Flavonoids, Blood Pressure and Blood Vessel Function (FASTCHECK)

This study has been completed.
Sponsor:
Information provided by (Responsible Party):
University of East Anglia
ClinicalTrials.gov Identifier:
NCT01530893
First received: February 1, 2012
Last updated: February 27, 2014
Last verified: February 2014
  Purpose

The primary aim of this placebo-controlled study is to determine whether flavonoids beneficially affect markers of cardiovascular disease risk in healthy subjects at elevated cardiovascular risk.

The underlying mechanisms of action of flavonoids will be assessed on blood biomarkers and we will assess the effects of the food matrix, and aspects of isoflavone metabolism.


Condition Intervention
Cardiovascular Disease Risk Reduction
Dietary Supplement: Flavanone - supplement
Other: Flavanone - food
Other: Flavanone - placebo
Dietary Supplement: Isoflavone - supplement
Other: Isoflavone - food
Other: Isoflavone - placebo
Dietary Supplement: Isoflavone - metabolite supplement
Dietary Supplement: Flavan-3-ol - supplement
Other: Flavan-3-ol - food
Other: Flavan-3-ol - placebo
Dietary Supplement: Anthocyanin - supplement
Other: Anthocyanin - food
Other: Anthocyanin - placebo

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Factorial Assignment
Masking: Double Blind (Subject, Investigator, Outcomes Assessor)
Primary Purpose: Basic Science
Official Title: Are the Cardiovascular Responses of Individuals at Mild to Moderate Cardiovascular Risk Influenced by Dietary Flavonoid Sub-class and Dietary Form?

Resource links provided by NLM:


Further study details as provided by University of East Anglia:

Primary Outcome Measures:
  • Change from baseline in blood vessel control (pressure and endothelial function) at time points coinciding with postprandial [anticipated] peak plasma flavonoid concentration. [ Time Frame: acute postprandial; up to 24 hours, dependent on flavonoid sub-classification studied ] [ Designated as safety issue: No ]
    Assessment of vascular function


Secondary Outcome Measures:
  • Differences in effects of flavonoids introduced by food matrix [ Time Frame: acute postprandial; up to 24 hours dependent on flavonoid sub-classification studied ] [ Designated as safety issue: No ]

Enrollment: 64
Study Start Date: February 2012
Study Completion Date: December 2013
Primary Completion Date: December 2013 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Intervention group A: flavanones
All experimental days will be exactly the same. All volunteers will attend the clinical research and trial unit in a fasted state. Prior to test administration, baseline vascular function will be assessed and biological samples taken by a trained and qualified research nurse. Subsequently, assessments will be repeated at times corresponding to anticipated peak plasma concentration of the flavonoid of interest.
Dietary Supplement: Flavanone - supplement
acute single optimal dose
Other: Flavanone - food
acute single dose
Other: Flavanone - placebo
acute single dose (flavanone free)
Experimental: Intervention group B: isoflavones
All experimental days will be exactly the same. All volunteers will attend the clinical research and trial unit in a fasted state. Prior to test administration, baseline vascular function will be assessed and biological samples taken by a trained and qualified research nurse. Subsequently, assessments will be repeated at times corresponding to anticipated peak plasma concentration of the flavonoid of interest.
Dietary Supplement: Isoflavone - supplement
acute single optimal dose
Other: Isoflavone - food
acute single optimal dose
Other: Isoflavone - placebo
acute single dose (isoflavone free)
Dietary Supplement: Isoflavone - metabolite supplement
acute single optimal dose of commercial product
Experimental: Intervention group C: Flavan-3-ols
All experimental days will be exactly the same. All volunteers will attend the clinical research and trial unit in a fasted state. Prior to test administration, baseline vascular function will be assessed and biological samples taken by a trained and qualified research nurse. Subsequently, assessments will be repeated at times corresponding to anticipated peak plasma concentration of the flavonoid of interest.
Dietary Supplement: Flavan-3-ol - supplement
acute single optimal dose
Other: Flavan-3-ol - food
acute single optimal dose
Other: Flavan-3-ol - placebo
acute single dose (flavan-3-ol free)
Experimental: Intervention group D: Anthocyanins
All experimental days will be exactly the same. All volunteers will attend the clinical research and trial unit in a fasted state. Prior to test administration, baseline vascular function will be assessed and biological samples taken by a trained and qualified research nurse. Subsequently, assessments will be repeated at times corresponding to anticipated peak plasma concentration of the flavonoid of interest.
Dietary Supplement: Anthocyanin - supplement
acute single optimal dose
Other: Anthocyanin - food
acute single optimal dose
Other: Anthocyanin - placebo
acute single dose (anthocyanin free)

