Non-HDL Cholesterol and The New Cholesterol Guidelines

If non-HDL cholesterol was viewed as a key predictor of cardiac disease risk (on par with apoB or LDL particle testing), why was it abandoned in the new November 2013 cholesterol guidelines?

This is something I’ve been thinking about for a while.  Because for those with diabetes or high triglycerides, it was considered vital to know non-HDL cholesterol. (Do You Know Your Non-HDL Cholesterol? explains why, and how easy it is to calculate from just a standard cholesterol lipid blood test.)

Let me start with a brief, very non-technical definition (for more technical info click blog post link above).  Non-HDL cholesterol is a measure that estimates the level of ALL the bad types of cholesterol in the blood.  Think of it this way: subtracting HDL (good) from total cholesterol yield the non-HDL cholesterol number, which is a measure of all the ‘bad’ cholesterol in the blood. That means it’s a measure of all LDL: the ‘regular-old’ LDL (bad) cholesterol number, which is the number that appears on a report, plus all the other carriers of ‘bad’ cholesterol, such as VLDL (very low density lipoprotein) and IDL (intermediate density lipoprotein) – which are not included in the regular-old LDL cholesterol measurement listed on a cholesterol lipid panel report.

Though it was not as widely known/used by doctors as regular-old LDL cholesterol, it’s true that non-HDL-C was  proven to be a better indicator of cardiac disease risk than just LDL cholesterol.

Indeed, as explained in the Mayo Clinic’s Cardiovascular Risk Assessment Beyond LDL Cholesterol: Non-HDL Cholesterol, LDL Particle Number, and Apolipoprotein B, non-HDL-C  is a better measure of cardiac risk than LDL cholesterol:

“Several known limitations make LDL-C a less accurate marker of cardiovascular risk than either non-high-density lipoprotein cholesterol (non-HDL-C), LDL particle number, or apolipoprotein B (apoB).”

“Advocacy for non-HDL-C began following widespread recognition of its superiority over LDL-C as a measurement of vascular event risk and demonstrated equivalency to apoB or LDL particle number in some clinical trials.”

If it was widely accepted in the medical community that non-HDL-C was a better predictor than LDL alone – and indeed, a good proxy for apoB or LDL particle testing, why were BOTH the LDL and the non-HDL-C measures abandoned in the new guidelines?

The answer seems to be that there is no rationale for setting a specific number target for either LDL or non-HDL-C.

I get it for LDL cholesterol. LDL was used as a key measure to determine whether someone should take a statin, even though there was no real rationale for a specific LDL number as a goal (which is crazy but is basically what’s been the case for many years now). Thus, the committee recommended a new risk assessment measure that was based on research – and eliminated the ‘random’ LDL goal.

Makes sense.

And yet.

If it is/was widely accepted and studies have shown that apoB and LDL particle size are predictive of cardiac risk, and non-HDL-C is an easy, cost-effective way to approximately measure apoB and LDL particle size (because non-HDL is calculated from a typical cholesterol test – not a whole new test like apoB) then it seems to me that knowing your Non-HDL-C is a good idea.

But hey, I’m no doctor. (And I don’t even pretend to play one on TV). So I could be wrong.

That said, I’m concerned. The new guidelines say I’m (suddenly, now) very low risk for cardiac disease. But my non-HDL cholesterol is significantly higher than the old “goal” of 130 for those with high triglycerides.

And I get that the 130 figure is not, in and of itself, a meaningful target.

I do.  Truly.

But it seems clear since my non-HDL-C is “high” compared with ‘normal’ or a lot of other people, that this might indicate a potential problem. And thus warrant action.  Not treatment – I get that it doesn’t make sense to recommend a statin based on a goal number that’s not grounded in research.

But to me, it seems that if non-HDL-C is greater than 130 then further testing could be indicated.

Again, I’m no doctor.

But I think it’s important to ASK about this.  Perhaps the fact that my non-HDL is high indicates the need apoB and/or particle size testing – or one or several of the tests the AHA now indicates for those who might be at risk: see New Cholesterol Guidelines – An App For That.

Good thing I’m due for my annual checkup soon.  I will ask my doctor about these tests. AGAIN.

