Overweight, hungry, diabetic, and fat-free

15. December 2009 William Davis (52)
Let me tell you about my low-fat experience from 20 years ago.

At the time, I was living in Cleveland, Ohio, and served on the faculty at a large metropolitan university-affiliated hospital, supervising fellows-in-training and developing high-tech cath lab procedures like directional athererectomy and excimer laser coronary angioplasty. (Yes, another life.)

I was concerned about personal heart disease risk, though I knew next to nothing about lipids and coronary risk prediction outside of the little I learned in training and what the drug industry promoted.

I heard Dr. Dean Ornish talk while attending the American College of Cardiology meetings in Atlanta. Dr. Ornish spoke persuasively about the dangers of fat in the diet and how he "reversed" coronary disease using a low-fat, no added oils, no meat, vegetarian diet that included plenty of whole grains. So I thought I'd give it a try.

I eliminated all oils; I removed all meat, eggs, and fish from my diet. I shunned all nuts. I ate only low-fat products like low-fat yogurt and cottage cheese; and focused on vegetables, fruit, and whole grains. Beans and brown or wild rice were a frequent staple. I loved oatmeal cookies--low-fat, of course!

After one year of this low-fat program, I had gained a total of 31 lbs, going from 155 lbs to 186 lbs. I reassessed some basic labs:

HDL 28 mg/dl
Triglycerides 336 mg/dl
Blood sugar 151 mg/dl (fasting)


I became a diabetic. All through this time, I was also jogging. I ran on the beautiful paths along the Chagrin River in suburban Cleveland for miles north and south. I ran 5 miles per day most days of the week.

It was diabetes that hit me alongside the head: I was eating low-fat meticulously, exercising more than 90% of the population, yet I got fat and diabetic!

I have since changed course in diet. Last time I checked, my lipid values on NO statin agent:

HDL 67 mg/dl
Triglycerides 57 mg/dl
Blood sugar 91 mg/dl

That was my lesson that fat restriction is a destructive, misguided notion. The data since then have confirmed that restricting total fat is unnecessary, even undesirable, when fat calories are replaced by carbohydrate calories.

This is your brain on wheat

10. December 2009 William Davis (32)
Here's just a smattering of the studies performed over the past 30 years on the psychological effects of wheat consumption.

Oddly, this never makes the popular press. But wheat underlies schizophrenia, bipolar illness, behavioral outbursts in autism, Huntington's disease, and attention deficit hyperactivity disorder (ADHD).

The relationship is especially compelling with schizophrenia:

Opioid peptides derived from food proteins: The exorphins.
Zioudrou C et al 1979
"Wheat gluten has been implicated by Dohan and his colleagues in the etiology of schizophrenia and supporting evidence has been provided by others. Our experiments provide a plausible biochemical mechanism for such a role, in the demonstration of the conversion of gluten into peptides with potential central nerovus system actions."


Wheat gluten as a pathogenic factor in schizophrenia
Singh MM et al 1976
"Schizophrenics maintained on a cereal grain-free and milk-free diet and receiving optimal treatment with neuropleptics showed an interruption or reversal of their therapeutic progress during a period of "blind" wheat gluten challenge. The exacerbation of the disease process was not due to variations in neuroleptic doses. After termination of the gluten challenge, the course of improvement was reinstated. The observed effects seemed to be due to a primary schizophrenia-promoting effect of wheat gluten."


Demonstration of high opioid-like activity in isolated peptides from wheat gluten hydrolysates
Huebner FR et al 1984


Is schizophrenia rare if grain is rare?
Dohan FC et al 1984
"Epidemiologic studies demonstrated a strong, dose-dependent relationship between grain intake and the occurrence of schizophrenia."

Small LDL: Perfect index of carbohydrate intake

8. December 2009 William Davis (15)
Measuring the number of small LDL particles is the best index of carbohydrate intake I know of, better than even blood sugar and triglycerides.

In other words, increase carbohydrate intake and small LDL particles increase. Decrease carbohydrates and small LDL particles decrease.

Why?

