LDL, ApoB, HDL, cholesterol - the guide to blood lipid levels

Laboratory testing of blood lipid levels is one of the routine tests carried out in the doctor's office. LDL cholesterol and HDL cholesterol are determined most frequently. But what do these values tell us? What's the story behind "bad" and "good" cholesterol? Why are blood lipid levels an important cornerstone of your longevity and why does Dr. Peter Attia dedicate an entire chapter to this topic in his new book? You can find out in this article.

Background - where do blood lipid levels come from?

To better understand the laboratory values, it is worth taking a closer look at our own fat metabolism, also known as lipid metabolism. Fats are distributed throughout the body and occur in different forms. As phospholipids the envelope of cells, they are the basis for the synthesis of various hormones, such as cortisol or testosterone, and serve as energy stores in the form of triglycerides . We absorb fatty acids daily from our food via the intestines and then distribute the individual molecules to every corner of our body with the help of the blood - ideally to where they are actually needed. The right composition of fatty acids and a sufficient supply of omega-3 fatty acids are particularly important.

Omega-3 fatty acids are an excellent way to shift the balance towards healthy fats.

Did you know Phospholipids are not only found in the cell membranes of our body. They are also found in chocolate, ice cream, margarine and cosmetic products. In medicine, they are used as a component of food supplements to increase bioavailability .

The effect this use can have can be seen in the example of Quercesome. The specially formulated quercetin C complex from MoleQlar is around 20 times more bioavailable than conventional quercetin powder . The key players here arephospholipids from the sunflower and the clever combination with natural vitamin C - a bio-booster from Quercetin. With Berbersome - the berberine mineral complex from MoleQlar - the plus in berberine bioavailability due to phospholipids is 10 times.

Fat and water - the transportation challenge

Fats are chemically insoluble in water (hydrophobic). This phenomenon can be easily recognized by adding a few drops of oil to water. The oil does not mix with the water, but floats on the surface in the form of drops. So how does our body do this when blood also consists largely of water? So-called apolipoproteinsexist to overcome this challenge. These enclose the fatty acids and form a water-soluble (hydrophilic) shell. You can imagine the whole thing as a small sphere. The water-soluble proteins are on the outside and the water-insoluble fats are on the inside. Apolipoproteins and fatty acids together are also known as lipoproteins and form the basis for laboratory measurements of fat metabolism.

Which blood lipid values can be measured?

Lipoproteins are divided into different categories based on their density. The following parameters are usually measured:

• LDL-Cholesterin
• HDL-Cholesterin
• Gesamt-Cholesterin
• Triglyceride
• Non-HDL-Cholesterin

In some laboratory findings, these two values also appear:

• ApoB
• Lp(a)

In Germany , blood lipid levels in healthy adults are usually examined once as part of the health check-up. From the age of 35, blood lipid levels can be checked every three years. In the neighboring country to the south Austria the statutory health insurance companies are somewhat more generous. Here, an annual laboratory test is possible as part of the preventive medical check-up.

What are the standard values for blood lipid levels?

The standard values vary depending on age and personal risk. The European Society of Cardiology (ESC) defines the following thresholds for people under 65 at low risk :

Did you know In patients with far too many fatty acids in their blood, a so-called hypertriglyceridemia , this can sometimes be seen with the naked eye. If the patient's blood is separated into liquid (serum) and solid blood components (cells) using a centrifuge, the serum looks milky white . Normally the serum is clear and yellow in color.

Triglycerides - more than just fat

Triglycerides do not contribute directly to vascular calcification . For this reason, they are not always given sufficient attention. However,& triglyceride levels are just as important for your longevity .

Values above 800 mg/dL can, for example, trigger pancreatitis at any time. And even though triglycerides, unlike LDL, cannot be deposited directly in the vascular wall, they have an indirect effect on arteriosclerosis via IDL particles (more on this later). For this reason, your triglyeride levels should not exceed the limits mentioned above.

In addition to exercise and a healthy, Mediterranean diet, the ESC mentions two supplements that can lower triglyceride levels . One of these is berberine, which has been shown in studies to lower both LDL cholesterol and triglycerides. In MoleQlar berberine is available in phospholipid form, which has a 10-fold better bioavailability than normal berberine powder .

Blood lipid levels: The myth of "good" and "bad" cholesterol

If you want to have your blood lipid levels determined, doctors will usually measure your total cholesterol, HDL cholesterol, LDL cholesterol and triglycerides. As a patient, you often hear phrases such as: " Your bad cholesterol (LDL) is a little high, but your good cholesterol (HDL) makes up for it. " Metaphors such as "don't do that" (LDL) and "love you" (HDL) are also frequently used. Or you're just told that your blood lipid levels are normal. But what does normal actually mean and why is good and bad cholesterol actually just a fairy tale

To understand this in more detail, we need to take another look at cholesterol metabolism. Cholesterol is absolutely vital for our body . Put simply, it is a special fat molecule that we need for every cell in our body. Very briefly, you can imagine the cholesterol metabolism as follows:

• Cholesterol is produced in the liver . The body's own cholesterol, triglycerides and apolipoproteins are then combined. So entstehen VLDL-Partikel (Very-low-density-lipoproteins)
• These VLDL molecules are quite large and are now transported with the blood.
• In the body these VLDL molecules release triglycerides (for example to muscle cells) and thus become smaller. They are now called VLDL remnants or also IDL molecules .
• The more cholesterol or triglycerides the VLDLs release, the smaller they become. Via the intermediate stage of IDLs they ultimately become the familiar LDL molecules .
• The LDL molecules can ultimately be taken up by cells via receptors. These are located, for example, in the liver, muscle cells or lipid cells.
• HDL molecules have a different purpose. If too much cholesterol accumulates outside the liver, HDL collects it and transports it back to the liver .

The cholesterol-egg untruth

Cholesterol occurs naturally in our food (eggs in particular are rich in cholesterol). However, most of the cholesterol in our blood is produced by ourselves. It is therefore called endogenous or endogenous cholesterol. Exogenous, externally supplied cholesterol contributes very little to the increase in cholesterol levels .

For a long time, eggs were believed to lead to a sharp increase in LDL levels and thus to a higher risk of cardiovascular disease. More recent studies have shown that eggs do cause a slight increase in LDL, but of a subgroup of LDL molecules that are too large to be deposited in the vascular wall. This means that eggs are healthier than assumed, as they contain lots of vitamins and other healthy substances . (Blesso & Fernandez, 2018)

Eggs cause your cholesterol to skyrocket? According to recent scientific research, this is a myth from times gone by.

The moral of the story? A functioning organism needs all forms of cholesterol molecules. LDL transports vital cholesterol from the liver to the other regions of the body and HDL can retrieve excess cholesterol . If, on the other hand, there is an LDL excess or LDL/HDL imbalance, this first leads to vascular deposits and, over a long period of time, to arteriosclerosis.

Arteriosclerosis - the number one killer in the western world

Arteriosclerosis - also known colloquially as vascular calcification - is a silent killer. Over decades, small fat molecules accumulate in our blood vessel walls and gradually become larger and larger . This leads to inflammatory reactions, plaque formation and ultimately to the narrowing of entire vessels. You usually only notice arteriosclerosis when a vessel is almost completely blocked. The result is a lack of oxygen in the supplied tissue (ischemia). people with severely "calcified" coronary vessels can feel "ischaemia pain" when they exert themselves. The vessels are too narrow for the blood due to the "calcifications". This leads to an insufficient supply of oxygen and those affected notice a stabbing pain in the chest. In the worst case scenario, a heart attack or stroke can occur if parts of the plaque become detached, blocking entire vessels. (Khatana et al., 2020)

Did you know When we talk about vascular calcification, we often mean the fatty deposits caused by LDL particles. However, it is not only LDL that plays a role, but also calcium . Too much calcium in the blood vessels can lead to significantly more "calcification". This is counteracted by vitamin K2 . Several studies have shownthat vitamin K2-dependent proteins can reduce vascular calcification . (Halder et al., 2019)

According to one of the world's largest studies (Global Burden of Disease), which was published in the Journal of the American College of Cardiology, cardiovascular disease, which includes arteriosclerosis, is the most common cause of death worldwide. Millions of people die from it every year. The authors estimate that up to a third of the population worldwide dies from cardiovascular disease and atherosclerosis is one of the most important factors in this. (Roth et al., 2020)

High LDL levels are a modifiable risk factor for cardiovascular disease . This is where the colloquial term "bad" cholesterol came from in the past. However, researchers have only discovered in recent years why this is too short-sighted.

In addition to high LDL levels, high blood pressure and high blood sugar are at least equally important risk factors. You can find out what insulin resistance is and why it is so important for your longevity in our article on insulin resistance .

Why is LDL cholesterol measurement so important - and at the same time prone to error?

Short warning, in this section we need to dive a little deeper into some studies. Admittedly, the topic is complex, but hopefully by the end of this section, it will be clear, why measuring LDL cholesterol alone is not enough for you .

LDL is one of the main factors in the development of arteriosclerosis. In healthy adults the level should not exceed 115mg/dL .

Imagine for a moment that your vessel walls are not a perfectly tight tube. Instead, they are full of little "holes" that we need to allow nutrients and cells to move freely between our blood system and other compartments of our body.

The LDL particles are so small that they can push through our blood vessel walls. HDL molecules, on the other hand, are too large and cannot enter the vessel wall. When passing through the vessel wall, small errors naturally occur, which means that an LDL molecule does not get through the perforated wall in your blood vessel and gets "stuck". If this happens too often, "vascular calcification" occurs via complex remodeling mechanisms. The more LDL molecules there are in your blood, the greater the risk of these "natural errors". For this reason, LDL cholesterol is used as a laboratory parameter. However, it is not only LDL molecules that have this so-called atherosclerotic effect, but also the IDLs . These would not be "counted" in a measurement. This is the first "blind spot" in the measurement of LDL cholesterol. It is simply only part of the fat truth.

