Lipoprotein A - what it is and how to reduce it at elevated rates
- Lipoprotein (a) - what is it?
- Causes of lipoprotein growth (a)
- Physiological characteristics
- Why does the body need lipoprotein (a)
- Lipoprotein test - what is it?
This mysterious lipoprotein (a) (LP (a)) does not exist in cholesterol (cholesterol) metabolism regimens. Why does the body need it? An unequivocal answer can not give anyone. And yet it is present in the blood.
On the one hand, lipoprotein (a) is a low-density cholesterol-free chop, it is also called “bad”, since a high content of LDL leads to atherosclerosis and its complications. On the other hand, it is a “relative” of beneficial plasminogen, which is involved in the softening and excretion of blood clots.
High LP (a) is a common cause of hereditary vascular pathologies that provoke heart attacks and strokes . At the same time, this indicator for long-livers who have stepped over a 100-year milestone is consistently high.
Should I deal with him to clarify all the details? When calculating cholesterol, we take into account lipoprotein (a). What we call our low-density lipoprotein values is actually the sum of the LDL cholesterol and the LP (a). How to correctly decipher the result of the lipid profile?
Lipoprotein (a) - what is it?
A dangerous relative of “harmful” cholesterol is actually LDL, only with the appendage. Glycoprotein, Apo (a) is an alipoprotein (a) associated with Apo B alipoprotein, which is also present in the LDL complex. In its composition - cholesterol, triglycerol, phospholipids, Apo B, alipoprotein Apo (a).
It is produced in LP (a) in the liver when LDL and Apo (a) are combined with a disulfide bond of the covalent type. Compared with other types of LP, catabolism of such lipoproteins occurs in the kidneys.
The plasma value of lipoprotein (a) is associated with Apo (a): the smaller the aliproprotein (a), the higher the LP (a), it is determined by the genes encoding Apo (a). The content of lipoprotein (a) varies from <0.1 to> 200 mg / dL. For lipoprotein (a) the norm is up to 14 mg / dl.
AT lipoprotein composition (a) there is also LDL cholesterol together with its main alipoprotein B. These components have little effect on the content of LP (a) (only 10%). 90% of this indicator determines the genes, and it is associated with the rate of formation of Apo (a). Since infancy, the indicator LP (a) is constantly growing, reaching a maximum in adulthood. Then this figure remains unchanged, with the exception of women in the postmenopausal period, when they see another increase in its concentration.
When compared with other risk conditions, the danger of a high lipoprotein (a) is not associated with either sex or age. It does not depend on diet and living conditions. But the prerequisites affecting the level of lipoprotein (a) are still defined.
Causes of lipoprotein growth (a)
The lipoprotein catabolism (a) is carried out in the kidneys, therefore, lipoprotein (a) is significantly increased in the following conditions:
- Renal failure;
- Everyone on hemodialysis;
- Nephropathy in diabetics;
- Persons with nephrotic syndrome.
According to the results of tests in volunteers with the last disease on this list, the lipoprotein index (a) was 69.1 mg / dl. When compared with analyzes of healthy participants (18.2 mg / dL), it can be concluded that the rate is exceeded several times. During remission, patients had a decrease in the level to 8.9 mmol / l.
With a change in catabolism, the values of lipoprotein (a) reach 100 mg / dl, and when the rate of glomerular filtration falls below 70 ml / min. this figure may be even higher.
An increase in the values of lipoproteins (a) is actually related to renal dysfunction, but there are cases when renal pathologies developed against the background of already high LP (a). Doctors associate this phenomenon with hereditary predisposition.
Long-term observations of an objective picture of the physiology of lipoprotein (a) did not reveal. It has been reliably established that, as a component of LDL and a “relative” of plasminogen, it participates in the coagulation and metabolism of cholesterol and triglycerol.
In this regard, lipoprotein (a) actually provokes cardiovascular diseases (CVD) and stimulates the formation of blood clots. In blood clots (plaques), lipoproteins (a) involved in thrombus formation were detected. The American Heart Association, the authoritative association of cardiologists, claims that high lipoproteins (a) increase the risk of fatal coronary thrombosis by up to 70%.
- Atherogenic capabilities enhance the transport effect of oxidized phospholipids.