Carbohydrates increase small LDL via a multistep process:

First step: Increased fatty acid and apoprotein B production in the liver, which leads to increased VLDL production. (Apoprotein B is the principal protein of VLDL and LDL)

Second step: Greater VLDL availability causes triglyceride-rich VLDL to interact with other particles, namely LDL and HDL, enriching them in triglycerides (via the action of cholesteryl-ester transfer protein, or CETP). Much VLDL is converted to LDL.

Third step: Triglyceride-rich LDL is "remodeled" by enzymes like hepatic lipase, which create small LDL.


Carbohydrates, especially if they contain fructose, also prolong the period of time that triglyceride-rich VLDL particles persist in the blood, allowing more time for VLDL to interact with LDL.

Many people are confused by this. "You mean to tell me that reducing carbohydrates reduces LDL cholesterol?" Yes, absolutely. While the world talks about cutting saturated fats and taking statin drugs, cutting carbohydrates, especially wheat (the most offensive of all), cornstarch, and sugars, is the real key to dropping LDL.

However, the effect will not be fully evident if you just look at the crude conventional calculated (Friedewald) LDL cholesterol. This is because restricting carbohydrates not only reduces small LDL, it also increases LDL particle size. This make the calculated Friedewald go up, or it blunts its decrease. Conventional calculated LDL will therefore either underestimate or even conceal the real LDL-reducing effect.

The reduction in LDL is readily apparent if you look at the superior measures, LDL particle number (by NMR) or apoprotein B. Dramatic reductions will be apparent with a reduction in carbohydrates.

Small LDL therefore serves as a sensitive index of carbohydrate intake, one that responds literally within hours of a change in food choices. Anyone following the crude Friedewald calculated LDL will likely not see this. This includes the thousands of clinical studies that rely on this unreliable measure and come to the conclusion that a low-fat diet reduces LDL cholesterol.

Fat "conditioning"

4. December 2009 William Davis (0)
Here's a great study from the prolific laboratory of Dr. Jeff Volek from the University of Connecticut. (Full text here.)


http://jn.nutrition.org/cgi/content/full/134/4/880

Video Teleconference with Dr. William Davis

2. December 2009 William Davis (0)

Dr. Davis is available for personal
one-on-one video teleconferencing

to discuss your heart health issues.


You can obtain Dr. Davis' expertise on issues important to your health, including:

Lipoprotein assessment

Heart scans and coronary calcium scores

Diet and nutrition

Weight loss

Vitamin D supplementation for optimal health

Proper use of omega-3 fatty acids/fish oil


Each personalized session is 30 minutes long and by appointment only. To arrange for a Video Teleconference, go to our Contact Page and specify Video Teleconference in your e-mail. We will contact you as soon as possible on how to arrange the teleconference.


The cost for each 30-minute session is $375, payable in advance. 30-minute follow-up sessions are $275.

(Track Your Plaque Members: Our Member cost is $300 for a 30-minute session; 30-minute follow-up sessions are $200.)

After the completion of your Video Teleconference session, a summary of the important issues discussed will be sent to you.

The Video Teleconference is not meant to replace the opinion of your doctor, nor diagnose or treat any condition. It is simply meant to provide additional discussion about your health issues that should be discussed further with your healthcare provider. Prescriptions cannot be provided.

Note: For an optimal experience, you will need a computer equipped with a microphone and video camera. (Video camera is optional; you will be able to see Dr. Davis, but he will not be able to see you if you lack a camera.)

We use Skype for video teleconferencing. If you do not have Skype or are unfamiliar with this service, our staff will walk you through the few steps required.

Track Your Plaque challenges

1. December 2009 William Davis (31)
Of all the various factors we correct in the Track Your Plaque program in the name of achieving reversal of coronary plaque, there are two factors that are proving to be our greatest challenges:

1) Genetic small LDL

2) Lipoprotein(a)

More and more people are enjoying at least marked slowing, if not zero change or reduction, in heart scan scores following the Track Your Plaque program. We achieve this by correcting a number of factors. Some factors, like vitamin D deficiency, are easily corrected to perfection--supplement sufficient vitamin D to achieve a blood level of 25-hydroxy vitamin D of 60-70 ng/ml. Correcting standard lipid values--LDL cholesterol, HDL cholesterol, and triglycerides--child's play, even to our strict targets of 60-60-60.

