What is Cholesterol?
What are LDL and HDL?
Cholesterol must be transported via the bloodstream by lipoproteins. The two main lipoproteins are LDL (low density lipoprotein), which is considered the "bad" cholesterol because it causes plaque buildup in the arteries, which can lead to heart disease. HDL is the other main lipoprotein and it is considered the "good" cholesterol because it collects the LDL/plaque from the arteries and transports them to the liver, where they are passed from the body.
How do LDL and HDL Differ?
HDL and LDL differ both structurally and functionally. Structurally, LDL is composed of around 25% protein and 50% lipid (hence the name: lipoprotein). Since protein is more dense than lipid, LDL stands for low-density lipoprotein since it has less protien. HDL consists of around 20% lipid and 50% protein, so it is named high-density lipoprotien.
Functionally, LDL is used to transport cholesterol throughout the body, but it may leave some in the arteries, causing plaque buildup. HDL is used to collect the LDL/plaque buildup in the arteries and transport it to the liver, where it is passed from the body.
What other molecules are monitored in the blood besides LDL and HDL?
There are two other components besides LDL and HDL that are measured in the blood and they are Triglycerides and VLDL.
Triglycerides are a type of fat responsible for energy supply for the muscles and energy storage. Even though there are very small amounts of triglycerides in the blood, too many of thm can increase the risk of heart disease.
VLDL is very-low-density lipoprotein, which contains very little protein. Their process is to transport triglycerides from the liver. High amounts of VLDL may also increase the risk of heart disease.