Triglycerid

Triglyceride (often spelled triglycerid in some languages) is a triester formed from glycerol and three fatty acids. It is the main form in which animals and many plants store energy. The glycerol backbone is esterified at all three hydroxyl groups with fatty acids, creating a neutral lipid whose physical properties depend on the chain length and saturation of the fatty acids.

Dietary triglycerides are ingested as fats and oils. In the small intestine they are emulsified by bile and hydrolyzed by pancreatic lipase into fatty acids and monoglycerides, which are absorbed by enterocytes and reassembled into triglycerides. These are packaged with cholesterol and proteins into chylomicrons, released into the lymph and then the bloodstream.

In circulation, triglycerides are carried mainly by chylomicrons and very-low-density lipoproteins. Endothelial lipoprotein lipase hydrolyzes their triglycerides, supplying fatty acids to tissues for energy or storage. In adipose tissue, triglycerides are broken down by hormone-sensitive lipase under hormonal control and released as free fatty acids and glycerol.

Variability in triglyceride composition leads to saturated, monounsaturated, and polyunsaturated species with short to long chains. Regulation depends on hormones: insulin promotes synthesis and storage, while glucagon and catecholamines promote mobilization.

Clinically, fasting triglyceride levels reflect lipid metabolism and cardiovascular risk. Normal fasting triglycerides are below about 150 mg/dL (1.7 mmol/L); higher levels indicate borderline to very high triglyceridemia and associated risk, especially with metabolic syndrome.

Triglyceride is the standard term in English; triglycerid appears in other languages. The triglyceride pool supports energy storage, thermal insulation, and lipid transport.