However, what I call "genetic small LDL" and a subset of lipoprotein(a) are proving to be the most resistant of all.

Let's first consider genetic small LDL. Small LDL is generally the pattern of the carbohydrate-ingesting, overweight person. It has exploded in severity over the past decade due to overconsumption of carbohydrates due to the ridiculous low-fat notion. Reduce or eliminate carbohydrates, especially wheat, which permits weight loss, and small LDL drops like a stone. But there is a unique subset of people who express the small LDL pattern who start at or near ideal weight. Take Chad, for instance. At 6' 2" and 152 lbs and BMI of 19.6, there's no way excess weight could be triggering his small LDL. Yet he starts with 100% small LDL particles. All efforts to reduce small LDL, such as wheat, cornstarch, and sugar elimination; niacin; vitamin D normalization; thyroid normalization; and several supplements that yield variable effects, such as phosphatidylcholine, all leave Chad with more than 90% small LDL.

Lipoprotein(a) is a bit different. Over the past 5 years, our choices in ways to reduce Lp(a) expression have improved dramatically. Beyond niacin, we now have high-dose EPA + DHA, thyroid normalization that includes use of T3, and hormonal manipulation. In the Track Your Plaque experience, approximately 70% of people with Lp(a) respond with a reduction in Lp(a). (In fact, the 4 out of the 5 record holders for reduction of heart scan scores have Lp(a) that was successfully treated.) But about 30% of people with Lp(a) prove resistant to all these treatments--they begin with a Lp(a) of, say, 260 nmol/L and, despite niacin, high-dose EPA + DHA, and various hormones, stay at 260 nmol/L. It can be frustrating and frightening.

So these are the two true problem areas for the Track Your Plaque program, genetic small LDL and a subset of Lp(a).

We are actively searching for better options for these two problem areas. Given the collective exploration and wisdom that develops from such collaborative efforts as the Track Your Plaque Forum, I am optimistic that we will have better answers for these two stumbling blocks to plaque reversal in the future.

I'll supply the tar if you supply the feathers

30. November 2009 William Davis (13)
The results of the latest Heart Scan Blog poll are in.


DIRECT-TO-CONSUMER PHARMACEUTICAL ADVERTISING HAS:

Increased public awareness of medical conditions and their treatment
19 (11%)

Has had little overall effect on health and healthcare
29 (18%)

Needlessly increased healthcare costs
81 (50%)

Further empowered the revenue-obsessed pharmaceutical industry
130 (81%)


Clearly, there's a lot of negative sentiment against direct-to-consumer (DTC) drug advertising.

It looks as if a small minority believe that good has come from DTC advertising, judging by the meager 11% who voted for increased awareness. In fact, the poll results are heavily weighed towards the negative: 50% voted for "needlessly increased healthcare costs," while an astounding 81% voted for "empowered the revenue-obsessed pharmaceutical industry."

It is, indeed, an odd situation: Pharmaceutical agents available only by prescription being hyped directly to the consumer.

Personally, I would vote for choices 1,3, and 4. While awareness has increased, it has come with a hefty price, not all of it well spent. I believe the pharmaceutical industry still adheres to the rule that, for every $1 spent on advertising, $4 is made in revenue. They are, in effect, printing money.

What goes up can't come down

28. November 2009 William Davis (13)
According to conventional wisdom, heart scan scores cannot be reduced.

In other words, say you begin with a heart scan score of 300. Conventional wisdom says you should take aspirin and a statin drug, eat a low-fat "heart healthy" diet, and take high blood pressure medications, if necessary.

If your heart scan score goes up in a year or two, especially at an annual rate of 20% or more, then you are at very high risk for heart attack. If the heart scan score stays the same, then your risk is much reduced. These observations are well-established.

