Effect of Concord Grape Juice on Endothelial Function

Study Overview
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Brief Summary
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The study will compare Concord grape juice to a beverage that contains no grape flavonoids, but has a similar appearance and taste (placebo juice). A total of 60 overweight and obese participants over age 50 will be enrolled. Each participant will drink each beverage for 4 weeks with a 2-week rest period between two beverage consumption periods. The order of beverages (grape juice first or placebo juice first) will be randomized. The investigators will use ultrasound to measure brachial artery flow-mediated dilation, a measure of endothelial vasodilator function. The investigators will also collect blood samples to further assess the cardiovascular effects of grape juice. The aim of the study is to determine whether Concord grape juice improves endothelial function in patients at risk who do not have cardiovascular disease and may provide information that would guide dietary recommendations. The results may also be used by the sponsor to substantiate claims and labeling of their product.

Official Title
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Effect Of Concord Grape Juice On Endothelial Function In Obese And Overweight Individuals Over Age 50

Conditions
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Obesity, Overweight

Intervention / Treatment
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* Other: Active Concord Grape Juice 12 oz per day
* Other: Placebo Grape Juice 12 oz per day


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Body mass index ≥ 25 and < 40 kg/m2 Age ≥ 50 years Otherwise healthy Exclusion Criteria: Clinical diagnosis of atherosclerotic vascular disease. Clinical history of diabetes mellitus or fasting glucose ≥126 mg/dl Uncontrolled hypertension Treatment with an investigational new drug within the last 30 days Clinical history of other major illness including end-stage cancer, renal failure, hepatic failure, or other conditions that in the opinion of the principal investigator make the study inappropriate Psychological illness or condition such as to interfere with the subject's ability to understand the requirements of the study Use of Vitamin E, Vitamin C, beta carotene, lipoic acid, or other food or herbal supplements within 1 month of enrollment. Subjects taking multivitamins or other forms of vitamin E and C in doses that do not exceed two times the recommended daily allowance will not be excluded Extreme dietary habits (i.e. Atkins, very high protein/low carbohydrate, or vegan diet

Ages Eligible for Study
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Minimum Age: 50 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

Primary Purpose: Other
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Active First<br>Active Concord Grape Juice 12 oz per day Placebo Grape Juice 12 oz per day | Other: Active Concord Grape Juice 12 oz per day<br>* Grape Juice 12 oz per day<br>Other: Placebo Grape Juice 12 oz per day<br>* Placebo Grape Juice 12 oz per day<br>|
| Other: Placebo First<br>Placebo Grape Juice 12 oz per day Active Concord Grape Juice 12 oz per day | Other: Active Concord Grape Juice 12 oz per day<br>* Grape Juice 12 oz per day<br>Other: Placebo Grape Juice 12 oz per day<br>* Placebo Grape Juice 12 oz per day<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Brachial artery flow mediated dilation | Endothelial function will be assessed as brachial artery flow-mediated dilation using vascular ultrasound | 4 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Nitroglycerin-mediated dilation | Non-endothelium-dependent dilation will be assessed by measuring the dilator response to sublingual nitroglycerin using vascular ultrasound | 4 weeks | 
| Carotid-Femoral Pulse Wave Velocity | Central aortic stiffness will be assessed as carotid-femoral pulse wave velocity using applanation tonometry | 4 weeks | 
| Reactive hyperemia | We will use vascular ultrasound to determine maximal hyperemic flow velocity in the brachial artery induced by 4-minute cuff occlusion. | 4 weeks | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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Grape juice