Chapter 4 - 3D Health Discover
Updated on February 1, 2003

Introduction - Are You 3D Healthy?	Chapter 3 - The Noninvasive Biopsy of Your Arteries
Chapter 1 - A Cardiologist’s Story	Chapter 4 - 3D Health Discover
Chapter 2 - Life and Death of an Artery
	Back to Main 3D Health page

The ultimate goal of 3D Health is cardiovascular wellness. Now that you know something about cardiovascular disease and how it develops, its time to consider the first step in 3D Health, the Discover step. Before you can begin a journey, you need a map. Discover is really just a map of your cardiovascular status. I have chosen what I believe to be the key markers of your risk for cardiovascular disease. The following table lists each marker with a brief description:

MARKER	SIGNIFICANCE
Coronary artery calcium	Direct marker of plaque in the coronary arteries
Carotid artery calcium	Direct marker of plaque in the carotid arteries
Body mass index	Ratio of weight to height
Fat mass (%)	Percent of weight that is fat
Lean body mass (%)	Percent of weight that is not fat (60% of this is muscle)
Visceral fat	Abdominal cavity fat- the most dangerous kind
Blood pressure	Direct marker for endothelial dysfunction
Blood sugar (glucose)	Key measure for diabetes
Insulin	Goes up with insulin resistance
C-reactive protein	Goes up with inflammation
LDL cholesterol	Major component of plaque lipid core
LDL pattern	Pattern B means dangerous small LDL particles
HDL cholesterol	Carries cholesterol away from plaque
Lp(a)	Makes blood more likely to clot
Triglycerides	Marker for metabolic syndrome
Homocysteine	Amino acid that damages the artery wall
Fibrinogen	Molecule involved in clot formation
VO2 Max	Key fitness indicator

Does everybody need to measure all of these markers? Definitely not. When deciding whether to do a test, the most important consideration is your risk for cardiovascular disease. Here are some basic risk categories to consider before doing any of the above tests:

Age

Risk goes up with age. If you are a male under 40 or a female under 50, then you are in a low risk group for cardiovascular disease, unless you have one of the risks mentioned in the next few paragraphs. For those of you in these age groups with no strong family history, no diabetes and no long-term tobacco history, I would only recommend that once every three to five years you check your LDL and HDL cholesterol, your blood pressure and your blood sugar. If these tests reveal that you are in a high to very high risk group, then you need to consider your cardiovascular age higher than 40 for men or 50 for women.

For men over 40 and women over 50, the first Discover step is to measure your coronary and carotid calcium scores. Then, if you are in a higher risk group based on your plaque burden, you should consider doing all the Discover tests. With this biological profile, you can then proceed to Design a set of goals and Do the 3D programs.

Family History

When heart attacks or strokes occur below age 55 in men or 65 in women, it indicates a strong genetic tendency for cardiovascular disease. As a general rule, you should initiate your 3D Health program at least 10 years before your relative suffered a first cardiovascular event. If your dad had a heart attack at age 45, consider checking your arteries for plaque at age 35. Remember, the earlier you discover that you have a plaque problem, the easier it is to treat. A low plaque score means a small amount of disease. Arresting plaque growth when plaque is still in the mild category gives you the best chance of keeping your arteries healthy as you get older.

Diabetes

If you have diabetes, your arteries are more prone to plaque build-up. The age rule can be waived if you are a male under 40 or a female under 50 with diabetes. You should perform an EBCT scan at age 35.

Heavy Tobacco Use

If you have been smoking for over fifteen years, your arteries may have excessive plaque build-up. A male under forty or a female under 50 with a long-term smoking history should consider a first EBCT scan before the above noted recommendations. Age 35 for men and 45 for women would be appropriate.

Excessively High LDL Cholesterol

If you have been told that your LDL cholesterol is over 200, then you may want to consider an EBCT scan five years earlier than the standard recommendations. For most people, LDL is not a good predictor for plaque, because so many people with normal levels or mildly elevated levels get heart attacks and strokes. But very high levels definitely do confer higher risk.

Excessively Low HDL Cholesterol

Just as very high LDL is dangerous, very low HDL cholesterol is also dangerous. If your HDL is below 30, you may want to consider an EBCT scan five years earlier than the standard recommendations.

Extremely Low Risk Category

About 10-15% of the population has very low LDL cholesterol and very high HDL cholesterol, as well as low blood pressure, no diabetes, no family history of heart disease and no tobacco history. The likelihood of significant plaque in this group is low enough to postpone EBCT scanning for at least 10 to 15 years beyond the standard recommendations.