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Cholesterol Tests Your Doctor Hasn’t Told You About

A standard cholesterol lipid panel  provides four measures: Total Cholesterol, LDL Cholesterol, HDL Cholesterol and Triglycerides.  But did you know that there are two other blood tests — and one ratio that’s easy to calculate — that can better predict your risk of heart disease?  Which means that even with high cholesterol, you might not need a statin medication if these tests show low cardiac disease risk.

Or you might think you don’t need a statin … and in fact do.

And yet, your doctor probably has not told you about these tests.  So let me.

Apolipoprotein B – or as it’s commonly referred to, ApoB, is a simple blood test that measures the number and size of LDL (bad) cholesterol. Why this test is useful is well explained by Johns Hopkins Health Alerts:

“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.”

So if you have high LDL cholesterol (goal is under 130), you might want to find out if you have the ‘fluffy’ kind of LDL (pattern A), or the more dangerous, small, dense type of LDL (pattern B). Indeed, the Johns Hopkins Health Alert goes on to explain, “Research published in The Lancet reviewed five studies of LDL cholesterol and ApoB in nearly 200,000 people. The researchers concluded that high levels of ApoB were more strongly linked with future heart attack risk than LDL cholesterol levels.”  Compelling, no?

Low Density Particle Number, or LDL-P, is a similar measure – and again, one that’s been shown to be a more accurate predictor of heart disease than the typical cholesterol measurements.  LDL-P measures the number of LDL particles in the blood, whereas LDL is just the total LDL cholesterol.

As explained in The Difference Between LDL-C and LDL-P on the Primal Docs website, two people with the same LDL numbers can have vastly different heart disease risk because one has low LDL-P (fewer LDL particles of the type A, big, fluffy kind) while the other has high LDL-P, or a lot of LDL particles, of the small, dense, type B kind:

“…one person (person A) may have large cholesterol rich LDL particles, while another (person B) may have smaller cholesterol depleted particles. These two persons may have the same LDL-C concentration. However, person B will have higher LDL particle number (LDL-P). Despite similar levels of LDL-C, person B is at higher risk four future cardiovascular events. Furthermore, person B will have more small LDL-particles.”

The doctor who wrote this explanation of LDL-C vs. LDL-P goes on to explain that both LDL-P and ApoB are stronger predictors of heart disease risk than typical cholesterol measures:

“Some studies have suggested that the size of LDL-particles may be of importance. People whose LDL particles are predominantly small and dense, have a threefold greater risk of coronary heart disease.

ApoB and LDL-P both reflect the number of atherogenic lipoprotein particles. Measurements of ApoB and LDL-P are better predictors of cardiovascular disease risk than LDL-C. Furthermore, ApoB and LDL-P may predict residual risk among individuals who have had their LDL-C levels lowered by statin therapy.”

Non-HDL Cholesterol is a third important measure — and you don’t even need to take a blood test. Non-HDL-C is simply your Total Cholesterol minus HDL Cholesterol.  The tricky part is figuring out goal: if your LDL cholesterol is “at goal” you can roughly estimate your non-HDL-C goal by simply adding 30 to your LDL goal (these goals are usually on the cholesterol report – they are also online or you can ask your doctor.) And if it’s not at goal, discuss this ratio with your doctor.  I wrote about non-HDL-C and how to calculate it in this blog post, Do You Know Your Non-HDL Cholesterol?

While researching these in-depth cholesterol tests, I came across this compelling medical case study. It socked me in the gut, as this woman’s lipid panel cholesterol results were similar to mine, and yet it turns out from the additional LDL-P and ApoB testing that she was at high risk for cardiac disease. And needed statins.

Gulp.

So how do you get these tests?

I asked my internist about them months ago, and she said I didn’t need them — that my cholesterol numbers are fine. But now that I’ve read this case study I feel I would love more information.  I’ll have to ask her again about additional testing – especially now that I have more info.

