Clinical trial NCT04530916: Wild Blueberries and Cardiovascular Health in Middle-aged/Older Men and Postmenopausal Women
Official title: Antihypertensive and Vascular-Protective Effects of Wild Blueberries in Middle-Aged/Older Men and Postmenopausal Women.
Study type: INTERVENTIONAL
Overall status: RECRUITING
Phase: PHASE1
PHASE2
Conditions: Hypertension
Aging
Endothelial Dysfunction
Men
Keywords: Cardiovascular Disease
Blueberries
Hypertension
Vascular Dysfunction
Atherosclerosis
Aging
Lead sponsor: Colorado State University
Sponsor class: OTHER
Collaborators: name: Wild Blueberry Association of North America
First posted: 2020-08-28
Enrollment: 58
Sex: MALE
Minimum age (years): 45
Maximum age (years): 70
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: BASIC_SCIENCE

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.


Eligibility criteria: 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

Primary outcomes:
measure: Reactive hyperemia index
timeFrame: Baseline to 12 Weeks
Secondary outcomes:
measure: Augmentation index
timeFrame: Baseline to 12 Weeks
measure: Pulse wave velocity
timeFrame: Baseline to 12 Weeks
measure: Endothelial cell protein expression
timeFrame: Baseline to 12 Weeks
measure: Hemoglobin A1c
timeFrame: Baseline to 12 Weeks
measure: Lipid profile
timeFrame: Baseline to 12 Weeks
measure: Nitric oxide metabolites
timeFrame: Baseline to 12 Weeks
measure: ICAM-1
timeFrame: Baseline to 12 Weeks
measure: VCAM-1
timeFrame: Baseline to 12 Weeks
measure: Blood pressure
timeFrame: Baseline to 12 Weeks
measure: Gut microbiota
timeFrame: Baseline to 12 Weeks
measure: Plasma blueberry polyphenol metabolites
timeFrame: Baseline to 12 Weeks
Other outcomes:
Locations:
city: Fort Collins
country: United States
facility: Food and Nutrition Clinical Research Laboratory
state: Colorado
Study officials:
References:
citation: 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.