Study locates cholesterol genes; finds surprises about good, bad 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.

"Finding new gene regions associated with cholesterol levels may bring us one step closer to developing better treatments, said Cristen Willer, co-first author and a research fellow in the Department of Biostatistics. "Nearly all of the gene regions that we found to be involved in higher LDL levels were also involved in coronary artery disease risk. This is a remarkable result and suggests that new drug therapies that target the genes in these regions will also help prevent coronary artery disease and allow people to live longer and healthier lives." Serena Sanna, who worked on the paper as a post-doctoral student in Abecasis' group and who is now at the National Research Council di Cagliari in Italy, is co-first author.

Of the seven new variants, two influenced HDL, one influenced LDL, and three influenced triglycerides, which are found in fat and in the bloodstream and like LDL, are associated with increased risk of heart disease. One variant influenced triglycerides and LDL.

Scientists initially examined 2 million genetic variants in 8,800 individuals and ended up focusing on a total of 25 genetic variants on 18 genes. Altogether the variations reported are responsible for less than a quarter of the genetic contributions to lipid levels.

The completion of the map of human genetic variation, or HapMap, has fueled a surge in this type of genome-wide association study, with most of the growth coming in the past 10 months. Researchers around the globe have now associated more than 60 common DNA variants with the risk of more than 20 common diseases or related traits.

Source: University of Michigan

Blood pressure response to daily stress provides clues for better hypertension treatment
How the body regulates blood pressure in response to daily stress is the focus of a study geared toward helping people whose pressure is out of control.
Half of overweight adults may be heart-healthy
(AP) -- You can look great in a swimsuit and still be a heart attack waiting to happen. And you can also be overweight and otherwise healthy. A new study suggests that a surprising number of overweight people - about half - have normal blood pressure and cholesterol levels, while an equally startling number of trim people suffer from some of the ills associated with obesity.
Designer RNA fights high cholesterol, researchers find
Small, specially designed bits of ribonucleic acid (RNA) can interfere with cholesterol metabolism, reducing harmful cholesterol by two-thirds in pre-clinical tests, according to a new study by researchers at UT Southwestern Medical Center in collaboration with Alnylam Pharmaceuticals and the Massachusetts Institute of Technology.
Low vitamin D levels pose large threat to health
Researchers at Johns Hopkins are reporting what is believed to be the most conclusive evidence to date that inadequate levels of vitamin D, obtained from milk, fortified cereals and exposure to sunlight, lead to substantially increased risk of death.
People with heart disease still have trouble controlling blood lipid levels
Despite some improvements to lower "bad" cholesterol levels, people with cardiovascular diseases still need to do a better job controlling overall blood lipid levels, according to a UC Irvine Heart Disease Prevention Program study.
People with heart disease still have trouble controlling blood lipid levels
(PhysOrg.com) -- Despite some improvements to lower “bad” cholesterol levels, people with cardiovascular diseases still need to do a better job controlling overall blood lipid levels, according to a UC Irvine Heart Disease Prevention Program study.
Study: Spices may protect against consequences of high blood sugar
(PhysOrg.com) -- Herbs and spices are rich in antioxidants, and a new University of Georgia study suggests they are also potent inhibitors of tissue damage and inflammation caused by high levels of blood sugar.
Exercise pill is no replacement for exercise
Recently, researchers at the Salk Institute for Biological Studies, a research organization focused on biology and its relation to health, published a study in the journal Cell on the results of a substance that increased exercise endurance without daily exertion when tested in mice. Media reports have described this substance as an "exercise pill," potentially eliminating the need for exercise.

Study locates cholesterol genes; finds surprises about good, bad cholesterol

Related stories:

News discussion: