Simply Raising HDL Levels May Not Prevent CV Disease

Cholesterol efflux capacity—a new biomarker that demonstrates high-density lipoprotein’s (HDL) ability to extract cholesterol from cells—is inversely associated with the risk of developing atherosclerotic cardiovascular disease, according to a recent study.

While low levels of HDL cholesterol have previously been associated with the risk of developing atherosclerotic cardiovascular disease, studies on the effects of raising HDL levels have been unable to identify a causal relationship between the two.
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“These observations highlight the potential limitations of using the HDL cholesterol level to assess risk or responses to therapies targeted at HDL cholesterol,” said the study authors.

Instead, researchers focused their attention on the functionality of HDL cholesterol rather than levels of HDL in the body.

In their study, researchers measured HDL cholesterol levels, HDL particle concentration, and cholesterol efflux capacity in 2416 adults without a history of cardiovascular disease, with a primary end point of atherosclerotic cardiovascular disease after an average 9.4 years of follow-up.

In the final, fully-adjusted model including traditional risk factors, researchers identified a 67% decrease in cardiovascular risk in the highest cholesterol efflux capacity quartile compared to the lowest quartile.

“Adding cholesterol efflux capacity to traditional risk factors was associated with improvement in discrimination and reclassification indexes,” they wrote. “This association persisted after multivariate adjustment, suggesting that HDL function is associated with cardiovascular risk by means of processes distinct from those reflected by the HDL cholesterol level, HDL particle concentration, or traditional cardiovascular risk factors.”

The complete study is published in the November issue of the New England Journal of Medicine and was presented at the American Heart Association meeting in Chicago.

-Michelle Canales

Reference:

1. Rohatgi A, Khera A, Berry JD, et al. HDL cholesterol efflux capacity and incident cardiovascular events. NEJM. 2014 November [epub ahead of print] doi: 10.1056/NEJMoa1409065.