By Karen Miller-Lane, ND, L.Ac
As a Naturopath one of the seven principles[i] of Naturopathic Medicine is Physician as teacher. Thus, I feel it is important to explain to my patients what the results of their blood work mean and how it applies to them.
Blood work is generally ordered to help diagnose medical conditions, plan or evaluate treatments, and monitor diseases. That said, there isn’t always a test to diagnose a condition that you might be experiencing. Tests are also limited in their scope. For example, some of the measurements included in a lipid panel, may not, according to the latest research, adequately measure risk for cardiovascular disease.This lag time between what the research calls for and what happens in clinical practice can be decades.
To explain why I believe the measurements on your lipid panel need to change, let me provide you with some general information about cholesterol that will provide the context to understand why a lipid panel is important in assessing your cardiovascular risk.
Cholesterol is essential – you would die without it. Cholesterol is part of the cell membrane of every cell. It contributes to the fluidity of the cell membrane and this membrane affects the channels that allow things in and out of the cell. It’s essential to the creation of a cell and how our cells communicate. Cholesterol is also essential for the synthesis of steroid hormones like cortisol, testosterone, and estrogen. And it is necessary for the creation of bile acids, which is required to digest food.
Along with cholesterol being essential, I want to highlight that the cholesterol in our bloodstream has little to do with the cholesterol in foods we eat. Most of the cholesterol that we eat is excreted. The cholesterol we are monitoring via blood work is made in our body and transported between cells through lipoproteins. Lipids are fatty compounds that perform a variety of functions in your body. A lipoprotein is part protein and part fatty compound which enables lipids to travel through our circulatory system. Now, unhealthy foods are unhealthy foods, and they can negatively impact our health, but foods that have decent amounts of cholesterol such as eggs and shrimp are not in and of themselves unhealthy foods because of the amount of cholesterol they contain. (Look to future blogs on this subject.)
A lipid panel is a common blood test which looks at total cholesterol, LDL or low density lipids, HDL or high density lipids, Triglycerides, and non-HDL lipids to monitor and screen for your risk of cardiovascular disease. Your health care provider discusses your test results as they relate to your age, family history, and risk factors. Risk factors include high blood pressure, diabetes, or prediabetes, being overweight or obese, smoking, lack of exercise, diet of unhealthy foods, stress, or high total cholesterol.
But here’s the rub, we know through clinical research that total cholesterol isn’t the best marker for predicting mortality or morbidity for cardiovascular disease [CVD].
To understand this contradiction between the research literature and the current practice let me further discuss lipoproteins, the types of lipoproteins and how to understand what those letters stand for in our bloodwork. Apolipoprotein B (ApoB) is the primary protein component of low-density lipoprotein (LDL). Apolipoprotein A1 (ApoA1) is the primary protein component of high-density lipoprotein (HDL). ApoB is the major protein in Very Low Density (VLDL), Intermediate Density (IDL) and Low Density Lipoproteins (LDL). ApoA-1 is the major protein in High Density Lipoprotein (HDL) particles. There is HDL cholesterol and LDL cholesterol, abbreviated LDL-C and HDL-C. There’s LDL-P and HDL-P, which is the particle member of LDL, which can be counted via electrophoresis or nuclear magnetic resonance [NMR]. The measurement of LDL-P is a better assessment of risk than LDL-C or total cholesterol and the current lipid panel only includes LDL-C.
We can also count the number of these particles by measuring apoB. Peter Attia,MD who is both a practicing physician and a relentless researcher focusing on the applied science of longevity states:
“The apoB concentration to me is the most important number you want to understand to predict from a biomarker standpoint your ASCVD (Atherosclerotic Cardiovascular Disease) risk, because it captures all of the atherogenic particles
apoB gives you the total atherogenic burden of those lipoproteins… it’s the preferred metric by which we want to assess risk”‒ Peter Attia[ii]
In other words, LDL-P is a better assessment of risk than LDL-C and apoB concentrations may be a better overall biomarker for evaluating cardiovascular disease risk because it captures all of the atherogenic particles. This is important because LDL can go into artery walls, become oxidized and then dump their oxidized sterol (waxy solid) contents into the subendothelial (part of the vessel wall) space. This elicits an immune response and other things that lead to atherosclerosis. In short, oxidized cholesterol is what builds up on the artery walls. We want to better evaluate cholesterol as a risk for atherosclerosis. ApoB and LDL-P are two things that far exceed LDL-C or total cholesterol at doing this. They are not included in the existing labs.
To reiterate, health care practitioners currently get a lab report of 5 numbers: total cholesterol [C], triglycerides [TG], non-HDL-C, LDL-C, HDL-C. As I stated above, total cholesterol, LDL-C, and HDL-C may not be the best measures of CVD. The research has shown that the number of LDL particles is a more accurate index of risk than the LDL-C. The smaller the LDL particles the increase in CVD risk. However, we are still learning about the differences between HDL-C and HDL particles. Their relationship to our risk is much more complicated than previously assumed. For example, HDL may not confer the protection from CVD that we thought it did. Research is still investigating this very complex lipoprotein.
The other metrics on your blood work may include VLDL-C , which is a cholesterol that’s in the very low density lipoprotein particles – think small particles. These particles come out of the liver and can promote the formation of plaque in the arteries. This is a risk factor. The literature also shows that non-HDL cholesterol is a better measure to understand risk than LDL-C. The higher the non-HDL the increase in risk.
Triglycerides [TG] are on a lipid panel because people with high triglycerides are at increased risk of heart disease and have higher numbers of LDL particles and VLDL particles. For a long time, there has been a debate on whether serum TG constitutes an independent risk factor for CVD – and if so, at what levels. Currently, TG levels <150 mg/dL are usually described as “normal” or “optimal”. However, the latest research suggests the “optimal” value for TG to be around 50 mg/dL. Genetic studies are also pointing to the understanding that the risk factor of elevated TGs is more a reflection of elevations in apoB, in which case, measurement of apoB itself would provide the most accurate information about CVD risk. That said, TG are still an important marker for assessing the risk of CVD.
It is also important to note that regarding the relationship of TG to CVD, there is a stronger association for women than men. These differences call for gender-specific guidelines for what constitutes “optimal” TG levels.
I realize this is a lot to absorb, but stay with me for a little longer as we explore HDL. HDL is characterized by a different protein apoA-1, which is in a different family than ApoB. HDL metabolism is significantly more complex than LDL and there is much we have yet to learn. One of the questions being researched is if HDL confers protection against CVD. At present, we can’t assume anything if you have high HDL. I’m looking forward to what the research will show several years from now. One interesting side note is that observational data shows that apoA-1 is protective against neurological diseases. There are other blood work values to access CVD, but I will leave that for another post.
The take home message is, first, to make sure that your labs include ApoB, which by the way, is not an expensive lab to run and, second, that non-HDL and triglycerides are important to consider as you are assessing your overall risk and how to treat or prevent cardiovascular disease.
We have at least 30 years of research with ApoB and still most insurance companies will not cover the cost of including ApoB in a standard lipid panel. The research also shows it may be beneficial to include this testing at an earlier age, perhaps, starting in our mid to late 30’s to address and affect the course of atherosclerotic cardiovascular disease.
The more we understand what is used to measure our health the better advocates we can be for ourselves. My hope is that we can use the research and available tests to support a better understanding of how to prevent disease and illness and support optimizing our health.
[i] If you are interested in what the seven principles of Naturopathic Medicine are – click on Services in the heading of the website and click on Naturopathic Medicine.
[ii] https://peterattiamd.com
Comments