|Iron and Heart Disease|
Why are we studying iron?
Several large studies suggest that high levels of iron may increase the risk of heart attack and other blood vessel diseases. Experiments in animals suggest that high levels of iron may be harmful to blood vessels, particularly to the inner-linning of these vessels which is called the endothelium.
What is the endothelium?
The endothelium is the inner lining of cells in blood vessels. It performs functions essential to these vessels including the regulation of blood clotting by releasing a number of factors including nitric oxide. We are able to measure how well the endothelium works by using ultrasound and other techniques to assess blood vessel dilation.
What happens to the endothelium in atherosclerosis?
In atherosclerosis, release of nitric oxide from endothelial cells is impaired. Since nitric oxide produces vasodilation and prevents platelet clumping, this abnormality may increase the risk for blood clot formation and vasospasm in the heart and brain. These abnormalities may lead to heart attack, stroke, and/or sudden death.
We believe that reducing body iron may improve the release of nitric oxide from the endothelium and thereby reduce the risk of cardiovascular disease.
What does the study involve?
The study involves one 4-hour visit to the Coronary Health Unit. A small plastic tube will be inserted in the artery in your arm (brachial artery) using a local anesthetic. You will be asked to lie quietly in bed for 4 hours while measurements of blood vessel function are made before and after deferoxamine treatment. Two inflatable cuffs will be put on your arm, and will squeeze your arm very slightly on and off throughout the study. Upon completion of the study, you will be paid a stipend of $100. We will also compensate you for parking in the Doctor's Office Building garage at Boston Medical Center.
Are there risks involved?
Deferoxamine is approved by the Food and Drug Administration for the treatment of iron overload and has been given safely to thousands of patients. During our studies, a few patients have developed local redness in the arm which ceases after stopping the medication. The total amount of iron removed during the study is very small and will not adversely affect your health.
Who is eligible for the study?
To be eligible for the study, you must have proven coronary artery disease (by angiogram, history of a heart attack, or a positive stress test). You cannot be taking regular antioxidant supplements including vitamin E and vitamin C. We also are excluding people who have smoked within one month and patients with diabetes mellitus requiring insulin.
Who do I contact to participate?