Role of Flavanols in Exercise and Aging
24 juin 2014 mis à jour par: Robert M. Brothers, University of Texas at Austin
Acute and Long-term Effects of Dietary Flavanols on Local Control of Skeletal Muscle Blood Flow During Exercise in Young and Old Humans
It has well known that diets rich in fruits, vegetables and cocoa products are associated with positive health benefits and these positive effects have been shown to be due to compounds they contain called flavanols.
Flavanols have been shown to exert their positive effects by indirectly increasing nitric oxide (NO) bioavailability.
NO is a potent vasodilator that is believed to play a role in increasing blood flow to active muscle during exercise.
This regulatory process is impaired with healthy aging.
The underlying premise to this study is that if NO bioavailability can be increased following flavanol ingestion, will there be a restoration of blood flow during exercise in older individuals?
Accordingly, the first part of this research project will compare the acute vascular effects of flavanol ingestion between a young and old group.
The investigators have hypothesized that both groups will show an improvement in blood flow to active muscle during exercise, though the magnitude of the change will be greater in the older group.
The second part of this project will look at the effects of 4 weeks of daily flavanol ingestion in the old group.
The investigators hypothesize that subjects will demonstrate an improvement in blood flow to active muscle during exercise after the 4 week intervention and that the magnitude of the change will be greater than the acute effects.
Findings from this proposal will provide evidence for the efficacy of flavanols to be used (as a simple and safe lifestyle intervention) to reverse or combat impaired blood flow regulation in older individuals.
Aperçu de l'étude
Statut
Complété
Les conditions
Type d'étude
Interventionnel
Inscription (Réel)
20
Phase
- N'est pas applicable
Contacts et emplacements
Cette section fournit les coordonnées de ceux qui mènent l'étude et des informations sur le lieu où cette étude est menée.
Lieux d'étude
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Texas
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Austin, Texas, États-Unis, 78712
- University of Texas at Austin: Environmental and Autonomic Physiology Laboratory
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Critères de participation
Les chercheurs recherchent des personnes qui correspondent à une certaine description, appelée critères d'éligibilité. Certains exemples de ces critères sont l'état de santé général d'une personne ou des traitements antérieurs.
Critère d'éligibilité
Âges éligibles pour étudier
18 ans à 80 ans (Adulte, Adulte plus âgé)
Accepte les volontaires sains
Oui
Sexes éligibles pour l'étude
Tout
La description
Inclusion Criteria:
- Males and Females between 18 - 30 years old
- Males and Females between 60 - 80 years old
Exclusion Criteria:
- cardiovascular and/or microvascular disease
- blood clotting disorder
- pregnant lady
- current smoker (or regularly smoked within last year)
- a history of an adverse reaction to cold
- taking medications known to effect the autonomic nervous system
Plan d'étude
Cette section fournit des détails sur le plan d'étude, y compris la façon dont l'étude est conçue et ce que l'étude mesure.
Comment l'étude est-elle conçue ?
Détails de conception
- Objectif principal: Science basique
- Répartition: Randomisé
- Modèle interventionnel: Affectation croisée
- Masquage: Double
Armes et Interventions
Groupe de participants / Bras |
Intervention / Traitement |
|---|---|
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Expérimental: Acute effects of flavanol consumption
The outcome measurements will be made on all study participants before and 2 hours after consumption of the high flavanol beverage.
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The experimental trial (high flavanol content) will involve the consumption of a beverage containing about 1000mg of cocoa flavanols.
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Comparateur placebo: Low Flavanol Trial; acute effects
Once again, the outcome measurements will be made on all study participants before and 2 hours after consumption of the low flavanol beverage.
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The placebo trial (low flavanol content) will involve the consumption of a beverage containing 75 mg of cocoa flavanols.
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Expérimental: Long-term effects of flavanol consumption
Only those study participants over 60 years of age will continue with this arm of the trial.
The same outcome measures will be performed following 4 weeks of daily consumption of a high flavanol beverage.
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The experimental trial (high flavanol content) will involve the daily consumption of a beverage containing about 1000mg of cocoa flavanols for 4 weeks.
Subjects will be provided with 28 packets of the beverage to take home with them.
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Comparateur placebo: Low Flavanol Trial; long-term effects
Only those study participants over 60 years of age will continue with this arm of the trial.
The same outcome measures will be performed following 4 weeks of daily consumption of a low flavanol beverage.
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The placebo trial (low flavanol content) will involve the daily consumption of a beverage containing 75 mg of cocoa flavanols for 4 weeks.
Subjects will be provided with 28 packets to take home with them.
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Que mesure l'étude ?
Principaux critères de jugement
Mesure des résultats |
Description de la mesure |
Délai |
|---|---|---|
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Change in femoral blood flow during exercise following flavanol consumption
Délai: During knee extension exercise, change from baseline in blood flow 2 hours post flavanol ingestion
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Blood flow regulation to active muscles during knee extension exercise can be assessed by using ultrasound to measure blood flow in the femoral artery.
This will be done before and after stimulation of the sympathetic nervous system.
A baseline value will be obtained and then the measurement will be performed again 2 hours after flavanol ingestion.
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During knee extension exercise, change from baseline in blood flow 2 hours post flavanol ingestion
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Mesures de résultats secondaires
Mesure des résultats |
Description de la mesure |
Délai |
|---|---|---|
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Change in flow-mediated dilation (FMD) following flavanol consumption
Délai: Change from baseline in FMD 2 hours post flavanol ingestion
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Flow-mediated dilation is commonly used as an index of nitric oxide bioavailability.
Nitric oxide is believed to play a role in blood flow regulation during exercise.
A baseline value will be obtained and then the measurement will be performed again 2 hours after flavanol ingestion.
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Change from baseline in FMD 2 hours post flavanol ingestion
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Collaborateurs et enquêteurs
C'est ici que vous trouverez les personnes et les organisations impliquées dans cette étude.
Parrainer
Les enquêteurs
- Chercheur principal: Michelle Harrison, M.A., University of Texas at Austin
Dates d'enregistrement des études
Ces dates suivent la progression des dossiers d'étude et des soumissions de résultats sommaires à ClinicalTrials.gov. Les dossiers d'étude et les résultats rapportés sont examinés par la Bibliothèque nationale de médecine (NLM) pour s'assurer qu'ils répondent à des normes de contrôle de qualité spécifiques avant d'être publiés sur le site Web public.
Dates principales de l'étude
Début de l'étude
1 décembre 2012
Achèvement primaire (Réel)
1 avril 2014
Achèvement de l'étude (Réel)
1 avril 2014
Dates d'inscription aux études
Première soumission
8 mars 2012
Première soumission répondant aux critères de contrôle qualité
15 mars 2012
Première publication (Estimation)
19 mars 2012
Mises à jour des dossiers d'étude
Dernière mise à jour publiée (Estimation)
25 juin 2014
Dernière mise à jour soumise répondant aux critères de contrôle qualité
24 juin 2014
Dernière vérification
1 mai 2014
Plus d'information
Termes liés à cette étude
Mots clés
Autres numéros d'identification d'étude
- 2012-02-0114
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