Lipoprotein Testing: Why it's So Important and Where You Can Get it Done
"My doctor saidmy cholesterol was fine . . . So why did I have a heart attack?"
Let's face it: Using cholesterol values alone to predict whether or not heart attack is in your future can lead to failure. Yes, it works statistically in a large population. But apply it to a specific individual, and you might as well roll the dice.
There are a number of reasons for the shortcomings of cholesterol values to predict heart disease. Among the reasons:
LDL (bad) cholesterol is usually not measured, but calculated. The calculation used is 40 years old, harking back to an age when measured LDL was not readily available. Calculated LDL is subject to enormous inaccuracy.
There's more to causes of heart disease than high cholesterol. Some causes, like low HDL or high triglycerides, are evident on any standard cholesterol panel. Others, likesmall LDL(number one cause for heart disease in the U.S.!), intermediate-density lipoprotein (IDL), and lipoprotein(a) (), are not part of a standard cholesterol panel.
由于这些原因,脂蛋白测试是usef之一ul solution that more confidently uncovers causes for heart disease. In past, lipoprotein testing was costly and only people deemed high risk (family history of early heart disease, diabetics, complex cholesterol disorders) would "qualify" for having the testing performed. However, costs for lipoprotein testing have dropped substantially (e.g., a basic NMR lipoprotein panel is under $100) and it's difficult to ration use of these tests any longer based on excessive cost. Yes, it is an added expense over and above standard cholesterol testing, but if the information provided is superior and more effectively prevents heart attack, hospitalization, and heart procedures, it's not too hard to justify.
There are three different methods used in lipoprotein testing:
Nuclear magnetic resonance (NMR) Your blood (plasma, actually) is placed in a magnetic field, similar to that of an MRI scanner. But in this case it's not your head being scanned, but your blood proteins. This is performed by a North Carolina company, Liposcience, Inc.
Gradient gel electropheresis (GGE) Blood proteins migrate in an electrified gel based on size and electrical charge. This service is provided by Berkeley HeartLab (www.bhlinc.com).
垂直Auto-Profile (VAP) Blood proteins are separated by density by spinning rapidly in a centrifuge. This service is provided by Atherotech, Inc. (www.thevaptest.com).
Despite the considerable advantages over standard cholesterol testing, these tests are often not well understood by most primary care physicians or even cardiologists. Many people therefore encounter difficulties in obtaining lipoprotein testing.
If your doctor is unable, unknowledgeable, or unwilling to help you, then what can you do?
There are several options:
Go to the websites for the three labs that actually perform the lipoprotein tests (above). While none of them will provide you with the names of actual health practitioners, they can provide you with the name of a local representative who should know which doctors in your area are well-acquainted with their technology. I prefer this route to just having a representative identify a laboratory in your area where the blood sample can be drawn, because you will still need a physician to interpret the results. The test is of no use to you unless someone interprets it intelligently and understands the range of treatment possibilities available. Don't be persuaded by your doctor if he/she agrees to have the blood drawn but has never seen the test before. This will be a waste of your time. That's like hoping the kid next door can fix your car just because he says he fixed his Mom's car once. Interpretation of lipoproteins takes time, education, and experience.
Seek out a lipidologist. Lipidologists are the new breed of physician who has completed additional training and certification in lipid and lipoprotein disorders. TheNational Lipid Associationmaintains a database of certified lipidologists and will provide names and contact information to you: Some lipidologists are listed in the yellow pages, or you can search online in your area.
If your doctor is truly motivated to help you use lipoprotein testing but is uncertain how to go about it, his/her staff can contact any of the lipoprotein companies (above) and they will show them exactly how to go about obtaining the blood, etc. Alternatively, the laboratories can direct you to blood draw sites across the country who will know how to draw and handle the blood specimen.
Make do with basic testing. Basic lipids along with apoprotein B and lipoprotein(a) can provide a reasonable facsimile of lipoprotein testing. You'll still lack small LDL and postprandial (after-eating) IDL, but you can still do reasonably well if you and your doctor aim for more intensive targets. For instance, in our program for heart disease reversal we aim for LDL-HDL-triglycerides of 60-60-60.Achieving these more ambitious targets can reduce the uncertainty present in basic cholesterol values.
Lastly, if you are brave and simply want to see what your values look like, you can have the tests performed without a doctor's order (or interpretation) by going towww.LabSafe.comorwww.lef.com, both of which offer self-testing. They will direct you to blood draw sites and then return results to you. (Many members of our website, www.trackyourplaque, will use our software tools and discussion forums to obtain information on what lipoprotein results mean.)
As helpful as lipoprotein testing can be, don't forget that there are other sources of risk for heart disease (beyond the obvious like smoking): 25(OH) vitamin D blood level, C-reactive protein (inflammation), fibrinogen (inflammation and clotting), possibly homocysteine.
