The latest analysis of the data from Treat to New Targets (TNT) Trial shows that higher HDL cholesterol values are associated with reduced risk of heart attack, even in those with low LDL cholesterol values.
This counters the argument that some have made that, if a person takes a statin drug, raising HDL adds no additional benefit.
In the 9770-participant trial (randomized, double-blind), participants were given atorvastatin (Lipitor®) 10 mg or 80 mg per day. The study was sponsored by Pfizer, the manufacturer of Lipitor®. All participants were survivors of heart attacks, significant coronary disease by heart catheterization, or had previously undergone coronary angioplasty, stent placement, or bypass surgery—a high-risk group.
At the third month of enrollment, lipid (cholesterol panel) values were obtained and used as the basis for analysis. Participants on 80 mg atorvastatin achieved an average LDL cholesterol (Friedewald) of 77 mg/dl; participants taking 10 mg achieved a level of 101 mg/dl. Using these values, 8.7% of participants taking the higher dose of drug experienced an event, compared to 10.9% on the lower dose (which the investigators called a 22% relative reduction).
However, when the groups were re-analyzed by HDL cholesterol levels, higher HDLs remained predictive of less heart attack and other events, with the group having the highest HDL of =55 mg/dl experiencing 25% less events. Most interestingly, this effect was upheld even in participants with very low LDL cholesterols of <70 mg/dl.
I’m always a bit leery of drug company-sponsored studies, especially ones in which virtually all the participants tolerated a drug like Lipitor 80 mg, a dose in my experience that is very poorly tolerated for more than a few months. (Muscle aches are, in my experience, inevitable. I do not even recommend this dose.) In other words, the data are, in that respect, too good to believe.
Anyway, despite my reservations about these big money studies, there was nothing to gain from the HDL observation. (Of course, at one time, there would have been, given Pfizer’s efforts to commercialize the now-kaput torcetrapib, scrapped because of excess mortality in phase II trials.)
Thankfully, there’s other data that likewise suggest that the higher the HDL, the better. Yet more validation for the Track Your Plaque lipid targets of LDL 60 mg/dl, triglycerides 60 mg/dl or less, HDL 60 mg/dl or greater.
Copyright 2007 William Davis,MD
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