Testing For Heart Disease Risk
A wide variety of blood tests measure factors related to heart disease. Some of these tests, however, do a poor job of indicating your chances of heart problems. To understand the true state of your cardiovascular system, you need to ask your healthcare provider for the tests that have proven to truly indicate your heart disease risk.
I’ve detailed the most important contributors to cardiovascular disease in my previous article. Hopefully, it became obvious what you need to do to lower your chances of atherosclerosis. I did not mention high cholesterol in that article because I wanted to address it and other important lab tests that further identify heart disease progression. Once you read this article, I hope you’ll ask your doctor for these tests if there is any question about where you stand with cardiovascular health.
Misleading Tests
You probably know what your LDL-C (the “bad” cholesterol) and HDL-C (the “good” cholesterol) levels are. The problem is that these are proving to be poor indicators of inflammation and atherosclerosis. However, when cholesterol becomes oxidized (electrically charged), then it becomes “sticky” and makes a major contribution to the plaque we call atherosclerosis. Mark Houston, M.D., who is the director of the metabolic cardiology fellowship training for the American Academy of Anti-aging Medicine and associate clinical professor at Vanderbilt University Medical School, teaches that using HDL-C and LDL-C levels gives us essentially no valuable information regarding cardiovascular risk. They simply miss heart disease so often that they cannot be relied upon anymore. Instead, we must measure the lipoprotein (LDL and HDL) particle number and size, which I’ll explain below.
We know that an electrocardiogram (ECG) can show abnormalities of heart function, but these will be late findings — after disease has already damaged your heart. A similar feeling holds true among physicians today about exercise treadmill testing (the cardiac stress test). This test has been a standard of care diagnostic tool for heart disease for many decades. However, its prognostic coronary artery disease detection capability is weakening in the eyes of the American Academy of Cardiology. [1] This test will not show any abnormalities in 10 to 27 percent of patients with coronary artery disease. Furthermore, 64 percent of men have a heart attack as their first symptom of cardiovascular disease. Of these men, cardiac stress testing carried out shortly prior to heart attacks does not predict atherosclerosis in the majority of individuals.
A useful imaging study consists of visualizing the inside lining of the carotid artery (in your neck). This test, called the Intima Media Thickness (IMT) is an ultrasound measurement that reflects the atherosclerosis going on in your heart. To actually visualize arterial narrowing in this way is more than just measuring a risk factor. It actually measures atherosclerotic disease that is present.
Blood Pressure
Yet another imaging test you can ask for (although, it is costly) is called Electron Beam Computed Tomography. This test quantifies the percentage of calcification in your heart arteries, giving a real picture of atherosclerosis already present.
The most simple, cost-effective and predictive test of heart disease is a resting blood pressure measurement. Current science shows us that even before blood pressure increases, there are markers of inflammation in the blood.
Hypertension is now defined as “a progressive cardiovascular syndrome arising from complex interrelated etiologies [causes] which features early markers [in the blood] that are often present before blood pressure elevation is sustained.” [2]
Therefore, when you see high blood pressure, think of one or more of these [3] going on as well:
- Blood vessels are losing their ability to stretch (vessel compliance).
- Atherosclerosis is already developing on the inside of the arteries.
- Abnormal blood sugar and insulin metabolism are occurring.
- Hormones that affect blood vessel and heart health are dysfunctional.
- Kidney function is changing and less fluid is filtered out of blood into urine.
- Sticky cholesterol and platelets are joining to create atherosclerotic plaque.
- Left heart muscle is thickening, which affects heart pumping function.
While there are about 400 known cardiovascular disease risk factors, let’s just look at the ones that you can have checked. After checking blood pressure, blood sugar, cholesterol levels and body weight, I’d say it’s time to go to the next level. Therefore, I’ll explain the most useful blood and urine tests used directly to assess cardiovascular risk.
Early Detection Blood Tests
Lipoprotein (LDL and HDL) particle number and size: Regarding atherosclerotic plaque progression: The more LDL particles you have, the more plaque that is being formed. In other words, the higher the number of LDL particles, the greater the likelihood for their entry into the arterial wall where they deposit their contents and form atherosclerotic plaque. Measurement of LDL-cholesterol on traditional lipid panels does not reflect the LDL particle number. [4] There are some specialty labs that perform this test, such as the lab found athttp://www.theparticletest.com/.
Plasma renin activity and serum aldosterone level: Renin (an enzyme of the kidney) and aldosterone (a hormone) control blood pressure via the effects of blood vessel constriction and salt/fluid retention. When aldosterone is abnormally high, it is an independent risk factor for cardiovascular disease. [5]
Serum iron, TIBC (total iron binding capacity) and ferritin (stored iron): Increased iron correlates with increased risk for heart disease, heart attack and stroke due to increased oxidative stress and inflammation it causes when too high. It is also known that iron supplementation directly increases LDL cholesterol levels. According to the American Heart Journal in 2011, [6] lowering iron by phlebotomy lowered heart attack and stroke risk and improved life expectancy.
Microalbuminuria: Finding protein in a spot urine sample can be one of the earliest signs of abnormalities in your vascular system, because your kidneys reflect endothelial dysfunction and increased blood vessel permeability. This is highly correlative of progression to future cardiovascular disease, heart attack and stroke.[7]
Fasting blood sugar and insulin levels: The relationship of these to inflammation in the heart was explained in my report recently on metabolic syndrome and insulin resistance.
Free testosterone and DHEA-S: Low testosterone is known to contribute to diabetes and insulin resistance, abnormal blood lipids (i.e., cholesterol), increased blood vessel lining inflammation, and central (belly) obesity. Low DHEA (dehydroepiandrosterone) increases death rate by heart attack and all causes. [8]
Homocysteine level: A higher level of this amino acid clearly increases atherosclerosis development. Ideally, the homocysteine you obtain from food is efficiently converted into SAMe (S-adenosyl methionine) and glutathione, both of which have health-promoting effects.
Highly sensitive C – reactive protein (HS-CRP): This test for inflammation in the body is equally or more predictive of heart attack risk than cholesterol levels.
Pro-inflammatory cytokines: These chemical mediators of inflammation include interleukin-6 and TNF (tumor necrosis factor) which can be measured.
Lipoprotein(a): This lipoprotein is highly associated with coronary artery disease. It is genetically determined and gives you a good idea of hidden heart disease risk, independent of LDL cholesterol levels.
Apolipoprotein A1 and B: Apo A1 is the major high-density lipoprotein (HDL) cholesterol protein. Low Apo A1 levels are seen most often with high-fat diet consumption, inactivity and central obesity. It is clearly associated with increased risk of early cardiovascular disease. Apo B is the main measurable protein of low-density lipoprotein (LDL) cholesterol. A high level of Apo B contributes to atherosclerosis and is an even better indicator of heart attack and heart disease risk than LDL cholesterol.
Fibrinogen: This blood protein enhances clotting. High levels are linked to an increased risk for cardiovascular disease and heart attack.
Myeloperoxidase (MPO): Myeloperoxidase is an enzyme marker of atherosclerosis, and high levels indicate an increased risk of heart attack.
Beta Natiuretic Peptide (BNP): This blood protein is made in the heart. High levels are not only associated with increased risks of cardiovascular disease, but also a weakening heart (congestive heart failure).
25-hydroxy Vitamin D: Vitamin D levels less than 10 mg/mL are correlative with nearly double the risk for heart attack, independent of other risk factors. [9]
No comments:
Post a Comment