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Blueberry Consumption Improves Vascular Function and Lowers Blood Pressure in Postmenopausal Women With Pre- and Stage 1-hypertension

This study has been completed.
Sponsor:
ClinicalTrials.gov Identifier:
NCT01686282
First Posted: September 18, 2012
Last Update Posted: January 14, 2015
The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
Collaborator:
U.S. Highbush Blueberry Council
Information provided by (Responsible Party):
Bahram Arjmandi, Florida State University
  Purpose

Cardiovascular disease (CVD) continues to be the leading cause of death in the U.S. Americans have been more concerned about their blood cholesterol levels and dietary cholesterol intakes rather than their overall cardiovascular health risk factors leading to CVD such as hypertension, vascular dysfunction, inadequate consumption of fruits and vegetables and physical activity. Statistics show that approximately 91% of individuals with CVD have vascular dysfunction which is attributed to endothelial and autonomic dysfunction leading to increased arterial stiffness.

The investigators long-term goal is to provide feasible and effective dietary ways for pre- and stage 1- hypertensive individuals to normalize their blood pressure (BP), improve vascular function and thereby reducing their cardiovascular risk and enhancing the quality of life. Blueberries are a rich source of phenolic compounds and these compounds may play an important role in promoting cardiovascular health. Considering the strong possibility that phytochemicals present in blueberry work additively or synergistically, it would be ideal to investigate the cardioprotective effects of blueberry as a whole. The investigators overall objective to bring forth evidence that blueberry consumption will reduce BP and cardiovascular risk factors including endothelial dysfunction, arterial stiffness, and autonomic dysfunction in pre- and stage 1-hypertensive postmenopausal women. The investigators hypothesize that blueberry supplementation will improve vascular function and will lower blood pressure in postmenopausal women with pre-hypertension. The findings of this study will provide a foundation for disseminating feasible, safe approaches for preventing and combating hypertension at its early stage which does not require drug therapy.


Condition Intervention Phase
Blood Pressure Dietary Supplement: Freeze-dried Blueberry Powder Dietary Supplement: Placebo Phase 2

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Double (Participant, Investigator)
Primary Purpose: Treatment
Official Title: Daily Incorporation of Blueberries Into a Diet Favorably Improves Vascular Function and Lowers Aortic Blood Pressure in Postmenopausal Women With Pre- and Stage 1-hypertension.

Resource links provided by NLM:


Further study details as provided by Bahram Arjmandi, Florida State University:

Primary Outcome Measures:
  • Blood Pressure [ Time Frame: 8 weeks ]
    By measuring aortic blood pressure at rest and during physiological stress (handgrip exercise and post-exercise muscle ischemia).


Secondary Outcome Measures:
  • Autonomic Control of Blood Pressure [ Time Frame: 8 weeks ]
    By measuring blood pressure variability and baroreflex sensitivity at rest and during physiological stress.

  • Autonomic Control of Heart Rate [ Time Frame: 8 weeks ]
    By measuring heart rate variability at rest and during physiological stress.

  • Endothelial Function [ Time Frame: 8 week ]
    By measuring markers of vascular inflammation (adiponectin, leptin, endothelin-1, angiotensin II and 8-isoprostane).

  • Inflammation [ Time Frame: 8 weeks ]
    By measuring a marker of inflammation (tumor necrosis factor-α [TNF-α]).

  • Oxidative Stress [ Time Frame: 8 weeks ]
    By measuring markers of oxidative stress (superoxide dismutase [SOD], nitrate/nitrite [NOx], ET-1, angiotensin II, 8-isoprostane, MDA, and oxidized LDL).

  • Arterial Stiffness [ Time Frame: 8 Week ]
    By measuring the augmentation index and arterial stiffness at rest and during physiological stress (handgrip exercise and post-exercise muscle ischemia).


Enrollment: 48
Study Start Date: January 2012
Study Completion Date: January 2014
Primary Completion Date: March 2013 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Placebo Comparator: Placebo
8 weeks of freeze-dried blueberry powder taken in two doses of 22g each per day.
Dietary Supplement: Placebo
8 weeks of freeze-dried taken in two doses of 22g each per day.
Experimental: Blueberry
8 weeks of freeze-dried blueberry powder taken in two doses of 22g each per day.
Dietary Supplement: Freeze-dried Blueberry Powder
8 weeks of freeze-dried taken in two doses of 22g each per day.
Other Name: U.S. Highbush Blueberry Council

Detailed Description:

The purpose of this study is to examine the effects of 22 grams of freeze-dried blueberry intake on a daily basis for eight weeks in:

The purpose of the study is to examine the effects of 22 grams of freeze-dried blueberry intake on a daily basis for eight weeks on arterial function and blood pressure in postmenopausal women with pre- and stage 1-hypertension. The specific aims of the study are:

  1. To investigate the extent to which daily consumption of 22 g blueberry drink-mix reduces blood pressure in individuals with pre- and stage 1-hypertension.
  2. To determine whether daily consumption of 22 g blueberry drink-mix will improve the autonomic control of blood pressure and heart rate in individuals with pre- and stage 1-hypertension.
  3. To measure serum markers of oxidative stress to determine whether increased antioxidant defense is in part responsible for blueberry's vascular protective effects.
  Eligibility

Information from the National Library of Medicine

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Ages Eligible for Study:   45 Years to 65 Years   (Adult)
Sexes Eligible for Study:   Female
Accepts Healthy Volunteers:   No
Criteria

Inclusion Criteria:

  • 40 women (1 to 10 years after natural menopause or bilateral oophorectomy) 45-65 years of age.
  • Seated blood pressure ≥ 130/85 mm Hg but ≤ 160/90 mm Hg.

Exclusion Criteria:

  • Blood pressure >160/100 mmHg
  • Taking insulin
  • Cardiovascular disease
  • Active cancer
  • Asthma
  • Glaucoma
  • Thyroid disease
  • Kidney disease
  • Liver disease
  • Pancreatic disease
  • Enrollment in a weight loss program
  • Heavy smokers (>20 cigarettes per day)
  Contacts and Locations
Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT01686282


Locations
United States, Florida
The Department of Nutrition, Food, and Exercise Sciences, Florida State University
Tallahassee, Florida, United States, 32306
Sponsors and Collaborators
Florida State University
U.S. Highbush Blueberry Council
Investigators
Principal Investigator: Bahram H Arjmandi, PhD, RD Florida State University
Principal Investigator: Arturo Figueroa, MD, PhD Florida State University
Principal Investigator: Sarah A Johnson, PhD, RD, CSO Florida State University
  More Information

Publications automatically indexed to this study by ClinicalTrials.gov Identifier (NCT Number):
Responsible Party: Bahram Arjmandi, Margaret A. Sitton Professor and Director of the Center for Advancing Exercise and Nutrition Research on Aging, Florida State University
ClinicalTrials.gov Identifier: NCT01686282     History of Changes
Other Study ID Numbers: 021259
First Submitted: September 11, 2012
First Posted: September 18, 2012
Last Update Posted: January 14, 2015
Last Verified: January 2015

Keywords provided by Bahram Arjmandi, Florida State University:
Blood pressure
Arterial Stiffness
Blueberry Supplementation
Aortic Blood Pressure
Hypertension
Postmenopausal
Pulse Wave Velocity

Additional relevant MeSH terms:
Hypertension
Vascular Diseases
Cardiovascular Diseases