Triglycerides

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Latest Edit: Hector 2014-03-21 (EDT)

See Also Lab Tests


Triglycerides are composed of fatty acid molecules attached to a glycerol backbone. They can enter the blood stream both endogenously from the liver and exogenously from the diet. Exogenous sources of triglycerides, or dietary fat, is emulsified and broken down by pancreatic lipase into its constituent free fatty acids within the digestive tract. These free fatty acids then enter the intestinal mucosal cells where they are re-formed into triglycerides and incorporated into chylomicrons. Through lymphatic lacteals, the chylomicrons enter the bloodstream and are then cleared from the blood by tissue lipoprotein lipase, which breaks the triglycerides down into free fatty acids and glycerol. The free fatty acids are mainly used for energy by the heart and skeletal muscle. They are also transported to the liver bound to albumin and/or reformed into triglycerides to be stored in adipose tissue.[1],[2]


Patient Preparation

  • Dietary fat consumption can greatly influence serum triglyceride levels. The source of elevated triglycerides is often found to be non-fasting samples. A 12-hour fast is normally recommended to prevent the influence of dietary intake of fat on the sample. Post-prandial levels of triglycerides are found to rise 2 hours after a meal, peaking at 4-6 hours.
  • Patient should fast for 12-14 hours before the test. Water is permitted.
  • Patient should not drink alcohol for 24 hours before the test.
  • Note: dietary indiscretion for as much as 2 weeks before this test will influence results.
  • Factors which can cause increased levels
  • Factors which can cause decreased levels
  • Drugs: ascorbic acid, asparaginase, clofibrate, colestipol

Clinical Implications

Ranges: The following are the reference ranges for this lab. However, lab ranges can vary by laboratory and country. [2]

Standard U.S. Units Standard International Units
Conventional Laboratory Range 30-150 mg/dl 0.34-1.7 mmol/L
Optimal Range 70-110 mg/dl 0.79-1.24 mmol/L
Alarm Ranges <35 or > 350 mg/dl <0.39 or > 3.95 mmol/L

High levels indicate:

Low levels indicate:

Associated Tests

References

  1. Pagana Kathleen D, Pagana Timothy J, (1998) Mosby's Manual of Diagnostic and Laboratory Tests, Mosby, Inc
  2. 2.0 2.1 Weatherby Dicken, Ferguson Scott (2002) Blood Chemistry and CBC Analysis: Clinical Laboratory Testing from a Functional Perspective, Bear Mountain Cite error: Invalid <ref> tag; name "weatherby" defined multiple times with different content