What is normal ast in the blood? Intracellular enzyme ast in biochemical blood analysis. The structure of the liver and its functions

A biochemical blood test, deciphering AST and ALT allow us to assess the condition of internal organs, heart muscle and liver. AST (AcAt) and ALT (AlAT) are transaminases, enzymes that serve to transport amino acids. AST and ALT are found in healthy and intact cells of internal organs, especially in the liver, skeletal muscles and heart muscle. If these cells are destroyed as a result of illness, the enzymes enter the blood. This is how a biochemical blood test allows you to detect pathological changes in the functioning of internal organs. Which doctor prescribes AST and ALT blood tests?

1. Gynecologist to monitor the course of pregnancy.
2. Endocrinologist, for hyperthyroidism.
3. Gastroenterologist, to monitor the condition of the liver and pancreas.
4. Cardiologist, to examine the heart.
5. Nephrologist when it is necessary to evaluate the condition of the kidneys.

Women are tested for liver enzymes once during a normal pregnancy. If there are indications, for example, chronic liver disease, blood tests may be performed more often. A biochemical blood test for liver enzymes takes into account not only AST and ALT, but also other substances:

• bilirubin;
• alkaline phosphatase;
• lactate dehydrogenase;
• creatine kinase;
• gamma glutamyl transferase.

Assessing the volume of a number of enzymes makes the study more reliable.

1 Biochemical composition of blood

The biochemical composition of blood in a healthy person is sensitive to any changes in the functioning of internal organs. Therefore, a blood test is very informative and allows you to detect diseases in the early stages, when there are no obvious symptoms. In what cases is an AST and ALT test prescribed?

1. For gestosis in pregnant women. Preeclampsia is a serious complication during pregnancy that jeopardizes carrying a fetus to term. Preeclampsia is characterized by increased blood pressure, debilitating nausea and uncontrollable vomiting, headaches and abdominal pain. Analyzes of women with gestosis show an increase in AST and ALT tens and even hundreds of times.
2. Hepatitis. Viral and alcoholic hepatitis destroy liver cells, causing enzymes to be released into the blood. A blood test detects the presence of hepatitis before jaundice begins. In acute viral hepatitis, AST monitoring results show an increase to 500-3000 conventional units per liter of blood (U/l). After infection with the hepatitis virus, AST and ALT levels increase and reach peak values ​​after 2-3 weeks. In severe cirrhosis, tests show AST and ALT much lower than normal. In addition to hepatitis, using blood biochemistry you can determine mononucleosis, cancer and other liver tumors.
3. Heart diseases. Changes in the levels of AST and ALT are especially obvious during myocardial infarction. 6 hours after the attack, the volume of enzymes circulating in the blood begins to increase, peak values ​​are reached after 48 hours, and within 6-8 days the enzyme levels return to normal. This dynamics is used to assess damage to the heart muscle during coronary artery disease, myocardial infarction, myocarditis and pericarditis.
4. Other diseases. The level of AST and ALT increases with massive hemorrhages, burns, skeletal muscle injuries, hemolytic anemia and pulmonary infarction. As a result of hypoxia, pain or mental shock, the level of ALT and AST can be increased hundreds of times relative to normal.

Changes in the biochemical composition of the blood make it possible to assess the severity of damage to internal organs, especially the liver and heart.

In pregnant women, this study makes it possible to detect gestosis and suggest what complications from the heart and liver may arise during pregnancy and childbirth. If the results of the test for AST and ALT are unfavorable, women are placed on a separate register and regular additional studies are prescribed to monitor their condition and bring the pregnancy to a successful birth.

What is the norm for ALT and AST tests in women and men? About it .

2 How to prepare for the procedure

In order for the tests to show the real situation, you need to follow the rules for preparing for blood donation:

1. 1 week before the test, you should not consume alcohol or drugs, since any intoxication affects the volume of enzymes.
2. In 2-3 days you need to limit stress, anxiety and conflict situations.
3. 2-3 days before donating blood, you need to avoid intense physical work, sports training, jogging, and weight lifting. This limitation is due to the fact that microtraumas to skeletal muscles can give a false increase in AST and ALT.
4. Stop eating 10 hours before blood sampling. Usually the analysis is carried out in the morning, so it is not advisable to have breakfast, especially sweets. You can drink plain water, but you cannot drink strong coffee, tea, or energy drinks.
5. If the patient takes any medications on an ongoing basis, be sure to inform your doctor about this. There is no need to stop taking medications unless necessary, but medication information will be taken into account when interpreting the results. A blood test, interpreted by the attending physician, will be informative only if the results are interpreted correctly. The decoding should be done by a doctor, since only he is aware of the entire clinical picture and can take into account all the factors that affect the level of ALT and AST in the blood.

