Why You Should Have the CIMT Test
There is a simple ultrasound test that can be performed, which research has demonstrated to predict 98.6% of future adverse cardiovascular events.
The Big Question
Is your healthcare provider performing the test that the medical research shows is the superior lipoprotein metric of your risk to build plaque in your arteries or for your future heart attack risk?
Background
Cholesterol is typically discussed as either ‘good’ or ‘bad;’ but, I’m here to say that is wrong! I want to give the whole truth (in a simplified and understandable way) to help both healthcare consumers, and providers, gain a better understanding of lipoprotein metrics and which test is superior to order to assess a patient’s risk.
Lipoproteins are spherical particles that primarily traffic around things called sterols (cholesterol and cholesteryl ester), and triglycerides, in the blood. Lipoproteins are classified by their particle density as measured by routine laboratory methods, like when your healthcare provider measures your ‘cholesterol.’ The two terms most people are familiar with are high-density lipoprotein (HDL) and low-density lipoprotein (LDL). If you have your blood drawn, which is akin to a snapshot at that point in time, the lab can measure the concentration of cholesterol contained in these different particles. We call it either HDL-cholesterol (HDL-C) or LDL-cholesterol (LDL-C) – but the cholesterol in these different particles is identical.
Lipoproteins have an outer surface composed primarily of something called phospholipids (think back to 8th grade bio class). The surface of lipoproteins has apoprotein structures plugged in to it and we call the entire thing an apolipoprotein. Each apoprotein can cause the entire structure to behave differently inside of the body.
Apolipoproteins
There are two particular apolipoproteins that are referred to in this post that must be differentiated to better understand the bigger picture: apolipoprotein B (apoB) and apolipoprotein A-1 (apoA-1).
The different types of particles that contain apoB – all of which are potentially atherogenic. All of which can simply be measured by a single blood test – Serum apolipoprotein B.
Illustration credit: Thomas Dayspring, MD, FACP, FNLA.
Why “They” Say Good and Bad Cholesterol
Cholesterol can’t be good or bad. Cholesterol is just cholesterol; it just gets carried around in different lipoproteins, which act differently in the body, largely in part because of their surface apoproteins. It’s tempting to ramble on about the complexities of the behavior of each different apoproteins in the body but I’ll save that for another day.
To Make it Simple
Apolipoprotein B particles have the ability to deposit sterols in to the wall of an artery and cause atherosclerosis (plaque buildup). Apolipoprotein A-1 particles have the ability to remove sterols from the artery wall and then deliver them back to an apoB particle (indirect), the liver (direct), the intestine, or the peripheral tissues (such as the adrenals or gonads) to contribute to the manufacture of particular hormones.
Recommendation
If you live in the United States and are routinely having your cholesterol checked, or are on cholesterol lowering medication, you should have your apolipoprotein B concentration assessed and tracked. Some recommendations for high-cardiovascular-disease-risk groups is to use a threshold for Apolipoprotein B of 60 mg/dL; and some practioners who are authorites in the field have even advocated for levels that would be seen in infants and young children (e.g., 30-50 mg/dL). For average risk groups, a threshold of 80 mg/dL may be acceptable.
