Low Density Lipoprotein (LDL)
|See Also||Lab Tests|
Low Density Lipoprotein or LDL, is the lipoprotein that carries the majority of the essential fatty acids from the liver and the intestines to the tissues where it can be sued for membrane formation and steroid hormone production. It contains most of the cholesterol in the serum and the levels are inversely related to HDL with respect to their ratios. Hence, when LDL increases, HDL levels decrease and vice versa. LDL has been found to have a better correlation with risk of atherosclerosis than total cholesterol., 
|Article||The Clinical Significance of Oxidized Low-density Lipoprotein Cholesterol, NDNR; 2012 October|
- LDL aids in the transport of cholesterol and other fatty acids from the liver to the peripheral tissues for uptake and metabolism by the cells.
- LDL is commonly known as "bad cholesterol", as the process of transporting cholesterol from the liver to the peripheral tissues increases the risk for atherosclerosis.
- Patient must fast for 12-14 hours before testing. Water is permitted.
- Note: dietary indiscretion within the previous few weeks may influence test results.
- Factors which can cause increased levels
- Drugs: aspirin, oral contraceptives, phenothiazines, steroids, thiazides, some beta blockers, sulfonamides, estrogens, progestins, androgens
- Factors which can cause decreased levels
- None noted
Ranges: The following are the reference ranges for this lab. However, lab ranges can vary by laboratory and country. 
|Standard U.S. Units||Standard International Units|
|Conventional Laboratory Range||60-130 mg/dL||1.55-3.36 mmol/L|
|Optimal Range||<120 mg/dL||<3.10 mmol/L|
|Alarm Ranges||>200 mg/dL||>5.17 mmol/L|
High levels indicate:
- Diet-high in refined carbohydrates
- Syndrome X/hyperinsulinemia
- Cardiovascular disease
- Anemia - Vitamin B12, folate deficiency, hemolytic
- Oxidative stress
- Non-specific tissue inflammation
- Tissue destruction
- Fatty liver (early development) and liver congestion
- Other conditions: heavy metal/chemical overload, hypothyroidism, increased saturated fat diet, nephritic syndrome, familial type II hypercholesterolemia, multiple myeloma, hepatic obstruction, anorexia nervosa, diabetes mellitus, chronic renal failure
Low levels indicate:
- Total cholesterol, HDL, triglycerides, apolipoprotein A and apolipoprotein B, blood glucose, lipid electrophoresis, homocysteine, oxidata free radical test and Uric acid, RBC, HCT, and HGB
- Pagana Kathleen D, Pagana Timothy J (1998) Mosby's Manual of Diagnostic and Laboratory Tests, Mosby, Inc
- Weatherby Dicken, Ferguson Scott (2002) Blood Chemistry and CBC Analysis: Clinical Laboratory Testing from a Functional Perspective, Bear Mountain