The results of the analysis are affected by acetylsalicylic acid, which is part of Aspirin and some other painkillers.

Paracetamol, which is found in the drug Paracetamol and many non-steroidal anti-inflammatory drugs, may also have an effect. The analysis data is especially affected by the intake of vitamin B6, so the doctor must be aware of all medications that the patient takes.

3 Effect on enzymes

In a healthy adult, fluctuations in ALT and AST in the blood during the day are acceptable within 10-30% of the norm. What affects the volume of enzymes?

• pregnancy in the 1st trimester;
• consumption of alcohol and drugs;
• chronic diseases of the liver, kidneys, pancreas and thyroid glands, heart and blood vessels, skeletal muscles;
• taking medications, vitamins, hormonal contraceptives;
• physical activity and overwork, intense sports training;
• mental stress, shock, stress, chronic lack of sleep, nervous overstrain.

Typically, test results are presented in units per liter (U/L), but some laboratories may use other measurement systems. When transferring from one system to another, you need to take into account the rules for converting units in order to obtain correct results. AST and ALT in the blood, normal for adults:

• for men - 39-41 U/l;
• for women - 29-31 U/l.

For pregnant women in the 1st trimester, the indicator may differ from the norm by 5-10% in favor of an increase or decrease. This is not a pathology and does not indicate any serious illness. Fluctuations in the level of AST and ALT are due to the fact that fetal development requires a large amount of vitamin B6, which is involved in the synthesis of transaminase.

When there is not enough vitamin B6, the body takes it from liver and muscle cells, so enzymes are released into the blood. In order to compensate for the increased load on the body that pregnancy gives, special vitamin complexes are prescribed for women. If after the 1st trimester the AST and ALT levels are still higher or lower than normal, the gynecologist suspects gestosis and prescribes additional studies to clarify the clinical picture. In a normal pregnancy in the 2nd-3rd trimester, the enzyme level should be from 29 to 31 U/l. This allows us to conclude that a woman’s liver, heart and kidneys do an excellent job of maintaining pregnancy.

4 De Ritis Index

For diagnosis, not only the absolute values ​​of AST and ALT are important, but also their ratio. The de Ritis index is designated DRr. This is the coefficient that is obtained if the AST values ​​are divided by the ALT values. Normally, DRr should be equal to 1.3. Fluctuations in a healthy person up or down are 0.42. How to interpret test results if the de Ritis index does not coincide with the norm?

• if DRr is more than 1.3, hepatitis can be assumed;
• if DRr is less than 1, dystrophic changes occur in the liver;
• if DRr is more than 2, cirrhosis or myocardial infarction can be assumed.

It should be understood that tests for AST and ALT are not used in isolation, but in combination with other studies. When examining the liver, the following are used:

• general clinical blood and urine tests;
• blood test for cholesterol;
• blood test for liver enzymes (including AST and ALT);
• Ultrasound of the liver, gallbladder and bile ducts.

Enzymes tend to decay; for ALT and AST, the half-life is 12-24 hours, so when monitoring the patient’s condition, tests are carried out no more than once every 2 days. To diagnose heart disease, in addition to a biochemical blood test, an ECG is required.

5 Pathological processes

In pregnant women, tests often show decreased levels of liver enzymes. If the decrease is more than 10%, you need to undergo a full liver examination, be tested for hepatitis, and rule out cirrhosis. Liver diseases can occur without symptoms as long as the body manages to compensate for the breakdown of liver cells. After which jaundice and liver failure begin. The benefit of ALT and AST tests is that they detect pathological processes in the liver even before adverse symptoms appear. The most common reason for a decrease in ALT and AST in the blood of pregnant women is an acute lack of vitamin B6. You can also suspect this violation based on the following signs:

About AST and ALT blood tests

Biochemical blood test for ALT, ALAT, AST in women, men: what is it, the norm

Pregnant women consume much more B6 than any other person. In the usual case, no special food supplements are required to obtain this vitamin, but in women during pregnancy, even good nutrition may not cover the costs that go into the formation of the fetus. In the following cases, B6 injections are prescribed for pregnant women:

• if tests for liver enzymes (AST, ALT and others) differ from the norm;
• if there is hepatitis, cirrhosis, HIV, in some cases - with heart disease;
• if toxicosis is severe during pregnancy, gestosis develops;
• if a woman is taking antidepressants or steroid drugs for another disease.

