Fat in the bloodstream linked to heart attacks

New research, by Dr. Sotirios Tsimikas of the University of California, San Diego, has produced the first convincing evidence that a type of fat in the bloodstream can trigger the earliest conditions that lead to clogged blood vessels, the highest cause of heart attacks.

These encouraging results will need further research to consolidate the findings, but it could mean that someday, people could be tested for this particular fat, just as they are now tested for cholesterol, in order to establish if there is a danger of a heart attack.

In the study it was found, especially in people under age 60, that levels of the fat strongly correlated with the risk of heart disease.

Judith Berliner, a professor of medicine at the University of California, Los Angeles, says the findings give people another reason to limit fat in their diets.

She says no one really knows what causes the formation of blockages, which can squeeze blood vessels shut and deprive the heart of nourishment, and most of the studies in the past have concentrated on cholesterol, but many doctors have felt that other factors also must also be involved, because cholesterol levels are often normal in many heart attack victims.

Berliner says the research also raises the possibility of new approaches to treating and preventing heart disease.

Many scientists have been suspicious that one such factor might be oxidized phospholipids, a type of fat that's a major component of LDL or "bad cholesterol", and research in animals has found that this fat, which is floating in the bloodstream, contributes to blockage formation.

The new research, is the first to show the same is true in people.

In the study Tsimikas examined 504 people being tested for clogged arteries. Among those who were age 60 or younger, the people with the highest levels of oxidized phospholipids, were three times more likely to have blockages than those with the lowest levels, and those who had high phospholipids and high cholesterol were at even greater risk.

To achieve a measurement of the level of this fat, separate tests must be done from those for total cholesterol and LDL.

Dr. Sidney Smith, director of the center for cardiovascular diseases at the University of North Carolina at Chapel Hill, and past president of the American Heart Association, says more research of phospholipid levels in all types of people is needed.

The study was funded by the federal government and the La Jolla Specialized Center of Research in Molecular Medicine and Atherosclerosis and two foundations.

Several of the authors have consulted for drug companies with heart disease products.

The study and an editorial accompanying it, by Judith Berliner, are published in the current edition of the New England Journal of Medicine.