Why You Should Ask For Advanced Lipid Testing

Controversies in Cardiovascular Medicine is the intriguing title of a 2009 article in the American Heart Association’s Circulation publication.

Stop laughing – cholesterol research can be intriguing!  I’d label the situation frustrating more than intriguing, but here’s what is going on.

The controversy is essentially that advanced lipid testing (explained in Cholesterol Tests Your Doctor Hasn’t Told You About) has been around for 50 years and is a better predictor of cardiovascular disease risk than standard cholesterol blood tests, and yet these ‘advanced’ tests are still not widely prescribed.

In fact, the ‘standard’ cholesterol blood panels (total cholesterol, LDL and HDL) often inaccurately portray risk for many people: those, for example, with normal cholesterol levels who heart attacks. And yet, standard lipid testing is still the norm.  It’s kind of crazy.

As explained in the Circulation article:

“Standard tests of low-density lipoprotein cholesterol (LDL-C) and high-density lipoprotein cholesterol (HDL-C) misidentify coronary heart disease (CHD) risk status in a substantial portion of the population. Tests of apolipoprotein concentrations are superior to standard LDL-C tests, and it can be argued that they should replace standard lipoprotein cholesterol testing.”

The Circulation article goes on to explain that the advanced testing used to be difficult and expensive – but this testing is now more widely available:

“Advanced lipoprotein tests that were previously available only from university research laboratories are now provided by several commercial laboratories.”

Indeed, since Berkeley Heart Lab (which was one of very few offering advanced lipid testing years ago) was bought first by Celera Corp in 2007 and then by Quest Diagnostics in 2011, it is now far easier — and inexpensive — to get advanced lipid testing!

And yet, it’s not widely prescribed.  Sigh.

I just had an advanced lipid panel done in December 2014. It wasn’t easy to get (my internist said not necessary; it wasn’t until I had to see cardiologist for sudden high blood pressure that he agreed it was a good idea). But I’m glad I did because I now have a much better understanding of my personal cardiac disease risk.

Here’s what I learned – and below these key points is some further info about test results that may be pertinent as you consider ASKING FOR advanced lipid testing:

  • My total cholesterol is ‘high’ at 266 and my LDL cholesterol is ‘high’ at 159
  • I have elevated ApoB (score of 123) which contributes to higher cardiac disease risk. But that is offset by other test results.
  • My LDL pattern is type A, which is optimal.  This is the fluffy kind that doesn’t stick to the arteries like the smaller, denser, more dangerous Type B LDL cholesterol.
  • My C-Reactive Protein score of 0.8 is also considered optimal / low risk.

Total and LDL Cholesterol: I find it frustrating that the lab reports still characterize my Total 266 and LDL cholesterol of 159 as ‘abnormal’ or ‘high’ (meaning, high ‘risk’) even though the November 2013 cholesterol guidelines say these scores are not, indeed, high or risky or need treatment. (The new guidelines indicate risk when  LDL>190, along with other factors).

Why do the lab reports not match the new guidelines?  This is inane.

ApoB: I am concerned about my elevated ApoB.  I wrote about apolipoprotein (ApoB) testing and explained why many believe it’s a better predictor of cardiac risk than LDL and total cholesterol testing in ApoB and Cardiovascular Risk.  So this is something I need to keep track of. Interestingly, the lab report says my score is ‘high’ risk and yet, when I dug further, I found a table that showed my personal target is probably <130 (see blog post for details).  Frustration #2 that there are not clear standards.

LDL Pattern Type: The type of LDL cholesesterol you have matters. As explained in the Physican’s Weekly article In The LDL World, Size Matters, roughly half of all people who have heart attacks have ‘normal’ cholesterol levels.  That’s because small sized LDL (Pattern B) can puncture the walls of the arteries and cause plaque buildup – so even ‘normal’ amounts can be dangerous.  If you have high LDL but it’s the Pattern A type which is big and fluffy, that cholesterol bounces off arterial walls so causes less plaque buildup and is thus less dangerous even if you have a ‘lot’ of it.

While I have the preferred / less dangerous Pattern A LDL cholesterol, I found in researching that Pattern B can be modified: if you have Pattern B, you can get it to change to pattern A with diet and exercise!  Which is great.  But that leads me to wonder whether just because I have pattern A now means it sticks (sorry, pun intended) or if it can change to pattern B.  I intend to stay with my lo-co diet and exercise plan, just wondering if I risk changing to Pattern B if I’m not careful. I need to check in with my cardiologist on this.

C Reactive Protein: I was relieved to find my C Reactive Protein score was low. As explained in a Circulation article from 2003 entitled C Reactive Protein: A Simple Test to Help Predict Risk of Heart Attack and Stroke, the C Reactive Protein test is an important measure in assessing cardiac risk. “When measured with new “high sensitivity” CRP assays, levels of CRP less than 1, 1 to 3, and greater than 3 mg/L (milligrams per liter) discriminate between individuals with low, moderate, and high risk of future heart attack and stroke…  Evidence also indicates that individuals with high CRP levels are at increased risk of developing diabetes.”

