Another Blood Fat Fuels Heart Attack Risk

June 10 -- TUESDAY, June 9 (HealthDay News) -- Yet another type of blood fat may be linked to higher cardiac risk, a new study suggests.

A Danish study finds an increased risk of heart attacks in people whose genes give them high blood levels of a cholesterol-related blood fat, lipoprotein(a), but the researchers say more work is needed to justify treatment to reduce those levels.

"We show that those with the 10 percent highest lipoprotein(a) have a two- to threefold increased risk of myocardial infarction [heart attack], similar to that for the highest LDL cholesterol levels," said Dr. Borge G. Nordestgaard, a professor of clinical biochemistry at Copenhagen University, and lead author of a report in the June 10 issue of the Journal of the American Medical Association.

However, a large-scale trial is needed to tell whether drugs aimed at reducing lipoprotein(a) (LPA) levels would lower the risk, Nordestgaard said. One compound, niacin, also known as nicotinic acid or vitamin B3, is known to reduce LPA levels, he said.

"I am not aware of other drugs being developed to lower lipoprotein(a), but I certainly hope that our study will make big pharmaceutical companies interested in developing such drugs," Nordestgaard said.

LPA consists of a molecule of LDL cholesterol, the "bad" kind that clogs arteries, attached to a number of units of protein. The number of protein units attached to the LDL unit can vary widely.

Nordestgaard and his colleagues have been studying the relationship of LPA to heart disease for years. Their latest report uses data from three studies that included more than 40,000 Danes, with follow-up periods as long as 16 years.

"We observed an increase in risk of myocardial infarction with increased levels of lipoprotein(a)," the researchers wrote. The risk was highest in people whose LPA had a smaller number of lipoprotein attachments, they noted.

Caution is needed in interpreting the results because all the people in the studies were white, Nordestgaard said. "People of African descent have the highest lipoprotein(a) levels, while those of European descent and most Asians have similar levels, but lower levels than blacks," he noted.