Most fat in the body is in the form of triglycerides which are primarily stored in the adipose tissue and liver. It is one of the three main forms of lipids in the body, along with cholesterol and phospholipids. Triglycerides are derived from food or manufactured in the liver.
It is transported through the body by bonding to lipoproteins – VLDL (very low density lipoproteins), IDL (intermediate density lipoproteins), LDL (low density lipoproteins), HDL (high density lipoproteins) and chylomicrons. These lipoproteins allow the water insoluble triglycerides to travel to various tissues and circulate through the blood stream. The main function of triglycerides is to serve as a source of energy but it is also a component of cell membranes although to a lesser extent than cholesterol and phospholipids.
High levels of triglycerides are associated with elevated levels of VLDL, IDL and/or chylomicrons. These three lipoproteins carry the greatest concentration of triglycerides. LDL and HDL contain very small amounts of triglycerides but higher quantities of cholesterol. An elevation of triglycerides in the blood is known as hypertriglyceridemia and is associated with an increased risk of cardiovascular diseases. This is compounded by a high blood level of LDL cholesterol (LDL-C or the “bad cholesterol”) and low HDL cholesterol (HDL-C or the “good cholesterol”).
Triglycerides Blood Test
While triglyceride levels can be monitored on its own through a blood test, it is usually conducted as part of a lipid profile. This allows for a complete assessment of a person’s risk of cardiovascular disease by monitoring the cholesterol levels as well. The test is conducted after a minimum of an 8 hour fast (ideally 9 to 12 hours). A lipid profile will provide values for the following :
- Total cholesterol
- LDL cholesterol
- HDL cholesterol
In addition, the VLDL levels may also be monitored as part of a more comprehensive lipid profile test. The range of values for total, LDL and HDL cholesterol are discussed further under Cholesterol Blood Tests. If the LDL cholesterol is elevated as well as the triglyceride levels, then this is known as hyperlipidemia. Along with a low level of HDL cholesterol, hyperlipidemia is a strong risk factor for conditions like coronary artery disease or strokes.
Triglycerides Levels (Values and Reference Range)
- Normal : less than 150 mg/dL (1.7 mmol/L)
- Bordline High = 150 to 199 mg/dL (1.7 to 2.2 mmol/L)
- High = 200 to 499 mg/dL (2.3 to 5.6 mmol/L)
- Very High = 500 mg/dL or higher (5.6 mmol/L)
VLDL Levels (Values and Reference Range)
- High : greater than 30 mg/dL (0.77 mmol/L)