High Density Lipoprotein (HDL)

Latest Edit: Iva Lloyd, ND 2021-08-24 (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.,

Discussion

• HDL is viewed in relation to the total cholesterol and the LDL cholesterol levels.
• HDL can be used as a strong independent diagnostic indicator to determine the risk for atherosclerotic coronary artery disease if the total cholesterol is high.
• Increased HDL is viewed as protective.

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.

	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:

• Autoimmune processes
• Other conditions: Hypothyroidism, excessive alcohol consumption

Low levels indicate:

• Hyperlipidemia and atherosclerosis
• Diets high in refined carbohydrates
• Syndrome X/hyperinsulinemia
• Oxidative stress
• Heavy metal/chemical overload
• Fatty liver (early developement) and liver congestion
• Hyperthyroidism
• Lack of exercise or sedentary lifestyle
• Other conditions: obesity, Genetic predisposition, starvation, uremia

Associated Tests

• Total cholesterol, LDL, triglycerides, apolipoprotein A and apolipoprotein B, blood glucose, lipid electrophoresis, homocysteine, oxidata free radical test, RBC, HCT, and HGB