And just so you know, you don’t have to travel to the Cleveland Clinic or the Mayo Clinic or Berkeley, California to get these tests. The Johns Hopkins Health Report explains,

“One widely used test, called the NMR LipoProfile, analyzes the size of lipoprotein particles in the blood by measuring their magnetic properties. Several others, including the LipoPrint and the Berkeley (from Berkeley HeartLab) use electrical fields to distinguish the size and other attributes of lipoprotein particles. Still another, known as the VAP (for Vertical Auto Profile) test, separates lipoprotein particles using a highspeed centrifuge.”

Even though my cholesterol is at goal, I’ve got to put in a call to my internist to ask about getting both the LDL-P and ApoB testing done. Will keep you posted.

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Do you know your non-HDL cholesterol?

Reviewing my latest cholesterol test results with my doctor last week, she bandied about a term I’d never before heard: non-HDL cholesterol.

Here is how Discovery Fit & Health describes non-HDL cholesterol (which is VITAL to understand if you have diabetes or other cardiovascular disease risk factors). Unless you’re a doctor, don’t get too fussed about the jargon – I kept it here for those who like all the details.  If that’s not you, just skim over the jargon and keep reading and it should all make sense:

“Non-HDL cholesterol is the total of VLDL and LDL cholesterol, both of which contain atherogenic apolipoprotein B (apo B) particles. Because it approximates the amount of apo B particles, non-HDL cholesterol is a better predictor of the risk of coronary heart disease than a simple measure of LDL cholesterol.

It’s a useful measurement in people with triglyceride levels between 200 mg/dL and 500 mg/dL who likely have substantially more apo B particles.

To calculate non-HDL cholesterol, subtract HDL cholesterol from the total cholesterol. When LDL cholesterol is at goal, non-HDL cholesterol should be lowered to 30 mg/dL greater than the LDL-cholesterol goal.”

Why do I care about this? Why should you? Well, if you have high triglycerides or diabetes or other cardiovascular disease risks, it appears that non-HDL cholesterol is a better predictor of heart disease than total cholesterol or LDL or HDL levels.

Said differently, non-HDL cholesterol appears to be a good way to decide if you need more tests or more aggressive treatment. I’ve been worried I need more tests (and I might) but for now, I felt better after understanding my non-HDL cholesterol level.

It’s easy to calculate. You don’t need a new lab test – just your latest fasting cholesterol test results and a pad/paper…ok, calculator. Here’s what you do:

  1. Calculate your own non-HDL cholesterol by subtracting HDL from your total cholesterol number. Mine was 168: my total cholesterol of 224 minus my 56 HDL.
  2. To calcualte your GOAL for non-HDL cholesterol, just add 30 to your LDL goal. (Your doctor should give you a goal – or you can see it on your lab report.  OR you can figure it out on the Mayo Clinic or American Heart Association sites.) My LDL goal is <130 so my non-HDL cholesterol goal is 160.
  3. Compare — and discuss with your doctor. My non-HDL cholesterol is 168 vs 160 goal (though my doctor calculated my goal as 190 – she started with an LDL goal of 160 not 130 – I need to call her about that.) So I’m either well below 190 goal or slightly above 160 goal.

So my next steps based on all this? Besides following up on that pesky 160 vs 190:

  • Continue going lo-co lifestyle. My doctor asked what I’m doing other than blogging (ha ha) as it IS slowly bringing my cholesterol numbers down. Thus, we agreed that I should continue my (mostly) low-fat/low cholesterol diet, ramped up exercise, and daily doses of both fish oil and Metamucil.
  • Sadly, she wants me to add 2 things to lower my triglycerides: cut starches and impose a limit of 1 glass of wine per night.  UGH. We’ll see about that.
  • Regarding more testing – since all my cousins are on cholesterol meds, she wants me to poll them – find out about their coronary calcium scores, if they had them done. If they are high, she’ll want to send me for more testing. If not, no need.

One last thought – if you have prior test results, it’d be good to do your own non-HDL cholesterol calculation before you meet with your doctor.  It’s a lot of numbers and my doc whipped through this so quickly I didn’t have time to notice – much less ask about – the fact that she listed my LDL goal as 160 but the lab results chart said it was 130. If I’d known about this calculation ahead of time, I’d like to think I’d have caught it and asked.

Hope this is helpful – it was total news to me. Drop me an email or post a comment if you want any further info on non-HDL cholesterol.

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