Does Cholesterol Really Count?
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Does Cholesterol Really Count?

Is high LDL worse than low HDL? And how low do you have to go, anyway? If you're confused, you're not alone.

Understanding Cholesterol

It has been drummed into our heads by doctors that keeping cholesterol in check is one of the best ways to avoid a heart attack. Nevertheless, many of us are still confused about the best ways to tame cholesterol. For starters, it doesn't help that there are four different numbers to measure cholesterol and triglycerides, the other blood fat that affects heart health. Which levels count the most depends on your individual health situation. Your total cholesterol count and level of low-density lipoprotein (LDL), the so-called bad cholesterol, are only two pieces of a complicated puzzle. Also important are your levels of high-density lipoprotein (HDL), the "good" cholesterol, and triglycerides, another blood fat that affects your cholesterol levels. An additional key difference is the type of LDL you have: One kind may put you at much higher risk of dying of heart disease than the other. All these factors go into figuring out what you need to do to keep your heart strong -- and whether reaching those goals requires taking medication. Here, the latest, best advice.

Is 200 the Magic Number?

Not necessarily. To keep the low-cholesterol message simple, that's the number doctors have focused on for the past decade: Keep your total cholesterol level -- the sum of your "good" HDL and "bad" LDL cholesterols and 20 percent of your triglycerides (the third blood fat) -- below 200 and you're in the clear, we've been told. But the truth is a lot more nuanced. If total cholesterol is below 200 because you have very low HDLs, you're not out of danger. And if it's slightly above 200 because your HDLs are high, you may be okay. Protecting yourself begins with knowing your levels of all three blood fats and what scores you need for a healthy heart.

The Ideal Numbers for Women

LDL cholesterol below 100 milligrams per deciliter
LDL in your blood causes the buildup of fatty plaque inside the walls of your arteries. This narrows your blood vessels, creating a condition called atherosclerosis, which makes people more vulnerable to heart attacks and strokes from blood clots that block circulation to the heart or brain.

HDL cholesterol above 50
HDL in the blood works like a mop to sponge up excess LDL in the blood vessels and cart it to the liver for disposal. Young women often have more HDL than men. When estrogen levels drop after menopause, HDL does, too -- that may be why women on average get heart disease at least a decade later than men, usually after age 60.

Triglycerides below 150
This blood fat is a source of fuel for active muscles. When the body produces too much, however, the excess is stored in the fat cells and the liver. As you triglyceride level rises, your liver may produce less HDL and your LDL particles can become dangerously small and dense (see "LDL and Heart Attack Risk").

LDL: How Low Should You Go?

Everyone agrees that having too much LDL cholesterol in your blood raises your risk of heart attack and stroke. The push in recent years has been to ratchet down LDL cholesterol to lower and lower levels, which most people can't reach without medication. How low do you really need to get for maximum protection? The answer depends on your level of heart disease risk.

Not everyone whose LDL level is higher than the 100 that experts call ideal is in danger. LDLs of 130 may be considered satisfactory if you're considered only at moderate risk of having a heart attack, according to the most recent American Heart Association guidelines. That means you have one or more of the following risk factors: high blood pressure, a family history of heart disease, high LDL cholesterol levels, poor diet, cigarette smoking, physical inactivity, obesity, coronary calcification, or poor stress-test results. However, some doctors recommend pushing LDL cholesterol below 100 if you have only one of these risk factors -- with medication if diet and exercise don't accomplish that goal.

If you're at high risk, on the other hand, an LDL of 100 may be too high. This means you already have heart disease or diabetes or have certain types of artery or kidney disease. High-risk women should aim for an LDL of 70 or less, which generally requires medication. "Every time we make the goal lower, coronary events have dropped," says Nanette Wenger, MD, a cardiology professor at the Emory University School of Medicine.

A new look at the cholesterol-heart health connection at the University of Michigan found that for people at low to moderate risk, whittling LDL cholesterol levels below 130 didn't provide significant benefits. Talk with your doctor about your level of heart disease risk at your next physical, when you go over the results of your blood tests.

 

LDL and Heart Attack Risk

Measuring how much LDL you have in your blood is not the only -- and maybe not even the best -- way to predict your risk of having a heart attack. The newest research links susceptibility to the kind of LDL you have. Your heart disease risk is 300 percent higher if your LDL is in the form of small, dense particles -- called Pattern B -- than if you have lighter and fluffier Pattern A particles. About half of men and women with coronary heart disease have the genetic tendency to make the smaller, denser LDL particles. People are also likelier to have them if they eat too many carbs or are sedentary and overweight.

There is some controversy over whether to screen for particle concentrations. A study last year in the Journal of the American Medical Association said that standard cholesterol tests were sufficient heart disease predictors. In 2006, however, an international panel of scientists from more than 10 countries including the United States, Canada, Australia, and Sweden maintained that measuring the concentration of Pattern B particles is a superior test. Several blood tests are available, costing between $100 and $250, but they may not be covered by insurance unless you already have heart disease.

