Liver function test is one of the routine clinical physical examination items, the purpose is to diagnose liver disease or check the degree of liver damage and find out the cause of liver disease. It has always been advocated that the fasting state in the morning is the best time for blood sampling, and the current reference interval is also based on fasting blood sampling. Then in the liver function test, blood sampling in the non-fasting state will have the liver function test. Is there a significant impact on the results?

The survey showed that the results of 8 liver function indicators, ALT, AST, TP, ALB, TBIL, DBIL, ALP, and GGT, were compared after eating a normal breakfast and before the meal, and the difference was not obvious. However, the results of fasting and after meals have minor changes regardless of people with medical history or health examinations. This may be a physiological change or an error in biochemical testing, but in fact, ordinary diet has little effect on testing items.

Is the level of transaminase after meals higher than before meals?

Although previous studies have suggested that there may be lipemia and endogenous pyruvate after eating, which have a certain effect on transaminase. It is believed that after a meal or in an incomplete fasting state, blood lipids, proteins and carbohydrates are higher than those on an empty stomach. When the body's metabolism is enhanced, oxidative metabolism generates pyruvate, and the amount of pyruvate in the blood may be higher than that in an empty stomach. The measured value of transaminase will also be affected. Therefore, ALT and AST levels may be higher than those of fasting blood during non-fasting blood sampling.

But now the determination of ALT (alanine aminotransferase) usually uses a two-reagent pyruvate substrate method, and AST (aspartate aminotransferase) uses a two-reagent aspartate substrate method. Both reagents contain lactate dehydrogenase, which can be used in the determination. The endogenous pyruvic acid in the sample is removed during the delayed incubation time, which eliminates the influence of pyruvate on the test results. Therefore, the double-reagent method is used to determine ALT and AST, and the impact before and after meals is not significant. When determining serum alanine aminotransferase, the substrate and serum should be warmed in a 37℃ water bath in advance, and then the substrate should be added to the serum for accurate timing. This substrate can be chromogen substrate produced by Desheng or Elesa reagent Box for measurement.

Will a high-fat, high-protein diet affect liver function?

Lipemia can interfere with the determination of many biochemical items. When the lipemia concentration is equal to 2%, the detection of TP, TBIL, GLU will cause positive interference, and the results of ALT, AST, GGT, and ALB will cause negative interference. High-fat diet or drinking can cause serum turbidity to increase. Lipid turbidity can scatter light, interfere with absorbance, and change biochemical indicators. Therefore, it is recommended that you should not drink alcohol and high-fat diet before 12 hours of testing. Will not cause lipemia.

The high-protein diet does not have a big impact. The protein in the food needs to be digested and hydrolyzed in the intestines into small molecular amino acids before it can be absorbed into the blood. Therefore, amino acids are first added after a meal instead of protein. Part of the amino acid absorbed into the blood synthesizes albumin in the liver, and the new albumin synthesized is used by the tissues. Its synthesis and catabolism are in dynamic balance in the human body, and its changes mainly depend on the state of the body. Therefore, TP and ALB in plasma are not affected by high-protein diet.

And now with the development of inspection technology, the improvement of inspection project methodology and the use of automatic biochemical analyzers, many biochemical projects adopt dual reagents and dual wavelength determinations, which can avoid or reduce the interference from reagent blanks and sample blanks to the determination. The specificity and sensitivity of the determination are improved, and it can basically eliminate the interference of light and moderate lipemia on the detection of most biochemical indicators. Desheng is a manufacturer specializing in the production and development of biochemical detection additives. If necessary, you can enter the official website to contact customer service. For professional consultation.