An international study of 20,000 people found seven new genes that influence blood cholesterol levels, a major factor in heart disease, and confirmed 11 other genes previously thought to influence cholesterol.
The international study led by researchers from the University of Michigan School of Public Health set out to identify or confirm genetic variants that influence lipid levels, and secondly, to see if those variants were linked to the decreased or increased risk of heart disease. The findings will be published online in the journal Nature Genetics on Jan. 13.
The results may lead the medical community to rethink the role of HDL (good cholesterol) and LDL (bad cholesterol) in heart disease, said Goncalo Abecasis, associate professor in the U-M School of Public Health. Abecasis co-directed the study with Karen Mohlke, assistant professor of genetics at the University of North Carolina at Chapel Hill School of Medicine.
"It was surprising that while genetic variants that increase your bad cholesterol are also associated with increased risk of heart disease, we did not find that variants influencing your good cholesterol were associated with decreased risk of coronary artery disease. Perhaps that result will lead us to reexamine the roles of good and bad cholesterol in susceptibility to heart disease," Abecasis said.
Coronary artery disease, a condition where plaque accumulates on the walls of coronary arteries, is the most common type of heart disease and a leading cause of death in industrialized countries. The type and amount of cholesterol and other lipids in the bloodstream contribute to the risk of coronary artery disease, which can cause heart attack, stroke, angina and other heart conditions. Both genetic and environmental factors influence a person's cholesterol and blood lipid levels.