Now that the Advanced Lipid testing has provided a more in-depth look at my cardiac disease risk, I understand why my cardiologist feels that my 266 Total cholesterol is not terribly concerning. And doesn’t need treatment.

So if you, like me, want a far clearer understanding of your personal risk of cardiac disease, you should ask your doctor to order Advanced Lipid Testing, including scores for:

  • Advanced Lipid Panel Reflex Direct LDL (measures direct LDL and provides the info on particle pattern, number and size)
  • ApoB
  • C-Reactive Protein – the high sensitivity test

Sad to say you’ll probably have to ask your doctor to order Advanced Lipid Testing – he or she is NOT likely to order these tests unless you ask. Which is a shame.

Because as the Circulation article concludes, these tests have been around for 50+ years, are now easily and widely available, and they pick up risk that typical cholesterol panel testing might miss:

“One advantage of ALTs is the greater insight they provide clinicians into individual patient disorders often masked by standard lipid tests considered to be within “normal” ranges.”

It’s important to ask, because advanced lipid testing might reveal that although your cholesterol is not high, you are still at risk. This testing is easy, cheap and could save your life. It will provide you with a more in depth understanding of your cardiac disease risk.

It’s a simple, important question. Ask about advanced lipid panel testing the next time you see your doctor.

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ApoB and Cardiovascular Risk

In Cholesterol Tests Your Doctor Hasn’t Told You About, I briefly describe a cholesterol blood test for Apolipoprotein B (ApoB).  This simple blood test measures the number and size of LDL (bad) cholesterol: it’s an important test if you have high LDL (bad) cholesterol or are at ‘high risk’ of cardiac disease, as it provides a more finely tuned assessment of cardiovascular risk.

In fact, it might be a critical test for those with low LDL (bad) cholesterol – because it can reveal hidden cardiac risk.

While studies show ApoB is a better predictor of cardiac risk, it is not yet a test that is widely prescribed. Indeed, the American Heart Association is waiting for more studies to determine if ApoB is a test doctors should recommend. Personally, I find this frustrating (of course this means nothing as I’m not a doctor, but…) To me, it’s frustrating because this is a simple blood test that provides a detailed risk assessment.

Scientific American’s Heart Health Special Report entitled ApoB – A Better Marker For Heart Attack Risk Than LDL-Cholesterol explains why it’s an effective and important test:

“A high level of low-density lipoprotein (LDL, or “bad”) cholesterol is an important risk factor for a heart attack. Yet about half of the people who develop coronary heart disease have normal or even low LDL cholesterol levels. Some research suggests that a component of LDL—called apolipoprotein B, or apo B—may be more accurate at predicting coronary heart disease.

A Limitation with LDL Cholesterol Testing
The problem with using LDL cholesterol levels to determine heart attack risk is that the test measures only the amount of cholesterol in the LDL cholesterol particles, not the number or size of these particles. Apo B measurements, on the other hand, provide information on the number of LDL cholesterol particles.

For example, people with a higher apo B value than LDL cholesterol value tend to have smaller, denser LDL cholesterol particles. Studies have shown that small, dense LDL cholesterol particles are more strongly associated with heart attack risk than large, “fluffy” LDL cholesterol particles.

The test itself is a simple blood test. It’s easy and cheap: easier, even than the standard cholesterol lipid panel as it does not require fasting.  In fact, the test can be done in conjunction with a standard lipid panel.

Finally, after I visited a cardiologist, I got the ApoB test and my results were, of course, mixed.

Ha! ha ha ha ha ha ha ha

Part of the problem is that since ApoB testing isn’t a standard test there is conflicting info on what the goal ApoB levels should be. My cardiologist was happy with my results because my ApoB is lower than my LDL level, my LDL Pattern is the far healthier Type A / Fluffy LDL, and because my C-Reactive Protein was low risk (more on C-Reactive Protein and LDL patterns in another post.).

But my actual lab report shows my ApoB level of 123 as ‘high risk’ and simply references a desired range of 49-103.  So at 123, I have ‘high’ ApoB.

Ruh Roh.

Who to believe?

Well, it’s simple.  My cardiologist. After a lot of online research (again, I’m no doctor so take all this with a grain of salt), I think the reason my cardiologist is OK with my ApoB score of 123 is because of all those elements I mention above AND ALSO because  I fall into the ‘low risk’ of cardiac disease segment. It turns out that there are different ApoB goals based on a person’s general cardiac disease risk, and the lab report seems not to take this into account.

ApoB goals by risk pool is well explained in Medscape’s emedicine article entitled Apoliprotein B article, in the chart here:

Screen Shot 2015-03-14 at 5.22.44 PM

 

Since my 10 year risk factor via the cardiac disease risk calculator is low (and I also have just 1 risk factor from the ‘old’ way of calculating risk), then it’s probably OK that my ApoB is 123 as it’s lower than 130.

I’m glad I got the ApoB test done – but it’s only because I asked two doctors for it.  If you want a more detailed risk assessment, ask your internist or cardiologist about ApoB testing.

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