Blood protein linked to heart disease

By David Douglas

NEW YORK (Reuters Health) - As levels of lipoprotein(a), a compound that carries fats in the blood, increase, so does the risk of heart disease, researchers report in the Archives of Internal Medicine.

Although a number of lipoproteins exist, lipoprotein(a) differs from many others in that its levels don't vary with diet and exercise. Instead, they seem to reflect a person's genetic makeup and remain more or less stable.

"The data," investigator Dr. John Danesh told Reuters Health, "should rekindle interest in research that can find out whether there is a cause-and-effect relationship between lipoprotein(a) and heart disease."

Danesh of the University of Cambridge, UK and colleagues examined data on participants in an Icelandic study that began in 1967. Levels of lipoprotein(a) were measured in 2,047 subjects who later died from heart disease and in 3,921 subjects who did not die from heart disease.

After accounting for the effect of established risk factors, the subjects with the highest levels of lipoprotein(a) were 60 percent more likely to develop heart disease than those with the lowest levels. Moreover, the higher the lipoprotein(a) level rose, the greater the risk of heart disease.

The investigators found little or no correlation between lipoprotein(a) levels and heart disease risk factors such as older age, high cholesterol and high blood pressure. Thus, measuring lipoprotein(a) levels may provide information above and beyond that obtained from looking at traditional risk factors.

"The findings from the current study," concluded Danesh, "provide the most persuasive evidence yet that lipoprotein(a) is associated with risk of subsequent (heart) disease."

He and his colleagues call for further studies to investigate the value of lipoprotein(a) measurement in preventing heart disease.

SOURCE: Archives of Internal Medicine, March 24, 2008.