Biometric Screening: Lipid Panel
A biometric screening is a set of laboratory tests and body measurements that help determine metabolic health. Many Americans complete a biometric screening annually, at their doctor’s office, a convenience clinic or perhaps even at their worksite. But many never receive much guidance around the results. This post is part of a five part series that will help you interpret your results and determine whether you need to take action to improve your metabolic health.
Part Three: Lipid Panel
Part three: lipid Panel
What is a lipid panel?
The lipid panel is a blood draw that churns out a set of numbers: total cholesterol, triglycerides, HDL, LDL and VLDL. This is perhaps the most misunderstood set of labs commonly performed. While they can be incredibly helpful at determining heart disease and diabetes risk, it’s important that we look at the right set of numbers in the right context.
For starters, let’s review what “cholesterol” even is. Cholesterol is not technically a fat. It’s a type of lipid molecule known as a sterol, which is a steroid with a grouping of oxygen and hydrogen attached to it (chemically known as an alcohol group). Cholesterol is an essential component of our cell membranes and a precursor for the biosynthesis of steroid hormones, bile acid and vitamin D. Cholesterol is also implicated in cell signaling processes, particularly within the nervous system.
Given its importance, you won’t be surprised to know that the body is capable of making its own cholesterol, primarily in the liver. On days when we don’t eat much of it, the body will make more. If we eat more, the body will make less. Cholesterol levels in the blood are actually tightly regulated by the body.
Speaking of cholesterol in the blood, it’s important to note that blood is primarily made up of water. Cholesterol is classified as a lipid molecule, which means it mixes well with other lipids like fat, but it doesn’t like mixing with water. In order for cholesterol to travel in the watery blood stream, it has to be carried by special particles called lipoproteins.
You can think of lipoproteins like little cars. The paint on the outside of the car loves water, so the car can easily drive around in the watery blood. But the upholstery inside is fatty, so cholesterol and triglycerides (fatty acids) can happily ride inside. Lipoproteins allow us to transport cholesterol and triglycerides throughout the body. One type of lipoprotein, called a chylomicron, primarily has the job of driving the fat and cholesterol that we eat from our intestines to our liver and body tissues. Chylomicrons are only present right after eating, and a lipid panel is almost always performed in the fasting state. Thus, they are not measured in a lipid panel.
When we have been fasting for at least eight hours, cholesterol and triglycerides can be found traveling through the blood in one of three types of cars (lipoproteins): very low density lipoproteins, low density lipoproteins and high density lipoproteins. These are abbreviated as VLDL, LDL and HDL, respectively. The reference to density in their names is a hint to what is riding in the cars. Lipids like triglycerides and cholesterol are less dense than protein. Thus, lower density lipoproteins have more triglycerides and cholesterol in them, and less protein. Higher density lipoproteins have more protein and less triglyceride and cholesterol.
When we eat more sugar than we need in the moment, it is transported to the liver to be converted into triglycerides, our main form of storage fat. This conversion process also produces cholesterol as a byproduct. The triglycerides and cholesterol are packaged up into VLDL “cars” which head out into the bloodstream. First, the VLDL particle heads to the fat cells to drop of the triglycerides. Once the triglycerides have been largely off-loaded, the VLDL particle is less dense and its name switches to LDL. The LDL particle’s job is to deliver the cholesterol to cells throughout the body.
On the flip side, the liver also produces HDL “cars.” The HDL particles are sent out mostly empty - their job is to pick up cholesterol and triglycerides that the cells no longer need and bring them back to the liver for recycling.
All of these processes are natural and physiologically necessary. It is wrong to characterize the cholesterol contained in an LDL particle as “bad” and the cholesterol contained in an HDL particle as “good.” It’s all the same cholesterol molecule, just riding in a different car! But understanding why you might have a lot of cholesterol or triglycerides in the various types of cars can be very helpful in finding the root cause of your health issues.
One quick note on the mechanics of a lipid panel. When the lab tests your blood they are really only measuring three things:
Triglycerides: The total amount of triglyceride present, regardless of what type of car it was in.
