Wednesday, January 16, 2008

Zetia is No Zocor!

Ok, so I wanted to talk a little bit today about cholesterol and how the human body is often misunderstood. In the ENHANCE trial which tested the effect of Vytorin (ezetimibe and simvastatin combined) versus Zocor (simvastatin alone), results showed that the Vytorin, was no better than the Zocor by itself.

Why did this study get such a big press coverage? Because Zocor costs about 4 USD at WalMart whereas Vytorin can runs hundreds of dollars. But more importantly, it speaks to the fact that what we thought we know about heart disease and atherosclerotic plaques may not be the whole story. This is a very important point.

I urge caution with these test results though. The study only assessed the reduction of cholesterol plaque, NOT, I repeat, NOT a clinical outcome such as reduction in heart attack or stroke. It's not like the original Vytorin studies covered this well either though.

Why do statins work? No one know. Maybe it is a reduction in inflammation, maybe it is the lowering of LDL, maybe it is some pathway none of us know about. This is why GWAS(GenomeWide Association Studies) are so important, they give us clues into what causes a disease by unbiased search of the genes in our body. If we put all our eggs in the cholesterol basket, then, as this study suggests, then we could end up pretty hungry, and pretty poor.
In a recent study published in the journal Nature Genetics, there is an article which identifies new genes linked to high cholesterol and triglycerides (The building blocks of atherosclerosis)

These genes or regions of DNA could be new targets for drug discovery. The problem I have is, until we know what the true cause of heart disease is, designing drugs based on our assumptions could be just as useless as Zetia (the other drug in Vytorin)

The Sherpa Says:
What does this have to do with personalized medicine? Everything! We must challenge old assumptions and cast a doubt on new things that have not been validated. This study should remind us "All that glitters is not Always gold, But Does always have a hell of a marketing team behind them"

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