Effect of Beetroot Juice on Coronary Blood Flow and Walking Performance in PAD (HeartBeet)
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|ClinicalTrials.gov Identifier: NCT02553733|
Recruitment Status : Recruiting
First Posted : September 18, 2015
Last Update Posted : January 7, 2019
|Condition or disease||Intervention/treatment||Phase|
|Peripheral Arterial Disease||Drug: Beetroot juice Drug: Beetroot juice placebo||Phase 2|
Peripheral arterial disease (PAD) is a strong predictor of cardiovascular mortality and negatively affects functional capacity and quality of life for as many as 14 million patients in the U.S. alone. One open-label study showed that acute consumption of beetroot juice improved 6 min walk performance, reduced blood pressure, and enhanced leg muscle oxygenation in PAD patients. However, no studies have rigorously confirmed these findings in a double-blind manner, nor have the effects of this supplement been investigated (acutely or short-term) in the coronary circulation of PAD patients.
In addition to studying its effects on graded treadmill walking performance and consequent large artery vasodilation, the present study will examine the effects of short-term beetroot juice consumption (twice/day) on both coronary and leg vasodilator (graded calf flexion) and vasoconstrictor (isometric handgrip, voluntary apnea) responses in patients with PAD. Participants will randomly consume either nitrate-rich or nitrate-depleted beetroot juice with a 7 to 14 day wash-out period between. Effects of beetroot juice consumption on plasma nitrate, nitrite and methemoglobin will also be assessed.
|Study Type :||Interventional (Clinical Trial)|
|Estimated Enrollment :||12 participants|
|Intervention Model:||Crossover Assignment|
|Masking:||Double (Participant, Investigator)|
|Official Title:||Effects of Dietary Nitrate Supplementation on Coronary Blood Flow and Walking Performance in Peripheral Arterial Disease|
|Study Start Date :||December 2015|
|Estimated Primary Completion Date :||December 2020|
|Estimated Study Completion Date :||December 2022|
Active Comparator: Beetroot juice (Beet-It Organic Shot)
Subjects will consume 70 ml of beetroot juice (Beet-It Organic Shot) twice per day (morning, afternoon) for 5 to 7 days to assess the short term effects of this nitrate supplement on graded treadmill walking responses (day 4) and vasodilator/vasoconstrictor responses in the coronary and lower leg circulations (day 5 or 6 or 7). On both study visits, subjects will consume their morning dose 1 hour 45 min before experiments begin.
Drug: Beetroot juice
This beverage contains 0.3 g of inorganic nitrate per 70 ml container, and is bottled and supplied by James White Drinks (UK).
Other Name: Beet-It Organic Shot
Placebo Comparator: Beetroot juice placebo (Beet-It Organic Placebo)
Subjects will consume 70 ml of beetroot juice placebo (Beet-It Organic Placebo) twice per day (morning, afternoon) for 5 to 7 days to assess the short term effects of this nitrate supplement on graded treadmill walking responses (day 4) and vasodilator/vasoconstrictor responses in the coronary and lower leg circulations (day 5 or 6 or 7). On both study visits, subjects will consume their morning dose 1 hour 45 min before experiments begin.
Drug: Beetroot juice placebo
This beverage is identical in look and taste to the Beet-It organic shot, but has the nitrate removed. It is also bottled and supplied by James White Drinks (UK).
Other Name: Beet-It organic placebo
- Exercise performance [ Time Frame: 5 to 7 days after initiating daily ingestion of beetroot juice ]Exercise capacity will be assessed using a graded treadmill walking test to peak exertion with expired gas analysis and determination of peak oxygen uptake, calf muscle oxygenation, blood pressure, claudication onset time, and peak walking time.
- Coronary vascular function [ Time Frame: 4 days after initiating daily ingestion of beetroot juice ]Coronary artery (transthoracic ultrasound) blood flow responses to plantar flexion and handgrip exercise.
- Leg vascular function [ Time Frame: 4 days after initiating daily ingestion of beetroot juice ]Popliteal artery and near infrared spectroscopy (NIRS) responses to plantar flexion and handgrip exercise.
- Blood measures of nitrate absorption and conversion [ Time Frame: 4 to 7 days after initiating ingestion of beetroot juice ]Venous blood will be withdrawn (venipuncture) for determination of plasma nitrate, nitrite and methemoglobin levels
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): NCT02553733
|Contact: David N Proctor, PhDfirstname.lastname@example.org|
|United States, Pennsylvania|
|Milton S. Hershey Medical Center||Recruiting|
|Hershey, Pennsylvania, United States, 17033|
|Contact: Urs A Leuenberger, MD 717-531-7455 email@example.com|
|Principal Investigator:||Urs A Leuenberger, MD||Penn State University|