Cholesterol a Mystery to Most

Nov. 6, 2007 -- Nearly all Americans claim to know how to avoid heart attacks, but most of us don't know our cholesterol or blood-fat numbers, a Harris poll demonstrates.

The poll was commissioned by Merck & Co. Inc., which makes one of the cholesterol-lowering statin drugs. The telephone survey of 1,005 U.S. adults took place in September 2007.

Pollsters asked people whether they thought they were fairly informed about how to avoid a heart attack. Nearly everyone -- 95% -- said they did.

But:

• 77% did not know the upper limit of a healthy cholesterol level.
• A third said they had "no idea" what the terms "LDL" or "HDL" mean.
• Half said they knew exactly what "total cholesterol" means.
• Fewer than half knew their LDL and HDL numbers.
• Only 28% knew their triglyceride numbers.

Of course, you as a WebMD reader already know these things. But just in case you're emailing this story to your thinks-he-knows-but-doesn't-know brother-in-law, here are the facts:

• You have two basic kinds of cholesterol: "bad" low-density lipoprotein (LDL) cholesterol and "good" high-density lipoprotein (HDL) cholesterol. There's also very low-density lipoprotein (VLDL), which is also bad.
• Triglycerides are lipids detected in the blood -- think of them as blood fats. High triglyceride levels are bad.
• Total cholesterol is a measure of all the cholesterol and triglycerides in your blood. It's measured in milligrams per deciliter (mg/dL). It's desirable to have a total cholesterol level under 200; at 240 and over, you are at high risk of heart disease.
• Your LDL level should be less than 100, but a level of 100-129 ranges from near optimal to above optimal. LDL levels of 130-159 are borderline high, and those at 160 or above are too high.
• The higher your HDL level, the better. HDL of less than 40 for men and less than 50 for women puts you at higher risk of heart disease.
• Triglyceride levels of less than 150 are normal. Levels of 200 or higher are too high.

Merck reported the poll results at sponsored events held in conjunction with the American Heart Association's Annual Scientific Session in Orlando, Fla.