Antihypertensive and Vascular-Protective Effects of Wild Blueberries in Middle-Aged/Older Men and Postmenopausal Women.
Overview
- Phase
- Phase 1
- Intervention
- Not specified
- Conditions
- Hypertension
- Sponsor
- Colorado State University
- Enrollment
- 58
- Locations
- 1
- Primary Endpoint
- Reactive hyperemia index
- Status
- Active, Not Recruiting
- Last Updated
- 5 months ago
Overview
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.
Investigators
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)
Outcomes
Primary Outcomes
Reactive hyperemia index
Time Frame: Baseline to 12 Weeks
Endothelial function assessed as reactive hyperemia index using peripheral arterial tonometry (EndoPat)
Secondary Outcomes
- Lipid profile(Baseline to 12 Weeks)
- VCAM-1(Baseline to 12 Weeks)
- Endothelial cell protein expression(Baseline to 12 Weeks)
- Augmentation index(Baseline to 12 Weeks)
- Pulse wave velocity(Baseline to 12 Weeks)
- Gut microbiota(Baseline to 12 Weeks)
- Plasma blueberry polyphenol metabolites(Baseline to 12 Weeks)
- Nitric oxide metabolites(Baseline to 12 Weeks)
- Blood pressure(Baseline to 12 Weeks)
- Hemoglobin A1c(Baseline to 12 Weeks)
- ICAM-1(Baseline to 12 Weeks)