SGOT (Aspartate aminotransferase, AST, Glutamic oxaloacetic Transaminase)
- This is done on the serum of the patient.
- A random sample can be used.
- The serum is stable for 24 hours at room temp. and 28 days at 4 °C.
- Avoid hemolysis because RBC contains AST and ALT which will increase the value.
- Pregnancy may cause a decrease in the AST level.
- Exercise may increase the AST level.
- There is a false decreased level in:
- Pyridixoin deficiency (Beriberi).
- Severe long-standing liver diseases.
- Diabetic ketoacidosis.
- Drugs that may increase the value are:
- Digitalis preparation.
- Anticoagulants like coumarine.
- Oral contraceptives.
- Hepatotoxic drugs.
Purpose of the test (Indications)
- This is done in suspected liver diseases.
- This also helps in heart diseases to diagnose acute myocardial infarction.
- This enzyme is distributed in all tissues (primarily all the tissues) but primarily found in the liver, heart and skeletal muscles in high concentration.
- SGOT is found in the plasma, bile, CSF, and saliva.
- It is not found in urine unless there is a kidney lesion.
- Minimal activity occurs in the skin, kidneys, pancreas, and RBCs.
- In the liver, it is present in cytosolic and mitochondrial forms.
- This is also called as GOT (glutamate oxaloacetate transaminase).
- It is released into circulation:
- in liver diseases.
- In myocardial infarction, there is a rise after 6 to 8 hours of the damage or chest pain. Abnormal values are seen almost in more than 97% of the cases.
- Renal infarction.
- Brain infarction.
- Skeletal diseases.
- This test is advised in hepatocellular diseases and coronary occlusive diseases leading to muscle necrosis.
- The amount of SGOT is directly related to the number of cells affected by the disease or injury.
- After the cell injury:
- It appears in the blood after 6 to 8 hours.
- The peak level is in 24 to 36 hours.
- It returns to normal in 3 to 7 days.
- In acute hepatitis, AST level rises 20 times the normal.
- In acute extra-hepatic obstruction, the level rises 10 times the normal and rapidly falls.
- In cirrhosis, it depends upon the amount of active inflammation.
- In chronic injury, the elevated level will persist.
- In Acute hepatitis, the level may increase 20 times to the normal.
- SGOT >8 to 10 time more than the normal indicates:
- Acute viral hepatitis.
- SGOT >30 times more than the normal seen in:
- Alcoholic patients taking acetaminophen.
- In acute extrahepatic obstruction like gallstones, the SGOT level rises to 10 times the normal value and it returns normally quickly when the obstruction is relieved.
- The AST/ALT ratio is usually greater than 1 in:
- The patient with alcoholic cirrhosis.
- Liver congestion.
- Metastatic tumor of the liver.
- The AST/ALTThe ratio of less than 1 is seen in:
- Acute hepatitis.
- Viral hepatitis.
- Infectious mononucleosis.
- The ratio will be less accurate if the AST level is more than 10 times normal.
- The SGOT level as compared to serum is 7800 times in the heart, 7100 times in liver, skeletal muscles 5000 times, kidney 4500 times, pancreas 1400 times, spleen 700 times, lungs 500 times, and RBCs 15 times.
|Newborn||25 to 75|
|Infants||15 to 60|
|Adult||8 to 20|
|>60 years||Male = 11 to 60|
|Female = 10 to 20|
- Newborn/ infants = 15 to 60 units/L
- Child = Value like adult
- Adult = 0 to 35 units/L
Elderly = Slightly higher than the adults
- Men = 14 to 20 U/L (0.23 to 0.33 µKat/L).
- Women = 10 to 36 U/L (0.23 to 0.33 µKat/L).
- Newborn = 47 to 150 U/L (0.23 to 0.33 µKat/L).
- Children = 9 to 80 U/L (0.23 to 0.33 µKat/L).
- Newborn = 25 to 75 U/L
- Infants = 15 to 60 U/L
- Male = 15 to 40 U/L at 37C.
- Female = 13 to 35 U/L at 37C.
- Elderly = slightly higher than the adult.
