Liver function and related tests

About Hepatobiliary System Enzymes

The liver performs functions such as (1) detoxification of harmful substances (2) synthesis, metabolism and storage of nutrients (3) synthesis and metabolism of bile. Liver function tests check for abnormalities in the liver, gallbladder, and bile ducts. In addition to liver damage, heart disease and strenuous exercise can also raise levels. AST, ALT, γ-GTP, total bilirubin, ALP, and LDH are measured at our university's health checkups.

AST

Although it is mainly a liver test, it is also present in heart muscle, skeletal muscle, kidney, etc. in addition to the liver, and the value increases when there is an abnormality in the cells of the organ. Therefore, it is an effective test for diagnosing liver damage, myocardial infarction, hemolysis, etc.

lab standard range （IU/L）	Checkup evaluation
	normal	minor abnormality	Re-examination / lifestyle improvement required.	Detailed examination / treatment required
	A	B	C	D
10 ~ 40	30 or less	31 ~ 35	36 ~ 50	51 or more

ALT

In particular, it is an effective test for diagnosing diseases of the liver and biliary system because it reacts sharply to degeneration and necrosis of hepatocytes.

lab standard range （IU/L）	Checkup evaluation
	normal	minor abnormality	Re-examination / lifestyle improvement required.	Detailed examination / treatment required
	A	B	C	D
5 ~ 45	30 or less	31 ~ 40	41 ~ 50	51 or more

γ-GTP

The value increases when there is a lot of alcohol intake, when there is a fatty liver, when the bile duct is blocked due to a stone or cancer, etc.

lab standard range （IU/L）	Checkup evaluation
	normal	minor abnormality	Re-examination / lifestyle improvement required.	Detailed examination / treatment required
	A	B	C	D
M: 80 or less F: 30 or less	50 or less	51 ~ 80	81 ~ 100	101 or more

Total bilirubin

Bilirubin is a yellow pigment found in blood. When red blood cells that have reached the end of their lifespan are destroyed, hemoglobin is broken down into heme and globin, which are converted into heme and bilirubin by the action of enzymes. This is called "indirect bilirubin". This bilirubin is transported to the liver where it is reactivated by an enzyme to convert it into a substance called "direct bilirubin" which is stored in the gallbladder. It becomes part of the stool and is excreted by the kidneys as part of the urine. The combination of the indirect and direct forms is called "total bilirubin".

Bilirubin increases in the blood when there is hepatic dysfunction or bile duct disorder. Excess bilirubin causes jaundice, a yellow discoloration of the body. By measuring the amount of bilirubin in the blood, disorders can be detected before jaundice occurs.

■ If there is an abnormality

It is considered together with the results of liver function tests, and more detailed tests are performed as necessary to make a diagnosis.

■ Diseases suspected in abnormal cases

Constitutional jaundice, chronic/acute hepatitis, liver cirrhosis, hemolytic anemia, pulmonary infarction, sepsis, hyperthyroidism, etc.

lab standard range （mg/dL）	Checkup evaluation
	normal	minor abnormality	Re-examination / lifestyle improvement required.	Detailed examination / treatment required
	A	B	C	D
0.2 ~ 1.2	~ 2.5	2.6 ~ 3.4	-	3.5 ~

The Japan Society of Ningen Dock and Preventive Medical Care does not set an evaluation criteria for total bilirubin because, up to a moderate level, it reduces the mortality rate in proportion to the increase and prevents arteriosclerosis. Although the above standards are set for health checkups by the Health Service Center, the final judgment is given by a doctor who comprehensively judges the results of each individual, so even if the numbers are high, you may be judged as normal.

Please refer to the following link.

https://medlineplus.gov/ency/article/003479.htm

 

ALP

A high level may indicate liver damage or biliary tract disease. ALP is an enzyme produced by various cells, including the liver, and is also present in bile. When the flow of bile in the liver is impaired due to liver damage, or when the bile duct is clogged with gallstones, etc., ALP present in the bile leaks into the blood, increasing the level. In addition, since ALP is also produced in bones, the level may increase in growing children and bone diseases.

*From FY2021 (IFCC)

lab standard range （IU/L）	Checkup evaluation
	normal	minor abnormality	Re-examination / lifestyle improvement required.	Detailed examination / treatment required
	A	B	C	D
38 ~ 113	38 ~ 113	36 ~ 37	29 ~ 35 OR 114 ~ 130	~ 28 OR 131 ~

The evaluation criteria for health checkups are basically based on the standards of the Japan Society of Ningen Dock and Preventive Medical Care but no standards are presented for ALP. The above standards are set based on the past data of the University of Tokyo. When making an actual judgment, the doctor will make a judgment based on the overall test results and past test results of each person.

*Until FY2020 (JSCC)

lab standard range （IU/L）	normal	minor abnormality	Re-examination / lifestyle improvement required.	Detailed examination / treatment required
	A	B	C	D
100 ~ 325	~ 325	326 ~ 449	-	450 ~

 

Please refer to the following link.

https://medlineplus.gov/ency/article/003470.htm