- An indicator of 26 mg / dl provokes the formation of blood clots.
- LP (a) is a plasminogen inhibitor that breaks down fibrin, dissolving blood clots.
- Lipoprotein (a) can overcome the barrier of the spine, falling into the cerebrospinal fluid, it has a negative effect on the central nervous system.
Most scientists adhere to the concept that a high plasma lipoprotein index (a) increases the risk of CVD, especially for men. But long-term observations of 32 thousand women confirmed that a high lipoprotein index (a) increases the CVD statistics by a factor of 2.
In the process of aging of the body, the relationship between the values of this component and cardiorisc decreases: in the elderly, this factor is already associated with longevity, and for the elderly after 65 years, there is no sense in determining it. One person out of 10,000 lives to the centenary milestone in the world, so it’s not worth counting on this criterion.
In diabetes mellitus (DM), the values of lipoprotein (a) in the analyzes are often elevated, but the relationship between the nature of diabetes and lipoprotein (a) is not established above the norm. Only the fact of increasing the likelihood of retinopathy in type 2 diabetes and lipoproteins (a) above normal is proved. In insulin-dependent diabetics, with liposuction (a) values of 36 mg / dL, the risk of death increases.
In a prospective experiment, 186 children under the age of 12 years took part, it was revealed that lipoproteins (a)> 30 mg / dl increase the likelihood of venous thromboembolism as early as childhood. Elevated results of lipoprotein analysis (a) are noted primarily in children with excess body weight.
Why does the body need lipoprotein (a)
Vital indispensable this type of lipoprotein is not. People with little content of it do not observe obvious ailments. Lipoprotein values (a) can change up to 1000 times. It is believed that it improves wound healing, helps restore tissue and blood vessels.
Experiments have shown that Apo (a) contributes to the reduction of the primary tumor. By blocking its development, it increases the survival of experimental animals with primary human malignant neoplasms.
A high lipoprotein (a) (> 30 mg / dL) predicts an increase in CVD, especially at high (from 60 mg / dL) LDL-C. The experiments, in which 1486 eighteen-year-old boys participated, showed that parents of young people with a plasma level of 25 mg / dL had a heart attack 2.5 times more often than those with whom this indicator was normal.
In another experiment, lipoproteins (a) were studied in males 40-50 years old as a predictor of mortality, not associated with other risk factors. This indicator also depends on race: in people with white skin, it is higher than in blacks. 14 mg / dl is considered to be the norm for men, and 15 mg / dl for women.
Values above 30 mg / dL are elevated. Such an indicator, according to large-scale studies, is in 25% of US citizens.
In hypercholesterolemia, it is important to determine not only the lipoprotein data (a), but also the size of the particles themselves, which genetically determines the degree of cardiac risk.
Lipoprotein test - what is it?
To determine a competent and economically viable course of treatment with high levels of LDL cholesterol and Apo B, it is important to clarify the role of the genetically determined growth of lipoprotein (a) and apo (a) in the analyzes.
Since lipoprotein (a) is a familial risk factor for coronary conditions, CVD, stroke, it is imperative to check them:
Patients with early CVD history.
Patients with a familial predisposition (there are many cases of CVD in the case history of the next of kin).
- Persons diagnosed with CVD without the risk factors listed;
- For cholesterolemia, which is not amenable to treatment with statins;
- Patients with renal diagnoses;
- Anyone who has been prescribed angioplasty or coronary artery bypass surgery;
- With diabetes of any kind;
- Children with thromboembolism.
With lipid analysis are guided by reference indicators:
- <14 mg / dL - normal;
- 14-30 mg / dl - borderline condition;
- 31-50 mg / dL - high level;
- > 50 mg / dL is a very high degree of risk.
And in conclusion - the main question on lipoprotein a: how to reduce high levels of lipoprotein (a)? Due to the fact that its content is laid at the genetic level, a special diet, weight correction, lifestyle changes, statin therapy cannot lower the concentration of the drug (a).
Some results were recorded with the use of nicotinic acid and hormone replacement treatment, but this information requires confirmation. There are no drugs to reduce the concentration of lipoprotein (a), and it is not known whether the decrease in its concentration leads to a real decrease in cardiac risk.