The term “hyperlipidemia” is actually a very general term. It encompasses a number of different types and terminology that doctors sometimes misunderstand when communicating with patients. This article explains these terminologies in detail.
In fact, lipid is a very broad concept that includes cholesterol, triglycerides, phospholipids, glycolipids, sterols, and steroids. Among them, cholesterol and triglycerides are the most important. Therefore, what we usually call “high blood lipids” means “high triglycerides and/or high cholesterol”.
Total Cholesterol
Total cholesterol refers to all cholesterol in the blood. When it is elevated, it is called hypercholesterolemia.
Triglycerides
Elevated triglycerides are called hypertriglyceridemia.
Elevated cholesterol or triglycerides can both be called hyperlipidemia; if both are elevated, it can be called mixed hyperlipidemia.
Lipoproteins
Lipids cannot exist independently in the blood, but must be combined with proteins (called apolipoproteins) to do so. When combined, they become lipoproteins.
That is, lipoprotein = lipid + protein.
According to the density, lipoproteins can be divided into 5 categories: celiac, very low density lipoproteins, medium density lipoproteins, low density lipoproteins, and high density lipoproteins. Among them, LDL and HDL are the most clinically significant.
High-density lipoprotein cholesterol
HDL cholesterol = high-density lipoprotein + cholesterol.
Abbreviated as “high density”, it is a good cholesterol and has a protective effect on blood vessels.
Low-density lipoprotein cholesterol
LDL cholesterol = low-density lipoprotein + cholesterol.
Abbreviated as “low density”, it is a bad cholesterol that has a pro-atherosclerotic effect on blood vessels. Therefore, the most commonly used oral statin drugs (e.g. atorvastatin, resevastatin, simvastatin, etc.) are mainly targeted at it. The lower the LDL, the better, and the latest evidence suggests that for patients with severe coronary artery disease, the goal should be to reduce it to less than 1.8 mmol/l. For “basically healthy” people, it is best to keep it below 3.4, but if this is not possible, 3.4-4.1 is acceptable. Above 4.1, it is not good.
To sum up: “high density” should be high, “low density” should be low, each in its place, is good.
Apolipoprotein A1 and Apolipoprotein B
As mentioned earlier, Apolipoprotein is a protein that “loads blood lipids”. There are more than 20 types of apolipoproteins, and the most important ones are ApoA and ApoB.
Apolipoprotein A is mainly involved in the formation of HDL; Apolipoprotein B is mainly involved in the formation of LDL.
It can be simply considered: Apo A ≈ high density; Apo B ≈ low density.
According to the previous article “high density is good, low density is bad”, we can conclude that Apo A should be higher and Apo B should be lower.
Total cholesterol: elevated, not good, need to bring it down!
Triglycerides: normal range, good, keep it up!
High density: normal range, not good or bad, better raise the high density!
Low density: elevated, not good, need to bring it down!
Apo A1: elevated a little, good, keep it up!
Apolipoprotein B: elevated, not good, need to bring it down!
APOA/APOB: 0.93, not good, normal should be around 1.5.
Of course, doctors usually don’t analyze it this way when they see a doctor, because it’s too much trouble. Among these indicators, there are 4 most important ones: total cholesterol, triglycerides, high density, and low density. If we pick the most important one, it is: LDL cholesterol, which is a very important culprit of coronary heart disease.