Since 1987, the National Cholesterol Education Program has been trying to get Americans to "know their cholesterol."
That campaign resulted from studies over the past 20 years linking an increased level of cholesterol in the bloodstream with a greater incidence of heart attacks and coronary-related deaths - the No. 1 cause of death in America.The proliferation of simple pin-prick cholesterol blood tests - available everywhere from grocery stores to health fairs - has been part of the program's educational effort.
Unfortunately, such tests may be inaccurate and misleading, said Gregory C. Critchfield, a medical director at Utah Valley Regional Medical Center.
"Measurement (of cholesterol) by pin prick hasn't been validated for accuracy or precision," he said. "It measures total cholesterol, which doesn't give a full picture of whether someone is at risk."
Such tests may have a margin of error of 20 percent, Critchfield said. And while a cholesterol value of less than 200 mg/dL is desirable, some people with levels below that are still at risk.
The laboratory at UVRMC has devised a serum lipid screening program that provides a more in-depth analysis of cholesterol level, as well as a correlation of how an individual's level compares to that of others of the same sex and age.
The $12 blood test, performed after a 12-hour fast, breaks total cholesterol level down into three components: total cholesterol, triglycerides and HDL-cholesterol (the good cholesterol that helps the body get rid of excess cholesterol). Then, LDL-cholesterol (the cholesterol associated with narrowing of the arteries) is computed based on the other three levels.
The level of each component is measured and then compared to a data base of 48,000 patients to take into account age- and sex-related differences in cholesterol levels.
A breakdown of these levels and comparisons is provided to the patient, along with a summary of the patient's cardiac risk and, if needed, recommendations for dietary changes or follow-up medical treatment.
"By giving a more complete profile of a person's risk we can say more about what to expect," said Critchfield, who wrote the computer program being used for UVRMC's lipid survey program. "The state of the art is currently going to a grocery store and getting a finger prick and finding out you need follow-up care. This offers a significant advantage over that."
Because the new test is referenced to nationally established standards, it is highly accurate. Also, the laboratory is able to maintain greater control over testing procedures, thus ensuring greater precision in test results.
"One out of every two Americans has elevated cholesterol because of what we eat and because many of us are sedentary and don't exercise," Critchfield said. "We feel it is important to offer this to people so they can figure out where they stand."
Cholesterol and you
- Heart disease is the No. 1 killer in the United States, claiming over 550,000 victims a year.
- More than half of all middle-age Americans have total cholesterol levels over 200 milligrams/deciliter.
- Most heart attacks occur in people with total cholesterol levels between 200 and 240 mg/dL.
- The average American diet results in a daily cholesterol intake of 350-450 mg/dL.
- For every 1 percent reduction in cholesterol, there may be a 2 percent reduction in the incidence of heart disease.
- Changes in diet and exercise can result in lower cholesterol levels within as little as three months.