The Discover Tests

Now it’s time to look at the Discover tests in detail. For each test we’ll explain how it is done, its significance, and the normal and abnormal value ranges.

Coronary Artery Calcium

As we saw in Chapter 3, EBCT measures the quantity of calcium in the artery wall. Calcium is a marker for atherosclerosis. I prefer to use the term plaque burden when thinking about the calcium score. Atherosclerosis is the underlying cause for heart attacks and most strokes. Atherosclerosis is itself a disease. Atherosclerosis starts in isolated areas of the artery wall and then spreads. A low plaque burden means relatively few spots of atherosclerosis in the arteries. A high plaque burden means the atherosclerosis has spread extensively down one or more coronary arteries. The goal of 3D Health is to prevent atherosclerosis. EBCT is the most important test in 3D Health because only EBCT tells us how much atherosclerosis we have. If you have a very low plaque burden, then you do not have an atherosclerosis problem, and the other Discover tests are not as critically important to your health.

The ‘Discover Tests-How They Work-3D E-Diagram’ shows the relationship between many of the factors involved in atherosclerosis. There are three levels to the diagram:

1. Lifestyle level
2. Tissue level
3. Biomolecular level
4. EBCT level

At the biomolecular level, genetic makeup modulates the endothelial equilibrium that protects us or makes us more susceptible to atherosclerosis. Genes are responsible for at least 50% of our risk for plaque. There are probably well over a hundred genes that may influence our susceptibility to atherosclerosis. If your genetic make-up is protective, then your calcium score will be low for your age. Once you know that you are in a low or low to moderate risk group you can use 3D Nutrition and 3D Exercise to stay there. 3D Health is all about basing your goals and your programs on your risk for atherosclerosis. If, on the other hand, your plaque burden is in the moderately high to high risk category, then you know your genes are not protecting you. Then all the markers depicted at the biomolecular level and at the tissue level are important pieces of information to help you set goals and programs for 3D Health.

How is Coronary Artery Calcium Measured?

The E-Diagram shows the principle for EBCT calcium measurement. You lie fully clothed on the scanner table. The electron beam is converted to low dose X-rays. A series of about 40 images are obtained at 3mm intervals from the top to the bottom of your heart. Each image is a cross-section. The coronary arteries can clearly be seen on the surface of the heart in each cross-section. They normally appear gray. Calcium within the artery wall appears white. When calcium is identified, the technician or physician circles the calcium using the computer mouse device. The calcium is precisely quantified based on its size. The process is repeated for each slice. All the slice scores are tallied to give a score for each coronary artery and these are summed for the final coronary calcium score. The most accurate way of scoring is called calcium volume scoring. Your test may also show the older way of scoring, called the Agatston score, after the physician who first described the method. Usually, both scores are reported. In our center, we still use the old scores and the new volume scores. The Agatston score is used to find how you compare to others of your gender and age. The volume score is more accurate, and best used to track changes over time.

How Do You Find Your Risk Level Based on Your Score?

Refer to the Coronary Plaque Risk 3D F-Diagram appropriate for your gender. The F-Diagram combines age information and score information into a single flow chart. For that reason, it is a different kind of presentation from most calcium score reports. Usually, your score will be called very mild (10 or below), mild (11-100), moderate (101-400) or severe (over 400). Your age-gender quartile will be less than 25^th, 25-50^th, 51-75^th or over 75^th percentiles. Each 25% spread from lowest to highest is one quartile. If you are in the lowest 25%, you are in the lowest quartile of risk. If you are in the top 25% of scores for your age, you are in the highest risk quartile.

Because some younger people with low scores are at high risk, and because some older people with higher scores may be at low risk, I have combined the age-gender concept and the absolute score concept into a single flow chart. Find your score in the diamond on the right. Then, take the appropriate decision tree for your age. You will be directed towards one of four risk categories. For example, if you are a male with a score of 50, you would be plaque low to moderate risk if you are 55 or older, but you would be plaque moderate to high risk if you are younger than 55.

Carotid Artery Calcium Score

The carotid artery calcium score has not been studied as extensively as coronary calcium. I believe our center was the first to start measuring it in large numbers of people. We have a database of 3,500 people who have had carotid calcium scoring. We have analyzed the data to develop the first age-gender tables for carotid artery calcium. Carotid calcium appears later than coronary calcium. For this reason, it need not be measured as early as coronary calcium. The standard recommendation for men is to have a baseline carotid calcium score at age 60-64. For women, the baseline scan can be done at age 70-74.

