Thursday, March 02, 2006

Statins and HDL

Continuing the discussion of the role of HDL cholesterol and heart disease, we have a study that indicates treatment with a cholesterol-lowering statin can significantly reduce the risk of heart disease and death only in those elderly individuals with low HDL.

Researchers examined the role of lipoproteins including high-density lipoprotein (HDL) cholesterol and low-density lipoprotein (LDL) cholesterol in persons over the age of 70, and found that HDL was a better predictor of cardiovascular risk and treatment benefit than LDL in this group.

In the study, at-risk men and women aged 70 and older were given a statin or placebo. Those with initial HDL cholesterol levels below 45 mg/dL who received statin therapy were one-third less likely to have a non-fatal heart attack or die of heart disease. In contrast, men and women with higher levels of good cholesterol did not appear to benefit from statins.

“We did not expect the benefits of statin therapy to vary according to starting HDL level. Also, unlike statin studies in younger persons, LDL was not what mattered."

“Since we knew from epidemiological studies that LDL has virtually no association with coronary risk in the elderly and also that a statin’s primary effect is to lower LDL, some questioned whether the drug would do any good at all in this age group.”

At the start of the study, two groups had average HDL levels of 50 mg/dL, average LDL levels of 147 mg/dL, and average total cholesterol levels of 221 mg/dL. At 3.2 years follow up, researchers found no association between baseline LDL levels and the risk of a coronary event in either the statin or placebo groups.

“If statin therapy could be targeted to at-risk elderly with low HDL levels who would benefit most, fewer people would have to be treated — a substantial time and cost saving,” said Packard.

So why do statins help only those elderly with low HDL levels?

“Since low HDL is associated with high inflammation, itself a risk factor for heart disease, and we know statins have anti-inflammatory properties, [the] working hypothesis is that statins block inflammation and thereby reduce the deleterious effects of low HDL, researchers said.

In another interesting study, HDL, not LDL cholesterol levels influence short-term prognosis after acute coronary syndrome (ACS). The finding suggests that the clinical benefit of the statin, atorvastatin, after ACS is mediated by qualitative changes in the LDL particle and/or by non-lipid-lowering effects of the drug.

Are they referring to inflammation reduction? Is this why a high HDL is so effective and why many biotechs are focusing on raising HDL?

What can you do naturally, now, to raise HDL?

So, let's do an unscientific study. Your homework for the weekend: Ask somebody, over age 70, without heart disease, and not on a statin, what his or her HDL level is. Let us know.

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