The reason the tiny particles are so much more dangerous, according to Ronald Krauss, MD, a senior scientist with Children's Hospital Oakland Research Institute, in California, and a leading LDL researcher, is that they aren't removed from the blood by the liver as quickly as the larger ones and are likelier to enter the coronary artery and deposit cholesterol on artery walls. This thickens and inflames vessels, which can help trigger cholesterol plaques to break off and lead to clots, explains Dr. Krauss.

Should you be tested for your blood concentration of small, dense LDL particles? It depends on your triglyceride levels, explains PK Shah, MD, director of cardiology at Cedars-Sinai Medical Center, in Los Angeles. Only people who have triglycerides below 70 are definitely unlikely to have Pattern B LDLs. Those with scores of 250 or more generally do have it. Testing makes the most sense for those scoring between 70 and 250 who also have low HDL and borderline-high LDL, notes Dr. Krauss, especially if they also have a family history of heart disease or related disorders such as diabetes or obesity.

Is HDL the Future of Heart Health?

Boosting HDL, the so-called good cholesterol that can help keep arteries clear of plaque, may be the next important front in the war on heart disease. A 2007 New England Journal of Medicine study found that the lower someone's HDL, the greater her heart attack risk. This was even true of patients who'd whittled their LDLs to 70 milligrams per deciliter, the current goal for those with heart disease, and were taking LDL-lowering medication.

Two niacin-based drugs that increase HDL are already on the market: Niaspan and Advicor (a combination of Niaspan and lovastatin). Niacin works on the liver to slow the body's production of blood fats. It can increase HDL by up to 30 percent, lower triglycerides by up to 20 percent, and convert LDLs from Pattern B to the less-dangerous Pattern A. While the drugs are effective, they aren't widely used because they cause flushing -- redness and tingling of the face -- and rapid heart rates. Cordaptive, a niacin drug that may be on the market later this year, doesn't seem to cause as much flushing and has the same benefits as existing products.

Several HDL-raising drugs that don't use niacin are in the research pipeline, with two possibly available in seven to 10 years if they make it through human testing. In December 2006 the field lost its most promising candidate to date, Torcetrapib, which faltered in late clinical trials because it significantly raised blood pressure. "Eventually we'll find the right way to raise HDL," says Steven Nissen, MD, immediate past president of the American College of Cardiology and chairman of cardiovascular medicine at the Cleveland Clinic.

Are Cholesterol Drugs for You?

There are several types of drugs that affect your heart health by altering your cholesterol count. It's important to understand how each of them works.

Statins: Virtually everyone agrees that statins are genuinely effective for women at high risk of heart attack. These LDL-lowering drugs reduce the chance that a woman with heart disease will die from a heart attack by 29 percent. They interfere with the liver's production of LDL cholesterol -- not only reducing it in women with high cholesterol -- but also slowing buildup of plaque in the arteries and keeping artery walls from hardening.

Statins' powerful preventive effects have prompted many doctors to start giving them to those at lower risk. There's medical debate on this point given that, as yet, there is no conclusive data. For example, a 2004 review by researchers at the University of California, San Francisco found that giving statins to men with risk factors but no actual heart disease did cut their chances of dying from heart problems but the same benefit did not show up for women. What's more, taking statins won't change Pattern B LDLs into safer Pattern A's. Sharonne Hayes, M.D., director of the Women's Heart Clinic at the Mayo Clinic, believes in giving statins to select women at moderate risk because "you don't want to withhold a potentially beneficial treatment."

Statins may be more helpful to women than studies suggest, according to Lori Mosca, MD, director of preventive cardiology at NewYork-Presbyterian Hospital. "Much of our research has looked at heart attack and death. But women are more likely to have angina and stroke than men and both conditions respond well to statins." And, notes Dr. Steven Nissen of the Cleveland Clinic, if studies followed people on statins for longer -- "six, seven, or 10 years, it's possible that even relatively low-risk people would get into an older age group and the benefits might be more evident."

Also review possible side effects: Older women on high doses are reportedly more sensitive than men. Muscle soreness may affect a higher percentage of users, and other side effects include liver irritation, cognitive impairment, and sleep disorders. Discuss the pros and cons in your particular case.

Fibrates: This class of drugs has been shown to reduce triglycerides by about 30 percent and raise HDL by about 9 percent. Fibrates help convert dangerous Pattern B LDL into the larger, less risky A type (niacin drugs also do this -- see "Is HDL the Future of Heart Health?") and may also lower LDLs in some patients. Side effects of fibrates can include liver irritation and -- particularly if you take them in combination with statins -- muscle damage. If you're prescribed the combo treatment, the type called fenofibrates may work better with statins than gemfibrozil does.

Omega-3 Fatty Acids: Over-the-counter omega-3 dietary supplements might help reduce triglyceride levels but lack and FDA guarantee of quality, purity, and potency. There's now a prescription-strength formula approved by the FDA to decrease very high triglycerides. It provides almost 4 grams of a fish-oil derivative, a dose found to lower triglycerides by up to 45 percent and increase HDL by 13 percent.

Originally published in Ladies' Home Journal, February 2008.

 
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