Triglycerides
See Also | Lab Tests |
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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
- High fat diet, alcohol intake, pregnancy, obesity, severe acute stress, high alkaline phosphatase levels to some degree
- Drugs: cholestyramine, estrogens, and oral contraceptives
- 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 | |
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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:
- Syndrome X/hyperinsulinemia
- Fatty liver(early developement) and Liver congestion
- Early stage of insulin resistance
- cardiovascular disease
- Atherosclerosis
- Poor metabolism and utilization of fats
- Early stage of Hyperglycemia or Diabetes
- Hyperlipidemia
- Primary hypothyroidism
- Adrenal cortical dysfunction
- Secondary Hypothyroidism (Anterior pituitary hypofunction)
- Hyperlipoproteinemia
- Alcoholism
- Other conditions: acute pancreatitis, Nephritic syndrome, Gout and uremia, viral herpes, glycogen storage diseases, anorexia
Low levels indicate:
- Liver/biliary dysfunction
- Nutrient deficient diet, insufficient fat intake, vegetarian diet
- Thyroid hyperfunction
- Autoimmune processes
- Adrenal hyperfunction
- Other conditions: endurance exercise, excessive oxidative stress, free radical pathology, chemical or heavy metal overload, digestive dysfunction/ malabsorption
Associated Tests
- Total cholesterol, LDL, HDL, lipoprotein A and B, blood glucose, lipid electrophoresis, homocysteine, oxidata free radical test
References
- ↑ Pagana Kathleen D, Pagana Timothy J, (1998) Mosby's Manual of Diagnostic and Laboratory Tests, Mosby, Inc
- ↑ 2.0 2.1 Weatherby Dicken, Ferguson Scott (2002) Blood Chemistry and CBC Analysis: Clinical Laboratory Testing from a Functional Perspective, Bear Mountain