The Effects of Red Wine Polyphenols on Microvascular Dysfunction

Study Overview
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Brief Summary
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Rationale: Epidemiological studies have shown that consumption of alcoholic beverages, red wine in particular, is associated with less cardiovascular mortality. In addition, there are reported beneficial effects of red wine on components of the metabolic syndrome, arguably the most menacing cardiometabolic condition facing us due to the unfolding obesity epidemic. Beneficial effects have also been reported with other polyphenol-rich food stuff, such as cocoa and green tea and points to a beneficial effect which does not seem to be dependent on the alcohol content of red wine. Experimental studies with mixed or separate Red Wine Polyphenols (RWPs) (i.e. without alcohol) have shown beneficial effects on cardiometabolic parameters associated with obesity. Most research has focused on resveratrol, a specific polyphenol components which is quite specific to red wine and has, at least in animal studies, beneficial effects on insulin sensitivity, insulin secretion, and endothelial function. Moreover, RWPs have shown to improve endothelial NO-mediated relaxation using the same PI3-kinase/Akt pathway as does insulin. However, data in humans are remarkably scarce Objective: To study effects of RWPs on insulin sensitivity, beta-cell function, microvascular function (skin, muscle and cardiac), blood pressure, insulin-mediated microvascular responsiveness. Study design: Randomized controlled trial (double blind). Study population: Obese (BMI >30); n=30, men or women, aged 18-60 years. Intervention: Mixed RWP 600mg/day or matching placebo for a total duration of 8 weeks.

Official Title
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The Effects of Red Wine Polyphenols on Microvascular Dysfunction

Conditions
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Obesity

Intervention / Treatment
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* Dietary Supplement: Red Wine Polyphenols 600mg/day
* Dietary Supplement: placebo


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Caucasian age 18-60 years obese (BMI >30) Exclusion Criteria: cardiovascular disease smoking diabetes mellitus recent history (<12 months) of high alcohol use > 4 U/day use of medication potentially affection insulin sensitivity or microvascular function pregnancy

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 60 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: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Quadruple


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: Red Wine Polyphenols<br>Red Wine Polyphenols 600mg/day (capsules) | Dietary Supplement: Red Wine Polyphenols 600mg/day<br> <br> * Other names: Provinols™;|
| Placebo Comparator: placebo<br>placebo (capsules) | Dietary Supplement: placebo<br> <br> |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| insulin sensitivity as determined by euglycemic clamp tests |  | 8 weeks | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Molecular mechanisms in muscle tissue |  | 8 weeks | 
| Glucose tolerance as assessed by the area under the curve for glucose (AUCgluc) during a standardized meal test |  | 8 weeks | 
| microvascular function (baseline and during hyperglycemia) |  | 8 weeks | 
| Blood pressure 24 hr measurement |  | 8 weeks |