Cholesterol Round 2Cholesterol Round 2
Cholesterol, Round 2
The second set of guidelines adds recommendations - and complexity
Many Americans monitor the vicissitudes of their blood cholesterol levels as closely as they follow stock market fluctuations. Investing in their heart's future, they broil instead of fry, eat fruit and pass up the pie, and jag when they'd rather sleep in. Their efforts are paying off. The average American's total cholesterol level now clocks in at 205 milligrams per deciliter of blood, a healthy drop from the 220 of 30 years ago.
But 52 million U.S. adults_or 29 percent_still have cholesterol that's too high. How best to treat them is the focus of a report released last week by an expert panel convened by the National Cholesterol Education Program, a coalition of 40 private and governmental groups coordinated by the National Heart, Lung and Blood Institute. The panel's thick report, its first in five years, emphasizes the need to consider a person's total risk for heart problems in deciding how aggressively to attack high cholesterol. Since few doctors and patients will digest the entire report, the NCEP will soon publish new educational materials for both groups. Meanwhile, the highlights:
"GOOD" Cholesterol
The NCEP's recommendation that everyone be tested not just for total cholesterol bet also for high-density
lipoproteins, or HDLs, is a first. What are HDLs, and check them?
Cholesterol doesn't travel on its own in the blood; it is coupled with protein molecules to form particles called lipoproteins. Some 20 to 30 percent of total cholesterol is carried in the form of HDLs; most of the rest consists of low density lipoproteins, or LDLs. HDL is often called the "good" cholesterol, because it seems to carry cholesterol out of the walls of the coronary arteries, thus preventing blockages from building up. The panel cites population studies showing that the rate of coronary heart disease falls as HDL levels rise. And for every 1 mg/dL drop in HDL levels, the risk of heart disease rises 2 to 3 percent.
What's a desirable HDL level?
The panel reaffirms existing findings U.S. News & World Report June 28, 1993. that an HDL level below 35 mg/dL increases the risk of developing coronary disease. In addition, the report classifies an HDL level of 60 or above as a
negative risk factor that actually protects against heart disease. On average, women-especially premenopausal women_have higher HDL levels than men. As a group, women 20 and older have an average HDL cholesterol of 56 mg/dl, compared with 47 for men that age. The difference probably helps explain why women tend to develop heart disease a decade or so later than men do.
Whir bother testing for HDL? isn't the total figure enough?
What's the bother? HDL can be measured with the same blood sample used to check total cholesterol, and neither test calls for fasting beforehand. Besides, knowing your HDL could put a new slant on your total cholesterol tally. For example, your total cholesterol the generally recommended 200 mg/dl limit only because of an unusually high HDL, not because your LDL is elevated. Or a desirable total cholesterol reading could give you a false sense of security if only a small part of it consists of R In a recent study, researchers at the Cleveland Clinic found that a third of patients with clogged arteries in their legs had total cholesterol levels below 200. Almost half of those people, however, also had HDL levels below the normal range.
Who should have their HDL checked?
The NCEP panel recommends that all adults 20 and older have their HDL as well as their total cholesterol tested at least once every five years. It's best to have the checks done by your doctor,. Mass screenings in shopping malls or supermarkets may not always yield accurate figures. Besides, an abnormal reading should be followed by a talk with a doctor who knows your medical history.
Are all medical laboratories capable of measuring HDL accurately?
Not all labs are up to speed on HDL testing yet, and an inaccurate measurement can be worse than none at all. A large proportion of Americans, especially those in urban areas, do have access to accurate HDL testing. You should ask your doctor for assurance that the lab that does the work uses tests standardized through one of the National Network Laboratories of the Centers for Disease Control and Prevention.
Can you raise your HDL?
The panel notes that losing excess weight, exercising more and stopping smoking can produce a small but worthwhile gain. Some drugs prescribed to lower LDL also raise HDL, among them nicotinic acid and lovastatin.
Which is better, high HDL or low LDL?
LDL, or "bad cholesterol," is still the NCEP panel's main target of cholesterol-lowering therapy. As LDL levels rise, so does the risk of coronary artery disease. A high total cholesterol usually goes hand in hand with a high LDL, which accounts for about 60 to 70 percent of the overall number.
Some doctors advocate using a ratio of total cholesterol to HDL to predict heart disease risk. Why doesn't the panel recommend using this figure?
