Monday, May 30, 2011

Interview with Jimmy Moore, and basics of intima-media thickness and plaque tests

Let me start this post by telling you that my interview with Jimmy Moore is coming up in about a week. Jimmy and I talk about evolution, statistics, and health – the main themes of this blog. We talk also about other things, and probably do not agree on everything. The interview was actually done a while ago, so I don’t remember exactly what we discussed.

From what I remember from mine and other interviews (I listen to Jimmy's podcasts regularly), I think I am the guest who has mentioned the most people during an interview – Gary Taubes, Chris Masterjohn, Carbsane, Petro (a.k.a., Peter “the Hyperlipid”), T. Colin Campbell, Denise Minger, Kurt Harris, Stephan Guyenet, Art De Vany, and a few others. What was I thinking?

In case you listen and wonder, my accent is a mix of Brazilian Portuguese, New Zealand English (where I am called “Need”), American English, and the dialect spoken in the “country” of Texas. The strongest influences are probably American English and Brazilian Portuguese.

Anyway, when medical doctors (MDs) look at someone’s lipid panel, one single number tends to draw their attention: the LDL cholesterol. That is essentially the amount of cholesterol in LDL particles.

One’s LDL cholesterol is a reflection of many factors, including: diet, amount of cholesterol produced by the liver, amount of cholesterol actually used by your body, amount of cholesterol recycled by the liver, and level of systemic inflammation. This number is usually calculated, and often very different from the number you get through a VAP test.

It is not uncommon for a high saturated fat diet to lead to a benign increase in LDL cholesterol. In this case the LDL particles will be large, which will also be reflected in a low “fasting triglycerides number” (lower than 70 mg/dl). While I say "benign" here, which implies a neutral effect on health, an increase in LDL cholesterol in this context may actually be health promoting.

Large LDL particles are less likely to cross the gaps in the endothelium, the thin layer of cells that lines the interior surface of blood vessels, and form atheromatous plaques.

Still, when an MD sees an LDL cholesterol higher than 100 mg/dl, more often than not he or she will tell you that it is bad news. Whether that is bad news or not is really speculation, even for high LDL numbers. A more reliable approach is to check one’s arteries directly. Interestingly, atheromatous plaques only form in arteries, not in veins.

The figure below (from: Novogen.com) shows a photomicrograph of carotid arteries from rabbits, which are very similar, qualitatively speaking, to those of humans. The meanings of the letters are: L = lumen; I = intima; M = media; and A = adventitia. The one on the right has significantly lower intima-media (I-M) thickness than the one on the left.


Atherosclerosis in humans tends to lead to an increase in I-M thickness; the I-M area being normally where atheromatous plaques grow. Aging also leads to an increase in I-M thickness. Typically one’s risk of premature death from cardiovascular complications correlates with one’s I-M thickness’ “distance” from that of low-risk individuals in the same sex and age group.

This notion has led to the coining of the term “vascular age”. For example, someone may be 30 years old, but have a vascular age of 80, meaning that his or her I-M thickness is that of an average 80-year-old. Conversely, someone may be 80 and have a vascular age of 30.

Nearly everybody’s I-M thickness goes up with age, even people who live to be 100 or more. Incidentally, this is true for average blood glucose levels as well. In long-living people they both go up slowly.

I-M thickness tests are noninvasive, based on external ultrasound, and often covered by health insurance. They take only a few minutes to conduct. Their reports provide information about one’s I-M thickness and its relative position in the same sex and age group, as well as the amount of deposited plaque. The latter is frequently provided as a bonus, since it can also be inferred with reasonable precision from the computer images generated via ultrasound.

Below is the top part of a typical I-M thickness test report (from: Sonosite.com). It shows a person’s average (or mean) I-M thickness; the red dot on the graph. The letter notations (A … E) are for reference groups. For the majority of the folks doing this test, the most important on this report are the thick and thin lines indicated as E, which are based on Aminbakhsh and Mancini’s (1999) study.


The reason why the thick and thin lines indicated as E are the most important for the majority of folks taking this test is that they are based on a study that provides one of the best reference ranges for people who are 45 and older, who are usually the ones getting their I-M thickness tested. Roughly speaking, if your red dot is above the thin line, you are at increased risk of cardiovascular disease.

Most people will fall in between the thick and thin lines. Those below the thick line (with the little blue triangles) are at very low risk, especially if they have little to no plaque. The person for whom this test was made is at very low risk. His red dot is below the thick line, when that line is extended to the little triangle indicated as D.

Below is the bottom part of the I-M thickness test report. The max I-M thickness score shown here tends to add little in terms of diagnosis to the mean score shown earlier. Here the most important part is the summary, under “Comments”. It says that the person has no plaque, and is at a lower risk of heart attack. If you do an I-M thickness test, your doctor will probably be able to tell you more about these results.


