Is HDL-C Really Protective Against Heart Disease?

[zoobyshoe]

"Good" Cholesterol in Doubt

Now, a new study that makes use of powerful databases of genetic information has found that raising HDL levels may not make any difference to heart disease risk. People who inherit genes that give them naturally higher HDL levels throughout life have no less heart disease than those who inherit genes that give them slightly lower levels. If HDL were protective, those with genes causing higher levels should have had less heart disease.

Researchers not associated with the study, published online Wednesday in The Lancet, found the results compelling and disturbing. Companies are actively developing and testing drugs that raise HDL, although three recent studies of such treatments have failed. And patients with low HDL levels are often told to try to raise them by exercising or dieting or even by taking niacin, which raised HDL but failed to lower heart disease risk in a recent clinical trial.

http://www.nytimes.com/2012/05/17/h...esterol-found-not-to-cut-heart-risk.html?_r=1

 

[lisab]

Damn! My "good" cholesterol has always been really, really high! My ace in the hole is a joker .

 

[Ivan Seeking]

I just drink a lot of coffee and hope for the best.

 

[zoobyshoe]

Damn! My "good" cholesterol has always been really, really high! My ace in the hole is a joker .

They've been tooting this as fact for quite some time now, and doctors even prescribe regimens to raise the "good" cholesterol. This quite undercuts faith in the medical establishment.

 

[turbo]

My faith in the medical establishment has been shaken to the core, anyway. My "good" cholesterol numbers have been quite high for decades, despite the fact that I can happily survive on cheeseburgers, if left to my own devices.

 

[gravenewworld]

Amazing what a healthy diet and exercise will do. You likely won't even have to worry about any of this.

 

[CDTOE]

I hate these medical studies. Everyday there's a new study contradicting previous studies, which then lead to the creation of health paranoia. I find it silly when a news channel report that researches have found that apples, or anions or whatever help to reduce heart disease and the rest of blah blah. It's like they have brought a groundbreaking discovery. Next day, I may find them reporting that researches have found that soda drinks decrease the possibility of having a heart attack.

Man, my ancestors who lived in the past 50-100 years, were very healthy, active and strong. Their diet was mostly dates, barley and wheat, all of which were farmed by them in their own farms. Their lifestyle made them that way, whereas modern lifestyle has brought health obsession to the mainstream, thanks to all different kinds of unhealthy food that the world is saturated by. From fast and genetically modified food, to food filled with poisonous materials.

 

[zoobyshoe]

Now, it seems, "bad" cholesterol isn't so bad. In fact, there's no such thing as "good" or "bad" cholesterol. If fact, get this, cholesterol turns out not to even be cholesterol!

Cholesterol is a strong and wonderful anti-inflammatory and a potent antioxidant. Shocked? Obviously, you don't want levels to run amok, but there is a point where you could lower excessively, and that's unhealthy.

Well-designed studies have demonstrated that cholesterol can block two different pathways responsible for inflammation and pain, 5-LOX and 5-COX. For the record, prescribed anti-inflammatories often work on those two pathways, but if you have enough natural cholesterol, it is doing the work ... without cramping your legs and making you weak!

We commonly refer to our "bad" LDL cholesterol and our "good" HDL cholesterol. LDL and HDL are not even made of cholesterol! They are fatty proteins, hence the name "lipoprotein" where "lipo" means fatty and "protein" means just that.

There is no such thing as "good" or "bad" cholesterol. LDL stands for low-density lipoprotein, and HDL stands for high-density lipoprotein. LDL is nothing more than a carrier molecule, that shuttles cholesterol (fat) to the tissues. You don't want too many deliveries of fat to your arteries and organs. HDL removes the fat from your tissues and returns it to the liver. That's why you are trying to raise HDL, while lowering LDL.

http://www.tulsaworld.com/scene/article.aspx?subjectid=361&articleid=20120519_222_D4_bDearP4428

 

[phinds]

My favorite advice from the medical world is, unfortunately, a spoof, but it is exactly what they SHOULD say, seems to me. The quote is

"As far as we in the medical community are concerned, regarding diet, we don't have a damn clue what's good for you and we wish you would stop asking !"

