 17 years old under clinical care at the UCSF WATCH clinic Body mass index> 95th percentile for age and gender according to the Centers for Disease Control and Prevention 2000 growth charts for the United States Insulin resistant after 6 months of healthy diet and exercise Able to understand the assent form Exclusion Criteria: Patients with known cardiac disease Patients with contraindications to metformin as listed below: Renal disease or renal (serum creatinine levels ≥1.5 mg/dL for males, and ≥1.4 mg/dL for females; Known hypersensitivity to Metformin; Acute or chronic metabolic acidosis; Patients with contraindications to MRI including: Cardiac pacemaker; Claustrophobia; Metallic foreign body in the eye, Aneurysm clip in the brain Pregnancy; Patients who could not stay still for 30 minutes within the MRI scanner due to other reasons besides claustrophobia

Ages Eligible for Study
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Minimum Age: 12 Years
Maximum Age: 17 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
Intervention Model: Single Group Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Metformin, Insulin Resistance, Cardiac Function,<br>Metformin Hydrochloride Tablets will be administered with a start dose of 500mg twice daily with meals. | Drug: Metformin<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Left Ventricular Circumferential Strain change after a six-month course of Metformin. | Circumferential strain will be measured by cardiac MRI before and after the treatment. Change in circumferential strain (measured as percentage from end-diastolic wall thickness) from baseline is the main outcome of this study. We hypothesize that abnormal baseline circumferential stain will increase and reach normal values after Metformin treatment. We hypothesized that the beneficial effects of Metformin will be progressive and sustained. | 6 months | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Metformin, Insulin Resistance, Cardiac Function