I like numbers, so I had an I-M thickness test done recently on me. When the doctor saw the results, which we discussed, he told me that he could guarantee two things: (1) I would die; and (2) but not of heart disease. MDs have an interesting sense of humor; just hang out with a group of them during a “happy hour” and you’ll see.

My red dot was below the thick line, and I had a plaque measurement of zero. I am 47 years old, eat about 1 lb of meat per day, and around 20 eggs per week - with the yolk. About half of the meat I eat comes from animal organs (mostly liver) and seafood. I eat organ meats about once a week, and seafood three times a week. This is an enormous amount of dietary cholesterol, by American diet standards. My saturated fat intake is also high by the same standards.

You can check the post on my transformation to see what I have been doing for years now, and some of the results in terms of levels of energy, disease, and body fat levels. Keep in mind that mine are essentially the results of a single-individual experiment; results that clearly contradict the lipid hypothesis. Still, they are also consistent with a lot of fairly reliable empirical research.

34 comments:

lightcan said...

Hi Ned,

I have very high LDL. You're saying that if I have such a test and the result is good I don't have to worry, at least in the short term.

Thanks

Ned Kock said...

Hi lightcan. This test is particularly recommended for folks with high LDL, so that they can be removed from the high-risk group.

For those who have numbers that suggest high risk, future tests can help identify the strategies that work. This is the basis of programs like Track Your Plaque.

js290 said...

Ned,

Conventional wisdom in popular media is looking every which way to blame meat for the atherosclerosis found in the Egyptian mummies. One of the researchers in an interview on NPR clearly stated, "Ancient Egyptians did have access to meat, their diet consisted mostly of grains, fruits and vegetables."

Jamie Scott said...

Great information Need! (But I call you Ned, as in rhymes with Ted... darn Kiwi accent!). Must be very reassuring to have that hard data to show anyone who might want to question why you eat the way you do.

Looking forward to your interview with Jimmy.

Jamie

Ned Kock said...

Hi js290. Yes, LDL-C is the establishment’s favorite target, and whatever they think increases it. The lipid hypothesis is resilient, but maybe this little test can bring it down once and for all. It is cheap and conclusive.

Ned Kock said...

Hi Jamie, thanks. Btw, thanks for putting up so many interesting posts lately, and keep it up!

Alex said...

Hi Ned,
Great post on CIMT measurement. What do you think of aortic pulse wave velocity measurements as a tool for measuring heart attack risk? Comparable to CIMT?
-Alex

Nick said...

Hi Ned,

Thanks for bringing this type of test to my attention. Do you recommend this test over a heart scan?

Ned Kock said...

Hi Alex. The IMT test takes into account many more inputs, it seems, than the pulse wave velocity (PWV) test. The latter is a measure of arterial stiffness, which is different from IM thickness, even though the two are correlated. The PWV test is also a lot older.

My doctor prefers the IMT test over any other test to track plaque progression, and he treats a lot of folks with CVD.

Ned Kock said...

Hi Nick. The advantage of the IMT test over the calcium scan test is that it can help identify problems earlier, so one can act on them sooner.

How to act is another matter. I would do essentially the things that I did to lose the excess body fat, which are not really a diet but a lifestyle change that is forever, and keep getting IMT tests done on a regular basis.

Glenn said...

Great post Ned. I'm still amazed at the things I learn from smart guys like you, Kurt, Stephan, et al, that my conventionally trained MD never even mentions!
So many of us in paleo community are lucky to have the resources to read and take our health into our own hands. Not everyone has this leisure.

Ned Kock said...

Thanks Glenn.

Cassandra said...

Hi Ned--

Re your comment: The advantage of the IMT test over the calcium scan test is that it can help identify problems earlier, so one can act on them sooner.

How does it help identify problems earlier than the calcium scan? I have very high LDL but a calcium scan of 3. The VAP shows it is "large fluffy" but I still worry. Would this test give my dr. more info?

Ned Kock said...

Hi Cassandra. I am not an expert in this, but my understanding is that the IMT test allows for direct visualization of plaque. Also abnormal IMT increases are a reasonably reliable predictor of future vascular disease.

A plaque is not only made of calcium. Calcium is one of the “debris” items that make up what is referred to as plaque.

One study concluded that the CS was a better predictor of future CVD than the IMT. While I don’t have the reference at the moment, I am not very confident about those results.

In short, it seems to me that the CS was found to be a better predictor of CVD because it was less sensitive. That is, if a test captures the beginning of a disease, but not the likelihood of future disease, the test results are going to be more highly correlated with the disease.

