LDL cholesterol: Low, lower, and lower still

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LDL cholesterol: Low, lower, and lower still

A federal panel of experts released a revised set of cholesterol guidelines in July, 2004. The overall message on "bad" LDL cholesterol is much the same as it has been: Lower is better and how low your level should be depends on your cardiovascular risk factors.

But the standard for what low LDL means keeps on getting lower. These revisions say that an LDL level under 70 should be a "therapeutic option" for people at the highest risk for cardiovascular disease; the previous guidelines set under 100 as the LDL goal for people at high cardiovascular risk and didn't have a separate very-high-risk category or mention therapeutic options. The revisions also ratchet down the thresholds for prescribing cholesterol-low erin g medications, so more people will be advised to take pills to meet LDL targets. ( For more detail on the revisions see "LDL Targets" below .)

The main impetus for the revisions came from some pretty remarkable results from studies of the statin drugs such as atorvastatin (Lipitor) and simvastatin (Zocor). The studies involved only people with heart disease, so the lessons learned don't directly apply to everyone, but there are certainly enough people with heart disease to make them important. Two findings stand out. First, if LDL levels are pushed down to 60 or so with statins, the risk of heart attack and other cardiovascular events falls further than if LDL levels are pushed down to just 90 or so. How much further varied with the study, but it was enough to matter. Second, although statins have been known to cause serious liver and muscle problems, side effects in these studies were relatively rare, and they were large studies involving thousands of people.

You can try to lower your cholesterol levels by changing what you eat, but studies have shown that the average person achieves only modest reductions (4%-13%) through dietary changes alone. Standard doses of statins reliably lower LDL levels by 30%-40%, so as a practical matter the vast majority of people who need to significantly cut their LDL levels need to take a statin.

The latest guidelines just tweak advice directed at people in the higher cardiovascular risk groups, but they are important because they're part of a larger trend. Over the past 20 years as new evidence about LDL rolls in, experts have been pushing their recommendations about the "ideal" LDL level lower and lower. So far, the experts recommend statins only for people who have heart disease or major heart disease risk factors. But that could change. Some are already saying that many more people should be taking statins and that everyone should try to lower their LDL levels. The average American LDL level is now about 130.

We're not there yet, but perhaps someday there will be a consensus that nearly everyone should make aggressive attempts to lower their LDL cholesterol with statins. If the overall LDL recommendation were to become 50-70, taking a statin may become part of the daily health routine.

LDL targets

If you are at.

Guidelines say.

Very High Risk

Presence of established cardiovascular disease and one of the following:

Multiple major risk factors for cardiovascular disease, especially diabetes
Severe and poorly controlled risk factors, especially smoking
Multiple risk factors for metabolic syndrome, especially high triglycerides (200 or over) and low HDL (below 40)
A history of heart attack or unstable angina.

An LDL of less than 70 is a "therapeutic option" if you fall into this new category.

High Risk

A history of heart disease (heart attack, unstable or stable angina, a heart procedure such as angioplasty or bypass) or one of the following:

Diabetes
Evidence of diseased blood vessels (peripheral artery disease,blocked carotid arteries, transient ischemic attacks, etc.)
Two or more risk factors for heart disease (cigarette smoking, high blood pressure, a family history of premature heart disease, age).

An LDL of less than 100 achieved with cholesterol-lowering medications if lifestyle changes haven't lowered it to this level.

Moderately High Risk

Having two or more risk factors for heart disease that create a 10%-20% chance of having a heart attack in the next 10 years.You can find a heart attack risk calculator at www.nhlbi.nih.gov/health/index.htm#tools.

An LDL of less than 130, but a "therapeutic option" to lower your LDL to less than 100.

Moderate Risk

Having two or more risk factors for heart disease that create less than a 10% chance of having a heart attack in the next 10 years.

An LDL of less than 130.

Low Risk

Having one or no risk factors for heart disease

An LDL of less than 160.

November 2004 Update