It seems like a week doesn't go by without yet more research coming to light, which paints the cholesterol-reducing drugs known as statins as wonder drugs. The latest example of such research was published earlier this month in the Annals of Internal Medicine [1].
The study was an analysis of individuals aged 65 or more who were treated with low (10 mg) or high (80 mg) doses of the statin atorvastatin (Lipitor) made by the drug company Pfizer. All of the individuals in the study were known to have pre-existing heart disease, which means they are generally regarded as "high-risk" for events such as heart attacks and strokes. These elderly, at-risk individuals are just the sort of people you would expect to benefit most from some sort of intervention.
The "highlight" of this study is that those individuals taking 80 mg of the drug compared to those taking the lower dose enjoyed a 19 percent reduced risk of a "major cardiovascular event" (for example, heart attack or stroke) and this difference was statistically significant. The abstract (summary) of the study goes on to tell us that: "Among the components of the composite outcome, the mortality rates from CHD [coronary heart disease], nonfatal non-procedure-related myocardial infarction, and fatal or nonfatal stroke (ischemic, embolic, hemorrhagic, or unknown origin) were all lower in older patients who received high-dose atorvastatin, although the difference was not statistically significant for each individual component. The improved clinical outcome in patients 65 years of age or older was not associated with persistent elevations in creatine kinase levels." (Creatinine kinase levels go up in certain conditions including muscle breakdown and heart attack.)
Looking good, no?
Well, first of all, let's have a look at all those outcomes other than major cardiovascular events, that is, mortality rates from CHD, nonfatal non-procedure-related myocardial infarction, and fatal or nonfatal stroke. NONE of these outcomes were lower in the 80 mg group compared to the 10 mg group from a statistical perspective.
Bearing this in mind, doesn't the wording in the abstract seem a little odd?
Now let's look at the hazards associated with the treatment. We are reassured in the abstract that, "The improved clinical outcome in patients 65 years of age or older was not associated with persistent elevations in creatine kinase levels." Closer analysis of this study reveals that the authors adjudged raised levels of creatinine kinase to be more than 10 times the upper limit of normal.
And the abstract fails to draw attention to the analysis of liver function. Deranged liver function (as defined as a level of one of two liver enzymes at more than three times the upper limit of normal) was found in one person on the lower dose of atorvastatin, compared to 24 on the higher dose.
Also, withdrawal from the study due to treatment-related side effects was twice as likely in the higher dose group (4.4. vs. 2.2 percent). Funny how none of this came out in the abstract. Though we can all relax in the knowledge that creatinine kinase levels were not persistently elevated to more than 10 times their normal upper limit in the higher dose group.
Overall, it would seem that the abstract puts a very shiny gloss on what, to my mind, amounts to very unimpressive results indeed.
References:
[1] Wenger NK, et al. Outcomes of using high- or low-dose atorvastatin in patients 65 years of age or older with stable coronary heart disease. Annals of Internal Medicine 2007; 147(1): 1-9
Dr. John Briffa is a London-based doctor, author, and health writer with an interest in nutrition and natural medicine.
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