“Apo B” Measurement More Effective Than Simple Cholesterol Counts
In the ongoing search for “the” important marker of cardiac risk, some scientists are now focusing on one you may not have heard of — and your doctor may not be evaluating. It’s a measurement called Apo B, which reveals the number of cholesterol particles in your bloodstream that can clog arteries and lead to a heart attack or stroke. This may be a more useful predictor of risk than the total cholesterol, which is what’s commonly measured.
According to cardiologist Michael Ozner, MD, medical director for the Cardiovascular Prevention Institute of South Florida and author of The Great American Heart Hoax, doctors in Canada routinely test Apo B, but in this country we are just starting to recognize its value.
Apo B stands for apolipoprotein B, a protein that is attached to the particles that transport cholesterol throughout the body. The number of Apo B-containing particles is a crucial measure because they are able to migrate out of the bloodstream and enter blood vessel walls. Once there, they can be retained and oxidized, creating an inflammatory response that can lead to atherosclerotic plaque, which is like a pimple in the artery wall. That, in turn, can rupture and result in a heart attack or sudden cardiac death. So, the more Apo B-containing particles you have, the greater your risk for heart attack and stroke.
Dr. Ozner suggested picturing these particles as cars carrying the cholesterol molecules within like passengers. It’s the number of cars on the highway (not the number of passengers riding in them) that leads to a traffic jam — and the number of particles is what’s important in predicting risk for atherosclerosis. An elevated Apo B level means that you have too many bad particles which put you at risk for heart attack or stroke, irrespective of how much cholesterol those particles contain. A desirable Apo B level is 80 mg/dl or below, Dr. Ozner told me, noting that high-risk patients, such as those who have had heart attacks or strokes, may need to aim for an even lower count.
Dr. Ozner pointed out that in addition to being a better predictor of heart attack risk than the conventional cholesterol blood work-up, the Apo B test is inexpensive and usually covered by insurance. It is widely available. “It is valuable in helping your physician to determine the optimum medical therapy to prevent cardiovascular disease,” he said.