Intermediate-density lipoprotein

Intermediate-density lipoprotein (IDL) is a type of lipoprotein, which is a particle composed of protein and lipid, that is intermediate in size between very-low-density lipoprotein (VLDL) and low-density lipoprotein (LDL). IDL is one of the five major groups of lipoproteins (chylomicrons, VLDL, IDL, LDL, high-density lipoprotein) that enable fats and cholesterol to move within the water-based solution of the bloodstream.

Function

IDL is formed from the degradation of very-low-density lipoprotein and is in the process of being converted into low-density lipoprotein. IDL particles are much richer in cholesterol than VLDL. They are consequently more atherogenic, and elevated levels of IDL are often associated with atherosclerosis and coronary artery disease.

Measurement

IDL levels can be measured as part of a lipid profile to assess the risk of cardiovascular disease. However, because they are typically present in relatively small quantities in the blood, they are often not directly measured but are instead calculated as part of the total cholesterol count.

Treatment

Treatment for high IDL levels typically involves lifestyle changes such as diet and exercise, and may also include medication such as statins.

See also

• Lipoprotein metabolism
• Hyperlipidemia
• Apolipoprotein