The study done by Farrall and his colleagues looked in exquisite detail at the genetic makeup of 3,145 people with coronary artery disease and 3,352 free of coronary disease. The study of more than 48,000 variants of 2,100 genes found that two variants affecting LPA levels were strongly associated with coronary disease.
"We speculate and anticipate that our finding may carry over to other cardiovascular diseases, such as some kinds of stroke," Farrall said.
The reason for the harmful effects of LPA is unknown, he said. "A number of speculative mechanisms have been proposed," Farrall said. "Our study doesn't help resolve those."
One immediate impact of the research could be widened use of a blood test for LPA, which has been available for years, Kathiresan said. "This kind of study shows that people who carry a genetically determined high level of LPA have an increased risk, and this will likely increase enthusiasm for measuring LPA blood levels, particularly for people who have heart disease at an early age or have a strong family history of heart disease," he said.
And while at least one available drug, niacin, is known to reduce LPA levels to some extent, "we need a drug that selectively reduces LPA," Kathiresan said. "There is some effort to do that."
A major controlled trial will be needed to show that an LPA-lowering drug reduces the incidence of coronary disease, he added.
One odd sidelight is that while participants in the new study -- and most previous trials -- were white Europeans, elevated LPA levels are more common among people from Africa and southern Asia, Kathiresan noted. Studies of those populations are needed, he stressed.
An introduction to the world of lipoproteins is provided by the American Heart Associatio
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