LDL and HDL are independent risk factors that should be considered individually. Besides, it's not clear whether this ratio accurately predicts heart disease risk in people who have extremely high or extremely low LDL levels.
THE DRUG DILEMMA
I don't like the idea of taking drugs to reduce my cholesterol. What are my chances of success with just diet and exercise?
For three quarters of people with high cholesterol, diet and exercise alone are enough to bring it down to a satisfactory level. And that level might be more liberal than 200 mg/dL, the high end of the so-called desirable range for the general population.
How long should I stick with diet and exercise before adding drugs?
For most people with no prior history of heart disease, six to 12 months is reasonable, unless their LDL is extremely high. If so, drug treatment could be started sooner. For those with such a history, three months is long enough.
Who should have their LDL checked?
In people with no symptoms of heart disease, LDL should be measured if total cholesterol is borderline high (200 to 239 mg/dL)
and HDL is below 35
or at least two other risk factors are present, such as diabetes or high blood pressure. LDL also should be measured if your total cholesterol is 240 mg/dL or higher. LDL should be tested in all patients with evidence of coronary heart disease or clogged arteries elsewhere in the body. You can have all three levels measured at the same time, but the LDL measurement is done after fasting for greater accuracy.
What LDL level is considered safe?
In adults without evidence of coronary artery disease, the NCEP panel considers LDL levels under 130 mg/dL desirable, while 130 to 159 is borderline high. An LDL level of 160 or more is high. But a high LDL alone doesn't necessarily mandate aggressive cholesterol-lowering treatment. For example, because their risk of developing heart disease over the next decade is remote, men under 35 and premenopausal women should receive cholesterol-lowering drugs only if their LDL is above 220, their total is above 300 or if they have multiple risk factors.
If I need drugs, which ones are best?
To lower LDL, the panel said that bile acid sequestrates, such as cholestyramine, and "statins," like lovastatin, are most effective. Nicotinic acid, while effective, requires large doses that often produce unpleasant side effects, especially flushing. Combining more than one drug can dramatically lower LDL with fewer side effects and lower cost. Drugs called fibric acids, which include gemfibrozil and clofibrate, are not recommended because of their relatively modest effect.
THE RISK FACTORS
Who should be put on cholesterol-lowering drugs if diet and exercise don't make enough of a dent?
A third of the people who need cholesterol-lowering medication already have coronary heart disease. The other two thirds are at great risk of developing heart disease because their cholesterol is extremely hig or because it's relatively high and they have at least two other risk factors.
What are these risk factors?
Because heart disease becomes more common as people get older, the NCEP panel has addedage to its list of risk factors. A typical 62-year-old man is 500 times more likely to die of coronary heart disease in the next year than a 22-year-old man. For men, age becomes a risk factor at 45; for women at 55. Several other risk factors besides high total cholesterol or a high LDL should be part of a decision to take cholesterol-lowering drugs. They include smoking, high blood pressure, diabetes, a low HDL level and a family history of early heart disease (before age 55 in a father or brother or before age 65 in a mother or sister).
What about obesity and lack of exercise? Aren't they risk factors for heart disease?
Yes, but they're too commonplace to determine whether someone should be taking cholesterol-lowering drugs. If they were part of the equation, just about everyone with high LDL would have to be placed on medication.
DIET AND EXERCISE
Can vitamin supplements protect against heart disease?
Recent studies have suggested that when LDL undergoes a chemical change called oxidation, it becomes more likely to clog arteries. In addition, population studies have found that vitamins that inhibit oxidation, or antioxidants, do seem to lower heart disease risk. Taken together, these two lines of research have persuaded some scientists of the merits of daily doses of vitamin C, vitamin E and beta carotene, all of which have antioxidant properties. No harm has been associated with this, but there is not yet enough evidence to support recommending antioxidant vitamin supplements to reduce coronary disease risk. The prudent course is to consume the recommended daily allowance of all the major vitamins by elation at least five servings of fruits and vegetables a day.
Could a couple of drinks a day be part of a cholesterol-lowering diet?
Alcohol can raise HDL levels. It's not known, however, whether an alcohol-induced increase actually protects against coronary heart disease. Moderate alcohol consumption also has been linked to lower heart disease rates than abstinence, but a cause-and-effect relationship has not been proved. In addition, the ills caused by excessive drinking are well documented. The NCEP panel does not recommend alcohol consumption as part of a program to reduce the risk of heart disease. Its report supports federal dietary guidelines that advise men against drinking more than two drinks and women one drink a day.
