Diagnosis
A blood test for cholesterol should now include the entire lipoprotein profile: LDL, total cholesterol, HDL, and triglycerides. (It is very difficult to measure LDL levels by themselves, but LDL levels can be reliably calculated using total cholesterol and HDL levels.)
To obtain a reliable cholesterol reading, experts advise the following:
- Avoid strenuous exercise for 24 hours before the test.
- Do not eat or drink anything but water for 12 hours beforehand.
- If the test results are abnormal, a second test should be performed between one week and two months after the first test.
Home Tests. Tests are available for home use and in public locations, such as shopping malls and pharmacies. For example, the CholesTrak Test can be taken at home with results in 10 minutes, but it measures only total cholesterol. The BioSafe Cholesterol Panel Test is also a home test, but it needs to be sent to a laboratory. This test, however, is very accurate and provides a full lipid profile -- total cholesterol, HDL, LDL, and triglycerides.
Tests for Markers of Heart Disease in People with Unhealthy Lipid Levels
Certain blood tests for factors suggesting inflammation in the arteries are proving to demonstrate a higher risk for heart disease, some even in people without unhealthy lipids:
- C-reactive protein (C-RP). C-RP is regulated by a very potent immune factor called interleukin-6 and elevated levels have been strongly associated with the inflammatory response and a higher risk for heart attack, even in people with normal cholesterol levels. In fact, some evidence suggests that it may prove to a more important marker than LDL cholesterol itself. It is also associated with high blood pressure, insulin resistance (the primary problem in type 2 diabetes), and obesity.
- A high white-blood cell count.
- Elevated fibrinogen (a factor responsible for blood clotting).
- Lipoprotein-associated phospholipase A2 may be prove to be another marker for inflammation and heart disease. In fact, studies suggest that it may play some causal role in coronary artery disease.
Skin Test
A test that measures cholesterol levels in the skin is in development. (High skin levels appear to be an indicator of a high risk for serious heart disease.)
Screening Guidelines
General Screening Recommendations. Experts groups differ slightly on when screening should start, the following are generally accepted recommendations:
- Periodic cholesterol testing in all adults starting at age 20. An adult with normal cholesterol levels does not need to have the test repeated for five years unless changes occur in his or her lifestyle, including weight gain and changes in medication or diet. Adults with risk factors for heart disease or stroke should be rechecked every two years.
- Selective screening of children who are at risk for high cholesterol and heart disease or familial hypercholesterolemia, which is genetically elevated cholesterol. (Risk factors include having parents with total cholesterol levels greater than 240, or having a parent or grandparent who had overt heart disease at age 55 or younger.
- Patients already being treated for high cholesterol should be checked every two to six months.
Early screening is important for the following reasons:
- Evidence is accumulating on the dangers of early unhealthy cholesterol levels in both young people and older adults.
- Screening of young people will encourage them to make important lifestyle changes, possibly early enough to make significant differences.
- The obesity epidemic is increasing the numbers of young people with unhealthy cholesterol levels. One study reported that one-third of all young adult men have cholesterol levels over 200 mg/dL.
- Late screening would miss the one out of every 500 individuals with inherited familial hypercholesterolemia, for whom early treatment could be life saving.
The major expert panel on Cholesterol Education has also recommended testing for the total lipoprotein profile (which includes HDL, LDL, and triglycerides) instead of merely measuring total cholesterol. Testing only for the overall cholesterol level misses specific lipids and blood proteins that are becoming increasingly important in determining an individual's particular risk for heart disease.
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