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

Sponsor

Colorado State University (Other)

Overall Status

Recruiting

CT.gov ID

NCT04530916

Collaborator

Wild Blueberry Association of North America (Other)

Enrollment

Location

Arms

Anticipated Duration (Months)

1.2

Patients Per Site Per Month

Study Details

Study Description

Brief 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.

Condition or Disease	Intervention/Treatment	Phase
Hypertension Aging Endothelial Dysfunction Men	Dietary Supplement: Blueberry Powder Dietary Supplement: Placebo Powder	Phase 1/Phase 2

Study Design

Study Type:

Interventional

Anticipated Enrollment :

58 participants

Allocation:

Randomized

Intervention Model:

Parallel Assignment

Masking:

Triple (Participant, Investigator, Outcomes Assessor)

Primary Purpose:

Basic Science

Official Title:

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

Actual Study Start Date :

Jan 1, 2020

Anticipated Primary Completion Date :

Jun 1, 2023

Anticipated Study Completion Date :

Dec 31, 2023

Arms and Interventions

Arm	Intervention/Treatment
Experimental: Blueberry 22 g blueberry powder per day	Dietary Supplement: Blueberry Powder 22 g/day wild blueberry powder
Placebo Comparator: Control 22 g placebo control powder per day	Dietary Supplement: Placebo Powder 22 g/day placebo powder

Arm

Intervention/Treatment

Experimental: Blueberry

22 g blueberry powder per day

Dietary Supplement: Blueberry Powder

22 g/day wild blueberry powder

Placebo Comparator: Control

22 g placebo control powder per day

Dietary Supplement: Placebo Powder

22 g/day placebo powder

Outcome Measures

Primary Outcome Measures

Reactive hyperemia index [Baseline to 12 Weeks]
Endothelial function assessed as reactive hyperemia index using peripheral arterial tonometry (EndoPat)

Secondary Outcome Measures

Augmentation index [Baseline to 12 Weeks]
Arterial stiffness assessed as augmentation index using an automated blood pressure monitor (SphygmoCor)
Pulse wave velocity [Baseline to 12 Weeks]
Arterial stiffness assessed as carotid-femoral pulse wave velocity using an automated blood pressure monitor (SphygmoCor)
Endothelial cell protein expression [Baseline to 12 Weeks]
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
Hemoglobin A1c [Baseline to 12 Weeks]
Blood hemoglobin A1C will be measured
Lipid profile [Baseline to 12 Weeks]
Blood lipid profiles will be measured
Nitric oxide metabolites [Baseline to 12 Weeks]
Blood nitrate/nitrite will be measured
ICAM-1 [Baseline to 12 Weeks]
Blood ICAM-1 will be measured
VCAM-1 [Baseline to 12 Weeks]
Blood VCAM-1 will be measured
Blood pressure [Baseline to 12 Weeks]
Brachial and Aortic blood pressure (systolic blood pressure, diastolic blood pressure, pulse pressure, aortic pressure) assessed using an automated blood pressure monitor (SphygmoCor)
Gut microbiota [Baseline to 12 Weeks]
Determine the effects on stool sample microbial populations
Plasma blueberry polyphenol metabolites [Baseline to 12 Weeks]
Targeted analysis of plasma metabolites by GC-MS and LC-MS

Eligibility Criteria

Criteria

Ages Eligible for Study:

45 Years to 70 Years

Sexes Eligible for Study:

Male

Accepts Healthy Volunteers:

Yes

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