BAD NEWS ON CHOLESTEROL

By Christine Gorman

First the doctors were warning all of us about the artery-clogging dangers of plain old cholesterol. Then we had to start keeping track of "good cholesterol" and "bad cholesterol." Now comes the latest complication: really bad cholesterol. Its scientific name is lipoprotein(a), or Lp(a), and after years of preliminary evidence, researchers have now firmly established just how bad it is. A study published in last week's Journal of the American Medical Association says high levels of Lp(a) in the blood can double a man's risk of having a heart attack before the age of 55. Worse yet, conventional cholesterol tests do not pick up the presence of Lp(a). Doctors estimate that up to 1 person in 5 has an elevated level of the fatty substance in the blood.

The survey of 2,191 men is part of the much larger, ongoing Framingham Study, which since 1948 has poked, prodded and bled two generations of men and women to uncover the roots of heart disease. It could help solve a medical problem that has long frustrated cardiologists: Why do some people with normal cholesterol levels have heart attacks? According to Dr. Andrew Bostom of Tufts University, who led the research team, all the men entered the study with no signs of heart disease. And even today their total cholesterol counts are only slightly elevated, averaging 200 mg/dL. (Women also participated in the research, but so few suffered heart attacks that the results were not statistically significant.)

During the 15-year investigation, however, 129 of the men developed premature heart disease--a result comparable to that for men with total cholesterol counts in the danger zone of 240 mg/dL. Blood tests revealed one important reason: as long as the subjects had high levels of Lp(a), it didn't matter if they had normal levels of HDL, the so-called good cholesterol, and LDL, the so-called bad cholesterol.

The results could complicate matters for doctors. No one knows where Lp(a) comes from or what its normal role in the body is. Scientists believe people's Lp(a) levels are 90% determined by their genes. Lp(a) may promote cholesterol buildup on artery walls. But there is no sure way to reduce high levels of it, although the Framingham researchers speculate that aspirin, which thins the blood, may mitigate its effects. Preliminary evidence also suggests that red wine may drive down the levels of Lp(a)--possibly explaining why the French can eat lots of high-fat foods without suffering high rates of heart disease.

Even if aspirin and Bordeaux turn out to be dead ends, a routine test for Lp(a) could prove a life-saver for men with other risk factors. The researchers found that study subjects with high levels of both Lp(a) and LDL had an especially high risk of premature heart disease. So even though such people can do nothing about their Lp(a) levels, lowering their LDL through a low-fat diet and drug treatment is more critical for them than it is for most people.

The same logic applies even more powerfully to smoking. Smokers in the study were four times as likely to develop early heart disease as nonsmokers, no matter what their Lp(a) level. "Smoking," says Bostom, "blows everything out of the water in terms of being a risk factor for coronary disease." Men who light up almost don't need to worry about cholesterol of any sort. They have a much bigger problem to deal with.

--By Christine Gorman. Reported by Marguerite Michaels/New York

With reporting by MARGUERITE MICHAELS/NEW YORK