But more than 99% of physicians will tell you that reducing your heart scan score is impossible. Don't even try: Heart scan scores can go up, but they can't go down.

Baloney. Heart scan scores can indeed go down. And they can go down dramatically.

It is true that, following conventional advice like taking a statin drug, following a low-fat diet, and taking aspirin will fail to reduce your heart scan score. A more rational approach that 1) identifies all causes of coronary plaque, 2) corrects all causes while including crucial strategies like omega-3 fatty acid supplementation, vitamin D supplementation, and thyroid function normalization, is far more likely to yield a halt or reduction in score.

While not everybody who undertakes the Track Your Plaque program will succeed in reducing their heart scan score, a growing number are enjoying success.

A small portion of our experience was documented this past summer. (I collected and analyzed the data with the help of Rush University nutrition scientist, Dr. Susie Rockway, and statistician, Dr. Mary Kwasny.)


Effect of a combined therapeutic approach of intensive lipid management, omega-3 fatty acid supplementation, and increased serum 25 (OH) vitamin D on coronary calcium scores in asymptomatic adults.

Davis W, Rockway S, Kwasny M.

The impact of intensive lipid management, omega-3 fatty acid, and vitamin D3 supplementation on atherosclerotic plaque was assessed through serial computed tomography coronary calcium scoring (CCS). Low-density lipoprotein cholesterol reduction with statin therapy has not been shown to reduce or slow progression of serial CCS in several recent studies, casting doubt on the usefulness of this approach for tracking atherosclerotic progression. In an open-label study, 45 male and female subjects with CCS of > or = 50 without symptoms of heart disease were treated with statin therapy, niacin, and omega-3 fatty acid supplementation to achieve low-density lipoprotein cholesterol and triglycerides < or = 60 mg/dL; high-density lipoprotein > or = 60 mg/dL; and vitamin D3 supplementation to achieve serum levels of > or = 50 ng/mL 25(OH) vitamin D, in addition to diet advice. Lipid profiles of subjects were significantly changed as follows: total cholesterol -24%, low-density lipoprotein -41%; triglycerides -42%, high-density lipoprotein +19%, and mean serum 25(OH) vitamin D levels +83%. After a mean of 18 months, 20 subjects experienced decrease in CCS with mean change of -14.5% (range 0% to -64%); 22 subjects experienced no change or slow annual rate of CCS increase of +12% (range 1%-29%). Only 3 subjects experienced annual CCS progression exceeding 29% (44%-71%). Despite wide variation in response, substantial reduction of CCS was achieved in 44% of subjects and slowed plaque growth in 49% of the subjects applying a broad treatment program.

Gretchen's postprandial diet experiment

27. November 2009 William Davis (11)
Gretchen sent me the results of a little experiment she ran on herself. She measured blood glucose and triglycerides after 1) a low-fat diet and 2) a low-carb diet.









Gretchen describes her experience:

Several years ago I received a windfall of triglyceride strips that would expire in a week or so. I hated to waste them, so I decided to use them to test my triglyceride and BG responses to two different diets: low carb and low fat.

The first day I followed a low-fat diet. For breakfast I ate a lot of carbohydrate, including 1 oz of spaghetti cooked al dente and ¾ cup of white rice. For the rest of the day I ate less carbohydrate but continued to eat low fat.

The second day I followed a low-carb diet. For breakfast I ate a lot of fat, including a sausage, mushrooms fried in butter, 2 slices of bacon, and ¼ cup of the creamy topping of whole-milk yogurt. For the rest of the day I ate less fat, especially less saturated fat, but continued to eat low carb.

Both days I measured both BG and triglyceride levels every hour until I went to bed. On the low-carb day I had 3 meals. On the low-fat day, I was constantly hungry, had 4 meals, and kept snacking.