LDL - Estimating versus measuring

What makes the topic of blood lipid levels even more complex is the fact that there are different types of measurement. Classically, the LDL cholesterol (LDL-C) is estimated using the Friedwald formula . (Martin et al., 2013). Correctly heard, the LDL value in common laboratory findings is mostly based on an estimate.

However, it is also possible to measure the LDL particles numerically (LDL-P). This is a direct measurement and much more accurate. What is also missing here, however, are the other molecules, in particular IDLs.

In a large review study, different measurement methods were compared with each other. (Mora et al., 2014) Concordant and discordant measured values are shown here. What does this mean? Let's assume your LDL cholesterol is an unremarkable 105mg/dl. As a reminder, the cholesterol in your LDL particles is estimated here. You can now also count the LDL particles directly to obtain the LDL-P value . If this is the same as your LDL-C value, this is referred to as concordance. If your LDL-P value is significantly higher/lower, this is referred to as discordant values.

Discordant values are deceptive, as a "normal" LDL-C can appear in the normal routine laboratory even though your LDL-P is elevated. However, your doctor would tell you on the basis of the findings: "Everything is fine."

But is that really the case?

In this study it was shown that women in particular have an increased risk of death if they have discordant LDL levels . In addition to LDL-P values, apoB and non-HDL cholesterol were also compared as a measurement method. For all three parameters for blood lipid levels, discordant values were associated with a higher risk compared to LDL-C.

In summary: The sole measurement of LDL cholesterol may suggest a false sense of security due to the measurement method.

Arteriosclerosis (also known as atherosclerosis) is the number one silent killer. The vessels become increasingly narrow until sufficient blood flow is no longer possible.

ApoB - the better measurement than LDL?

We have seen that measuring LDL cholesterol alone, using the estimation formula, simply does not give us enough information. For this reason, among others Dr. Peter Attia in his book "Outlive: The Science and Art of Longevity" advocates a different measurement for blood lipid levels: ApoB

ApoB is an apolipoprotein - a complex of fatty acids and a water-soluble envelope, if you remember the introduction. ApoB binds triglycerides and cholesterol to make them water-soluble. The ingenious thing about ApoB is that every lipoprotein (except HDL) has exactly one molecule of ApoB . ApoB can therefore be used to determine much more precisely how many lipoproteins are in our bloodstream. For this reason, Longevity physician Dr. Attia advocates focusing more on the determination of ApoB.

The role of ApoB has been known in the scientific community for some time and was described in a review by Dr. Sniderman, among others. (Sniderman et al., 2019)

The European Society of Cardiology also recognizes the role of ApoB in its 2019 guidelines and currently recommends it as an additional diagnosis in high-risk patients .

Should we measure ApoB in all people

Should everyone now have their apoB level measured? This is currently still up for debate . On the one hand, supporters argue that this value is a much better way of assessing the risk of cardiovascular disease. On the other hand, it is argued that LDL-C is sufficient, as it is responsible for more than 90% of the underlying "vascular calcification".

Low ApoB levels are generally associated with a low probability of cardiovascular disease. It can therefore make sense to determine its level and adjust therapy accordingly.

In addition to apoB, there is another risk factor that indicates a high risk of arteriosclerosis. We are talking about Lp(a) .

Lp(a): a familial risk factor

Lp(a) (pronounced: lipoprotein small a) is a genetic risk factor . People with high levels of Lp(a) have a significantly increased risk of cardiovascular disease, independent of LDL cholesterol and ApoB. Lp(a) has similar properties to LDL, i.e. it is quickly deposited in the vessel wall. As with ApoB, there is currently a debate as to how useful it is for everyone in the population to be measured.

Blood sampling - for some a necessary evil, for others an important component of their own longevity.

Blood lipid levels - the lower the better?

Disclaimer: This article cannot give you precise medical recommendations on target values. You should always discuss these steps exclusively with doctors!

The European Society of Cardiology has published various LDL-C and ApoB limits in its guidelines. These vary greatly depending on personal risk.

The lowest LDL-C target values are around 40mg/dl and the lowest ApoB target values are below 65mg/dl. Currently, such strict limits are only recommended for people who are already severely ill.

It is currently under discussion whether an early reduction in LDL and apoB levels is beneficial. The idea behind this is as follows. We now know that arteriosclerosis is a disease that progresses slowly over decades. Every day, small fat particles are deposited unnoticed in the walls of our blood vessels. If you were to cut open the blood vessels of those affected, you would be able to see the "fatty plaques" with the naked eye. However, such plaques only develop after a long time, which is also referred to as a cumulative LDL load over a lifetime .

One idea is to never reach this cumulative LDL load and thus never develop enough arteriosclerosis to provoke disease. Dr. Braunwald, one of the leading cardiologists in America, has even hypothesized that by lowering LDL levels early, one can live to be 100 years old without ever developing cardiovascular disease . Since cardiovascular disease is the number one cause of death, early reduction of LDL and ApoB would bring a brilliant improvement in both quality of life and life expectancy.