 

[nobahar]

I was under the impression the ratio is important:

From The LDL to HDL Cholesterol Ratio as a Valuable Tool to Evaluate Coronary Heart Disease Risk, Fernandez and Webb (2008).

"A more tenable option that has been proven to be an accurate predictor of cardiovascular risk is the LDL-C/HDL-C ratio, which can be obtained from a standard lipid profile and is more accurate than LDL-C or HDL-C alone... Changes in ratios have been shown to be better indicators of successful CHD risk reduction than changes in absolute levels of lipids or lipoproteins..."

I think the paper is open access.

 

[Rooted]

My favorite advice from the medical world is, unfortunately, a spoof, but it is exactly what they SHOULD say, seems to me. The quote is

"As far as we in the medical community are concerned, regarding diet, we don't have a damn clue what's good for you and we wish you would stop asking !"

Haha! I like it!

Seriously though, we are all scientists. Every theory is only a theory, right? The best theory stands until it is disproven. I know there is a tendency to think any medical study is corrupt because of 'evil pharma' companies, and 'money grabbing' doctors and other things, but there is a lot of good work going on out there, at least in my opinion. Each thing learned seems to open up so many more things still to find out.

Interestingly this study is not really news. A big meta-analysis back in 2004 showed a similar outcome. http://doctor.cardiovalens.com/newcvd/navnewsdisplay.asp?newsid=6613&cat=cvd

 

[SW VandeCarr]

Very rarely do to these kinds of studies establish causal connections. The lipid value that correlates best with fatal MIs and some other cardiovascular (CV) outcomes is the total cholesterol/HDL-C ratio. Ratios below 4 are considered lower risk. Ratios above 5 indicate higher risk. While elevated LDL-C is correlated with higher risk, as many as half the MIs occurred in men with normal LDL-C levels in some studies. Many now believe that inflammation associated with unstable plaques in the coronary arteries (leading to clot formation) is the precipitating event for many MIs. High levels of C reactive protein (CRP) are correlated with this kind of inflammation. I gave some references in a previous thread in this forum (Bohm2:Statin therapy for healthy people with high cholesterol) . HDL-C is believed to play a role in stabilizing these plaques by removing LDL.

Statins have never been considered very effective in raising HDL-C. They are effective in lowering LDL-C, but with one exception (rosuvastatin, Crestor), they are only approved for reducing future MIs in MI survivors (secondary prevention). The most dramatic increases in HDL-C seem to be associated with increased exercise. HDL-C exists in 5 known fractions, and it's the heaviest fractions that seem to be most effective. It may be that certain people with very high levels of HDL-C (possibly hereditary) have more of the lighter fractions which are less resistant to oxidation.

http://www.jci.org/articles/view/1649

http://heartdisease.about.com/cs/cholesterol/a/raiseHDL.htm

http://www.ncbi.nlm.nih.gov/pubmed/15459089

 

[SW VandeCarr]

http://www.nytimes.com/2012/05/17/h...esterol-found-not-to-cut-heart-risk.html?_r=1

I only read the abstract, but it makes no mention of the (total cholesterol)/(HDL-C) ratio. The HDL-C value is included in the numerator. This ratio has been used as a fairly good predictor of the risk of cardiovascular disease for at least 25 years. The greater the ratio, the greater the risk. In any discussion of the effect of HDL-C levels on risk, this ratio should be mentioned. If there are increases in LDL-C and/or VLDL-C (which contain triglycerides) in addition to HDL-C, then the ratio may stay the same or increase. Evaluating HDL-C alone would not be an adequate analysis in terms of risk evaluation.

EDIT: If anyone read this with a discussion of the statistical significance of the finding, it was deleted because I read the significance level as p=0.085 when it was in fact p=0.85, meaning there was no evidence of an effect of HDL-C alone on the risk for an MI. In post 12, rooted linked to a study where the significance level for an effect was p=0.08 which would not be statistically significant at the usual level (p=0.05), but would be suggestive enough to question it's clinical relevance as evidence for no effect. In general, statistical tests are not designed to evaluate the lack of an effect.