You can see the results in Figure 1. On the low-fat diet, after a “healthy” low-fat breakfast of low-glycemic pasta with low-fat sauce, my BG levels shot up to over 200 mg/dL and took more than 6 hours to come down. My triglycerides, however, remained low, and at first I thought perhaps the low-fat diet might be better overall. However, after about 6 hours, the triglyceride levels started to increase steadily, and by the next morning, they were higher than they had been the day before.
On the low-carb diet, my BG levels stayed low all day. However, after meals, the triglyceride levels skyrocketed. After meals they came down, and by the next morning they were lower than they had been the day before.

As I interpret these results, the high triglyceride levels after eating the high-fat meals represent chylomicrons, the lipoproteins that transport fat from your meals to the cells of your body. The high triglyceride levels the morning after eating the low-fat meals represent very low density lipoprotein, which takes the cholesterol your liver synthesizes when your intake of dietary cholesterol is low and distributes it to cells that need it, or again, to the fat for storage.

There are several interesting factors to consider here. First, when you have a lipid test done at the lab, it’s usually done fasting, which means first thing in the morning after not eating for 8 to 12 hours. It tells you nothing about what your triglyceride levels were all day.

Second, the low-carb diet resulted in lower fasting triglyceride levels, but much higher postprandial triglyceride levels. Which are more dangerous? I’m afraid I don’t know. You should also note that the high-fat, low-carb breakfast was extremely high in fat, including saturated fat. I don’t normally eat that much fat but wanted to test extremes.

Third, although the low-fat diet didn’t produce the very high postprandial triglyceride levels that the high-fat diet did, it produced extremely high BG levels that persisted for 6 hours. Some people think that it’s oxidized and glycated lipids that are the dangerous ones, so high BG levels and normal triglyceride levels might be more dangerous than very high triglyceride levels and normal BG levels. Note that high BG levels also contribute to oxidation rates.

Fourth, this shows the results of an experiment with a sample size of one. My physiology might not be typical. If you want to know how your own body’s lipids respond to different types of diets, you should get a lipid meter and test yourself. Unfortunately, your insurance is unlikely to want to pay for this, so it will be an expensive experiment.

The main point of this is that the results of different diets are complex. We have to eat. And what we eat can affect many different systems in our bodies. Finding the ideal diet that matches our own physiology and results in the best lipid levels as well as BG levels is a real challenge.



This was a lot of effort for one person. Thanks to Gretchen for sharing her interesting experience.

Gretchen makes a crucial point: Some of the effects of diet changes evolve over time, much as triglyceride levels changed substantially for her on the day following her experiment. Wouldn't it be interesting to see how postprandial patterns develop over time if levels were observed sequentially, day after day?

The stark contrast in blood sugars is impressive--Low-carb clearly has the advantage here. Are there manipulations in diet composition in low-carb meals that we can make to blunt the early (3-6 hour) postprandial lipoprotein (triglyceride) peak? That's a topic we will consider in future.

More of Gretchen's thoughts can be found at:

http://wildlyfluctuating.blogspot.com
http://www.healthcentral.com/diabetes/c/5068

After-eating effects: Carbohydrates vs. fats

25. November 2009 William Davis (17)
In the ongoing debate over whether it's fat or carbohydrate restriction that leads to weight loss and health, here's another study from the Oxford group examining the postprandial (after-eating) effects of a low-fat vs. low-carbohydrate diet. (Roberts R et al, 2008; full-text here.)

High-carbohydrate was defined as 15% protein; 10% fat; 75% carbohydrate (by calories), with starch:sugar 70:30.

High-fat was defined as 15% protein; 40% fat; 45% carbohydrate, with starch:sugar 70:30. (Yes, I know. By our standards, the "high-fat" diet was moderate-fat, moderate-carbohydrate--too high in carbohydrates.)

Blood was drawn over 6 hours following the test meal.




Roberts R et al. Am J Clin Nutr 2008

The upper left graph is the one of interest. Note that, after the high-carbohydrate diet (solid circles), triglyceride levels are twice that occurring after the high-fat diet (open circles). Triglycerides are a surrogate for chylomicron and VLDL postprandial lipoproteins; thus, after the high-carbohydrate diet, postprandial particles are present at much higher levels than after the high-fat diet. (It would have been interesting to have seen a true low-carbohydrate diet for comparison.) Also note that, not only are triglyceride levels higher after high-carbohydrate intake, but they remain sustained at the 6-hour mark, unlike the sharper decline after high-fat.

