High Density Lipoprotein (HDL)

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Latest Edit: Hector 2014-03-24 (EDT)

See Also Lab Tests

HDL, or High Density Lipoprotein, is composed mainly of phospholipids and apoproteins. It functions to transport cholesterol from the peripheral tissues and vessel walls back to the liver for processing and metabolism into bile salts. It is known as "good cholesterol" as the process of bringing cholesterol from the peripheral tissue to the liver protects against atherosclerosis. It also has the ability to influence the absorption and binding of LDL by smooth muscle and other cells, which provides protective benefits.[1],[2]

Discussion

Patient Preparation

  • Patient must fast 12 to 14 hours before testing. Water is permitted.
  • Note: dietary indiscretion within the previous few weeks may influence lipoprotein levels.
  • Factors which can cause increased levels
  • hypothyroidism, HDL values are age and sex dependent
  • Drugs: aspirin, oral contraceptives, phenothiazines, steroids, thiazides, some beta blockers, sulfonamides, estrogen, insulin
  • Factors which can cause decreased levels
  • Ascorbic acid (may cause 5-15% decrease), temporary decrease after heart attack, smoking and alcohol ingestion
  • Drugs: thiazide diuretics, antihypertensive medications, beta blockers without sympathomimetic activity, sympatholytic agents

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 40-90 mg/dL 1.03-2.32 mmol/L
Optimal Range > 55 mg/dL > 1.42 mmol/L
Alarm Ranges < 35 mg/dL < 0.91 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