The Health Effects of Blueberry Anthocyanins in Metabolic Syndrome (the CIRCLES-study)

This study is currently recruiting participants. (see Contacts and Locations)
Verified January 2014 by University of East Anglia
Sponsor:
Collaborator:
Harvard School of Public Health
Information provided by (Responsible Party):
University of East Anglia
ClinicalTrials.gov Identifier:
NCT02035592
First received: January 10, 2014
Last updated: NA
Last verified: January 2014
History: No changes posted
  Purpose

The purpose of this study is to determine the dose-dependent impact of 6 month freeze-dried blueberry powder intake on insulin sensitivity and resistance, cardiovascular disease risk factors, and lung and cognitive function in overweight and obese participants with metabolic syndrome. We will also examine acute post-prandial effects of blueberry intake (at baseline and at 6-months).


Condition Intervention
Insulin Resistance
Metabolic Syndrome X
Other: Full dose blueberry
Other: Half dose blueberry
Other: Control

Study Type: Interventional
Study Design: Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Masking: Double Blind (Subject, Caregiver, Investigator, Outcomes Assessor)
Primary Purpose: Basic Science
Official Title: The Effects of Blueberry Anthocyanins on Insulin Resistance and Vascular, Lung and Cognitive Function in a Population With Metabolic Syndrome.

Resource links provided by NLM:


Further study details as provided by University of East Anglia:

Primary Outcome Measures:
  • Insulin resistance [ Time Frame: Chronic (0 to 6 month) ] [ Designated as safety issue: No ]
    Assessed, in the fasted state, via HOMA-IR calculation in all participants; indirect assessment.


Secondary Outcome Measures:
  • Insulin resistance [ Time Frame: Chronic (0 to 6 month) ] [ Designated as safety issue: No ]
    Assessed in a sub-group via hyperinsulinemic euglycaemic clamp.

  • Blood pressure and blood vessel regulation [ Time Frame: Chronic (0 to 6 month) ] [ Designated as safety issue: No ]
    Measurements taken of arterial stiffness, endothelial function and blood pressure.

  • Lung function [ Time Frame: Chronic (0 to 6 month) ] [ Designated as safety issue: No ]
    Assessed via standard spirometry techniques and biological assessment of exhaled samples.

  • Cognitive function [ Time Frame: Chronic (0 to 6 month) ] [ Designated as safety issue: No ]
    Assessed via a validated cognitive test battery.

  • Liver fat and blood flow assessment [ Time Frame: Chronic (0 to 6 month) ] [ Designated as safety issue: No ]
    Assessment via 3T MRI in a sub-group of participants.

  • Bio-availability [ Time Frame: Chronic (0 to 6 month) ] [ Designated as safety issue: No ]
    Flavonoid and metabolite levels will be assessed in blood and 24 hour urine samples.

  • Metabolite phenotype effects [ Time Frame: Chronic (0 to 6 month) ] [ Designated as safety issue: No ]
    The gut microbiome will be assessed from faecal sample collection and the impact on metabolism and of genotype, will be assessed via a targeted approach.

  • Acute +24 hour effect of single (26g) intervention intake, given with high fat challenge [ Time Frame: Chronic (0 to 6 month) ] [ Designated as safety issue: No ]
    Insulin resistance, lipaemia, vascular, cognitive and lung function measured pre- and post-intervention in combination with a high fat challenge in a sub-group of participants. Urine samples and blood samples (over a 24 hour period) will be taken for biomarker analysis.


Estimated Enrollment: 144
Study Start Date: January 2014
Estimated Study Completion Date: August 2016
Estimated Primary Completion Date: August 2016 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Active Comparator: Full dose blueberry

26g of freeze dried blueberry powder; equivalent to 2 portions of fresh blueberries per day.

Frequency: 26g per day.

Total duration: 6-month.

Other: Full dose blueberry

Full dose: 26g of freeze dried blueberry powder to be incorporated into the habitual diet.

Dietary restrictions will be observed (i.e. avoidance of blueberry, and restricted intake of anthocyanin rich foods) for 21 days prior to the first assessment visit and throughout the study.

Active Comparator: Half dose blueberry

26g of freeze dried powder; containing 13g of freeze dried blueberry powder and 13g of placebo comparator material; equivalent to 1 portion of fresh blueberries per day.

Frequency: 26g per day.

Total duration: 6-month.

Other: Half dose blueberry

Half dose: 26g of freeze dried powder (containing 13g of freeze dried blueberry powder and 13g of placebo comparator material) to be incorporated into the habitual diet.