It's counterintuitive: Postprandial lipoproteins, you'd think, would be plentiful after ingesting a large quantity of fat, since fat must be absorbed via chylomicrons into the bloodstream. But it's carbohydrates (and obesity, a huge effect; more on that in future) that figure most prominently in determining the pattern and magnitude of postprandial triglycerides and lipoproteins. Much of this effect develops by way of de novo lipogenesis, the generation of new lipoproteins like VLDL after carbohydrate ingestion.

We also see this in our Track Your Plaque experience. Rather than formal postprandial meal-testing, we use intermediate-density lipoprotein (IDL) as our surrogate for postprandial measures. A low-carbohydrate diet reduces IDL dramatically, as do omega-3 fatty acids from fish oil.
What else is there?

What else is there?

7. September 2008 William Davis (11)
This question comes up frequently:

Aren't there any alternatives to heart scans performed on a CT or EBT device?

Yes, there are.

First of all, heart scans are performed best on an electron-beam CT device (EBT) or a 64-slice multi-detector CT (MDCT) device. (While they are also obtainable through less-than-64 slice CT devices (e.g., 16 slices and less), I would advise against it because of the excessive radiation exposure and poor accuracy.) CT heart scans are not to be confused with now more popular CT coronary angiograms, which are performed on the same devices but require intravenous x-ray dye and many times more radiation.(See CT scans and radiation exposure and Heart scan frustration.) Heart scans currently form the basis for the Track Your Plaque program, a program of tracking plaque in the hopes of stopping or reversing the otherwise inevitable 30% per year increase.

Let's confine our discussion to people without symptoms, meaning people like you and me sitting at home, not in an emergency room having chest pain or other similar acute symptomatic presentation.

Among the other ways to uncover hidden coronary plaque:

--Heart catheterization--to yield a coronary angiogram. Yes, this does tell us whether coronary plaque is present. However, it is invasive, expensive, and crude. (I've performed 5000 over my career; they are crude, though useful, tools in acute settings like unstable symptoms or heart attack, a different situation.) Coronary angiography is also non-quantitative. While they provide a value like "40% blockage mid-way in right coronary" or "90% blockage in left anterior descending" they do not provide a trackable lengthwise index of total plaque volume. Identifying severe blockages in people with symptoms leads to stents, bypass surgery and the like, but it is not practical nor of long-term usefulness in apparently, healthy people without symptoms.

--Carotid ultrasound--Here's is where a lot of confusion comes from. Standard carotid ultrasound (U/S) performed in virtually every hospital and many clinics will yield crude qualitative results, e.g., "16-49% stenosis (blockage) in right internal carotid artery". The crude value range is because much of carotid U/S is based on flow velocities, not just direct visualization of the plaque itself ("2-D imaging). However, if carotid stenosis of any degree is identified, the likelihood of silent coronary plaque is much greater.

Limitations: The qualitative, non-quantitative nature of carotid U/S make it difficult to follow long-term in a precise way. Also, this is carotid plaque, not coronary plaque. It makes it very difficult to follow carotid plaque as an indirect means of tracking coronary plaque. The two arterial territories, carotid and coronary, do not track together: there are divergences in many people, with carotid plaque absent in some people with advanced coronary plaque, carotid plaque more susceptible to different risk factors than coronary. So carotid U/S is helpful for its own purposes, but not terribly helpful for coronary tracking.

How about carotid intimal-medial thickness (CIMT) obtained also with carotid U/S? CIMT is a useful index of bodywide atherosclerosis. CIMT is simply a measure not of plaque (and is measured in regions of the carotid artery away from plaque), but of the thickness of the lining of the carotid arteries. Everybody has a measurable CIMT, but it thickens as atherosclerosis grows. CIMT is a radiation-free test that takes several minutes.

