The Effect of Blueberry Powder Supplementation on Cardiovascular Risk Factors in Subjects With the Metabolic Syndrome

This study is ongoing, but not recruiting participants.
Sponsor:
Collaborators:
United States Highbush Blueberry Council
USDA Beltsville Human Nutrition Research Center
Information provided by (Responsible Party):
William Cefalu, MD, Pennington Biomedical Research Center
ClinicalTrials.gov Identifier:
NCT01399138
First received: June 1, 2011
Last updated: December 4, 2013
Last verified: December 2013
  Purpose

The purpose of this study is to examine the effects of a blueberry powder on insulin sensitivity, blood pressure, and vascular reactivity in subjects with metabolic syndrome.


Condition Intervention
Metabolic Syndrome
Dietary Supplement: Blueberry Powder

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: Prevention

Resource links provided by NLM:


Further study details as provided by Pennington Biomedical Research Center:

Primary Outcome Measures:
  • Change from Baseline in Systolic and Diastolic Blood Pressure at 6 weeks [ Time Frame: Baseline and Week 6 (The study has 6 weeks) ] [ Designated as safety issue: No ]
    This procedure records your blood pressure and heart rate. You will wear a device the size of a small camera connected to a blood pressure cuff on your arm for a period of seven days. The cuff of this device inflates automatically every 30 minutes during the day and every 60 minutes during the night. Upon inflation, the device will make a quiet noise and will cause pressure on your arm. At the end of the seven days, you will return to the clinic or Inpatient Unit at Pennington to have the monitor removed. Depending upon the amount of data collected, you may be asked to wear the monitor for additional days.


Secondary Outcome Measures:
  • Change from Baseline in Response of Blood Vessels to a Stimulus at 5 weeks [ Time Frame: About 1 hour (Baseline and at Week 5) ] [ Designated as safety issue: No ]
    This procedure is performed to determine the response of your blood vessels to a stimulus. You will lie on your back on a bed and have a blood pressure cuff placed on your non-dominant arm (the arm you do not write with). Probes will be attached to the index finger on both of your hands, and these probes will be slightly inflated to be held in place. The blood pressure cuff will be inflated for five minutes. It will then be deflated rapidly. Data will be recorded continuously throughout the test. The entire procedure will take approximately 1 hour.

  • Change from Baseline in insulin sensitivity at 6 weeks [ Time Frame: About 5 hours(Baseline and Week 6) ] [ Designated as safety issue: No ]
    This test measures how well your body produces insulin in response to a sugar challenge. Insulin is normally produced in your body during meals and helps your body use sugar. There will be 2 IV lines, one line inserted into a vein in each of your arms. After collecting a baseline sample of your blood we will inject a solution containing sugar into one of the IV lines. We will then monitor your blood sugar and insulin levels by drawing blood from the other IV for 20 minutes. After 20 minutes we will inject insulin into the IV line and we will continue to monitor your blood sugar and insulin levels for another 3 hours.


Estimated Enrollment: 50
Study Start Date: July 2010
Estimated Study Completion Date: April 2014
Primary Completion Date: July 2012 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: Blueberry Powder
A blueberry smoothie will be consumed at the breakfast and dinner meals.
Dietary Supplement: Blueberry Powder
The groups will be randomized to receive 45g of blueberry powder or control (i.e., placebo) per day. Blueberry powder will be given as a smoothie to be consumed at the breakfast and dinner meals and an identical smoothie will be given as a control. The second smoothie will be consumed at least 6 hours from the first smoothie. The smoothies will be prepared in the metabolic kitchen and a week supply of frozen smoothies will be given to participants. Both the blueberry powder and control smoothie contain comparable energy and macronutrients
Placebo Comparator: Placebo
A placebo smoothie will be consumed at the breakfast and dinner meals.
Dietary Supplement: Blueberry Powder
The groups will be randomized to receive 45g of blueberry powder or control (i.e., placebo) per day. Blueberry powder will be given as a smoothie to be consumed at the breakfast and dinner meals and an identical smoothie will be given as a control. The second smoothie will be consumed at least 6 hours from the first smoothie. The smoothies will be prepared in the metabolic kitchen and a week supply of frozen smoothies will be given to participants. Both the blueberry powder and control smoothie contain comparable energy and macronutrients

  Show Detailed Description

  Eligibility

Ages Eligible for Study:   20 Years and older
Genders Eligible for Study:   Both
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

Men and women with metabolic syndrome and meeting all criteria listed below will be included in the study:

  • Subjects ≥ 20 years of age.
  • Subjects not currently treated with diabetes medication; however, Metformin use for pre-diabetes is acceptable if the subject is willing to stop taking the medication 2 weeks prior to and during the study.
  • Subjects with impaired fasting glucose (100-125 mg/dL) or impaired glucose tolerance (140-199 mg/dL after 2-hr OGTT).
  • Subjects with fasting insulin ≥ 10 µIU/ml.
  • Subjects with a body mass index (BMI) ≥ 30 and ≤ 45.
  • Subjects with hypertension: no medication (140-179 mmHg systolic or 90-109 mmHg diastolic) or currently taking antihypertensive medication.
  • Written informed consent obtained PRIOR to performing any screening tests or study procedures.

