Lipoprotein( a) in serum

Reference values ​​of lipoprotein( a) [LP( a)] in blood serum - 0-30 mg / dl.

LP( a) consists of apo( a), which is inherently a glycoprotein and covalently bound to apo-B100.LP( a) has a significant structural similarity with plasminogen. LP( a) is larger than LDL, but has a higher density in comparison with them and has electrophoretic mobility of pre-R-LP.On lipid composition, LP( a) does not differ from LDL, but protein in LP( a) is greater. LP( a) is synthesized in the liver. All modern immunochemical methods for determining LP( a) in fact reveal a protein - apo( a).

Increased concentration of serum lipoprotein( a) is a risk factor for the development of IHD.According to the literature, the average content of apo( a) in the blood of patients with ischemic heart disease is 12 mg / dl. In 2/3 of the patients, the development of atherosclerosis depends on the presence of elevated concentrations of lipoprotein( a) in the blood. A close correlation was found between the concentration of lipoprotein( a) in serum and the development of IHD.Epidemiological studies have shown that in individuals with normal cholesterol concentration, but with elevated lipoprotein( a)( above 30 mg / dL), the risk of developing CHD is at least 2 times higher. The risk increases by 8 times, if the concentrations of LDL and LP( a) are simultaneously increased. MI develops 4 times more often in young people, to which the content of apo( a) exceeds 48 mg / dl. In patients with obliterating atherosclerosis, the content of apo( a) is also increased.

The concentration of LP( a) in the blood increases after surgical operations, in patients with oncological diseases, with diabetes mellitus, acute phase of rheumatism.

The similarity of the structure of apo( a) and acute phase proteins allows us to consider it as a specific acute phase protein in destructive atherogenic processes in the vascular wall. Definition of LP( a) is an evaluation test of the activity of the atherosclerotic process. Its content in the blood correlates with the area of ​​atheromatous lesion of the aorta, the level of hyperglycemia, the time of blood clotting and markers of excretory excretory renal function. Arterial hypertension in atherosclerosis is often combined with an increase in the concentration of lipoprotein( a) in the blood.

The concentration of LP( a) in the blood is genetically determined, and at the present time there are no drugs that reduce it. In this regard, the only strategy for treating patients with elevated concentrations of LP( a) is to eliminate all other risk factors for IHD( smoking, overweight, hypertension, high LDL concentration).

The efficacy of the above research methods for diagnosing lipid status disorders is presented in the table.

Currently, there is a clear correlation between the concentration of total cholesterol in the blood and the mortality from cardiovascular diseases. When the cholesterol level in the blood is below 200 mg / dL( 5.2 mmol / L), the risk of developing atherosclerosis is the least. If the LDL-C concentration in the blood is below 100 mg / dL( 2.59 mmol / L), heart damage occurs very rarely. An increase in LDL-cholesterol above 100 mg / dl is noted when eating foods rich in animal fats and cholesterol. Improper nutrition, smoking and arterial hypertension

is synergistically acting factors that increase the risk of coronary heart disease. The combination of one of these factors with any other for about 10 years accelerates the development of a critical degree of coronary atherosclerosis. Reducing the concentration of total cholesterol in the blood and the increase in HDL-cholesterol reduces the rate of progression of atherosclerosis. Reducing the concentration of total cholesterol in the blood by 10% leads to a reduction in mortality from heart disease by 20% [Levine G. N. et al., 1995].An increase in HDL-CI concentration of 1 mg / dl( 0.03 mmol / L) reduces the risk of coronary pathology by 2-3% in men and women. In addition, regardless of the total content of cholesterol in the blood( including those exceeding 5.2 mmol / l), the inverse relationship between the content of HDL-C and the frequency of cardiac pathology remains. Concentrations of HDL-cholesterol( less than 1.3 mmol / L) and TG in the blood are independent prognostic indicators of the probability of death from ischemic heart disease [Bainey R., Spirov L., 2001].Therefore, the content of HDL-XC should be considered a more accurate prognostic indicator for mortality from coronary artery disease than the concentration of total cholesterol.

Table Effectiveness of laboratory tests for diagnosis of lipid status violations

Table Effectiveness of laboratory tests for diagnosis of lipid status violations

In clinical practice, the following aspects should be considered.

■ Reducing the concentration of LDL-C and increasing the concentration of HDL-cholesterol reduces the incidence of atherosclerosis.

■ The "total cholesterol / HDL-XC" ratio is normally 3.4, to 75-89 years, it rises to 4.7;the ratio 3.5 is considered optimal, and for 5 and more the risk of CHD is significantly increased.

■ The lipid profile is directly related to the dominance of testosterone in men and estrogens in women.

■ The concentration of LP( a) in the serum reflects the activity of the atherosclerotic process.

■ Excessive nutrition, obesity, smoking and low physical activity have an adverse effect on the lipid profile.

■ Correction of lipid abnormalities should include not only a decrease in the concentration of cholesterol, but also the normalization of the unfavorable lipid profile.

■ Weight loss and physical exercise increase the concentration of HDL in the blood, and LDL-XC and TG - reduce.

■ The development of atherosclerosis begins at a young age, so its manifestation at later stages of life can be prevented, leading a healthy lifestyle from a young age.

The optimal cholesterol-lipoprotein profile provides the following level of serum levels.

■ Total HS less than 200 mg / dL( 5.2 mmol / L).

■ HDL-XC - more than 50 mg / dl( 1.3 mmol / l).

■ LDL-C, less than 130 mg / dL( 3.4 mmol / L).

■ TG - less than 250 mg / dL( 2.3 mmol / L).