Are We Paying Too Much Attention to HDL-C Levels?

Only a couple of weeks ago I posted a piece about how important the high-density lipoprotein cholesterol (HDL-C, the ‘good’ cholesterol) might be in preventing cancer.  I ended by saying “Either way, it’s worth trying to raise your HDL-C level into the healthy range (over 60 mg/dL) while you try to keep your LDL-C below 100 mg/dL.”  Well, now an analysis published in the Lancet suggests that the HDL-C level is no longer important if the ‘bad’ cholesterol is under control.  This is in spite of the fact that other studies have shown that low HDL-C levels are associated with cardiovascular ‘events’.

Researchers from Brigham and Women's Hospital, Boston, undertook an additional analysis of data from the JUPITER trial, which was designed to determine whether a statin prevents cardiovascular disease in healthy people who have normal LDL-cholesterol levels.  The results showed that if a normal, healthy person has a level of LDL-C substantially lowered by a statin drug, then their level of HDL-C (the ‘good cholesterol’) no longer bears any relation to the remaining cardiovascular risk.

When over 17,500 individuals were classified into 4 groups according to their HDL-C concentrations, in those placebo-treated subjects with the highest HDL-C levels had a 46% reduced risk compared to those with the lowest HDL-C levels.  In contrast, however, in subjects given the statin, cardiovascular risk was similar for subjects in both the top and bottom HDL-C level groups.    

The authors of the study concluded: “Although measurement of HDL-cholesterol concentration is useful as part of initial cardiovascular risk assessment, HDL-cholesterol concentrations are not predictive of residual vascular risk among patients treated with potent statin therapy who attain very low concentrations of LDL cholesterol".  In other words, taking care of the LDL-C is enough – the HDL-C becomes irrelevant.  This is important, because medications targeting high HDL-C levels carry unpleasant side-effects, and are not inexpensive.

This somewhat revolutionary suggestion has been countered by experts from the European Society of Cardiology.  For instance, the methodology can be attacked; “More data are needed before the scientific community can make a qualified decision about whether raising HDL-C levels is beneficial or not”.  In the meantime, we’ll concentrate on the ‘bad’ LDL-C, and just keep an eye on the HDL-C.