A review article published in the Annals of Internal Medicine on October 3 calls into question the currently accepted dogma that achieving very low LDL cholesterol levels (less than 70 mg/dl) is important for patients at high risk for cardiovascular disease.
The authors examined all the scientific evidence used by the National Cholesterol Education Program's (NCEP) expert panel when they settled upon the current NCEP guidelines on treating cholesterol. In those guidelines, issued in 2004, the NCEP urged doctors to use a target LDL level of 70 or less when treating their high-risk patients. These recommendations were based on the results of several large clinical trials, all of which showed that achieving ultra-low LDL levels with the use of high-dose statins resulted in significantly better clinical outcomes in these patients.
However, the authors of the new Annals review article conclude that, from the available evidence, it may be the statins themselves, and not entirely the low LDL levels, that produce the benefit. If this proves to be the case, then it is entirely possible that producing very low LDL levels by some means other than statin drugs may not result in equivalent outcomes.
DrRich Comments:
This new review article will be treasured by many in the pharmaceutical industry (which even now is likely creating a spike in Kinko's stock, what with all the reprints and other "educational" materials it must be madly reproducing), but will just as certainly create a lot of despair (or anger) in other quarters, including among purveyors of alternative medicines and other natural remedies (whose ads often can be enjoyed on this very site), diet-and-exercise gurus, and the very vocal anti-statin consumerism crowd (hi, guys, it's me again with yet another pro-statin report, for which I am, as ever, sorry).
That the statins themselves, instead of purely the LDL reduction, may be largely responsible for improved clinical outcomes should not entirely be a surprise. Prior studies have shown that statins can produce a signficant improvement in outcomes for very high-risk patients in a very short period of time - a much shorter time than one would expect from simply slowing-down the atherosclerotic disease process by reducing LDL levels. Furthermore, it is known that statins have many salutary effects on the cardiovascular system in addition to lipid lowering, such as reducing inflammation, reducing abnormal blood clotting, and (most likely) helping to stabilize unstable plaques. (It is the rupture of unstable plaques in the lining of coronary arteries that is thought to trigger most heart attacks.)
The idea that it's the statins, and not purely the lower LDLs, that improve clinical outcomes is one that can be studied in well-designed clinical trials. It's almost a sure thing now that these studies will be undertaken.
Sources:
Hayward RA, Hofer TP, Vijan S. Narrative review: lack of evidence for recommended low-density lipoprotein treatment targets: a solvable problem. Ann Intern Med 2006; 145:520-530.