Moreover, the study had some major confounders, and if I recall it properly, it also concluded that IMT was a better predictor of stroke.

Let me see if I can find it.

Ned Kock said...

Here is the link to a presentation based on the study:

http://medicine.georgetown.edu/residency/IJC/IJC061709(Luc).ppt

One of the confounders I referred to is on slide 16:

“Patients informed of CAC and IMT scores at baseline – may have influenced pts to alter risk factors, especially since 17% of those with high CAC score were referred to their primary MD’s vs 1% of those with high IMT.”

Cassandra said...

Thanks, Ned. That really gives me something to go on. It certainly is a non-invasive test, I'm going to ask my dr. about it. I have low triglycerides, high HDL; but high LDL and high overall cholesterol. I wish I knew what to do and this might help.

Found two more discussions on calcium scan vs. IMT:

http://www.theheart.org/article/877457.do

http://www.med.nyu.edu/cvprevention/lipids_health/imt_evaluation.html

Ned Kock said...

Thanks for those links Cassandra. I think the first requires a subscription.

A related comment I’d like to make is that a more sensitive test (e.g., IMT) may provide a more solid basis for the assessment of the short-term impact of diet/lifestyle changes.

With this folks can see what really works for them, especially those at higher risk, because presumably in higher-risk folks the impact of diet/lifestyle changes will have a more noticeable effect on the results of a sensitive test.

gwarm said...
This comment has been removed by the author.
gwarm said...

What do you make of Oatmeal? Should my 58yr old dad continue eating it every other day for breakfast?

http://www.youtube.com/watch?v=FcAoUbq_bi8&feature=autoplay&list=PL53AA35449C7DD652&index=11&playnext=2#t=16s

'Whole-grain intake was inversely associated with CCA IMT'
http://www.missclasses.com/mp3s/Prize%20CD%202010/Previous%20years/Whole%20grains/carotid.pdf
http://www.missclasses.com/mp3s/Prize%20CD%202010/Fiber/carotid%20and%20fiber.pdf

David Isaak said...

"What do you make of Oatmeal?"

Oatmeal-raisin cookies, if I recall...but I don't eat it anymore.

Ned Kock said...

Hi gwarm. Oats are seeds and as such have entered the human diet recently, in evolutionary terms. I suspect some people are well adapted to them, and others not. American natives and close descendants, for example, are probably not well adapted to the consumption of oats.

Typically one seems modest reductions in cholesterol levels in certain groups as a result of oatmeal consumption. Whether those reductions do anything good or bad for one’s health is unclear. An IMT test is a much better indication of future CVD than cholesterol levels, in my opinion.

One thing to bear in mind is that almost all industrialized seed-based products raise blood sugar levels, leading to glycation of proteins, including lipoproteins. Glycation of LDL particles makes them somewhat “evil”:

http://atvb.ahajournals.org/cgi/content/abstract/18/7/1140

Instant oatmeal and pre-soaked whole eats tend to lead to abnormally high blood glucose levels, not much unlike white bread. Whole oats that are not pre-soaked are harder to digest, so the response is a little lower. Eating protein together with oats, and almost any sources of carbs, tends to reduce the magnitude of the glucose response as well:

http://pathways4health.org/wp-content/uploads/2011/04/Chart3.jpg

I don’t eat seeds, thus I don’t eat oats.

Jack C said...

Hi Ned,

I gather from this post and others that you do not eat dairy foods which are the main source of vitamin K2 in the western world. Vitamin K2 is required to activate the calcification inhibitor matrix Gla protein (MGP).

I am curious. Do you avoid dairy foods because they are "not paleo", or are there other reasons?

Ned Kock said...

Hi Jack. Actually I eat about 1.5 lbs of aged raw milk cheese per week. Occasionally I eat ice cream, but that is rare. No milk.

Jack C said...

Ned,

Wow! A pound and a half of aged cheese a week is a lot of cheese! No wonder you had such great results on the intima-media thickness test. That is a lot of vitamin K2.

I eat about a pound a week of aged raw milk cheese, but I also eat a fair butter and some organic pasteurized, but not homogenized, milk. (All from grass fed cows.)

Aged cheese is my favorite dairy product for a lot of reasons. Aged cheese is the only raw dairy that you can ship across state lines without fear of arrest by the Feds. It has a high vitamin K2 content, no lactose, apparently no beta-casomorphins (the milk devil) and has a long shelf life.

I buy milk from a dairy here in Alabama that recently switched from standard commercial dairy production to production of organic milk, a process that take several years. The owners told me that their cows on grass feed give only half as much milk but live twice as long as they did on grain feed. I have read that the grain feed, soy in particular, damages the cow's liver and results in reduced lifespan and fertility. That alone is enough to keep me from drinking "regular" milk.

