Know Your Numbers: Cholesterol Testing

The reason for testing your cholesterol levels is to understand your risk for developing heart disease, stroke, or any of the other consequences of atherosclerosis. High blood-cholesterol has no visible symptoms. The only way to learn whether your cholesterol levels place you at risk for a heart attack or stroke is to measure your levels. You can get your cholesterol levels tested in your medical doctor’s office, at a medical laboratory, or at public screenings.

When to Check Your Cholesterol Levels

Although cholesterol levels alone are not predictive of heart disease in all people, knowing your levels is a valuable first step toward understanding your risk status. When you know your cholesterol levels, as well as the status of your other risk factors, you gain valuable insight into the health of your current lifestyle and what you need to do to create and maintain your well-being. Furthermore, for those people who learn that they fall into high-risk categories, the sooner they begin a treatment plan to lower levels of bad cholesterol and increase levels of good cholesterol, the sooner they can start to reduce their risks of heart attack or stroke.

Cholesterol Testing for Healthy Adults

Federal government guidelines recommend that all Americans check their cholesterol levels with a complete fasting lipoprotein profile at the age of twenty. The measurements taken by this test include your levels of total cholesterol, HDL cholesterol, LDL cholesterol, and triglycerides. If test results indicate that all levels are in a healthy range, then government guidelines recommend retesting at a minimum of five-year intervals. The full lipoprotein profile test is preferred over a test that only provides data regarding total cholesterol and HDL levels. Since diabetes is considered to carry a risk equivalent to that of heart disease, it is also a good idea to have your blood glucose levels checked.

If you do not fast before testing your cholesterol, you can only measure total cholesterol and HDL levels. To receive more detailed information regarding your levels of LDL cholesterol and your triglycerides, fasting is necessary. If your test scores place you in a category for treatment, your health-care provider needs a complete, fasting, lipoprotein profile to plan your therapy.

Although federal government guidelines recommend cholesterol testing for adults at least every five years, if you have had a major change of lifestyle during that five-year period, your cholesterol levels may be different and, therefore, worth checking again before five full years elapse. For example, if you were a college student at age twenty and then became a working professional after graduation at age twenty-one or twenty-two, your physical activity levels, dietary choices, and stress levels may have changed significantly. All of these factors can impact your cholesterol levels. Therefore, it may be worth your time and effort to know your numbers as a measure of your health status in your new lifestyle.

Under current government guidelines, if you fall into a category that requires treatment for your cholesterol levels, you will have your cholesterol tested at much more frequent intervals to evaluate the success of the treatment program and to make any necessary adjustments. For example, if your health-care provider suggests that you adopt therapeutic lifestyle changes, the follow-up visit and test should be within six weeks. If your health-care provider suggests drug therapy, the initial follow-up visit and test should also be within six weeks. Subsequent visits for additional monitoring and adjustment of therapy should be scheduled at appropriate intervals depending on the nature of the individual therapy.

[ Read: Low Cholesterol Diet ]

Cholesterol Testing for Children

Evidence from research shows that atherosclerosis can start in childhood. If heart disease runs in the family, children should have their cholesterol levels checked regularly. In families that are high risk, it’s even more important that from two years of age onward, children follow a healthy lifestyle that includes a nutritious low-fat diet and regular physical activity.

Dr. Kenneth H. Cooper, M.D., M.P.H., of the Cooper Institute in Dallas, Texas, recommends that children have a baseline cholesterol test around age five or six. In the future, if any issues come up, this baseline reading can serve as a reference point. If no other problems occur, Dr. Cooper recommends that the next childhood cholesterol test be conducted when the child becomes a teenager.

Cindy Zedeck, Program Director of the Stanford Pediatric Weight Control Program at the Stanford Prevention Research Center in Palo Alto, California, agrees that cholesterol testing for kids is a good practice to motivate families to establish healthy habits for children at an early age. She states:

Many families with overweight children believe that the health risks from poor eating habits either will not occur to their child because their child will outgrow the overweight, or that the health risks are so far away that they will not worry about them now. Seeing the concrete result of high cholesterol may be just what it takes to motivate families to make changes now, reducing worse risk factors in the long run.

Cholesterol testing could also be .just the motivation for a child of healthy weight to improve eating and exercise habits. Many kids who are not “over­weight” do not make healthy choices and feel that they can “get away” with eating whatever they want. Since thin people also have heart disease, perhaps a concrete result of high cholesterol would also motivate a thin child and family to make healthier eating and exercise choices. This would prevent both future disease and the risk of eventually becoming overweight. Since only half of adults who are overweight were overweight as children, this means that a lot of these thinner kids will become overweight in adulthood, if they don’t change their unhealthy eating and exercise habits now.

Influence of Prescription Drugs

Certain prescription medications may also lead to an increase in cholesterol levels. These medications include the following:

  • ACTH (adrenocorticotrophic hormone)
  • Anabolic steroids
  • Beta-adrenergic blocking agents (beta blockers)
  • Corticosteroids
  • Epinephrine
  • Oral contraceptives
  • Phenytoin
  • Sulfonamides
  • Thiazide diuretics
  • Vitamin D

If you are taking any medications that have a potential adverse impact on your cholesterol levels, be sure to discuss this with your health-care provider. Make sure that you understand how you will monitor your cholesterol levels over time to ensure that they remain within a healthy range.

Your Blood Cholesterol Test

When you have your cholesterol tested, the test you should have is the full lipid profile. The results of this test include your levels of total cholesterol, HDL or good cholesterol, LDL or bad cholesterol, and triglycerides. For accurate results, you need to fast for nine to twelve hours before the test. That means you may have nothing to eat or drink but plain water during that time. It is important that you do not consume any alcoholic beverages, coffee, tea, or soda-only drink water.