- SGOT > 450 U/L in blunt abdominal injury is an indicator of liver injury.
|Age||Normal values U/L|
|0 to 5 days||35 to 140|
|<3 years||15 to 60|
|3 to 6 years||15 to 50|
|6 to 12 years||10 to 50|
|12 to 18 years||10 to 40|
|Adult||0 to 35 (female slightly low than males)|
|Elderly||slightly higher than the adults|
Increased SGOT level seen in:
- Fulminant type of hepatitis especially viral type.
- In liver cell necrosis or injury like chronic hepatitis,
- Alcoholic hepatitis.
- liver metastasis and Hepatoma (increase maybe 5 to 10 folds and is of both enzymes).
- In necrosis of heart muscle or skeletal muscle e.g acute myocardial infarction.
- Severe exercise.
- Severe burn.
- Hypothyroidism ( in 40 to 90% of cases).
- In cholestatic and obstructive jaundice.
- May see a transient increase in acute pancreatitis, acute renal diseases, musculoskeletal diseases, or trauma.
- Other diseases than liver and heart which can increase the level:
- Toxic shock syndrome.
- Mushroom poisoning.
- Pulmonary embolism and infarction.
- Hemolytic anemia.
- malignant hyperthermia.
Decreased SGOT level seen in:
- Chronic renal dialysis.
- Acute renal diseases leading to Azotemia.
- Vit.B6 deficiency.
Myocardial infarction (MI) SGOT pattern:
- The SGOT level will be raised but this is not a specific test but useful when there is raised the level of Creatine phosphokinase(CPK) and Lactic dehydrogenase(LDH).
- In Myocardial Infarction:
- SGOT appears in 6 to 8 hours. This rise is 3 to 5 times normal.
- The peak level is between 18 to 24 hours.
- Returns to normal in 4 to 6 days.
- The average increase in MI is 4 to 5 times normal.
- The increase of 10 to 15 times indicates massive MI.
- The abnormal level is seen in >97% of the patient if it is done at the right time.
- A myocardial injury like Angina, pericarditis and rheumatic carditis does not lead to rising in the level.
Liver diseases SGOT pattern:
- There is raised the level of SGOT in liver cell necrosis. This may be 10 to 100 times increase.
- The SGOT level may be compared with SGPT.
- SGOT/SGPT ratio is usually greater than 1 in a patient with alcoholic cirrhosis, liver congestion, and metastatic tumors of the liver.
- The ratio of less than 1 may be seen in acute hepatitis and viral hepatitis.
- Acute viral hepatitis:
- The rise of SGOT seen before the onset of jaundice.
- Peak level has seen from 7 to 12 days after the onset of jaundice.
- The normal level has seen 3 to 4 weeks after the onset of jaundice.
- Characteristically SGPT is greater than SGOT.
Table showing the increase of SGOT in various conditions:
The rise in SGOT level with reference to the normal value
|Viral hepatitis and liver diseases||may reach 100 times|
|Infectious hepatitis||ALT > AST|
|Toxic hepatitis||Extremely high level|
|Infectious mononucleosis||20 times|
|Intrahepatic cholestasis||lower values|
|Extrahepatic cholestasis||Increased value|
|Cirrhosis||Normal to 4 to 5 times|
|Metastatic carcinoma||5 to 10 times|
|Acute myocardial infarction||4 to 5 times|
|Fatal myocardial infarction||10 to 15 times|
|Progressive muscular dystrophy||May reach 8 times|
|Dermatomyositis||May reach 8 times|
|Pulmonary emboli||2 to 3 times|
|Acute pancreatitis||2 to 5 times|
|Crushed muscular injury, Gangrene||2 to 5 times|
|Hemolytic diseases||2 to 5 times|
Critical value: >20,000 U/L seen in alcohol-acetaminophen syndrome.
Comparison of AST (SGOT) / ALT (SGPT)
- AST (SGOT) is always is raised in acute myocardial infarction, where ALT (SGPT) will be normal unless there is damage to the liver.
- ALT (SGPT) is more raised in acute hepatobiliary obstruction than AST (SGOT).
- ALT (SGPT) is more specific than AST (SGOT) for liver cell injury.
- The AST/ALT ratio is higher in alcoholic liver diseases.
- AST (SGOT) is more sensitive to alcoholic liver cell injury.