HDL cholesterol is often called “good” cholesterol, because it carries cholesterol out of the bloodstream back to the liver, where it’s broken down. Now HDL has been found to have another beneficial effect.

In mice, HDL expands the coronary arteries supplying blood to the heart, German and US researchers report in the American Heart Associations journal Circulation.

“By inducing coronary vessel relaxation and thus the blood supply to the heart,” lead investigator Dr. Bodo Levkau told AMN Health, “HDL helps protect the heart against myocardial infarction” - i.e., a heart attack.

Levkau, at University Hospital Essen, and colleagues found that injecting mice with human HDL produces a rapid increase in the amount of a bloodflow tracer in the heart by about 18 percent.

The increase in perfusion, Levkau continued, may be the mechanism by which “high HDL levels reduce cardiovascular risk, and one that may contribute to the long-known but still enigmatic beneficial effect of HDL.”

The finding, he concluded, “suggests that both a much closer control of HDL blood levels and measures designed to increase HDL may reveal novel approaches to the treatment of heart disease.”

SOURCE: Circulation, November 23, 2004.