PEOPLE WITH HEART DISEASE
Do different rules apply to people who have heart disease or who have had a heart attack?
The panel found that the majority of people with diagnosed heart disease get much less aggressive cholesterol-lowering therapy then they should. Only about a third of heart disease patients are getting appropriate cholesterol-lowering treatment, yet probably 6 out of 7 actually need it. This neglect is ironic, considering that half of all heart attacks occur in people who have already had one and men with coronary heart disease are five to seven times more likely to have a heart attack than men without it. For heart disease patients, the panel concluded that lowering total cholesterol to levels acceptable for the general population doesn't go nearly far enough. Instead, these people should strive to reduce their total cholesterol below 160 and their LDL below 100. As many as a third of the 12 million Americans who have coronary disease need medication to get their cholesterol levels that low.
When it comes to lowering cholesterol, can there be too much of a good thing?
In heart disease patients, lowering cholesterol with drugs almost certainly extends lives. In people without heart disease, though, some studies have raised the possibility that cholesterol-lowering drugs might actually
shorten lives. While the drugs clearly reduce the risk of heart attacks, some clinical trials suggest that such therapy might somehow increase the chance of dying from violence, accidents or cancer. These studies weren't designed to determine whether the higher death rates were due to the drugs or to chance. But they do fuel the argument for using drugs sparingly in people without heart disease symptoms, because they stand to gain less than those who are already sick. A cholesterol-lowering diet, which has not been associated with increased deaths from other causes, should be the main treatment for most people who have no symptoms of heart disease.
THE OBESITY FACTOR
How much responsibility does obesity bear for unhealthy cholesterol levels?
Losing just 5 to 10 pounds can lower LDL. In fact, the drop can equal the decline due to eating smaller amounts of saturated fat and cholesterol, according to the NCEP report. Finally, weight loss has been shown to raise HDL.
How else does obesity contribute to heart disease?
It raises blood pressure and increases the likelihood of diabetes, according to the panel. Both are risk factors for heart disease.
WOMEN AND THE ELDERLY
Do the same treatment recommendations apply both to women and to men?
Most studies linking lowered cholesterol with reduced heart disease risk have involved middle-aged men. Men in their 40s are four times likelier to die from coronary heart disease than women that age, but the difference is cut in half by age 70. Over age 65, coronary heart disease is the leading killer of women. The NCEP panel recommends that older women with elevated LDL should try to lower it with diet (making sure to get enough calcium to protect against osteoporosis) and exercise.
Should postmenopausal women take drugs or use hormone-replacement therapy to lower their cholesterol?
Research has shown that oral estrogen - already proved to reduce the risk of osteoporosis - lowers LDL levels by 15 percent and raises HDL by about the same amount after menopause. Studies of postmenopausal women without heart disease have found that oral estrogen replacement cuts the risk of developing it in half. In postmenopausal women with heart disease, the apparent benefit of oral estrogen is even greater. These population studies did not take into account whether the women taking estrogen had fewer heart disease risk factors to began with than those not on the hormone. Still, the NCEP panel concludes that there is enough evidence to suggest that postmenopausal women who are candidates for cholesterol-lowering drugs might do well to consider estrogen replacement as an alternative. Because estrogen use raises the risk of uterine tumors, women who opt for it should be monitored for any signs of precancerous changes.
What about the elderly?
Like women, elderly people generally have been omitted from studies focusing on prevention of heart attacks. However, the process underlying coronary artery disease in later life probably is the same in middle age. In addition, small studies have shown that diet and drugs lower cholesterol in the elderly at least as effectively as in younger patients.
Should all elderly people with high cholesterol be treated?
Aggressive cholesterol-lowering therapy should benefit elderly people who are in relatively good health, according to the NCEP panel. But studies in middle-aged men have shown that it takes at least two years for cholesterol-lowering drugs to reduce heart disease risk. Therefore, frail elderly people probably would not benefit significantly from such therapy.
What can I expect when the treatment panel releases its third report?
The second report, with its new recommendations about HDL, hints at what's yet to come. Just knowing your total cholesterol, or even your total and your LDL, isn't necessarily good enough anymore. Eventually, a variety of other measurements besides total cholesterol, LDL and HDL might help fine-tune decisions about who's most at risk for heart disease if not treated.
