Dietary Nitrate and Nitrite to Increase Nitric Oxide in Patients With Coronary Artery Disease
Completed · Phase 2
Conditions studied: Coronary Arteriosclerosis
In brief
This study will determine whether dietary nitrates and nitrites can produce nitric oxide in the body and dilate blood vessels in patients with coronary artery disease. Nitric oxide is normally made by endothelial cells that line blood vessels. It plays an important role in maintaining the normal function of arteries by keeping them open and preventing damage from substances such as cholesterol in the blood stream. Coronary artery disease is caused by atherosclerosis (hardening of the arteries or build-up of cholesterol and scar tissue within the walls of the arteries). Once arteries become clogged, the ability of the endothelium to produce nitric oxide diminishes considerably and may speed up the disease process, leading to shortness of breath, chest pain, and an increased risk of heart attack or stroke. Patients 21 years of age and older with coronary artery disease may be eligible for this study. Participants will have a medical history and physical examination, electrocardiogram (recording of the electrical activity of the heart), echocardiogram (ultrasound test of the heart), treadmill exercise stress test (see below), and will meet with a dietitian. They will be hospitalized at the NIH Clinical Center on two occasions. For 1 week before each admission, they will follow a diet prescribed by an NIH nutritionist. The diet before one admission will be high in nitrates and nitrites, and the diet before the other admission will be low in nitrates and nitrites. Each admission will last 4 days, during which participants will undergo the following tests: * Forearm blood flow study: Small tubes are placed in the artery and vein at the inside of the elbow of the dominant arm (right- or left-handed) and a small tube is placed in a vein of the other arm. The tubes are used for infusing saline (salt water) and for drawing blood samples. A pressure cuff is placed around the upper part of the dominant arm, and a rubber band device called a strain gauge is also placed around the arm to measure blood flow. When the cuff is inflated, blood flows into the arm, stretching the strain gauge at a rate proportional to the flow. Maximum grip-strength of the dominant arm is measured with a dynamometer. Forearm blood flow is measured and blood samples are drawn at the following times: 20 minutes after the tubes are placed; during a hand-grip exercise; and 4 minutes after the exercise is completed. * Brachial artery reactivity study: This test measures h...
Key facts
- Study ID
- NCT00069654
- Run by
- National Heart, Lung, and Blood Institute (NHLBI)
- People needed
- 42
- Starts
- 2003-09-25
- Last updated by the study team
- 2017-07-02
Who can join
Age: 22 and older. Sex: any. Healthy volunteers: not accepted.
You may not qualify if…
- Significant structural heart disease (e.g. hypertrophic or dilated cardiomyopathy, valvular heart disease) as determined by echocardiography.
- Subject physically unable to perform treadmill exercise due to neurologic or orthopedic conditions.
- Hypersensitivity to organ nitrates.
- Insulin-dependant diabetes mellitus.
- Coumadin therapy (because of vitamin K content of green leafy vegetables).
- Women of childbearing age unless recent pregnancy test is negative.
- Lactating women.
- Unwillingness to adhere to dietary requirements or allergy to necessary components of diets, as determined during interview by the dietician.
- Surgical or disease-related diminished acid secretion.
- Significant non-cardiac disease.
Where it is running
- National Institutes of Health Clinical Center, 9000 Rockville Pike — Bethesda, Maryland, United States
Full record on ClinicalTrials.gov
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