Limitations: Hardly anybody does it outside of research protocols. I know of no hospital or clinic in my area that performs CIMT, though it is slowly being adopted in some centers. It is also difficult to rely on repeated tests, because there is substantial variation when one technologist or another performs it. CIMT is also a flawed index of coronary plaque. When CIMT is compared to heart scan scores, CT coronary angiography, or conventional coronary angiography, CIMT correlates about 60-70% with the degree of coronary atherosclerosis.

CIMT is therefore a useful test for research, but a distant 2nd choice--if you can obtain it.

--Ankle-brachial index (ABI)--ABI is a crude measure, simply a comparison of the blood pressure (obtained with a blood pressure cuff) in the legs divided by blood pressure in the arms. The ratio is called ABI. Any ABI <1.0, meaning less pressure in the legs compared to the arms, is indirectly indicative of advanced coronary disease. ABI is, in fact, a very powerful predictor of cardiovascular events. If ABI is <1.0, your future risk for heart attack is very high, even in the absence of symptoms.

Limitations: The vast majority of people with heart disease, even those having undergone stents or bypass surgery, have normal ABI's. Virtually all people with high heart scan scores have normal ABI's. In other words, ABI is a measure of very advanced atherosclerosis only.

--Stress tests--I lump all stress tests together in their various forms, e.g., stress thallium, stress Cardiolite, stress Myoview, persantine/adenosine Cardiolite, dobutamine echocardiography, etc. Stress tests are tests of coronary blood flow, not of plaque. Stress tests are useful in people with symptoms, like chest pain or breathlessness, since stress tests are provocative tests that can help determine whether reduced coronary blood flow is the cause behind a symptom, or whether hiatal hernia, esophagitis, gallstones, pleurisy, musculoskeletal causes, or some other process is behind symptoms.

Limitations: Stress test are virtually useless in people without symptoms. This is why people like Tim Russert and Bill Clinton, both without symptoms, underwent several (Russert 3, Clinton 5) nuclear stress tests---all normal. You know what happened to them. Stress tests do not reliably uncover hidden coronary plaque in people without symptoms. Stress tests are, like coronary angiograms, non-quantitative. They are normal or abnormal.


Outside of experimental settings, that's it.

You can probably see why I advocate CT heart scans for tracking plaque. I do not advocate heart scans because I sell them (I don't), because scan centers pay me to say these things (they don't, and in fact my relationship with my usual heart scan centers has become deeply contentious, though I still endorse the technology). I say that heart scans are superior because they are, in 2008, the only way to 1) identify and 2) track coronary plaque that is easy, safe, low-radiation, and reasonably priced (<$200 in Milwaukee at 5 centers).

The need for a technology that allows tracking of plaque, not just initial identification, is also an important distinction. People who've had some measure of atherosclerosis all catch on to this eventually. "Can I reverse it?" is an inevitable question once the disease is identified in some way. So a tool for tracking over time to gauge the success or failure of a program of prevention can be assessed.

Perhaps in 10 years, another technology will emerge as the preferred means to do the same, but better. If that proves true, we will convert to that technology. But today heart scans performed on CT heart scans are the only rational way to both detect, then track, coronary atherosclerotic plaque.
Tags :

Comments (11) -

  • Steve

    9/7/2008 3:29:00 PM |

    is it true that heart scans do not show soft plaque,which minimizes their benefit since soft plaque is the real concern

  • lizzi

    9/7/2008 4:27:00 PM |

    I think that CIMT may be more widely available in different areas of the country.  I practice in Los Angeles and have the luxury of having Dr. Budhoff 15 minutes away.  I like that my referrals for EBT will contribute to a research protochol.  In addition, many internists are purchasing an ultrasound machine, hiring a tech, and providing CIMT for $350.00. There are two approved CIMT protocols, one which requires only a single measure of IMT, the other which requires six measurements.  Guess which one is more accurate? I am also fortunate that the internist next door to me hires an excellent tech and does 6 measurements.

