How high is your cholesterol and should you care? If it is high, yes, but if it is normal then don’t rest easy… Would you believe only 50% of people who develop heart disease are identified using total cholesterol levels alone? This is true, according to data from the landmark Framingham Heart Study, which up to now has been the main guide for deciding who needs treatment for heart disease prevention.
Heart disease starts early in the US, with about 1 in 6 adolescents showing a thickening of the protective artery lining. By age 50 about 85% of adults have significant artery thickening. This process typically remains silent, just simmering along, and the first warning symptom of heart disease is sudden death or heart attack for 62% of men and 42% of women with heart disease.
The 4 established risk factors for heart disease include high blood pressure, high cholesterol, diabetes, and smoking. Yet, approximately 19% of individuals already diagnosed with heart disease present with no risk factors, and 45% present with only 1 risk factor. The Adult Treatment Panel III national cholesterol guidelines acknowledge this by explaining that the major risk factors “account for only about half of the variability in coronary heart disease risk in the US population.”
If heart disease starts so early and is so common, then why are missing half the people dying from the leading cause of death? Because we aren’t looking hard enough! And thus we aren’t starting therapy early enough.
There is a misconception that a heart attack or stroke is the result of a slowly narrowing artery finally clogging due to the cholesterol plaque. In fact, most of the time, the heart attack occurs when the plaque has blocked less than 50% of the artery flow. Symptoms such as chest pain or shortness of breath don’t usually occur until the blood flow is more than about 70% blocked. Let’s examine how good arteries go bad.
Our arteries are lined by a thin layer of cells called endothelial cells. Imagine them like bricks lining the inside of a tunnel. Unlike bricks, however, the endothelial cells are very much alive and active, forming the keystone to artery health. They control the passage of nutrients and toxins through the artery wall. They control oxidation and inflammation within the artery wall. They control the reactivity of the arteries which means blood pressure control. When the endothelial cells begin to fail, it leads to high blood pressure and plaque.
So how does plaque develop? The “bad” LDL (low density lipoprotein) form of cholesterol normally accumulates within the artery wall, but only after becoming oxidized does LDL cholesterol start to cause plaque. Oxidation is a normal process, controlled by strong healthy endothelial cells. When this process is not controlled the oxidized LDL cholesterol invites white blood cells into the mix, stirs up inflammatory chemicals, and plaque starts to form.
Inflamed LDL cholesterol plaque within the artery wall is much like a boil covered by a thin fibrous cap. When that thin cap finally weakens and fails, the plaque contents spill into the bloodstream and cause the blood to clot in that section of the artery, leading to a sudden, complete blockage of the artery.
The “good” HDL (high density lipoprotein) form of cholesterol counters LDL by preventing oxidation and inflammation, and moving cholesterol from the artery back to the liver to be recycled.
I like to think of artery plaque like a fire, with LDL representing the raw material for a fire, and HDL being a squirt bottle of water to control the fire. To make a fire though, you need a spark and you need the right conditions to burn. These other elements are what we are missing in the typical analysis for heart disease risk.
Inflammation is one of the sparks that will “ignite” artery plaque. Blood tests such as the cardiac CRP measure subtle inflammation and correlates with more plaque. High homocysteine and high iron both correlate with increased artery plaque. Low testosterone and low estrogen also increase risk of plaque formation.
Certain types of LDL cholesterol are much more concerning than others. For example, the fraction called Lp(a), which is known as the “heart attack” cholesterol, can be markedly elevated even though the total LDL number is great. The size of the LDL particles is also important, with small dense LDL particles leading to more plaque than large buoyant LDL particles. Either of these conditions will cause about 3x the risk of heart disease. HDL has hidden information as well with only the HDL-2 subtype being protective. The “VAP cholesterol” test will give the specific information on LDL and HDL subtypes. I recommend this cholesterol test as routine instead of the usual lipid panel. The VAP test is more accurate and you do not need to fast before testing.
An exciting new blood test called “PLAC” has been used for several years, and is FDA approved in use for predicting risk of recurrent stroke. It also has great value in prediction of heart disease. PLAC measures a pro-inflammatory enzyme called Lp-PLA2, which is involved in the oxidation of LDL, and fuels early inflammation leading to plaque. Lp-PLA2 levels correlate with the activity of a plaque and predict when it is likely to rupture. Back to the fire analogy, I think of Lp-PLA2 as a measure of how hot the fire is burning.
If you are over age 50 then I recommend a “plaque assessment” with a Cardiac Calcium CT scan, a simple xray that will screen for calcified artery plaque. An ultrasound of the arteries in the neck and abdomen is another useful screen. These tests can help decide if you need to get further blood testing.
Better testing leads to more specific targets and more successful treatment!
Scott Rollins, MD, is Board Certified with the American Board of Family Practice and the American Board of Anti-Aging and Regenerative Medicine. He specializes in bioidentical hormone replacement for men and women, thyroid and adrenal disorders, fibromyalgia and other complex medical conditions. He is founder and medical director of the Integrative Medicine Center of Western Colorado (www.imcwc.com) and Bellezza Laser Aesthetics (www.bellezzalaser.com). Call (970) 245-6911 for an appointment or more information.