What is the Difference Between HDL and Non-HDL Cholesterol

The main difference between HDL and non-HDL cholesterol is that HDL cholesterol is the good cholesterol that brings cholesterol back to the liver, whereas non-HDL cholesterol is the total cholesterol minus HDL cholesterol. 

HDL and non-HDL cholesterol are the two types of cholesterol that occur in the body. Cholesterol is a waxy, fat-like substance important for producing hormones, vitamin D, etc.  

Key Areas Covered

1. What is HDL Cholesterol
– Definition, Structure, Function
2. What is Non-HDL Cholesterol
– Definition, Structure, Function
3. Similarities Between HDL and Non-HDL Cholesterol
– Outline of Common Features
4. Difference Between HDL and Non-HDL Cholesterol
– Comparison of Key Differences

Key Terms 

HDL Cholesterol, Good Cholesterol, Bad Cholesterol, Non-HDL Cholesterol

What is HDL Cholesterol

HDL (high-density lipoprotein) cholesterol is a type of cholesterol that benefits the heart by transporting bad cholesterol from the blood into the liver. It is also called good cholesterol. Since the particle density is high in good cholesterol, it is called high density. A rim of lipoproteins surrounds the cholesterol molecule to form the HDL molecule. Lipoproteins are the helper molecules that aid the transportation of cholesterol particles in the blood.

Figure 1: Lipid Metabolism

Good cholesterol is the scavenger of LDL (low-density cholesterol) and removes LDL from the bloodstream. It transports LDL into the liver, where it is reused and recycled. Thereby, good cholesterol maintains the inner walls of the blood vessels. It reduces the risk of atherosclerosis, which leads to cardiovascular diseases. The good cholesterol levels should be 60 mg/dL or above. A higher level of good cholesterol is good for health.

What is Non-HDL Cholesterol 

Non-HDL cholesterol is a type of cholesterol that increases the risk of cardiovascular disease. Therefore, it is also called bad cholesterol. The kinds of non-HDL include LDL and VLDL. LDL is an important marker of the development of cardiovascular disease. It forms clogged arteries, leading to atherosclerosis. Atherosclerosis leads to cardiovascular disease. HDL removes the plaques in the walls of the blood vessels. The normal level of LDL in the blood should be less than 70 mg/dL. The elevated level of bad cholesterol is harmful since it produces plaques.

Figure 2: Atheroma

Moreover, another type of non-HDL cholesterol includes VLDL (very low-density lipoprotein). It is also considered bad cholesterol since it involves plaque formation in arteries. 

Similarities Between HDL and Non-HDL Cholesterol

• HDL and non-HDL cholesterol are two cholesterol types that occur in the body.
• They circulate through the bloodstream. 

Difference Between HDL and Non-HDL Cholesterol

Definition

HDL or high-density cholesterol refers to good cholesterol, which absorbs cholesterol in the blood and carries it back to the liver. In contrast, non-HDL cholesterol refers to subtracting HDL from total cholesterol. 

Known as 

HDL is known as good cholesterol, while non-HDL is known as bad cholesterol. 

Diameter

The diameter of HDL cholesterol is 5-12 nm, while the diameter of non-HDL cholesterol is 18-25 nm.

Density

The density of HDL is 1.063- 1.210 g/ml, while the density of non-HDL cholesterol is 1.019-1.063 g/ml.

Composition

HDL contains 3% protein, 30% cholesterol, 29% phospholipid, 4-8% triglycerides, and cholesterol esters, while non-HDL cholesterol contains 25% protein, 46-50% cholesterol, 21-22% phospholipid, 8-10% triglycerides, and cholesterol esters.

Apoproteins

HDL contains Apo A-I, Apo A-II, Apo C, and Apo E, while non-HDL contains Apo B-100.

Normal Level

A normal HDL level is 60 mg/dl, while a normal non-HDL level is less than 40 mg/dl.

High Level

Higher levels of HDL are good for health, while higher levels of non-HDL are bad for health. 

Function

HDL carries lipids from the bloodstream to the liver, while non-HDL circulates lipids throughout the body. 

Conclusion

In brief, HDL and non-HDL are the two cholesterol types of the body. HDL is also known as good cholesterol since it brings lipids from the bloodstream to the liver. The diameter of HDL is 5-12 nm, and the density of HDL is 1.063- 1.210 g/ml. HDL comprises 3% protein, 30% cholesterol, 29% phospholipid, 4-8% triglycerides, and cholesterol esters. Also, it contains Apo A-I, Apo A-II, Apo C, and Apo E. Normal HDL levels are 60 mg/dl. Higher levels of HDL are good for health.

Meanwhile, non-HDL cholesterol is a bad cholesterol since it circulates lipids throughout the bloodstream. The diameter of non-HDL cholesterol is 18-25 nm, and the density is 1.019-1.063 g/ml. Non-HDL comprises 25% protein, 46-50% cholesterol, 21-22% phospholipid, 8-10% triglycerides, and cholesterol esters. Additionally, it contains Apo B-100. Higher levels of non-HDL cholesterol are harmful to health. Therefore, the main difference between HDL and non-HDL is their composition and function.

References:

1. Cholesterol: Understanding levels and numbers. Cleveland Clinic. 

Image Courtesy:

1. “Lipoprotein metabolism” By Npatchett – Own work (CC-BY SA 3.0) via Commons Wikimedia
2. “Atheroma.” By Manu5 – Own Work (CC-BY SA 4.0) via Commons Wikimedia