Most people are diagnosed and treated based on information derived from test results. Often, those tests are incomplete; they are lacking some bits of information. That is why I’m stressing the concept of “biomarkers”—those bits of information that, taken together, can point to an accurate diagnosis. Too often, a diagnosis is made based on just one biomarker. For example, many people are prescribed statin drugs to reduce cholesterol when that is the only biomarker outside the reference ranges.
Some tests results are expressed as just “positive” or “negative”; the best example of this is a test for infection. Other results are expressed as a number, which is then compared to a reference range. This is a range of numbers established by testing a big population of people and creating a big bell curve.
Let’s use resting heart rate as an example. To find yours, turn your palm up and place the tips of your second and third fingers on your wrist right below the muscles of your thumb. Count the number of beats in one minute. (You can also do this by placing your fingers on the side of your neck.) The so-called “average pulse rate” is around 68-70 beats per minute. This average is the reference range. But what happens if you get up quickly, or you have just run upstairs? That can cause a change in your resting heart rate. In order to understand what normal is for you, we must consider the normal range for people your age, as well as what you were doing just before the test.
The lipid panel on your blood test looks at several types of blood fats. If one value—HDL, LDL or total cholesterol—is outside the reference range, that may indicate a problem which warrants further evaluation. The test results should be considered along with a health history, physical exam, and other relevant factors to determine whether the values outside the reference ranges are significant for you. Moreover, your results from one test should be compared to your previous results. Often, a pattern will be evident, which further aids in the diagnosis.
Here are the reference ranges for the standard lipid panel:
Total Cholesterol 125-200
HDL Cholesterol > 40 (greater than 40)
LDL Cholesterol < 130 (less than 130)
Triglycerides < 150 (less than 150)
Chol/HDL ratio < 5.0 (less than 5.0)
If your total cholesterol value is 150, you assume everything is OK. What if it is 240, with nothing else measuring outside the range? Because we are all genetically unique, what if 240 is the normal value for you? Does this mean you need a statin drug to bring that 240 into the “normal” range?
What if the total cholesterol level is at 125 or below? Is that normal for you, or is there some illness brewing? Seriously low cholesterol is not healthy, and is an ominous sign that something could be wrong. What if the level is 127, or 195? Those values are at the ends of the reference range. In that case, you would want to compare those values to past and future test results, to see if a pattern exists that could lead to a diagnosis.
Here are some other examples: What if your total cholesterol is 200, LDL is 135, and HDL is 35? What if total cholesterol is 260 and no other value is out of range? What if total cholesterol is 220, and LDL is 192? The combinations are endless. Again, this data should be considered along with your lifestyle and other pertinent information to establish the risk factors for current and future illness. There is more than just “looking at numbers” in order to establish a diagnosis.
I’m not suggesting that you self- diagnosis, nor am I diagnosing, I’m giving you information, so you can control your health by being more educated. As with all the health data you gather, consulting with a healthcare professional is very important.
In future posts, I’ll discuss other biomarkers and potential risk factors involved with CAD and atherosclerosis. Are statin drugs right for you? Can you improve your blood fats with nutrition and supplementation? How do statin drugs work? What are the risks? Stay tuned…