Although HDL cholesterol is typically thought of as 'good' cholesterol, new data from a large study suggests that at very high levels, it may actually increase the risk of coronary artery disease.
On the other hand, apolipoprotein A-I or apoA-I - which like HDL cholesterol has been linked to a reduced heart disease risk - continues to show this association at very high levels, according to the report in the Journal of the American College of Cardiology.
To gauge the impact of very high levels of HDL cholesterol and apoA-I on cardiovascular risk, Dr John J. P. Kastelein from the Academic Medical Centre in Amsterdam, the Netherlands, and colleagues analysed data from the so-called IDEAL study.
Increased risk of coronary eventIn IDEAL, very high levels of HDL cholesterol were tied to an increased risk of a major coronary event, the researchers found. After making adjustment for levels of apoA-I and other factors, each 12-point increase in HDL cholesterol raised the risk by 21 percent.
IDEAL, which included 8888 patients, assessed the benefits of high-dose statin therapy for preventing the recurrence of cardiovascular events.
A persistently negative association was noted between apoA-I levels and the risk of a major coronary event, the researchers report.
In an editorial, Dr Jacques Genest, from McGill University in Montreal, points out some of the implications of the apparent link between very high levels of HDL cholesterol and elevated cardiovascular risk. "First, naturally occurring high levels of HDL cholesterol may not protect against heart disease, and second, and herein lies the most important and provocative finding, HDL cholesterol as a therapeutic goal may be fraught with potential dangers." - (Reuters Health)
SOURCE: Journal of the American College of Cardiology, February 12, 2008.
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