Effect of Beetroot Juice on Coronary Blood Flow and Walking Performance in PAD

Peripheral Arterial Disease Clinical Trial

— HeartBeet  

Official title:

Effects of Dietary Nitrate Supplementation on Coronary Blood Flow and Walking Performance in Peripheral Arterial Disease

Clinical Trial Details — Status: Active, not recruiting

Administrative data

• NCT number: NCT02553733
• Other study ID #: 00003242
• Status: Active, not recruiting
• Phase: Phase 2
• Start date: December 2015
• Est. completion date: December 2024

Study information

• Verified date: April 2023
• Source: Penn State University
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

In this study the investigators will test the hypothesis that short-term consumption of inorganic nitrate (supplied in concentrated beetroot juice) enhances coronary blood flow responses, large artery hemodynamics, and leg oxygenation/exercise tolerance in patients with peripheral arterial disease (PAD). Understanding and improving blood flow regulation in the heart and skeletal muscles of patients with PAD is important because exercise triggers symptoms of leg pain and substantially raises blood pressure and myocardial demand in these patients.

Description:

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.

Recruitment information / eligibility

• Status: Active, not recruiting
• Enrollment: 12
• Est. completion date: December 2024
• Est. primary completion date: December 2023
• Accepts healthy volunteers: No
• Gender: All
• Age group: 21 Years to 85 Years

Eligibility

Inclusion Criteria:

1. Patients with peripheral arterial disease (PAD)

2. Capable of giving informed consent

3. Men and women age 21- 85 years

4. Diagnosed with PAD (i.e., ankle-brachial index below 0.9)

5. Fontaine stage II or less - no pain while resting

6. Satisfactory history and physical exam

Exclusion Criteria:

1. Children

2. Pregnant or nursing women

3. Patients taking nitroglycerine or nitrate preparations

4. Patients taking phosphodiesterase inhibitors such as sildenafil or tadalafil

5. Patients taking proton pump inhibitors

6. Ejection fraction < 40%

7. Uncontrolled hypertension

8. Uncontrolled diabetes

9. Myocardial infarction within past 6 months or unstable angina

10. Severe lung disease (i.e., on supplemental oxygen or frequently use rescue inhalers)

11. Abnormality in hemoglobin or hematocrit or methemoglobin

12. Impaired renal function

13. Impaired liver function

14. History or diagnosis of Barrett's esophagus

15. Known allergy to beetroot juice or lemon juice

16. Inability to walk on a treadmill at a moderate pace (2.0 miles/hour)

Related Conditions & MeSH terms

• Peripheral Arterial Disease
• Peripheral Vascular Diseases

Intervention

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).
• 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).

Locations

Country	Name	City	State
United States	Milton S. Hershey Medical Center	Hershey	Pennsylvania

Sponsors (3)

Lead Sponsor	Collaborator
David N. Proctor, PhD	Milton S. Hershey Medical Center, Wake Forest University Health Sciences

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Other	Blood measures of nitrate absorption and conversion	Venous blood will be withdrawn (venipuncture) for determination of plasma nitrate, nitrite and methemoglobin levels	4 to 7 days after initiating ingestion of beetroot juice
Primary	Exercise performance	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.	5 to 7 days after initiating daily ingestion of beetroot juice
Secondary	Coronary vascular function	Coronary artery (transthoracic ultrasound) blood flow responses to plantar flexion and handgrip exercise.	4 days after initiating daily ingestion of beetroot juice
Secondary	Leg vascular function	Popliteal artery and near infrared spectroscopy (NIRS) responses to plantar flexion and handgrip exercise.	4 days after initiating daily ingestion of beetroot juice