Effects of Chronic Dietary Grape Seed Extract Supplementation on Aortic Stiffness and Hemodynamic Responses to Exercise in Obese Males

Study Overview
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Brief Summary
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It was demonstrated that acute dietary supplementation with GSE reduced arterial blood pressure via reduction in Q in obese individuals. However, no studies have investigated the chronic effects of dietary GSE supplementation on hemodynamic responses during exercise. Given the fact that obesity is associated with an impaired function of eNOS, the effect of chronic dietary GSE supplementation on abnormal blood pressure response to exercise and aortic stiffness (AoS) needs be elucidated. Thus, it is hypothesized that GSE decreases systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), Q, and aortic stiffness at rest and during exercise. This study would determine that this supplementation may be used as a non-pharmacological intervention to prevent incident hypertension and cardiovascular events during exercise via enhanced endothelial function.

Detailed Description
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We investigated whether elevated blood pressure and aortic stiffness (AoS) characterized in obese and overweight males (N=10) are reduced following chronic GSE supplementation during exercise. Systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), heart rate (HR), stroke volume (SV), cardiac output (Q), total vascular conductance (TVC), and AoS to two submaximal cycling exercises (40% and 60% VO2peak) were compared 7 days after ingestion of GSE or placebo (PL) within an one week washout period. Compared with PL, GSE supplementation significantly decreased MAP at rest, 40%, and 60% workloads. AoS was significantly reduced at rest. Q tended to be decreased, but there was no significant difference. GSE had no effect on HR, TVC, and SV. Our study indicates that chronic supplementation with GSE reduces arterial pressure at rest and during exercise primarily via the combined reduction of AoS and Q. Thus, GSE can be a dietary supplement to treat augmented blood pressure responses in obese and overweight males at rest and during exercise.

Official Title
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Effects of Chronic Dietary Grape Seed Extract Supplementation on Aortic Stiffness and Hemodynamic Responses in Obese/Overweight Males During Submaximal Exercise

Conditions
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Obesity Adult Onset

Intervention / Treatment
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* Dietary Supplement: Grape Seed Extract


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: Overweight: 25-29.9 kg/m2 Obese: > 30 kg/m2 Waist circumference: > 90 cm Exclusion Criteria: Antihypertensive medication Major systemic disease (cancer) Musculoskeletal diseases Cardiovascular diseases or symptoms including chest pain Myocardial infarction Arrhythmias Heart failure

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 29 Years

Sexes Eligible for Study
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Male

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: Prevention
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Double


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: GSE group<br>Subjects took a single dose of 600 mg GSE in capsule form through ingestion 7 days | Dietary Supplement: Grape Seed Extract<br>* Subjects took a single dose of 600 mg GSE in capsule form through ingestion 2 hours prior to testing Dietary Supplement: Grape seed extract Two capsule grape seed extract (total 600 mg) per day<br>|
| Placebo Comparator: Placebo group<br>Subjects took a single dose of 600 mg starch in capsule form through ingestion 7 days | Dietary Supplement: Grape Seed Extract<br>* Subjects took a single dose of 600 mg GSE in capsule form through ingestion 2 hours prior to testing Dietary Supplement: Grape seed extract Two capsule grape seed extract (total 600 mg) per day<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| change in heart rate at rest and during exercise | beats per minute | 7 day supplementation | 
| change in stroke volume at rest and during exercise | volume per stroke | 7 day supplementation | 
| change in cardiac output at rest and during exercise | total volume for one minute | 7 day supplementation | 
| change in systolic blood pressure at rest and during exercise | pressure exerted during contraction | 7 day supplementation | 
| change in diastolic blood pressure at rest and during exercise | pressure exerted during relaxation | 7 day supplementation | 
| change in total vascular conductance at rest and during exercise | one reported value (cardiac output/mean arterial pressure) | 7 day supplementation | 
| change in aortic stiffness at rest | Arbitrary unit | 7 day supplementation |