WilliamS said...

"Aged cheese . . . has . . . apparently no beta-casomorphins . . ."

Do you have any references for this? I had thought this was still unclear and that Keith Woodford still recommends avoiding cheese made from A1 milk.

Ned Kock said...

Hi Jack. My cheese is from grass fed cattle as well. I eat cheese on the days that I exercise, where I am usually in caloric surplus – in other words, I eat A LOT on the days that I exercise. On the days that I don’t exercise, I am usually in caloric deficit.

By doing this, I can eat to maintenance over a week, or be in a small caloric deficit if I want. Body composition seems to be changing – my weight has been stable for quite some time, but my waist is shrinking.

It is relatively easy to be on caloric deficit without feeling too hungry, by sticking mostly with seafood and veggies on the days that I don’t exercise. For example, yesterday I ate about 110 g of protein from seafood, but only about 1,000 calories overall.

There is another plus – dietary variation.

Ned Kock said...

Btw, I am not particularly concerned about the BCM7 issue. The reason is that long-term studies with humans and model animals generally suggest that aged cheese is quite healthy.

On the other hand, there is evidence suggesting that isolated casein is not.

It is not hard to show that particular biochemical paths spell trouble from a health perspective. Still, long-term studies may contradict some of those findings. The underlying reason is compensatory adaptation. The body adapts.

If you eat cheese, the body adapts too, and that adaptation may come in the form of production of certain enzymes. A good candidate here is dipeptidyl peptidase-4, which apparently breaks down BCM7.

Jack C said...

William S,

Regarding the apparent absence of beta-casomorphins from cheese:

For starters, in the epidemiological evidence presented in "Devil in the Milk', the relationship between heart disease, type one diabetes and beta-casein intake was based on casein intake "excluding cheese." In short, there is no evidence that aged cheese contains BCM7.

Keith Woodford states that there is "scientific evidence" that BCM7 is broken down during cheese fermentation, but does not give a reference.

Further, a study (PMID 8675779)
concluded: "Therefor, if formed in (making of) cheese, beta-casomorphins may be degraded under conditions common for cheddar cheese"

M & M said...

Or maybe a high LDL demonstrates the superiority of anabolism in the body in contrast to the low LDL-catabolism

Jack C said...

Ned,

I am not concerned about BMC7 either. BMC7 is a major problem for newborns, particularly during the first three months of life. I suspect that problems in commercial milk production, such as feeding soy and growth hormones to increase milk production, homogenization, pasteurization and ultra-pasteurization, cause as many problems as BMC7. I therefore drink organic milk from pastured A1 cows without concern.

In my opinion Keith Woodford did a masterful job putting all the information about BMC7 together, and in providing updates about recent developments. However, in the last chapter, "Bringing it all together", he gets off track. He addresses the question of whether milk is essential, noting that many people get along well without milk. He refers the reader to the website of the Harvard School of Public Health for a information on alternatives, where, he says, "you may be surprised by what you read."

I went to the Harvard website and was surprised. The website is so pathetically out of date. There is no mention of Vitamin K2, menaquinone, in the entire site. Most of the diseases which Harvard attributes to milk are, in fact, due to deficiency of vitamin K2 which is greatly exacerbated by Harvard's recommendation to substitute margarine for butter and consume only low fat and non fat dairy products, thereby getting little vitamin K2.

Prostate cancer, which Harvard says may be caused by milk, is a good example. A recent study found that the risk of prostate cancer decreased with increasing whole milk consumption and increased with increased low fat milk consumption, compared to no milk consumption. The Heidelberg study found that the relative risk the quartile that consumed the most vitamin K2 (and the most dairy)compared to those who consumed the least, was 0.37. So, contrary to Harvard's contention, it appears that whole fat dairy products decrease risk of prostate cancer.

My review of the Harvard website convinced that while dairy products may not be essential, they certainly are beneficial.

Christian Wernstedt said...

I listened to your Jimmy Moore interview. I heard you discussing TNF-alpha as a marker of systemic inflammation. I'm curious about what you think of TNF versus other markers, such as hsCRP, which is more often measured.

gwarm said...

If you don't eat seeds, do you supplement with magnesium? You should post the results and findings of the people mentioned on LLVLC who had better results working out less often.

viagra online said...

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Razwell said...

Hi, Ned :)

Have you heard about the IVUS test? Dr. Steven Nissen says it is by far the most accurate. The reason being so is that coronary artery disease is not a disease of the vessel lumen, BUT RATHER a disease of the vessel WALL.



Take care,

Raz