Triglycerides
Description
Triglycerides are a fatty substance in the body
that is stored as energy for later use. Triglycerides are often included
among the lipid indicators in metabolic syndrome, or as part of an evaluation
of coronary risk factors. Triglycerides are measured enzymatically in
blood serum or plasma using a series of coupled reactions in which triglycerides
are hydrolyzed to produce glycerol. Glycerol is then oxidized using glycerol
oxidase, and H2O2, one of the reaction products, is measured (http://www.cdc.gov/nchs/data/nhanes/frequency/l13amdoc.pdf).
The National Cholesterol Education Program (NCEP) Adult Treatment Panel
III (ATP III) adopts the following classification of triglyceride levels:
Normal fasting triglyceride levels are below 150 mg/dL: 150-199 mg/dL
is considered borderline high, 200-499 mg/dL high, and 500 mg/dL and greater
very high (Expert Panel, 2001).
Significance
of Measurement
High triglyceride levels have been associated with
heart disease such as heart attack (Gaziano et al., 1997), coronary heart
disease (CHD) (Cullen, 2000), and coronary artery disease (CAD) (Linton
& Fazio, 2003). Very high triglycerides can result in pancreatitis
(Toskes, 1990). Elevated triglycerides are one of the factors of the metabolic
syndrome, which represents a constellation of lipid and nonlipid risk
factors of metabolic origin (Expert Panel, 2001). Triglycerides are also
measured because the value is used to calculate LDL-cholesterol concentrations
(http://www.cdc.gov/nchs/data/nhanes/frequency/l13amdoc.pdf).
Method
of Measurement
A blood sample is drawn from a vein or a fingerstick.
Reliable triglyceride levels require fasting status.
References
· Cullen, P. (2000). Evidence that triglycerides
are an independent coronary heart disease risk factor. American Journal
of Cardiology, 86(90), 943-949.
· Expert Panel on Detection, Evaluation, and Treatment of High
Blood Cholesterol in Adults. (2001). Executive summary of the third report
of the national cholesterol education program (NCEP) expert panel on detection,
evaluation, and treatment of high blood cholesterol in adults (Adult Treatment
Panel III). Journal of the America Medical Association, 285(19),
2486-2497.
· Gaziano, J. M., Hennekens, C. H., O'Donnell, C. J., Breslow,
J. L., & Buring, J. E. (1997). Fasting triglycerides, high-density
lipoprotein, and risk of myocardial infarction. Circulation,
96(8), 2520-2525.
· Linton, M.F., & Fazio, S. (2003). A practical approach to
risk assessment to prevent to coronary artery disease and its complications.
American Journal of Cardiology, 92(1,supple), 19i-26i.
· National Center for Health Statistics. (2005). NHANES 1999-2000
data release: Laboratory 13AM- triglycerides and HDL-cholesterol.
Retrieved March 23, 2005, from http://www.cdc.gov/nchs/data/nhanes/frequency/l13amdoc.pdf
· Toskes, P. (1990). Hyperlipidemic pancreatitis. Gastroenterology
Clinics of North America, 19(4), 783-791.