Detailed Description:

The study population will be healthy males (aged 50-75 years) at elevated risk of cardiovascular (CV) disease.

A target of 60 participants will be required to complete the study and a total of 70 subjects will be targeted (n=70 subjects * ~85% anticipated completion rate = 60 subjects to complete the study).

This placebo-controlled study will test the relative efficacy of 4 different flavonoid sub-classes ((i) flavan-3-ol, (ii) anthocyanin, (iii) flavanone and (iv) isoflavone).

Accordingly, subjects will be randomised to one of the four flavonoid study groups ((i) to (iv) outlined above), and then will consume each of the following treatments in random order:

  1. dietary flavonoid + placebo supplement
  2. placebo food + commercially available/produced flavonoid supplement
  3. placebo food + placebo supplement

Additionally, an isoflavone metabolite will be fed to establish potential vascular effects.

Each sub-class will be assessed separately and a 1 week wash-out period between treatments will be observed.

At each assessment visit, vascular function will be assessed pre- and post-intervention, with subsequent assessments made to coincide with anticipated peak plasma concentrations.

Dietary intake will be monitored during the study and participants will be required to adhere to a range of dietary and lifestyle restrictions within 3 days of each assessment to reduce potential confounding of the data assessment of interest.

A standard battery of vascular function tests will be performed on all intervention groups, with each assessment visit performed in an identical manner.

  Eligibility

Ages Eligible for Study:   50 Years to 75 Years
Genders Eligible for Study:   Male
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

  • Males
  • 50 to 75 years old
  • At elevated risk of CV disease
  • Screening blood pressure of < 160/90mmHg (at rest)
  • Successful biochemical, haematological and urinalysis assessment at screening (as judged by clinical advisor)

Exclusion Criteria:

  • Current smokers, or ex-smokers ceasing < 3 months ago
  • Subjects with existing or significant past medical history of vascular disease or medical conditions likely to affect the study measures (as judged by clinical advisor)
  • Those with known allergies to the intervention treatments
  • Those unprepared to adhere to dietary restrictions during the trial
  • Parallel participation in another research project which involves concurrent dietary intervention and/or sampling of biological fluids/material
  • Having vaccinations (excluding the flu vaccination) or antibiotics within 3 months of start of trial, and those with vaccinations scheduled for during the trial
  • Taking flavonoid containing food / dietary supplements likely to affect the study results
  • Prescribed lipid lowering, hypertension, vasodilators (e.g. Viagra) or antibiotic medication
  • Unsatisfactory biochemical, haematological or urinary assessment at screening, indicating abnormal; renal or liver function, full blood profile, impaired glucose handling, deranged lipids or measurements considered to be counter indicative of the study by the clinical advisor
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its ClinicalTrials.gov identifier: NCT01530893

Locations
United Kingdom
Department of Nutrition, Norwich Medical School
Norwich, Norfolk, United Kingdom, NR4 7TJ
Sponsors and Collaborators
University of East Anglia
Investigators
Principal Investigator: Aedin Cassidy, PhD University of East Anglia
  More Information

No publications provided

Responsible Party: University of East Anglia
ClinicalTrials.gov Identifier: NCT01530893     History of Changes
Other Study ID Numbers: FASTCHECK
Study First Received: February 1, 2012
Last Updated: February 27, 2014
Health Authority: United Kingdom: Research Ethics Committee

Keywords provided by University of East Anglia:
flavonoids
vascular function
randomised controlled trial
placebo controlled

Additional relevant MeSH terms:
Cardiovascular Diseases

ClinicalTrials.gov processed this record on September 18, 2014