Only the attending physician should select the dosage and duration of the B6 course. In most pregnant women, a decrease in ALT and AST levels requires vitamin therapy.

If tests show an increased release of enzymes into the blood, additional research must be carried out in order to establish the cause of this disorder. Therapy for liver diseases is selected by a gastroenterologist or a more specialized specialist in pathologies of the liver, gallbladder and bile ducts - a hepatologist. Heart diseases, which often lead to increased AST and ALT, are treated by a cardiologist.

A biochemical blood test is an important study that allows us to evaluate the functional state of organs and systems of the human body by analyzing various microelements in the blood. Below are the components of a biochemical blood test used in the diagnosis of viral hepatitis.

Alanine aminotransferase (ALT, ALT, ALT) is an enzyme contained in tissues in the liver and released into the blood when it is damaged. Elevated ALT levels can be caused by viral, toxic or other liver damage. With viral hepatitis, ALT levels can fluctuate over time from normal values ​​to several normal values, so this enzyme must be monitored every 3-6 months. It is generally accepted that the ALT level reflects the degree of hepatitis activity, but about 20% of patients with chronic viral hepatitis (CVH) with a consistently normal ALT level have serious liver damage. It can be added that ALT is a sensitive and accurate test for the early diagnosis of acute hepatitis.

Blood test AST - astspartate aminotransferase (AST, AST) is an enzyme contained in the tissues of the heart, liver, skeletal muscle, nervous tissue and kidneys and other organs. An increase in AST in a blood test together with ALT in patients with chronic hepatitis may indicate liver cell necrosis. When diagnosing chronic hepatitis, special attention should be paid to the AST/ALT ratio, called the de Ritis ratio. An excess of AST over ALT in a blood test in patients with chronic hepatitis may indicate severe liver fibrosis or toxic (drug or alcohol) liver damage. If AST in the analysis is significantly increased, then this indicates necrosis of hepatocytes, accompanied by the breakdown of cellular organelles.

Bilirubin is one of the main components of bile. Formed as a result of the breakdown of hemoglobin, myoglobin and cytochromes in the cells of the reticuloendothelial system, spleen and liver. Total bilirubin includes direct (conjugated, bound) and indirect (unconjugated, free) bilirubin. It is believed that the increase in bilirubin in the blood (hyperbilirubinemia) due to the direct fraction (more than 80% of total bilirubin is direct bilirubin) is of hepatic origin. This situation is typical for chronic hepatitis. This may also be due to impaired excretion of direct bilirubin due to cytolysis of hepatocytes. An increase in concentration due to free bilirubin in the blood may indicate extensive damage to the liver parenchyma. Another reason may be a congenital pathology - Gilbert's syndrome. Also, the concentration of bilirubin (bilirubinemia) in the blood may increase when the outflow of bile is obstructed (blockage of the bile ducts). During antiviral therapy for hepatitis, an increase in bilirubin can be caused by an increase in the intensity of hemolysis of red blood cells. With hyperbilirubinemia above 30 µmol/l, jaundice appears, which is manifested by yellowing of the skin and sclera of the eyes, as well as darkening of the urine (urine takes on the color of dark beer).

Gamma-glutamyl transpeptidase (GGT, GGTP) is an enzyme whose activity increases in diseases of the hepatobiliary system (a marker of cholestasis). Used in the diagnosis of obstructive jaundice, cholangitis and cholecystitis. GGT is also used as an indicator of toxic liver damage caused by alcohol and hepatotoxic drugs. GGT is assessed together with ALT and alkaline phosphatase. This enzyme is found in the liver, pancreas, and kidneys. It is more sensitive to disorders in liver tissue than ALT, AST, alkaline phosphatase, etc. It is especially sensitive to long-term alcohol abuse. At least five processes in the liver increase its activity: cytolysis, cholestasis, alcohol intoxication, tumor growth, drug damage. In chronic hepatitis, a persistent increase in GGTP indicates either a severe process in the liver (cirrhosis) or a toxic effect.

