Such a simple diagnostic is important, they said, because up to half of patients who develop heart disease do not have the typical risk factors. Furthermore, using this new approach, the researchers demonstrated that exercise improved the marker in patients at risk for developing cardiovascular disease.
In their pilot study, the researchers linked the systemic production of nitric oxide, a chemical known to play a key role in controlling the ability of arteries to constrict or relax, with changes in the endothelial lining of arteries after being stressed.
"This is the first study to attempt to link whole body production of nitric oxide with regional endothelial function," said Jason Allen, Ph.D., who presented the results of the Duke study today (Nov. 22, 2003) during the 10th annual scientific sessions of the Society for Free Radical Biology and Medicine. "Both measures were found to discriminate between healthy participants and those with diagnosed cardiovascular disease."
In addition to its ability to dilate arteries, nitric oxide has other properties that protect against cardiovascular disease, such as inhibiting blood platelet clumping, preventing smooth muscle proliferation within the artery and inhibiting the immune response.
On the other hand, other risk factors, such as diabetes, high blood pressure, mental stress and smoking can reduce nitric oxide's protective properties, said the researchers. It is believed that these patients produce more oxygen free radicals, impairing the ability of the body to respond appropriately to nitric oxide. These oxygen free
Contact: Richard Merritt
Duke University Medical Center