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

NCT01399138 | Withdrawn

• 1 other identifier: PBRC 10014
• Study Type: interventional
• Target: N/A
• Locations: 1 country
• Sites: 1

Brief Summary

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.

Conditions

Metabolic Syndrome

Keywords

Pre-diabetes; Metabolic syndrome; Diabetes; Hypertension; Blueberries; Anthocyanins; Insulin sensitivity; Insulin resistance

Outcome Measures

Primary Outcomes (1)

• Change from Baseline in Systolic and Diastolic Blood Pressure at 6 weeks

  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.

  Baseline and Week 6 (The study has 6 weeks)

Secondary Outcomes (2)

• Change from Baseline in Response of Blood Vessels to a Stimulus at 5 weeks

  About 1 hour (Baseline and at Week 5)

• Change from Baseline in insulin sensitivity at 6 weeks

  About 5 hours(Baseline and Week 6)

Study Arms (2)

Blueberry Powder

EXPERIMENTAL

A blueberry smoothie will be consumed at the breakfast and dinner meals.

Dietary Supplement: Blueberry Powder

Placebo

PLACEBO COMPARATOR

A placebo smoothie will be consumed at the breakfast and dinner meals.

Dietary Supplement: Blueberry Powder

Interventions

Blueberry Powder DIETARY_SUPPLEMENT

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

Blueberry Powder; Placebo

Eligibility Criteria

• Age: 20 Years+
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• 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.

You may not qualify if:

• 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.

Sponsors & Collaborators

• Pennington Biomedical Research Center: lead
• U.S. Highbush Blueberry Council: collaborator
• United States Department of Agriculture (USDA): collaborator

Study Sites (1)

Pennington Biomedical Research Center

Baton Rouge, Louisiana, 70816, United States

Location

MeSH Terms

Conditions

Metabolic Syndrome; Glucose Intolerance; Diabetes Mellitus; Hypertension; Insulin Resistance

Condition Hierarchy (Ancestors)

Hyperinsulinism; Glucose Metabolism Disorders; Metabolic Diseases; Nutritional and Metabolic Diseases; Hyperglycemia; Endocrine System Diseases; Vascular Diseases; Cardiovascular Diseases

Study Officials

• William T Cefalu, MD

  Pennington Biomedical Research Center

  PRINCIPAL INVESTIGATOR

• April J Stull, Ph.D.

  Pennington Biomedical Researcher

  STUDY DIRECTOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: QUADRUPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
• Purpose: PREVENTION
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Study Record Dates

• First Submitted: June 1, 2011
• First Posted: July 21, 2011
• Study Start: July 1, 2010
• Primary Completion: July 1, 2012
• Study Completion: April 1, 2014
• Last Updated: June 12, 2023

Record last verified: 2023-06

Locations

US (1)