Dietary restrictions will be observed (i.e. avoidance of blueberry, and restricted intake of anthocyanin rich foods) for 21 days prior to the first assessment visit and throughout the study.

Placebo Comparator: Control

Matched control powder; matched for appearance, taste and sugar content.

Frequency: 26g per day.

Total duration: 6-month.

Other: Control

Control: 26g of placebo comparator material to be incorporated into the habitual diet.

Dietary restrictions will be observed (i.e. avoidance of blueberry, and restricted intake of anthocyanin rich foods) for 21 days prior to the first assessment visit and throughout the study.


  Eligibility

Ages Eligible for Study:   50 Years to 74 Years
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

  • Men and postmenopausal women (≥ 1 year since last menstruation)
  • 50 to 75 years old
  • BMI of ≥ 25 kg/m2 to ≤ 40 kg/m2
  • 3 characteristics of metabolic syndrome i.e: Waist circumference ≥ 102 cm for men, ≥ 88 cm for women; Triglycerides ≥ 1.7 mmol/L (or drug treatment for elevated triglycerides); HDL-cholesterol < 1.0 mmol/L for men, < 1.3 mmol/L for women (or drug treatment for low HDL-cholesterol); Blood pressure ≥ 130 mm Hg systolic and/or ≥ 85 mm Hg diastolic blood pressure; Fasting blood glucose ≥ 5.56 mmol/L
  • Successful biochemical, haematological and urinalysis assessment at screening

Exclusion Criteria:

  • Current smokers, or ex-smokers ceasing < 6 months ago
  • Existing or significant past medical history of vascular disease or medical conditions likely to affect the study measures
  • Fructose intolerance or known allergies to the intervention treatments
  • On therapeutic diets or having experienced substantial weight loss within 3 months of screening
  • Taking flavonoid containing supplements (and unwilling to cease intake during, and 1 month preceding the trial)
  • Planning on altering consumption of vitamin supplements / fish oil capsules during the course of the study.
  • Prescribed anti-hypertension, hypoglycaemic, vasodilators or HRT medication.
  • Unsatisfactory biochemical, haematological or urinary assessment at screening, or measures considered to be counter indicative for the study
  • < 3 characteristics of the metabolic syndrome.
  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: NCT02035592

Contacts
Contact: Peter J Curtis, PhD +441603591873 P.Curtis@uea.ac.uk
Contact: Lindsey M Berends, PhD +441603597162 L.Berends@uea.ac.uk

Locations
United States, Massachusetts
Harvard School of Public Health Active, not recruiting
Boston, Massachusetts, United States, 02115
United Kingdom
Addenbrooke's hospital Active, not recruiting
Cambridge, Cambridgeshire, United Kingdom, CB2 0QQ
Norwich Medical School University of East Anglia Recruiting
Norwich, Norfolk, United Kingdom, NR4 7TJ
Contact: Peter J Curtis, PhD    +441603591873    P.Curtis@uea.ac.uk   
Contact: Lindsey M Berends, PhD    +44 (0)1603 597162    L.Berends@uea.ac.uk   
Principal Investigator: Aedin Cassidy, PhD         
Sub-Investigator: John F Potter, MD         
Sub-Investigator: Anne-Marie Minihane, PhD         
Sub-Investigator: Colin Kay, PhD         
Sub-Investigator: Andrew Wilson, MD         
Sub-Investigator: Peter J Curtis, PhD         
Sub-Investigator: Luisa M Ostertag, PhD         
Sub-Investigator: Lindsey M Berends, PhD         
Sub-Investigator: Glyn Johnson, PhD         
Norfolk and Norwich University Hospital Active, not recruiting
Norwich, Norfolk, United Kingdom, NR4 7UY
Sponsors and Collaborators
University of East Anglia
Harvard School of Public Health
Investigators
Principal Investigator: Aedin Cassidy, PhD University of East Anglia
  More Information

No publications provided

Responsible Party: University of East Anglia
ClinicalTrials.gov Identifier: NCT02035592     History of Changes
Other Study ID Numbers: R21478-C
Study First Received: January 10, 2014
Last Updated: January 10, 2014
Health Authority: United Kingdom: Research Ethics Committee

Additional relevant MeSH terms:
Insulin Resistance
Metabolic Syndrome X
Hyperinsulinism
Glucose Metabolism Disorders
Metabolic Diseases

ClinicalTrials.gov processed this record on August 21, 2014