Alkaline phosphatase (ALP, AR, Alkaline phosphatase, ALP, ALKP) is used to diagnose liver diseases accompanied by cholestasis. A combined increase in alkaline phosphatase and GGT may indicate pathology of the biliary tract, cholelithiasis, or impaired bile outflow. This enzyme is located in the epithelium of the bile ducts, so an increase in its activity indicates cholestasis of any origin (intra- and extrahepatic). An isolated increase in alkaline phosphatase levels is an unfavorable prognostic sign and may indicate the development of hepatocellular carcinoma.

Glucose is used in the diagnosis of diabetes mellitus, endocrine diseases, and pancreatic diseases.

Ferritin indicates iron reserves in the body. An increase in ferritin in chronic hepatitis may indicate liver pathology. An increase in ferritin levels may be a factor that reduces the effectiveness of antiviral therapy.

Albumin is the main blood plasma protein synthesized in the liver. A decrease in its level may indicate liver pathology caused by acute and chronic diseases. A decrease in the amount of albumin indicates severe liver damage with a decrease in its protein synthetic function, which occurs already at the stage of liver cirrhosis.

Total protein (Protein total) - the total concentration of proteins (albumin and globulins) found in the blood serum. A strong decrease in total protein in the analysis may indicate insufficiency of liver function.

Protein fractions are protein components contained in the blood. There are quite a large number of protein fractions, but for patients with chronic hepatitis, special attention should be paid to five main ones: albumins, alpha1-globulins, alpha2-globulins, beta-globulins and gamma globulins. A decrease in albumin may indicate liver and kidney pathology. An increase in each of the globulins may indicate various disorders in the liver.

Creatinine is the result of protein metabolism in the liver. Creatinine is excreted by the kidneys in the urine. An increase in creatinine levels in the blood may indicate a disruption in the normal functioning of the kidneys. The test is done before antiviral therapy to assess its safety.

Thymol test (TT) has recently been used less and less in the diagnosis of chronic hepatitis. An increase in the TP value indicates dysproteinemia, characteristic of chronic liver damage, and the severity of mesenchymal-inflammatory changes in the organ.

Before prescribing treatment for any disease, it is first necessary to conduct a complete examination of the body in order to make the correct diagnosis. A general and biochemical blood test, which includes examinations for ALT and AST, will help you do this. Currently, medicine has such an indicator as the norm of ALT and AST in the blood. If it is elevated, it means that the person has a certain disease. But before you look for the reasons why the levels of ALT and AST, or one of the two indicators, are elevated, and also look for methods of treatment, you need to find out in more detail what it is.

Many cells of living organisms contain aminotransferases, which used to be called transaminases. They can be found both in the simplest unicellular organisms and in multicellular ones. Each such aminotransferase has functions unique to it that cells are able to tolerate (this also applies to amino acids, which each has its own). There are the following groups of aminotransferases:

• Aspartate aminotransferase (AST, AST) is a certain enzyme capable of transferring aspartate amino acids from biomolecules.
• Alanine aminotransferase (ALT, AlAT) is an enzyme that transfers the amino acid alanine into biomolecules.

The maximum activity of ALT and AST is observed in the human body in the kidneys, muscle tissue, heart and liver. The highest activity of ALT can be noted in the pancreas. Important: since each group of aminotransferases is located in a specific organ, if it is damaged, it easily enters the bloodstream. Thanks to this property of the enzyme AlAT and AST, it is possible to determine the presence of diseases that occur latently in the body. If, after taking blood in a biochemical analysis, ALT and AST are increased, this means that the patient suffers from hepatitis, pancreatitis, myocardial infarction, or some kind of injury has occurred in the body.

What does increased performance mean?

Since the level of AST and ALT in each internal organ differs, elevated levels indicate its disease.

The main part of the ALT enzyme is found in the liver, heart muscle, kidneys and pancreas. With pathologies of these organs, ALT enters the blood, which causes a strong increase in this enzyme during analysis.

