NEW YORK (Reuters Health) – Despite its association with increased HDL levels, low hepatic lipase activity is linked to an elevated risk of coronary artery disease, according to a report published in the December 18th issue of Circulation: Journal of the American Heart Association.
The association between hepatic lipase activity and coronary artery disease has been disputed. Logically, it would seem that high activity of an enzyme that breaks down HDL might promote coronary artery disease. However, that does not appear to be the case.
Dr. Klaus A. Dugi, from the University of Heidelberg in Germany, and colleagues measured hepatic lipase activity in plasma samples from 200 men who were undergoing elective coronary angiography.
The researchers found that hepatic lipase activity was inversely related to the extent of coronary artery disease (p < 0.01). Multivariate analysis confirmed the independent nature of the association. In addition, patients with coronary artery disease demonstrated significantly lower hepatic lipase activity than control subjects without disease (p < 0.01).
The presence of a thymidine polymorphism in the enzyme's promoter region, which has been linked to lower activity, was also associated with increased coronary artery disease.
"We have known about hepatic lipase for 30 years, but its effect on heart disease risk is very controversial," Dr. Dugi told Reuters Health. "One group of investigators believes it is pro-atherogenic, and another believes it is anti-atherogenic," he added.
"We found that even though people with lower hepatic lipase activity had higher HDL levels, they still had more coronary artery disease," Dr. Dugi noted.
"We used to think that high HDL levels were always good and low levels were always bad," Dr. Dugi said. "From human and animal studies, we now know that this is not always the case," he said. "There are people with high HDL levels who still develop premature atherosclerosis."
Dr. Dugi noted that the "current results indicate that it may be possible to identify patients with normal or high HDL levels who are actually at increased risk" for atherosclerosis. "Now that we have a better understanding of hepatic lipase's effects it could be a target for therapeutic intervention," he added.