What is colesterol or cholesterol?

Colesterol (Spanish for cholesterol) is a steroid that plays an important function in the body. It is used in many different cells to make important structures. That said, cholesterol also plays a major role in heart disease.

From a general perspective, there are two main types of cholesterol: low density lipoprotein, LDL, high density lipoprotein, or HDL. The general rule is that LDL is “bad,” and HDL is “good,” though what that means isn’t exactly clear.

Heart disease can occur when cholesterol builds up on arteries and helps in the formation of a plaque. This can be fatal because the plaques can clog the blood vessels completely. Imagine a lead pipe with a big pile of goo in the middle – water wouldn’t be able to go through it.

That’s what happens in your body pretty much, with cholesterol and your body’s own form of goo.

Additionally, the plaques can break off and float around, which doesn’t sound too bad. That is, until they reach a small enough blood vessel that they can block entirely, causing anything ranging from a stroke, deep venous thrombosis, or heart attack.

Colesterol or cholesterol is reused by the body, and you get a lot of it from your diet.

Some major medications lower cholesterol levels such as the statins.

What are healthy cholesterol levels?

As per the American Heart Association, total cholesterol levels should be lower than 200 mg/dl.

LDL levels should be optimally below 100 mg/dl

100 to 130 mg/dl is not too high risk of disease

130 to 160 mg/dl is moderately elevated

160 mg/dl and up is at significant risk of disease

HDL levels should be optimally be above 60 mg/dl

Less than 50 mg/dl of HDL is high risk for women

Less than 40 mg/dl of HDL is high risk for men

Coronary heart disease (CHD) is the single biggest cause of health problems and death in the USA and the world.

Statins offer a way to help treat CHD, but have become perhaps too heavily pushed. And the target level of cholesterol to reach may have been lowered too far.

What causes CHD?

CHD is most often caused by the build up of plaques on arteries and other blood carrying vessels. The plaque is made of various components, but deposits of cholesterol tend to play a key role. When it becomes too thick, it can stop blood flow, causing a heart attack or other damage.

The plaque can also break off and float around the body. If that happens, it can harmlessly dissolve. Or it can clog a blood vessel pretty much anywhere, potentially causing a stroke, heart attack, or thrombosis.

Statins discovered

The late 1980s heralded the discovery of a class of drugs called the statins.

These medications, technically termed 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors, lower levels of cholesterol. Because of the role cholesterol plays in plaque formation, the statins were found to dramatically decrease risk of serious heart damage.

Statins were so effective that a lot of influential doctors argued that the lower cholesterol levels were, the better. LDL, or low density lipoprotein, was specifically targeted. And in the early 2000s, aggressive new targets for treatment were released. LDL levels should be lowered below 100 mg/dL.

But a lot of the proponents of the new, lower levels were found to be on the pay for major drug companies. And it’s not entirely clear if aggressive lowering of LDL levels provides the most benefit.

LDL must be lowered?

It’s most likely that lowering of LDL follows a logarithmic pattern. In at risk patients, a small reduction provides a major reduction in risk of having a heart attack. As levels are lowered even further, however, the benefit becomes increasingly smaller.

A few major studies support the idea that LDL levels shouldn’t be over aggressively lowered. The HARP study showed that lowering levels below 100 mg/dL showed no increased benefit.

The WOSCOPS study gave similar results, as well as AFCAPS.  Additionally, several major studies into the non-statin drug Ezetimibe showed that its reduction of LDL did not mean better clinical results for patients.

Potential side effects:

There may be a downside to over aggressive treatment.  Low levels of LDL may theoretically contribute to hemorrhagic stroke. Statin therapy does have side effects including myopathy and we know especially little about the effects of the high doses needed to achieve the lowest levels of LDL.

Some data show a slight increase in certain types of cancer for statin use, although such an effect may be statistically insignificant.

Conclusion

There is no doubt that statins have played a major role in reducing heart disease across America. But it is also not entirely clear who should be given them, and how heavily they should be used.

With the guidelines for cholesterol treatment being written substationally by doctors on the payroll of major drug companies, skepticism is called for.

Sources:

The Aggressive Low Density Lipoprotein Lowering Controversy
“The Lower the Better” in Hypercholesterolemia Therapy: A Reliable Clinical Guideline?

Cholesterol lowering medications have been increasingly prescribed in the United States. The best selling medication of all time is Lipitor, one such drug. This blog will be exploring statin use and safety over the next week.

A recent non-statin drug is Ezetimibe. It was discovered by Shering-Plough as part of research into reducing LDL, or low density lipoprotein. And it’s pretty good at doing that.

Unfortunately, it’s not entirely clear how much clinical benefit it offers. Several large studies sponsored by the drug company showed that use of Ezetimibe alongside simvastatin did not mean less risk of adverse heart events.

And one of the studies even showed that Ezetimibe use slightly increased risk of developing cancer.

The ENHANCE study showed that Ezetimibe did not help decrease the intima-media thickness as opposed to standard treatment. The SEAS study showed that it did not have significant clinical impact.

Despite the lack of evidence, Ezetimibe is still being prescribed heavily. It’s clinical uses are not entirely clear, and it seems that it should not be a first line treatment.

Sources:

Is There a Problem With Ezetimibe or Just ENHANCEd Hype?