Exclusion Criteria:

  • Subjects with a prior history of Type 2 diabetes
  • Women who are pregnant or who are lactating.
  • Women of childbearing potential who are not using an effective method of birth control (i.e.,barrier method, intrauterine and cervical devices, oral contraceptives, hormonal injections (Depro Provera® ), condoms with spermicidal gel or foam, contraceptive patch (Ortho Evra), diaphragm, or abstinence), are not surgically sterilized (including tubal ligation and hysterectomy), or not at least 2 years postmenopausal. All women of childbearing potential will have a pregnancy test performed at the screening. If a subject becomes pregnant during the study, they will be dropped from the study.
  • Subjects who have type 1 diabetes.
  • Subjects who are currently on thiazolidinediones (rosiglitazone or pioglitazone) or who have taken these agents in the previous 12 weeks.
  • Subjects who are on concomitant therapy with glucocorticoids (except topical or inhalant glucocorticoids). Other medications that have an effect on glucose homeostasis (i.e. ACE inhibitors) are acceptable if they have been administered in a stable dosage during the preceding 6 months and dosage will continue unchanged during the study.
  • Subjects with a history or evidence of significant gastrointestinal dysfunction, e.g. irritable bowel syndrome; inflammatory bowel disease; ulcerative colitis or Crohn's disease; regional enteritis; diverticulosis or diverticulitis; significant gastroparesis; GI stricture, partial or complete gastrectomy or small bowel resection; autonomic neuropathy consisting of dysphasia; delayed gastric emptying or diarrhea; chronic, severe constipation; peptic ulceration, colonic ulceration, or GI bleeding.
  • Subjects who have chronic use of laxatives or cathartics. The use of stool softeners is acceptable. Use of bulking agents, if required, should remain constant.
  • Subjects who are taking concomitant therapy with medications known to be nephrotoxic, such as aminoglycosides, methicillin, and cyclosporin.
  • Subjects who have evidence of clinically significant renal dysfunction or disease, e.g. serum creatinine >1.5 mg/dL in males and >1.4 mg/dL in females and/or BUN >50 mg/dL, proteinuria of >1 gram/day or 4+ proteinuria on dipstick urinalysis.
  • Subjects with clinically significant cardiovascular dysfunction and/or history (within the preceding 6 months) of significant cardiovascular dysfunction, e.g., congestive heart failure or serious arrhythmia, myocardial infarction, cardiac surgery; transient ischemic attacks or cerebrovascular accident during the preceding six months; diagnosis of symptomatic autonomic neuropathy with a history of orthostatic hypertension, syncope, or hypertension with a systolic blood pressure of ≥180 mm Hg or diastolic blood pressure ≥110 mm Hg at the time of screening visit.
  • Subjects who have evidence within the preceding 6 months of hepatic disease or dysfunction, e.g. AST, ALT, alkaline phosphatase or total bilirubin twice the upper limit of normal; hepatitis; jaundice; cirrhosis.
  • Subjects with clinically significant pulmonary, neurologic, hematologic, immunologic, neoplastic or metabolic disease.
  • Subjects with evidence or recurrence of malignancy within the past five years, other than excised basal cell carcinoma.
  • Subjects for whom surgery is anticipated during the study period.
  • Subjects with a history of substance abuse or alcoholism within the past 5 years, or significant psychiatric disorder that would interfere with the subject's ability to complete the study.
  • Subjects who have donated blood during the month prior to study entry or planned during the study.
  • Subjects who have participated in other studies using an investigational drug during the preceding 3 months.
  • Subjects who are current smokers or have smoked within the previous 6 months. No smoking will be allowed during the study.
  • Subjects who are allergic to blueberries.
  • Subjects who are allergic to red dye or blue dye food coloring.
  • Subjects who are lactose intolerant.
  • Subjects who consume and drink daily servings of berries (i.e., blueberries, strawberries, bilberries, cranberries, elderberries, and raspberries), grapes, fruit juices that contain berries and grapes, and wine more than 3 times per week.
  • Subjects that have had a fluctuation in body weight >5% in the preceding 2 months.
  • Subjects who are taking prescription or over the counter medication or supplements for desired weight loss.
  • Subjects that have peripheral vascular disease in the arms.
  • Subjects that have a history of blood clots.
  Contacts and Locations
Please refer to this study by its ClinicalTrials.gov identifier: NCT01399138

Locations
United States, Louisiana
Pennington Biomedical Research Center
Baton Rouge, Louisiana, United States, 70816
Sponsors and Collaborators
William Cefalu, MD
United States Highbush Blueberry Council
USDA Beltsville Human Nutrition Research Center
Investigators
Principal Investigator: William T Cefalu, MD Pennington Biomedical Research Center
Study Director: April J Stull, Ph.D. Pennington Biomedical Researcher
  More Information

No publications provided

Responsible Party: William Cefalu, MD, Principal Investigator, Pennington Biomedical Research Center
ClinicalTrials.gov Identifier: NCT01399138     History of Changes
Other Study ID Numbers: PBRC10014
Study First Received: June 1, 2011
Last Updated: December 4, 2013
Health Authority: United States: Institutional Review Board

Keywords provided by Pennington Biomedical Research Center:
Pre-diabetes
Metabolic syndrome
Diabetes
Hypertension
Blueberries
Anthocyanins
Insulin sensitivity
Insulin resistance

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

ClinicalTrials.gov processed this record on April 15, 2014