all cell membranes. . Blood lipoproteins Lipids, such as cholesterol and triglyceride are insoluble in plasma which is the liquid component of blood. Therefore they bind with circulating lipoproteins that transport lipids to various tissues.
Lipoproteins in blood are the mode of transport for cholesterol through the bloodstream and lymphatic fluid. Lipoproteins consist of cholesterol, triglycerides, phospholipids, and protein. There are five major lipoproteins in the blood . Chylomicrons: They are the largest and the least dense lipoproteins.
They transport triglycerides from the intestine to the cells of the body. . Very low-density lipoprotein (VLDL): They are responsible for transporting lipids from the liver to the cells of the body. .
Intermediate-density lipoprotein (IDL): This is formed during the conversion of VLDL to LDL. . Low-density lipoprotein (LDL): These are formed from VLDLs and carry cholesterol from the liver to different cells. They are termed as ‘bad cholesterol’ since they aid in the fatty build up within arteries (atherosclerosis) blocking the free flow of blood.
High levels of LDL is associated with an increased risk of CVD. LDL cholesterol level below mg/dl of blood is considered ideal. When the level increases beyond this, it increases the risk of heart disease (NCEP, ). .
High-density lipoprotein (HDL: They are involved in “reverse cholesterol transport” where HDL carries LDL (bad cholesterol) from the arteries to the liver, where it is broken down and eliminated from the body. Therefore, UNIT - - - NUTRITION IN HYPERTENSION AND CARDIO-VASCULAR DISEASE HDL is also called ‘good cholesterol’, because it prevents atherosclerosis. High HDL levels are associated with lowered risk of CVD. HDL level below mg/dl of blood is considered to be a major risk factor for developing heart disease whereas HDL levels of mg/ dl or more greatly lowers the risk for CVD (NCEP, ).
Chylomicrons Proteins Cholesterol Phospholipids Triglycerides VLDL LDL HDL IDL Fig . : Types of lipoproteins A plaque is a fatty deposit of cholesterol within the arterial wall that accumulates over a period of time. It may grow in size eventually blocking the artery and cutting