Cholesterol is carried in the blood on protein particles called “lipoproteins”. A number of different types of lipoproteins exist, but they can be divided into high density lipoproteins (HDL), and everything else (non-HDL). The distinction is made on the basis of the different functions of HDL vs non-HDL. All non-HDL particles carry their cholesterol from the liver and deposit it in the walls of arteries, whereas cholesterol on…Cholesterol is carried in the blood on protein particles called “lipoproteins”. A number of different types of lipoproteins exist, but they can be divided into high density lipoproteins (HDL), and everything else (non-HDL). The distinction is made on the basis of the different functions of HDL vs non-HDL. All non-HDL particles carry their cholesterol from the liver and deposit it in the walls of arteries, whereas cholesterol on HDL is carried in the opposite direction. The implication of this is that non-HDL cholesterol (non-HDL-C) is “bad”, as it causes “furring up of the arteries” (atherosclerosis), which can lead to cardiovascular disease such as heart attacks and strokes. On the other hand, HDL cholesterol is known as good, as low concentrations are associated with atherosclerosis. One of the main components of non-HDL-C is LDL-C. Previously, LDL-C was used as the main measure of “bad” cholesterol. However, it is know recognised that other forms of non-HDL are also harmful, and not just LDL. Therefore, non-HDL-C is preferred to LDL-C in risk assessment. As well as LDL, non-HDL lipoproteins include very low density lipoprotein (VLDL), intermediate density lipoprotein (IDL), lipoprotein remnants, and lipoprotein (a). Non-HDL-C, is not directly measured by the laboratory, but is a calculated value determined from direct measurements of both total cholesterol and HDL-C. The various components of non-HDL-C, listed above, are not usually measured. See MoreSee Less