Most of the AST enzyme is found in the myocardium, nerve and muscle tissues, and liver. Damage to any of the above organs will cause the level of AST in the blood to increase.

The level of ALT and AST in the blood directly depends on the functioning of the liver, which is responsible for the following functions:

• Protein synthesis in the body;
• Removal of toxic substances and poison in case of poisoning;
• Creation of biochemical substances;
• Storage of glycogen, which is responsible for the vital activity and normal functioning of the body;
• Regulation of biochemical reactions.

What indicators are considered normal for AST and ALT?

A biochemical blood test helps to identify dangerous diseases that occur latently in the body at an “early stage.” Often, an increase in ALT means and indicates a dysfunction of the liver, while an increased AST rate reflects a malfunction of the heart. But which indicators are considered normal and which are abnormal, so that it can be argued that high or low levels of ALT and AST are a sign of a dangerous progressive disease.

Normal and acceptable levels of ALT and AST depend on gender, so they will vary significantly between men, women and children.

• In adult women, ALT and AST levels should be less than 31 U/L.
• In adult men, the AST norm in the blood should be less than 47 U/L, and the ALT norm should not be higher than 45 U/L.
• As children constantly grow, their ALT and AST levels change. In this case, the ALT level in children should be below 50 U/l, while the AST level in children in the first 5 days of life reaches 140 U/l. After 5 days and until the age of nine, the AST level in children should be below 55 U/l.

For the convenience of determining the level of ALT and AST, a table has been developed that reflects all indicators depending on the patient’s gender:

ALT and AST levels in children, men and women

Since the level of AST and ALT may vary depending on the modernity of the equipment used to perform the biochemical analysis, a table was developed that reflects the normal values ​​​​and degrees of deviation of enzymes present in the blood:

If the AST and ALT values ​​in the biochemical analysis are greatly increased, the patient can be diagnosed with liver pathologies. This phenomenon is often observed with hidden hepatitis and other dangerous diseases.

If a biochemical analysis showed that the AST level is increased several times, this means the presence of a myocardial infarction in the body. If AST was initially elevated and then decreased 4 days later, it means there was no heart attack.

Reasons for changes in indicator levels

After deciphering the biochemistry analysis, it was noticed that certain diseases affect the decrease in ALT, but this has nothing to do with liver functionality. A decrease in ALT can be caused by genitourinary infections, alcoholic hepatitis, tumor neoplasms, frequent alcohol consumption, and lack of vitamin B6 due to poor diet.

The main reasons why analysis rates in men, children and women are increased are:

• Myocardial infarction;
• Hepatitis;
• Forms of pancreatitis;
• Liver pathologies caused by drugs, alcohol or a viral infection;
• Taking steroids;
• The body's reaction to medications;
• Metastases in the liver;
• Fatty hepatosis;
• Burns and injuries where damage to muscles and muscle tissue occurs.

It is worth knowing that a decrease in the level of these enzymes occurs independently, after the underlying disease is cured.

The first symptoms indicating an increase in AST and ALT:

• Nervousness and depression;
• Poor sleep;
• Decreased appetite, which causes weight loss;
• General weakness of the body.

Late symptoms that enzyme levels are elevated include:

• Changed color of urine, which becomes darker;
• Discolored stool;
• The whites of the eyes and skin become yellowish;
• Nausea and feeling unwell;
• Swelling of the limbs.

Additional diagnostic measures to determine the presence of hidden diseases:

• Blood test for hepatitis B and C;
• Ultrasound of the abdominal organs;
• Clinical blood test;
• Liver biopsy;
• Donating blood for thyroid hormones.

Treatment

If the level of AST and ALT in children, men and women is elevated, it means there is some disease in the body. To lower the levels of these enzymes, you first need to get rid of the source of the disease, which caused their increase.

First of all, you need to properly organize your diet, which should be of high quality and healthy:

• You need to eat plenty of fresh fruits and vegetables because these foods contain fiber. This also includes brown rice, which has the same properties.
• Green and medicinal teas containing burdock, dandelion or milk thistle will help cleanse the liver and restore the body's water balance.
• It is important to consume foods containing large amounts of vitamin C. For example, Revit vitamins contain a whole range of useful substances.
• The drinking regime should be observed.
• It is necessary to take a cool shower.
• Breathing exercises, as well as morning exercises or sports - all this helps to defeat the disease, and therefore reduce the level of AST and ALT in the blood.