Total Cholesterol: The total amount of cholesterol present, regardless of what type of car it was in.
HLD-Cholesterol: The amount of cholesterol contained in high density lipoproteins.
The test assumes that virtually all of the triglycerides in the blood during fasting are riding in VLDL cars. It also assumes that VLDL cars always have 5 times more triglycerides riding in them than cholesterol. Thus, the VLDL-Cholesterol is calculated as [triglycerides divided by five].
LDL-Cholesterol is then calculated as [Total Cholesterol minus HDL-Cholesterol minus VLDL-Cholesterol], since any cholesterol not riding in HDL or VLDL cars must be riding in LDL cars. Unfortunately a number of these assumptions are not strictly true, so the VLDL-Cholesterol and LDL-Cholesterol numbers are not especially reliable.
What should your lipid values be?
I am not a fan of measuring total cholesterol. Cholesterol itself is not dangerous and this number only counts cholesterol - it doesn’t tell us much about the type of quantity of lipoprotein carrying all this cholesterol. Triglyceride numbers, on the other hand, can be quite telling. Since a lipid panel is always performed in the fasting state, this number tells us how much fat is being transported through your blood at random, not after a meal. High triglyceride numbers almost always indicate an energy imbalance - the carbs you are eating are not getting used by the muscles and instead being converted to fat and shipped all around for storage. It could also indicate over-stuffed, hypoxic fat cells that are leaking. One other metric that has a high correlation with metabolic disease is HDL. In fact, the Triglyceride to HDL ratio is an excellent way to predict insulin resistance and cardiovascular disease risk.
Fasting Triglycerides (mg/dL)
Optimal = < 100
Acceptable = < 150
HDL-Cholesterol (mg/dL)
Optimal = > 60
Acceptable = > 45
Triglyceride : HDL-Cholesterol Ratio (TG / HDL)
Even more useful than triglycerides and HDL alone is their ratio to each other. Of all the “standard” labs, this is the best predictor of heart disease risk.
Optimal = < 1.5
Acceptable = < 2.5
Bonus: ApoB (mg/dL)
ApoB is not part of a standard lipid panel, but it is a low cost test that is quite correlated with heart disease risk. Essentially, only lipoprotein particles tagged with apolipoprotein B can get lodged into an artery wall. While a high number of ApoB-tagged particles in the blood is not alone sufficient to cause heart disease, it is a necessary component. Thus, if someone has a very low ApoB level, the risk of heart disease is significantly lower.
Optimal = < 80
Acceptable = < 90
Non HDL-Cholesterol (mg/dL)
If you are unable to get an ApoB test, the next best indicator is your non HDL cholesterol. This is often called out as part of a lipid panel. It can also be calculated by Total Cholesterol - HDL Cholesterol.
Optimal = <100
Acceptable = <130
Should You Worry?
In short, yes. If your Triglycerides, HDL-Cholesterol or TG:HDL Ratio are out of whack, you should assume that you have an energy imbalance and should take action. While there’s no magic pill for triglycerides and HDL, diet and lifestyle can be hugely impactful. As a bonus, these same interventions will also lower blood sugar, if that is a concern. Once you are able to get those numbers in line, your ApoB and/or Non HDL-Cholesterol will likely improve as well. If not, you may want to take additional steps to investigate and possibly lower your cardiovascular disease risk. Working with a dietitian or physician with an in-depth knowledge of lipid testing can help you determine if follow-up testing is needed.
What should you do?
Lower Triglycerides. This is best done by reducing carbohydrate intake, especially sugar. Increasing omega-3 fatty acids and fiber intake and decreasing alcohol intake can also help.
Increase HDL-Cholesterol. This is best done through increased exercise. Adding healthy fats to your diet can also increase HDL-cholesterol.
Decrease Inflammation. This is best done by avoiding industrial seed oils found in deep fried and packaged foods.
Evaluate Risk. Regular lab testing and working with a knowledgeable dietitian or physician can help determine if further intervention is necessary.
It’s helpful to have a care team on your side that can help you create a plan that is tailored to you. Click here to learn more about working with Tera to improve your metabolic health today.