Cholesterol Screenings: Making Sense of the Results
Unless you live in a cave, you've heard about the relationship between cholesterol and heart disease. But who needs a doctor or tests when you're not sick?
Maybe you do. Clogged arteries don't happen overnight. Active adults with no outward symptoms may have unhealthy cholesterol and fats circulating through their arteries like silent time bombs, ready to explode in a heart attack or stroke.
To Test or Not to Test?
You're at the local pharmacy and a sign catches your eye. Cholesterol testing. Should you get tested? You feel fine, so why bother? Vowing that you don't have time to wait in a long line, you see that a technician is immediately available. Must be an omen. "Is this the cholesterol testing?" you ask.
"It sure is." He hands you a short form on a clipboard. "Fill this out and we'll do a quick finger-stick test and have your results in about five minutes."
No excuse now. You take the form and find that you have to make some choices. Should you have your total cholesterol tested? Total and HDL? A full lipid panel with a 12-hour fast? That's out of the question, because you already ate breakfast. As you waver between the first two choices, you wonder: Who is this technician? Does he know what he's doing?
"Probably," says Tammy Outly, MSN, ACNP-CS, director for the Center for Preventive Cardiology at St. Francis Medical Center in Pittsburgh. Independent cholesterol screening programs fall under the watchful eye of your state health departments, with requirements matching those of regular labs. "If you have no known disease or risk factors, a drug-store test site is probably an okay place to start," she says.
What to Expect at a Test Site
Outly cautions against paying any more than $20 for the tests, noting that $15-$20 is the norm. The person administering the test should also help you identify your risk factors, interpret your test results, refer you to a physician for follow up, and discuss eating habits, exercise, and other ways to control or lower blood cholesterol levels.
Risk factors for heart disease include:
- Gender: male (men have a greater risk of heart attack than women)
- Age (for men, age 45 or older; for women, age 55 or older—earlier with premature menopause)
- Diabetes: Type ]]>1]]> or ]]>2]]>
- Tobacco use (including chewing tobacco)
- ]]>Obesity]]> and overweight (body mass index [BMI] of 26 or above)
- Sedentary lifestyle
- ]]>High cholesterol]]>
- Family history of heart disease (before age 55 in father, or 65 in mother)
- ]]>Metabolic syndrome]]>
- Central obesity (fat accumulation around the core of the body)
- Stress and ]]>depression]]>
- Elevated blood homcysteine, hsCRP, fibrinogen levels
- Low estrogen blood levels (women)
It's not enough that you actually decided to go through with this. Now you have to decide which test to take.
This is a non-fasting screening, and the result tells you how much total cholesterol is in your bloodstream. Until recently, doctors thought that this number was a good indicator of whether or not a cardiac event was in your future; a total cholesterol level of less than 200 milligrams per deciliter of blood (mg/dL)(5.2 mmol/L) was considered good. But according to the Framingham Heart Study, 35% of participants who had a cardiac event such as bypass surgery, ]]>heart attack]]>, or a balloon angioplasty, had total cholesterol levels of less than 200 mg/dL (5.2 mmol/L).
Good and Bad Cholesterol
Low Density Lipoprotein (LDL) is considered the bad cholesterol—the slow-building culprit that binds with other substances to form thick, hard deposits called plaque. Plaque clogs the arteries and blocks the flow of blood, causing heart attacks and stroke. Blood levels exceeding 130 mg/dL is considered high. Lowering LDL cholesetrol from over 175 mg/dL to less than 100 mg/dL can reduce the risk of cardiovascular death by 25%.
High Density Lipoprotein (HDL) is considered the good cholesterol because it carries blood fats away from the arteries. Higher levels are considered protective against heart attack; lower levels of HDL are associated with a higher risk.
"Getting a total cholesterol reading is like getting half a social security number," says Outly. "It doesn't tell you enough. You need to look at the whole picture." When it comes to cholesterol screening, the big picture includes low density (LDL) vs. high density (HDL) cholesterol. If a total cholesterol reading is your only option, get the test and then follow up with your private physician.
Total and HDL Screening
For an overall picture of cardiac risk, the National Cholesterol Education Program recommends total and HDL screening. This non-fasting test measures your total cholesterol level and your level of HDL, or "good" cholesterol. Most importantly, this screening looks at your total cholesterol to HDL ratio.
How is the ratio calculated? Divide your HDL level into your total cholesterol level. For instance, if your total cholesterol level is 213 and your HDL level is 33, your total cholesterol to HDL ratio is 6.5. "A good ratio is less than 4," says Outly.
Full Lipid Panel
This test is done after a 12-hour fast and measures total, HDL, LDL (bad) cholesterol, and another component of fat called "triglycerides." A full lipid panel is recommended for persons who have known heart disease or whose total and HDL cholesterol levels indicate that further evaluation is needed.
Medical research indicates that high blood levels of triglycerides (ie over 150 mg/dL) constitute a risk for heart disease, even when HDL levels are good. High triglyceride blood levels increased the risk of heart disease by 14% in men and 37% in women. Also, high triglyceride blood level is an important component in the metabolic syndrome, a known risk factor for heart disease and diabetes. The metabolic syndrome is found in over 30% of Americans. Treatment for elevated triglycerides usually involves lifestyle changes, including the following:
- If you are overweight, cut down on calories to reach your ideal body weight.
- Reduce the saturated fat and cholesterol content in your diet.
- Reduce your intake of alcohol considerably. Even small amounts of alcohol can lead to large changes in plasma triglyceride levels.
- Start and stick to a regular exercise program.
Interpreting the Results
By the time you've located the aspirin and shampoo, the technician hands you a pamphlet with written results, explaining what the numbers mean. Since your total blood cholesterol is 200 and your HDL is 50, your ratio is 4.
"This isn't bad," the technician says. An HDL level of less than 40 mg/dL (1.0 mmol/L) would be considered high risk for a man (the level in women should be at least 50). "But a more desirable HDL level would be closer to 60mg/dl (1.6 mmol/L)." He turns the pamphlet over to show you the dietary recommendations that could help bring up the HDL and lower the total cholesterol levels. "You'll want to keep this record," he says. "And discuss the results with your doctor. A second screening is always a good idea."
Some test results include figures that compare your cholesterol levels with national averages. Don't let these numbers fool you into thinking you're not at risk. The general population isn't always healthy. Just because you fall into a range that is "average," doesn't mean it's a healthy cholesterol level. It is your numbers and risk factors that matter.
"Remember," says Outly, "one cholesterol reading is not enough." Her advice? Get a follow-up test a week later. If the two tests aren't comparable, see your doctor for a third.
American Heart Association
Live Healthier, Live Longer
National Heart, Lung, and Blood Institute
Heart and Stroke Foundation of Canada
Jacobson TA, Miller M, Schaefer EJ: Hypertriglyceridemia and cardiovascular risk reduction. Clint her. 2007; 29:763-77.
Stone NJ, Bilek S, Rosenbaum S: Recent National Choleseterol Education Program Adult Treatment Panel III update: adjustments and options. Am J Cardiol. 2005;96:53E-59E.
Last reviewed January 2009 by ]]>David Juan, MD ]]>
Please be aware that this information is provided to supplement the care provided by your physician. It is neither intended nor implied to be a substitute for professional medical advice. CALL YOUR HEALTHCARE PROVIDER IMMEDIATELY IF YOU THINK YOU MAY HAVE A MEDICAL EMERGENCY. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with any questions you may have regarding a medical condition.
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