Since ALT levels are often elevated in liver pathologies, the doctor must also prescribe medications that will help protect hepatocytes from the effects of other harmful factors. These drugs are collectively called hematoprotectors.

The doctor will also note that the liver during illness in children, men and women is greatly weakened, which means it cannot be exposed to unnecessary risk, as the organ will be damaged even more.

AST blood test allows you to find out many features of the human body. Based on such an examination, one can safely talk about the state of health of the whole organism, as well as the possible development of pathologies. An AST blood test helps make more accurate diagnoses and prescribe the necessary treatments. So, AST – what is it?

What is this?

AST analysis helps determine the presence in the cells of the body of a special enzyme that promotes complete catalysis, as a result of which oxaloacetate becomes safe aspart.

The AST compound can be found in various tissues of the body, namely:

• renal;
• hepatic;
• cardiac.

Also, molecules of this composition can penetrate into the structure of striated skeletal muscles and nerves. The AST enzyme complex (AST) is indispensable for amino acid metabolism.

Thanks to this compound, the transport of amino groups from aspartic acids to alpha-ketoglutaric acids is significantly accelerated. As a result of this transfer, a certain amount of glutamic and oxaloacetic acids is formed. To carry out transamination, a special coenzyme is required, which is a derivative of vitamin B6 - pyridoxal phosphate. The AST compound found in the body helps in detecting many liver diseases.

Scientists have discovered this enzyme not only in the abdominal organs, but also in:

• lungs;
• spleen;
• pancreas.

AST is active differently in different organs and tissues of the body. Thus, this substance is more active in the myocardium compared to blood serum. This enzyme complex is more active in women than in the male body. The condition of “myocardial infarction” is accompanied by an increase in the AST content in the blood several times.

Aspartate aminotransferase, another name for AST, helps to identify the performance of liver and heart cells, since the content of this enzyme is maximum here. Thanks to a recently discovered pattern, AST analysis helps determine existing disorders in the functioning of cardiac tissue, as well as liver cells.

To date, this enzyme has at least two different isoforms. One of them is mitochondrial, and the other is cytoplasmic. Mitochondrial structures are formed with the help of mitochondria (organelles that supply energy to cells), and cytoplasmic ASTs are formed in the cytoplasm. If cytoplasmic ASTs are detected in the cells, it means that the process of moderate tissue destruction has begun. If a significant amount of mitochondrial elements are detected in the cells of the liver or heart, we can safely speak of a severe degree of damage to the tissues of these organs. By the way, it is much more difficult for mitochondrial AST to penetrate the cell, since they first need to destroy the mitochondrial membrane, and then the cell membrane.

In the case of a sharp increase in the content of AST in cells, one can safely judge possible necrosis of the heart or liver. This parameter helps doctors make an initial diagnosis.

When is this analysis necessary?

AST analysis (AST) is prescribed to patients of certain categories. With its help, it is easier to identify the cause of the deterioration of the patient’s well-being and more accurately determine the necessary treatment tactics.

Biochemical blood test ASAT is required in the following cases:

• With systematic or binge use of alcohol or drugs.
• If taking medications causes damage to heart tissue. Such drugs can be various antidepressants, antiviral drugs, monoclonal antibodies, drugs for diabetics, anti-cancer drugs. The use of all these medications must be accompanied by consultation with the attending physician.
• Taking medications that have a destructive effect on liver cells. This study will help identify such exposure and stop it.
• Early diagnosis of viral hepatitis for patients who have come into contact with carriers of this pathology or patients. Appropriate blood tests will help reveal this information.

• For burns or various diseases of skeletal muscles. The biochemical blood test AST helps to detect increased levels of various isoforms of this enzyme complex in the blood.
• AST biochemical analysis is indispensable for various pathologies that disrupt the functioning of the heart muscles and the heart itself.
• Timely monitoring, as well as determining the success of ridding the body of liver diseases.
• Any suspicion of disturbances in the functioning of liver cells associated with damage to them by various pathologies. Among such diseases, the largest percentage is cirrhosis (viral hepatitis), as well as hepatic colic.