Carotid calcium is a measure of the plaque burden in the carotid arteries. More calcium signifies more atherosclerosis. A major cause of strokes is atherosclerosis of the carotid arteries. The carotid calcium score tells you how much atherosclerosis is present in the arteries that bring blood to the brain. After heart attacks, stroke is the 2^nd leading cause of death among cardiovascular diseases.

How is Carotid Artery Calcium Measured?

The carotid arteries are located on both sides of the neck. EBCT scanning is performed from the base of the neck to the base of the skull. About 20 slices are generated. Again, the slices are individually scored and totaled to provide a score for the right carotid artery and a score for the left carotid artery. We only use the calcium volume scores, not the Agatston scores.

Finding Your Risk Level

Use the Carotid Plaque Risk 3D F-Diagram for your gender. Again, find your score in the diamond on the right. Use the decision tree branch for your age. You will be directed to one of four risk categories. Your risk category will determine your 3D Health goals and programs.

Body Mass Index

Body mass index (BMI) is a very important indicator of cardiovascular risk. Recent data suggests that two thirds of Americans are overweight or obese. Overweight is defined as a body mass index of 25 to 29.9. Obesity is defined as a BMI of 30 or over.

The following table shows how BMI definitions of overweight and obesity can be used to determine future risk [1] :

CATEGORY	YEARS OF LIFE LOST
Overweight 40 year old male non-smoker	3.1
Overweight 40 year old female non-smoker	3.3
Obese 40 year old male non-smoker	5.8
Obese 40 year old male smoker	13.7
Obese 40 year old female non-smoker	7.1
Obese 40 year old female smoker	13.3

Why is it Dangerous to be Overweight or Obese?

The following two tables show how higher BMI affects your risk for various medical conditions. Excessive body fat causes metabolic syndrome, a condition characterized by high triglycerides, low HDL cholesterol, insulin resistance, high blood pressure, LDL cholesterol pattern B and high C-reactive protein levels.

The 3D E-Diagram ‘Fat Cells vs. Muscle Cells’ shows how fat cells influence many key markers for cardiovascular disease.

How Do We Measure BMI?

BMI is your weight in kilograms divided by your height squared in meters (Kg/M²). For pounds and inches the formula is lb/in² x 705. The concept is to index your weight to your height. For any given height, there is a range of ideal weight. If you exceed this range, your BMI will be high. Unfortunately, BMI is not always an accurate measure of body fat. Some of us are more muscular than others. Some of us have heavier bones. BMI really applies to average men and women. Men or women with higher than average muscle mass or bone mass may be incorrectly diagnosed as overweight, or even as obese. For this reason, I consider it important to consider getting a body composition test and, if possible, a visceral fat measurement. These are discussed in the next two sections.

Body Composition Testing (Fat Mass and Lean Body Mass)

There are several techniques available for measuring body composition. At our center, I use a device from RJL Systems called the Quantum II. The device performs something called bioelectric impedance analysis (BIA). After placing two electrodes on the right foot and two electrodes on the right hand, a small electrical current is sent through the body. The device pretends your body is two parallel circuits. It measures resistance in one of the circuits and reactance in the other. Body fat is a poor electrical conductor, while other types of living cells conduct well because of their water and electrolyte content. The resistance measurement rises as body fat goes up. Reactance is another measure of resistance to current. Our cells are little electrical capacitors, because the outside of the cell membrane is positive compared to the inside. In effect, our cells create an electrical gradient which makes it easier for current to flow. If we have a large amount of metabolically active cells, then reactance is low. Reactance tends to go down as our muscle mass goes up. Using both resistance and reactance measurements gives a more accurate assessment of body composition than just using resistance measurements.

What Should Your Body Fat Be?

The American College of Sports Medicine makes the following recommendations for percent body fat:

Male:

 Low: 6-10% fat

 Optimal: 11-17% fat

 Moderate: 18-25% fat

 Obesity: Greater than 25% fat

Female:

 Low: 14-18% fat

 Optimal: 19-22% fat

 Moderate: 23-30% fat

 Obesity: Greater than 30% fat

What is Lean Body Mass?

Lean body mass is what’s left after you subtract fat mass from total weight. For example, if you weigh 200 pounds and your percent body fat is 20%, you have 40 pounds of fat. Subtracting 40 from 200 leaves 160 pounds of lean body mass, and your percent lean body mass is 80%.

Why is Body Composition Analysis Important?