  • lizzi

    9/7/2008 4:46:00 PM |

    Dr. Davis.  Have you seen P Bhaggi's article in Lancet 8/28/08?  His hypothesis is that even "safe" doses of radiation MAY increase CV disease risk. (<5Gy). He sites a linear association between radiation exposure for peptic ulcer disease (1.6 - 3.9 Gy) and CV disease risk.  I don't know how Gy equates to Msv.

  • Bella6

    9/7/2008 6:58:00 PM |

    Bravo!

  • Anonymous

    9/7/2008 8:49:00 PM |

    Any newer technologies that look promising ?

  • MedPathGroup

    9/8/2008 1:28:00 AM |

    Very relevant information about CT Heart Scan and other alternatives to tracking coronary plaque. I will definitely add this to my research. I will keep on visiting your blog site. I've been a reading a lot of your posts and they are really interesting. Keep it up.

  • Anonymous

    9/8/2008 4:53:00 PM |

    in the new york area they do CIMT and use it as a proxy for CAD.  I would say that 60-70% correlation is pretty good and need for heart scan not necessary if CIMT is abnormal.

  • JD

    9/9/2008 1:56:00 PM |

    For Dr. Davis. He probably is aware of this type of study but thought I would post it.

    http://www.sciencedaily.com/releases
    /2008/09/080908085502.htm

    "For the study, researchers used cardiac and CT scans to measure multiple fat depots in 398 white and black participants from Forsyth County, N.C., ages 47-86. They found that the amount of fat a person had deposited around organs and in between muscles (nonsubcutaneous fat) had a direct correlation to the amount of hard, calcified plaque they had."

  • mike V

    9/9/2008 6:07:00 PM |

    Steve:
    See Heart Scan Blog
    Sunday, December 03, 2006
    Calcium reflects total plaque
    MikeV

  • Maureen Zilly

    9/9/2008 6:19:00 PM |

    I think that the Los Angeles Times story “CT scans can be better medicine for doctors than for patients” portrays an inaccurate picture of how physicians use computed tomography to care for their patients.  

    To begin with, the piece overstates the growth and utilization of CT. For example, the story uses GAO statistics to demonstrate an increase in CT scans, but the GAO's recent report on medical imaging did not account for the most recent data available. Had the GAO used the more current 2007 Medicare claims instead, its report would have actually shown a decrease in the growth of medical imaging services in recent years.

    Next, the story presents biased information as fact. Insurance companies are wholly motivated to pay less for health care services, which includes limiting medical imaging scans. In fact, insurers have created a cottage industry, called Radiology Benefit Managers, with the sole purpose of refusing coverage for scans. By citing subjective and unverified insurance company-generated analysis of how many scans are "inappropriate," readers are presented with a skewed view about how and why physicians order scans.  

    Clearly, CT has grown as it's become integral to modern day medicine. From best practices to patient advocate guidelines, CT is a powerful tool for improving patient outcomes. But, the larger issue is ensuring patients have access to the right scan at the right time. In computed tomography this is even more important because of the radiation CT employs to generate what are often life-saving images.    

    That's why it is vital for payers -- both private and Medicare -- to ensure that healthcare decision making remains between the physician and patient. The recent Medicare bill is an important step in the right direction because it embraces both accreditation and appropriateness criteria, and it is approaches such as these that will ensure that each scan ordered is appropriate, effective and safe for patients.

    Lastly, the article also claims that CT angiograms (CTA) are "less accurate" than traditional angiograms, but research has indicated otherwise. A recent study published in the Journal of the American College of Cardiology, for instance, found that CTA was 99 percent as effective in ruling out heart disease as the more expensive and invasive coronary angiography traditionally used by physicians. This CTA study is just one of many peer-reviewed data points demonstrating how medical imaging, and CT specifically, improves health outcomes and reduces overall costs.

    Maureen Zilly
    Medical Imaging & Technology Alliance

  • Anonymous

    9/10/2008 4:43:00 PM |

    Are there any options for young adults with a strong family Hx?  I contacted TYP, but they told me that based on my age, the risk of radiation exposure outweighs the potential benefits of the scans.  I'm a 26 y/o female.

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