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Lipoprotein (a) is an atherogenic lipoprotein consisting of: apolipoprotein B-100 (apo-B-100) and the large glycoprotein apoliprotein (a) [apo (a)]. Apo (a) exists in several genetically determined isoforms. It is similar to plasminogen, which blocks its receptors and inhibits the processes of fibrinolysis, i.e. the dissolution of blood clots.
Lipoprotein (a)
The chemical structure of lipoprotein (a) is similar to that of bad cholesterol (LDL) and has strong atherogenic properties. It consists of apolipoprotein B, cholesterol and other lipids, and the specific protein apolipoprotein (a). Increased concentration of lipoprotein (a) is one of the risk factors for cardiovascular diseases and atherosclerosis. While this is genetic, the mode of inheritance has yet to be determined. The particle size of lipoprotein (a) is the same in a given individual, but varies from organism to organism due to the different genetically determined number of repeating subunits called kringels. The level of lipoprotein (a) in the blood serum does not fluctuate greatly during the day. It should be mentioned, however, that it is slightly lower in men and increases in postmenopausal women.
The lipoprotein test (a) is an invasive test in which blood is collected into a test tube.
Note:
In people of African descent, lipoprotein (a) molecules are larger.
When do we do the lipoprotein (a) test?
The lipoprotein test (a) is used for determination risk factors for cardiovascular disease. It is recommended to perform it especially in people with an increased risk of these diseases, with a family history. In addition to Lp (a) determination, other lipid tests are also performed. The test is also performed in patients with a family history of premature ischemic heart disease. The test is also recommended in patients suffering from cardiovascular diseases, especially in the presence of normal or slightly elevated lipid levels. In some cases, testing of lipoprotein (a) is recommended in postmenopausal women to determine whether the increase in Lp (a) is associated with a decrease in estrogen, or perhaps it is a factor that increases the risk of ischemic heart disease.
Lipoprotein (a) – study
Material for the study of lipoprotein (a): serum.
Preparation for the test: on an empty stomach (at least 8 hours).
The course of the lipoprotein test: one-time blood sampling from a vein in the arm; the skin at the site of collection should be decontaminated. Blood collection takes from a few to several seconds.
Time to wait for the result: 1 Day.
Standard: less than 150 mg / l.
Comments: Lipoprotein (a) is not routinely measured. It belongs to the risk factors for atherosclerosis, thrombosis, stroke and myocardial infarction. Its concentration increases in smokers. In order for the result to be reliable, it is necessary to properly prepare for the test.
The level of lipoprotein (a) in the body is genetically determined, therefore it does not fluctuate too much throughout life. It also does not respond to treatment and lifestyle changes. For this reason, doctors often choose to use more aggressive treatment.
Lipoprotein (a) testing should not be performed in the following cases:
- after a stroke,
- during a fever,
- during infection,
- within four weeks after a heart attack
- After the surgery,
- after drinking alcohol,
- in people who have lost significant body weight rapidly.
Lipoprotein (a) – interpretation of results
A standard reference range has not been established for lipoprotein (a) as it depends on several factors: population tested, sex, age and assay method. Thus, the numerical values may differ depending on the laboratory where the test was performed. In any case, it is recommended to discuss the test results with your doctor.
The increase in lipoprotein (a) concentration may be due to:
- familial hypercholesterolaemia,
- estrogen deficiency,
- uncontrolled diabetes
- estrogen deficiency,
- hypothyroidism,
- nephrotic syndrome,
- chronic renal failure.
Low levels of lipoprotein (a) are not a dangerous situation and many people have undetectable levels of Lp (a) in their blood.