A high-density lipoprotein (HDL) test measures the level of good cholesterol in your blood. Cholesterol is a waxy substance that’s found in all of the cells in your body. … HDL is known as the good cholesterol because it carries LDL, triglycerides, and harmful fats and returns them to your liver for processing.
Also Known As: HDL, HDL-C, High-density Lipoprotein Cholesterol
Test Panel: Cholesterol, HDL Cholesterol, LDL Cholesterol, Triglycerides, VLDL Cholesterol, Non-High Density Lipoprotein Cholesterol
Why Get Tested:
- Advised to evaluate the coronary artery disease risk.
- This can be advised as the part of a lipid profile.
When to Get Tested:
- Screening: as part of a regular health exam with a lipid profile.
- when no risk factors for heart disease are present.
- once every four to six years in adults.
- children should have a lipid profile screening at least once between the ages of 9 and 11 and then again between the ages of 17 and 21.
Sample Required:
- This test is done on the serum.
- Fasting sample is preferred. Advised the patient to fast for 12 to 14 hours.
- This test can be done on plasma as well.
- Can store serum or plasma at 4 °C for 4 days (can keep for 5 to 7 days).
Normal Value:
- Male = 40 – 60 mg/dL
- Female = 40 – 60 mg/dL
Abnormal values of HDL:
- <25 mg/dl = Coronary heart disease risk is 2 times and this is a dangerous level.
- 26 to 35 mg/dl = The risk is 1.5 times. This is a high-risk group.
- 36 to 44 mg/dl = The risk is 1.2 times. This is a moderate risk group.
- 45 to 59 mg/dl = This is average risk group.
- Above 60 mg/dl = Below average risk group.
- Critical values:
- Male = less than 35 mg/dl.
- Female = less than 40 mg/dl.
Increased HDL-C value seen in:
- A chronic liver disease like cirrhosis, hepatitis, and alcoholism.
- Long-term vigorous exercises.
- Familial hyper- alpha-lipoproteinemia.
- The increased level may be due to some drugs.
- Estrogen therapy.
- Moderate intake of alcohol.
- Insulin therapy.
Decreased HDL-C values seen in:
- Poorly controlled diabetes
- Cholestasis.
- Chronic renal failure, uremia, and nephrotic syndrome.
- Hypertriglyceridemia.
- Familial hypo-alpha-lipoproteinemia.
- alpha and beta – lipoproteinemia.
- The decreased level may also be seen in some of the drugs.
- Steroids.
- Antihypertensive drugs.
- Diuretics.
- Beta-blockers.
- Thiazide.
Table showing the summary of characteristics of the lipoproteins
Characteristics | Chylomicron | HDL | LDL | VLDL |
PLasma appearance | Creamy layer, slightly turbid | Clear | Clear, or yellow-orange tint | Turbid to opaque |
Size (diameter nm) | >70.0 | 4 to 10 | 19.6 to 22.7 | 25 to 70 |
Electrophoretic mobility | Origin | α – region | β – region | Pre – β region |
Molecular weight | 0.4 to 30 x 109 | 3.6 x 109 | 2.75 x 109 | 5 to 10 x 109 |
Synthesized in (Tissue of origin) | Intestine | Intestine and liver | Intravascular | Liver and intestine |
Composition by weight in % | ||||
Cholesterol esterified | 5 | 38 | 49 | 11 to 14 |
Cholesterol unesterified | 2 | 10 | 13 | 5 to 8 |
Triglycerides | 84 | 9 | 11 | 44 to 60 |
Phospholipids | 7 | 22 | 27 | 20 to 23 |
Proteins | 2 | 21 | 23 | 4 to 11 |
Triglycerides | Markedly raised | Normal | Normal/ Raised | Moderately to Markedly raised |
Clinical significance of | Pancreatitis and acute abdomen | Decreased risk of CAD | Increased risk of CAD | Increased risk of CAD |
Functions | Transport dietary lipids to tissue | Carry cholesterol from tissue to liver | Carries cholesterol to tissue | Transport endogenous TG from liver to adipose tissue |
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