Timely analysis of AST allows not only to determine the degree of damage to organ tissue, but also helps in choosing the correct treatment model.

Rules for preparing for analysis

Like any other test, you need to prepare a little for the ASAT test. Although the rules for such preparation are very simple, following them will help in obtaining the most reliable results about the state of functionality of many vital organs, namely the heart and liver.

Usually the doctor warns the patient about the possibility of undergoing this test.

This is done to ensure that the patient does not abuse the following:

• overeating;
• alcoholic drinks;
• smoking;

• taking certain medications.

Blood must be donated on an empty stomach, preferably in the first half of the day. This routine is also more preferable for the patients themselves, who do not need to spend the whole day hungry on the day of the test. Typically, such people come to the appropriate laboratories before lunch break, where they hand over their biomaterial for study.

Long preliminary fasting before taking this test is also undesirable. You should fast from eight to fourteen hours with periodic drinking of water.

About the results

Blood biochemistry through AST analysis, depending on the diseases present in the body, can give different results. There are certain values ​​of the obtained parameters that correspond to the readings of a healthy person.

Thus, the normal values ​​of AST levels in the body are:

• newborns (from 22 to 70 U/l);
• children under 1 year (from 15 to 60 U/l);
• teenagers (from 6 to 40 U/l);
• persons aged from 15 to 65 (female body - from 3 to 40 U/l, male body - from 5 to 50 U/l);
• from the age of 65, the amount of this enzyme in the male and female body becomes the same and is measured in the range from 3 to 40 U/l.

To determine the amount of this enzyme, various laboratories use their own reagents, on the basis of which they determine their own normal values ​​​​of this compound in the blood. Aspartic transaminases may change in content in the presence of certain factors.

What affects the amount of enzyme in the blood?

The activity of this enzyme is directly dependent on certain factors. Thus, the presence of certain diseases can lead to both an increase in the level of AST in the blood and a decrease in it.

Increasing factors for AST levels are:

• drug poisoning;
• damage to liver cells;
• all manifestations of hepatitis infection;
• cancerous damage to liver cells;
• cirrhosis.

Also, various diseases and conditions can lead to changes in AST levels, namely:

• necrosis;
• burns of large areas of the body;
• heart attack condition;
• heart failure;
• pancreatitis.

AST plays an important role in the cells of the whole body, therefore a change in its value by deviation from the norm is the most important diagnostic indicator of health. The process of normalizing the amount of this enzyme is carried out at an automatic level, as a result of eliminating the harmful effects of the pathology existing in the body on the cells of the affected organ.

Timely drug intervention in combination with adequate therapy leads to a change in the existing AST indicator to a normal value. This usually takes at least one month.

A lack of vitamin B6 in the body can be one of the reasons for low levels of AST in the blood, so it is necessary to take care of the regular intake of this compound in the body.

To clarify the diagnosis of the disease, various laboratory tests are used. The main ones include a biochemical blood test, in which special attention is paid to Ast and Alt - these are enzymes that act intracellularly. They are found in the blood of any person. An increase indicates a pathological process in the body of various localizations: liver, heart, kidneys, lungs, brain, etc.

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Blood chemistry

Using a biochemical blood test, specific enzymes are determined that constantly circulate in the blood and enter the blood when cells are destroyed. Biochemical data fit into four main syndromes:

1. 1. Cytolytic - increase in aminotransferases, serum iron, vitamin B6.
2. 2. Parenchymal-inflammatory - increased ESR, changes in globulin fractions of blood proteins.
3. 3. Cholestatic - increase in total and direct bilirubin, cholesterol, fatty acids.
4. 4. Hepatic cellular failure - the concentration of indirect bilirubin and blood proteins increases, especially the albumin content.

The most frequently detected change in a patient's biochemical blood test is an increase in transaminase levels.



Aspartate aminotransferase is elevated, what does this mean?

AlAT and AsAT

These are enzymes that take part in the synthesis of amino acids - very important structural elements of protein.

There are two types of aminotransferases:

• Aspartic - transfers the amino group from aspartic amino acid to ketoglutaric amino acid.
• Alanine, transfers the ammonia residue from alanine to keto acid.





Alanine aminotransferase

Mainly found inside cells in the following organs: liver, skeletal muscles, heart, pancreas, spleen, lungs. But the highest concentration of Alt is found in the liver.



