THURSDAY, April 28, 2005 (HealthDay News) -- About 80 percent of the "good" high-density lipoprotein cholesterol produced by the body comes from the liver -- a finding that may lead to new ways to increase HDL levels, new research suggests.
Low levels of HDL are associated with a higher risk of heart attack.
Results of the study, conducted on mice, will be published in the May issue of the Journal of Clinical Investigation.
Researchers genetically engineered mice that lacked the ABCA1 gene in the liver, which meant that their livers could not produce HDL. The mice had HDL levels 80 percent lower than normal mice.
"In studies of mice, we provided the first definitive proof that the liver is the source of about 80 percent of the high-density lipoprotein, or 'good' cholesterol, that circulates in the blood," senior researcher John S. Parks, professor of pathology at Wake Forest University School of Medicine, said in a prepared statement. "Understanding more about how HDL is produced could lead to new treatments to raise its levels."
It was previously believed that HDL production occurred throughout the body. Some HDL production does occur in the walls of blood vessels.
"These results profoundly alter our concept of how HDL is manufactured in the body and establish the liver as the single most important source of HDL in a mouse model," Parks said.
The American Heart Association has more about HDL.