Why is it so important for me to fast before a lipid profile test?

The reason it is important not to eat for several hours before testing is that after a meal, triglycerides spike. Testing your triglyceride levels immediately after a meal would not give a clear reflection of the typical amount of triglycerides that tend to flow through your bloodstream at all times.

What to Expect

Since you need to obtain a fasting profile, schedule your test for first thing in the morning. Your health-care professional will take a blood sample, either from a vein or from a finger stick. After the health-care provider has collected the blood, he or she will either send it to a lab for analysis-if the test is being performed via a finger stick, a portable testing device will be used to analyze the sample.

If you are on any medications that affect cholesterol levels, work with your health-care provider to determine whether you should not take your prescription for a certain period of time before you take your cholesterol test.

Cholesterol Skin Testing

In 2002, the FDA approved a method of measuring cholesterol levels by testing the amount of cholesterol present in the skin. According to studies by the test manufacturer, International Medical Innovations, Inc., of Toronto, Canada, skin contains approximately 11 percent of all body cholesterol as measured by weight. As the severity of coronary artery disease increases, the levels of cholesterol present in skin also increase.

The test, however, is not designed as a screening device. It only detects cholesterol that is present in large quantities in the skin, a characteristic of people with severe coronary artery disease. The test is more valuable when used together with a blood cholesterol test to identify which people have the most severe arterial blockages.

According to the test’s manufacturer, the skin test provides 4 to 15 percent more information about the risk of severe coronary artery disease than what is already available from blood cholesterol tests and an assessment of other risk factors.

Lipid is the chemical family name for fat. Its root is the Greek word lipos, meaning “fat.” A blood lipid is a fat that circulates in the bloodstream. Cholesterol and triglycerides are both classified as blood lipids. A lipoprotein is a combination of fat surrounded by a protein to enable the fat to circulate.

Public Cholesterol Screenings

You may find public screenings for cholesterol at health fairs, your place of business, or at community events. Make sure that a reputable company is providing the screening and that they provide appropriate educational information, properly trained staff, and referral to health-care providers. Typically, technicians at screenings use a finger-stick sample and a portable testing device to measure test results. This test can still provide you with accurate and valuable information.

Cholestech Corporation offers a portable cholesterol testing system that is used in public screenings as well as in physician office settings. The Cholestech LOX system provides lab-accurate results in five minutes from only a single drop of blood. The Cholestech technology uses a variety of tests that range from a fasting, full-lipid profile and blood glucose levels to a simple, non fasting, total cholesterol test. This technology facilitates quick results.

Share your test results with your health-care provider if you have your cholesterol tested at a public screening. Even if you are only able to take a nonfasting total cholesterol and HOL test, it can provide you with helpful information. If it is available, make sure that you still obtain the fasting, full lipoprotein profile. Keep in mind that learning the individual levels of LOL and HOL cholesterol and triglycerides gives you a much more accurate assessment of the health of your circulatory system.

The Value of Public Screenings

The true value of public screenings for cholesterol is in raising awareness of the prevalence of the risk of heart disease among the public. Public screenings help people who have no idea whatsoever of what their heart health might be to realize that they are in need of further testing and evaluation. According to Claude Lenfant, director of the National Heart, Lung, and Blood Institute, “Americans at high risk for a heart attack are too often not identified and, so, don’t receive sufficiently aggressive treatment. Yet, studies show conclusively that lowering the level of low-density lipoprotein, or LOL, the ‘bad cholesterol,’ can reduce the short-term risk for heart disease as much as 40 percent.”

Public Screenings for Children

Both the federal government and the American Heart Association do not recommend mass public screenings of blood cholesterol for all children and adolescents. Health professionals are concerned that this type of mass screening would be costly and that it is likely to be inefficient. Children are often uncomfortable with needles and the sight of blood. Cholesterol testing for children is best conducted in the physician office setting.

According to the American Heart Association, about 10 percent of adolescents between the ages of twelve to nineteen years have total cholesterol levels higher than 200 mg/dL. This level is considered high risk.

Home Testing of Blood Cholesterol

At this time, home testing devices for cholesterol only measure total cholesterol and do not provide a breakdown of HDL cholesterol, LDL cholesterol, or triglycerides. Lifestream Technologies, Inc., based in Post Falls, Idaho, offers a cholesterol monitor for home use that allows you to test your total cholesterol levels. The Lifestream LSP system is not meant to replace the role of a medical professional. Instead, the device is designed to serve as an aid for those who want to monitor their cholesterol levels on a regular basis from the convenience of home.

Possible Future Tests

As scientific research continues to create a clearer picture of the mechanisms behind atherosclerosis, investigators are focusing more attention on other lipid-related risk factors. Studies continue to reveal more information about the subclasses of LDL and of HDL. As knowledge increases about the more exact role that each of these particles plays in the atherosclerotic process, scientists are developing tests that can identify risk with greater precision than simply looking at total LDL or HDL cholesterol levels. The focus of these studies includes the following particles, some of which are mentioned in Chapter “Diagnostic Test for other markers of heart disease”:

  • Small, very dense, low-density lipoprotein particles
  • High apoliprotein B levels
  • Low apoliprotein A-1 levels
  • High lipoprotein a or Lp(a) levels
  • High remnant lipoprotein cholesterol and triglyceride levels
  • Low high-density lipoprotein 2b levels

Watch for results from future research trials and updates to guidelines that incorporate what is being learned about these particles. An understanding of the role of these markers and emerging risk factors may shed more light on why as many as 50 percent of people who do not have high total blood cholesterol levels develop atherosclerotic plaque that leads to heart disease and stroke.

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