Triglycerides

Test/Range/Collection

Triglycerides , serum or plasma (TG)

<165 mg/dL

[<1.65 g/L]

SST, green, PPT

$

Fasting specimen required.

Physiologic Basis

Dietary fat is hydrolyzed in the small intestine, absorbed and resynthesized by mucosal cells, and secreted into lacteals as chylomicrons.

Triglycerides in the chylomicrons are cleared from the blood by tissue lipoprotein lipase.

Endogenous triglyceride production occurs in the liver. These triglycerides are transported in association with β-lipoproteins in very-low-density lipoproteins (VLDL).

Interpretation

Increased in: Hypothyroidism, diabetes mellitus (diabetic dyslipidemia), nephrotic syndrome, chronic alcoholism (fatty liver), biliary tract obstruction, stress, familial lipoprotein lipase deficiency, familial dysbetalipoproteinemia, familial combined hyperlipidemia, obesity, the metabolic syndrome, viral hepatitis, cirrhosis, pancreatitis, chronic renal failure, gout, pregnancy, glycogen storage diseases types I, III, and VI, anorexia nervosa, dietary excess. Drugs: β-blockers, cholestyramine, corticosteroids, diazepam, diuretics, estrogens, oral contraceptives.

Decreased in: Tangier disease (α-lipoprotein deficiency), hypo- and abetalipoproteinemia, malnutrition, malabsorption, parenchymal liver disease, hyperthyroidism, intestinal lymphangiectasia. Drugs: ascorbic acid, clofibrate, nicotinic acid, gemfibrozil.

Comments

If serum is clear, the serum triglyceride level is generally <350 mg/dL.

Elevated triglycerides are now considered an independent risk factor for coronary artery disease and a major risk factor for acute pancreatitis, particularly when serum triglyceride levels are > 1000 mg/dL. However, screening is not currently recommended.

Triglycerides > 1000 mg/dL can be seen when a primary lipid disorder is exacerbated by alcohol or fat intake or by corticosteroid or estrogen therapy.

Berglund L et al. Treatment options for hypertriglyceridemia: from risk reduction to pancreatitis. Best Pract Res Clin Endocrinol Metab. 2014;28:423.  [PMID: 24840268]

Parhofer KG. Interaction between glucose and lipid metabolism: more than diabetic dyslipidemia. Diabetes Metab J 2015;39:353.  [PMID: 26566492]

Pirillo A et al. Update on the management of severe hypertriglyceridemia—focus on free fatty acid forms of omega-3. Drug Des Devel Ther 2015;9:2129.  [PMID: 25914523]