An increase in enzyme activity is considered hyperenzymemia:

• Moderate: increase in concentration by 5 times;
• Medium: up to 9 times;
• High: increase in activity more than 10 times.

The amount of enzyme indicates the severity of cytolytic syndrome, but does not correlate with the depth of organ damage.

The main reasons for increased enzyme activity:

1. 1. Myocardial infarction. Specificity is about 70%. More often it appears in the blood precisely during necrosis of the heart muscle, when cardiomyocytes die and the contents of the cell are released into the blood.
2. 2. Liver diseases. Alanine aminotransferase is contained in the cytoplasm of hepatocytes, so the increase is mainly associated with diffuse liver damage: viral and toxic hepatitis, liver cancer, cirrhosis.

For the diagnosis of viral hepatitis A, the detection of an increased number of Alt, which, unlike Ast, persists for up to two days, is the most informative. With proper treatment, a decrease in transferase activity should occur by the end of the first month from the start of therapy. An unfavorable sign of the course of the disease is persistent increased enzyme activity.





Aspartate aminotransferase

Based on localization, it is divided into cytoplasmic and mitochondrial. The first is contained in the blood of a healthy person - up to 30 units. Mitochondrial is found in the blood during the pathological destruction of cells.

Ast is widely distributed in human tissues: heart, liver, muscles, kidneys, lungs, pancreas.

Diseases leading to increased enzyme activity:

1. 1. Myocardial infarction. An increase in AST in a blood test is a clear diagnostic criterion. An increase in the content of aspartate aminotransferase is observed within five hours, after the appearance of a focus of necrosis. Normally, when blood flow in the heart muscle is restored, Ast activity decreases on the fifth day. The degree of increase in enzyme levels reflects the depth and extent of heart damage. Thus, when a repeated increase in transferase in the blood appears on days 8–10, it indicates an expansion of the ischemic focus.
2. 2. Pathological processes in the liver: hepatitis, liver cancer, fatty hepatosis and cirrhosis. Liver dysfunction is associated with damage to hepatocytes and destruction of cell components. An increase in mitochondrial aspartate aminotransferase is observed.



Dayritis coefficient

The quantitative ratio Ast/Alt has additional diagnostic value.



Normally, the coefficient is no more than 1.33.

Inflammatory liver diseases are characterized by an isolated increase in the activity of mitochondrial aspartate aminotransferase, which leads to an increase in the level of the coefficient. Viral and bacterial hepatitis, liver cancer cause a coefficient value of less than 1.33. The condition persists for a long time, up to several months and years. In turn, an increased concentration coefficient (above 2) is characteristic of alcoholic toxic hepatitis. Cirrhosis is associated with a disorder of the liver structure, so these coefficients are often normal.

Damage to the heart muscle leads to a joint increase in Alt and Ast, which is accompanied by an increase in blood pressure. In uncomplicated cases, the values ​​decrease on the fifth day.



Notes

Hereditary liver diseases change test results throughout life. Diseases are associated with impaired synthesis of enzymes that regulate glucose metabolism. The main source of glucose is glycogen, which is localized in the liver. Accordingly, the body needs enzymes that convert glycogen into sugar, and vice versa, their absence leads to changes in the structure of the liver, which means test results change. In blood biochemistry, indicators of cholestatic and cytolytic syndromes have changed.



Individual cases:

• Complications of pregnancy - preeclampsia. A syndrome that is associated with failure of the organs and systems of a young mother. A terrible, life-threatening condition. A blood test for Ast and Alt contains elevated enzyme levels.
• Pregnant women. During these 9 months, an additional burden is placed on a woman’s body, because the fetus is unable to eliminate toxins on its own. The main supply of microelements and vitamins is aimed at maintaining intrauterine life, so the liver is under stress. This condition can lead to changes in study data towards an increase in aminotransferases. As a rule, the condition is compensated by taking hepatoprotectors and vitamin complexes.

Increases in aminotransferases can be observed transiently, that is, temporarily under various conditions.

And a little about secrets...

A healthy liver is the key to your longevity. This organ performs a huge number of vital functions. If the first symptoms of a gastrointestinal or liver disease have been noticed, namely: yellowing of the sclera of the eyes, nausea, rare or frequent bowel movements, you simply must take action.