Wild Blueberries and Cardiovascular Health in Middle-aged/Older Men and Postmenopausal Women

Hypertension Clinical Trial

Official title:

Antihypertensive and Vascular-Protective Effects of Wild Blueberries in Middle-Aged/Older Men and Postmenopausal Women.

Clinical Trial Details — Status: Recruiting

Administrative data

• NCT number: NCT04530916
• Other study ID #: WB2020
• Status: Recruiting
• Phase: Phase 1/Phase 2
• Start date: January 1, 2020
• Est. completion date: December 31, 2024

Study information

• Verified date: August 2023
• Source: Colorado State University
• Contact: Sarah A Johnson, PhD, RDN
• Phone: 970-491-3807
• Email: sarah.johnson[@]colostate.edu
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

Cardiovascular disease (CVD) is the leading cause of morbidity and mortality worldwide. Aging is the primary risk factor for CVD, in large part due to adverse modifications to the arteries. These modifications include vascular endothelial dysfunction and arterial stiffness. Vascular endothelial dysfunction is an initiating step in atherosclerosis, and is primarily caused by reduced nitric oxide (NO) bioavailability secondary to excessive superoxide-driven oxidative stress and inflammation. Endothelial dysfunction leads to arterial stiffness and the development of hypertension (HTN) which further increases CVD. Greater than 2/3 of the US population has elevated blood pressure or stage 1-HTN. As such, interventions that improve vascular endothelial dysfunction by increasing NO bioavailability and mitigating excessive oxidative stress and inflammation are needed. Blueberries are rich in bioactive compounds including flavonoids, phenolic acids, and pterostilbene. These compounds and their metabolites have been shown to attenuate oxidative stress and inflammation. The primary goal of this study is to assess the efficacy of blueberries to improve reduce blood pressure and improve vascular endothelial dysfunction and arterial stiffness in middle-aged/older men with elevated blood pressure or stage 1-HTN.

Recruitment information / eligibility

• Status: Recruiting
• Enrollment: 58
• Est. completion date: December 31, 2024
• Est. primary completion date: March 31, 2024
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: Male
• Age group: 45 Years to 70 Years

Eligibility

Inclusion Criteria:

• Men and postmenopausal women

• Aged 45-70 years

• Elevated blood pressure or stage 1-Hypertension

• Ability to provide informed consent

Exclusion Criteria:

• Have had a menstrual cycle within the past year

• Blood Pressure < 120 (systolic BP) or = 140/90 mm Hg

• Reactive hyperemia index > 3.00%

• Taking > 1 antihypertensive medication, taking 1 antihypertensive medication more than 1 time per day, and/or taking the antihypertensive medication for < 3 months

• Diagnosed cancer, cardiovascular disease, diabetes, or gastrointestinal, kidney, liver, lung, and/or pancreatic disease

• Triglycerides > 350 mg/dL, low-density lipoprotein cholesterol (LDL-C) = 190 mg/dL, hemoglobin A1c = 6.5%, and/or taking a lipid-lowering or glucose-lowering medication

• Testosterone or estrogen replacement therapy use 6 months prior to study start

• Weight change = 3 kg in the past 3 months, actively trying to lose weight, or unwilling to remain weight stable throughout the study

• Current smokers or history of smoking in the past 12 months

• Binge and/or heavy drinker (>3 drinks on any given occasion and/or >7 drinks/week for women, and >4 drinks on any given occasion and/or >14 drinks/week for men)

• Body mass index < 18.5 or > 40 kg/m2

• Antibiotic therapy within past two months

• Allergies or contraindication to study treatments or procedures

Related Conditions & MeSH terms

• Aging
• Endothelial Dysfunction
• Hypertension
• Men

Intervention

Dietary Supplement:
• Blueberry Powder
22 g/day wild blueberry powder
• Placebo Powder
22 g/day placebo powder

Locations

Country	Name	City	State
United States	Food and Nutrition Clinical Research Laboratory	Fort Collins	Colorado

Sponsors (2)

Lead Sponsor	Collaborator
Colorado State University	Wild Blueberry Association of North America

Country where clinical trial is conducted

United States, 

References & Publications (1)

Johnson SA, Figueroa A, Navaei N, Wong A, Kalfon R, Ormsbee LT, Feresin RG, Elam ML, Hooshmand S, Payton ME, Arjmandi BH. Daily blueberry consumption improves blood pressure and arterial stiffness in postmenopausal women with pre- and stage 1-hypertension: a randomized, double-blind, placebo-controlled clinical trial. J Acad Nutr Diet. 2015 Mar;115(3):369-377. doi: 10.1016/j.jand.2014.11.001. Epub 2015 Jan 8. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Reactive hyperemia index	Endothelial function assessed as reactive hyperemia index using peripheral arterial tonometry (EndoPat)	Baseline to 12 Weeks
Secondary	Augmentation index	Arterial stiffness assessed as augmentation index using an automated blood pressure monitor (SphygmoCor)	Baseline to 12 Weeks
Secondary	Pulse wave velocity	Arterial stiffness assessed as carotid-femoral pulse wave velocity using an automated blood pressure monitor (SphygmoCor)	Baseline to 12 Weeks
Secondary	Endothelial cell protein expression	Protein expression will be assessed as an exploratory analysis for markers of nitric oxide bioavailability, inflammation, and/or oxidative stress will be measured by quantitative immunofluorescence in biopsied venous endothelial cells	Baseline to 12 Weeks
Secondary	Hemoglobin A1c	Blood hemoglobin A1C will be measured	Baseline to 12 Weeks
Secondary	Lipid profile	Blood lipid profiles will be measured	Baseline to 12 Weeks
Secondary	Nitric oxide metabolites	Blood nitrate/nitrite will be measured	Baseline to 12 Weeks
Secondary	ICAM-1	Blood ICAM-1 will be measured	Baseline to 12 Weeks
Secondary	VCAM-1	Blood VCAM-1 will be measured	Baseline to 12 Weeks
Secondary	Blood pressure	Brachial and Aortic blood pressure (systolic blood pressure, diastolic blood pressure, pulse pressure, aortic pressure) assessed using an automated blood pressure monitor (SphygmoCor)	Baseline to 12 Weeks
Secondary	Gut microbiota	Determine the effects on stool sample microbial populations	Baseline to 12 Weeks
Secondary	Plasma blueberry polyphenol metabolites	Targeted analysis of plasma metabolites by GC-MS and LC-MS	Baseline to 12 Weeks