When you begin the 3D Health program, you should know your body composition in addition to your body mass index. Let’s say you decide you want to lose some fat mass and increase some muscle mass. You reduce your caloric intake and increase your exercise. Your body mass index goes down. Did you lose just fat, or both fat and muscle? Without a body composition analysis, you won’t know. Ideally, you want to lose fat mass and increase muscle mass. If your body composition shows 20% fat and 80% lean body mass at the beginning and after two months on your program, but your body mass index dropped 2 points, then you lost equal amounts of fat and muscle. This would indicate a need to increase the muscle strengthening component of your exercise program. Adequate muscle mass is critically important for health and vigor, and to create the metabolic equilibrium that will protect your cardiovascular system.

Visceral Fat

Fat cells store energy in the form of triglycerides. There are two fat cell compartments in the body. The subcutaneous fat compartment is located just under the skin. The visceral fat compartment is located inside the abdominal cavity. Visceral fat cells are more dangerous than subcutaneous fat cells. Many studies have shown that insulin resistance and type 2 diabetes correlate with visceral fat but not with subcutaneous fat. Visceral fat also correlates with high triglycerides and low HDL cholesterol. Finally, visceral fat releases inflammatory molecules called cytokines. These molecules initiate a generalized inflammatory response.

Visceral fat stores go up as we age. Even lean appearing people may have significant amounts of hidden visceral fat. Men tend to have more visceral fat than women, but women catch up after menopause. Visceral fat appears to be the cause of the metabolic syndrome.  The diagram ‘Two Kinds of Fat Cells’ shows the different metabolic effects of the two fat compartments. If you are overweight or obese, then chances are you have too much visceral fat.

How Do We Measure Visceral Fat?

At our center, we obtain a single cross-sectional CT scan slice of the abdomen. We then use special software to measure the volume of fat inside the abdominal cavity in one 6 mm thick slice. Fat is much lower density than other tissues, so the software can easily measure the volume of visceral fat. We have found that the average amount for a middle-aged man is 90 cm³. For a middle-aged woman the average amount is 60 cm³. A one-time measurement can give you an idea of whether your genes promote more visceral or subcutaneous fat formation. Follow-up measurements can determine if your 3D Health program is succeeding in lowering visceral fat.

It’s not essential to measure your visceral fat. Not many preventive scanning centers have the necessary software. Percent body fat measures both fat compartments. If your percent body fat is high and you have some of the metabolic abnormalities associated with visceral fat, then you can assume that you need to improve your body composition.

Blood Pressure

Blood pressure is the pressure inside your large arteries. It is usually measured in your left or right arm. Systolic blood pressure is the pressure in your arteries when the heart is pumping. Diastolic blood pressure is the pressure between heart beats. Mean blood pressure is the average blood pressure over many beats. Mean blood pressure is directly related to cardiac output and systemic vascular resistance. Cardiac output is the quantity of blood ejected by the heart each minute. Systemic vascular resistance is the total resistance in the blood vessels caused by constriction of the smooth muscles in the artery walls. Systemic vascular resistance goes up when there is endothelial dysfunction, because the balance between constriction and relaxation is shifted towards constriction. Cardiac output goes up when the sympathetic nervous system is activated. The sympathetic nervous system both speeds up the heart rate and increases the forcefulness of the heart beat.

Chronic stress, inactivity and poor diet all may produce endothelial dysfunction and high blood pressure. Much high blood pressure risk is inherited, because our genes determine our ability to cope with environmental stressors. Chronic stress may lead to chronic sympathetic activation, which both increases cardiac output and endothelial dysfunction. The diagram ‘Endothelial Dysfunction and Blood Pressure’ shows how normal endothelial function is associated with normal levels of nitric oxide. Nitric oxide is a short-lived molecule made by the endothelial cells. It is the principle molecule for blood vessel dilation. Endothelial dysfunction occurs when nitric oxide levels are low and levels of constricting molecules, like angiotensin II and Endothelin I, are relatively higher. These two molecules produce smooth muscle contraction in the wall of the artery. Angiotensin II is part of a complex system called the renin-angiotensin-aldosterone system. This system raises blood pressure. It is activated when renin is secreted by the kidneys in response to sympathetic nervous stimulation or decreased blood flow to the kidneys. Endothelin I is secreted by the endothelial cells in response to angiotensin II and free radical stress. Oxidative stress caused by too many free radicals is the main underlying cause of endothelial dysfunction. Lifestyles that lead to excessive fat, weakened muscles, low antioxidant and essential mineral levels and low omega-3 and omega-9 fatty acid levels create the perfect setting for endothelial dysfunction because all these lifestyle factors raise free radical levels (see the Endothelial Dysfunction 3D E-Diagram).