What is C-reactive protein (CRP)?
It is a blood-borne protein that originates in the liver and serves as an index of the body's inflammatory state. It is triggered by yet another inflammatory signal molecule, interleukin-6.
What triggers this cascade of inflammatory markers? Any inflammatory stimulus, such as being overweight, lack of exercise, vitamin D deficiency, viral illness no matter how trivial, any inflammatory disease like arthritis, small LDL, high triglycerides, poor diet rich in processed foods, resistance to insulin, any injury, incipient diabetes, hidden cancer, lack of education (no kidding), etc.
In other words, many, many conditions, from trivial to serious, trigger increased inflammatory markers like CRP.
A recent analysis (Genetically elevated C-reactive protein and ischemic vascular disease of persons with genetically elevated levels of CRP) suggests that CRP does not, by itself, cause atherosclerotic disease. CRP is therefore simply a marker for conditions that heighten inflammatory responses.
The AstraZeneca people sponsored the enormous JUPITER study of the statin drug, Crestor, that has been causing a stir, mostly glowing pronouncements of how the world would be a better place if everyone took Crestor.
In JUPITER, nealry 18,000 people (men 50 years and over, women 60 years and over) took 20 mg per day Crestor for two years. Participants all had starting LDL cholesterols in the "normal" range of no higher than 130 mg/dl and elevated CRP of 2 mg/dl or greater.
Crestor treatment resulted in 44% reduction in nonfatal heart attack, nonfatal stroke, hospitalization for unstable angina, revascularization (bypass surgery, stents) and death from cardiovascular causes. The reduction in nonfatal heart attack was most marked at 55%.
Admittedly, these are impressive results. Benefits held true for both males and females. At the very least, JUPITER should put to rest some of the fringe arguments that statins do not reduce cardiovascular events. They do. There is no sense in arguing against that. While we might argue about the value of statins in various subsets of people, there is no doubt that they do indeed exert a significant effect.
However, contrary to the hype and broad pronouncements of my colleagues, my concerns are:
1) Rather than shotgun the inflammatory response with a statin drug regardless of cause, doesn't it make more sense to ask why a specific individual has an increased CRP in the first place? For instance, if the answer is vitamin D deficiency, doesn't correction of the deficiency make more sense? (Vitamin D by itself reduces CRP around 60%--more than statin drugs.) Not to mention you obtain all the extraordinary benefits of vitamin D restoration, such as reduced cancer risk, increased bone density, relief from winter "blues," rise in HDL, etc. How about junk foods, obesity, and unrelated inflammatory conditions? Would we therefore indirectly be treating obesity with Crestor?
2) Crestor 20 mg per day, contrary to the study and to many statin studies, will not be tolerated for long by the majority. Muscles aches are not common--they are inevitable , sometimes incapacitating. While JUPITER showed 15% of both treatment and placebo groups experienced muscle effects--no different--this is wildly contrary to real life.
3) While there was a 55% reduction in the number of heart attacks, there continued to be a substantial number of heart attacks in the Crestor treatment arm. Clearly, reduction of CRP with Crestor, while helpful, is not a cure.
I view studies like JUPITER as simply an interesting piece of semi-scientific evidence, tainted to an unknown degree by commercial interests (including those of Dr. Paul Ridker, one of the principal investigators). It is not a mandate to use Crestor carte blanche in people with elevations of CRP.
My interpretation of these data in a practical sense is that Crestor 20 mg per day as sole therapy is useful in a disinterested, non-compliant patient who is unwilling to make substantial changes in lifestyle and nutrition. Helpful? Yes, but hardly an invitation for the world to take Crestor.
I believe that doesn't include any of the readers of this blog.