Liver function tests – AST and ALT

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One of the primary diagnostic methods indicating the condition of the liver are blood liver tests, commonly referred to as a "liver panel". It consists of tests of specific enzymes related to the functioning of the organ and bilirubin (the main pigment of bile). Liver tests can detect chronic diseases of this organ (e.g. inflammation caused by the B or C virus, steatosis caused by alcohol abuse, or drug-induced injury).  

What are AST and ALT?

The two main liver enzymes are:2

  • alanine aminotransferase (ALAT, ALT),
  • aspartate aminotransferase (AspAT, AST). 

Both play an important role in the body as they participate in protein transformation processes. Liver function tests include an assessment of activity of these enzymes, which are found in hepatocytes, i.e. liver cells. In the case of even a mild injury to the liver, regardless of its cause, these enzymes are released into the bloodstream. The greater liver injury, the higher their level in the tested blood.2

 

What can elevated or decreased levels of AST and ALT mean?

The elevated level of transaminases (AspAT and AlAT) indicates an injury to liver cells.1

AspAT elevated to >40 IU/l

It may indicate such disorders as hepatitis, fatty liver, cirrhosis, mechanical jaundice.2

ALAT elevated to >40 IU/l

It may indicate liver injury.3

When should liver function tests be performed?

The performance of liver function tests should be considered especially when certain medicines are taken or when jaundice, ascites or other symptoms that suggest a chronic liver disease are present:1,5

Bloating

Pain in the right subcostal region

Upper abdominal discomfort, sensation of pressure, fullness, distension,

Chronic fatigue, feeling of lack of energy, exhaustion,

Sleep disturbances – drowsiness, difficulties falling asleep.

How to prepare to the test?

No special preparation to the test, such as being in a fasting state, are required.1

FAQ

    Other enzymes that are assayed in liver function tests are:

    • GGT (gamma-glutamyl transpeptidase): an enzyme associated with cell membranes, occurs mainly in the liver, kidney, pancreas,2
    • LDH (lactate dehydrogenase): an enzyme that occurs in all cells of the body. As a result of cell death or increased permeability of cell membranes (caused, for example, by ischaemia or toxins) LDH is released into the bloodstream,2
    • Bilirubin: a yellow pigment created by the breakdown of red blood cells. It gives to the bile its characteristic colour. Indirect (unconjugated) bilirubin is formed as a result of breakdown of haemoglobin in red blood cells. The liver transforms this bilirubin into direct (conjugated) bilirubin than can be subsequently released into the bowels through the gallbladder for elimination. This is why the level of total bilirubin may indicate both destruction of red blood cells as well as normal functioning of the liver, gallbladder and bile ducts.1,4
    • AST: <40 IU/l, 
    • ALT: <40 IU/l,
    • GGT: <35 IU/l for women and <40 IU/l for men,
    • LDH: <480 IU/l in adults,
    • Bilirubin:

    total 5.1-20.5 µmol/l (0.3-1.2 mg/dl)

    conjugated 1.7-6.8 µmol/l (0.1-0.4 mg/dl)

    unconjugated 3.4-13.7 µmol/l (0.2-0.8 mg/dl).

Your liver quiz

Take our 5 minutes quiz to check your liver’s condition and get dietary advice on how to take care of it every day.

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Choose the right pack size to fit your needs and find about the differences between Phospholipids (Essentiale Forte P). 50s and Phospholipids (Essentiale Forte P). 10s

Phospholipids (Essentiale Forte P) 10s

CLINICAL PARTICULARS
Indications
Nutritional support in the management of damaged liver (due to chronic liver disease, liver cirrhosis, fatty liver & intoxication by hepatotoxic substances). Each hard gelatin capsule contains: De-oiled enriched phospholipids from soya-beans …………… 300 mg

Phospholipids (Essentiale Forte P) 50s

CLINICAL PARTICULARS
Indications
Nutritional support in the management of damaged liver (due to chronic liver disease, liver cirrhosis, fatty liver & intoxication by hepatotoxic substances). Each hard gelatin capsule contains: De-oiled enriched phospholipids from soya-beans …………… 300 mg

Learn more about what supports or harms your liver

Golden rules for a healthy liver diet

A liver diet is a more continuous and systematic mode of care for the liver. It’s all about keeping the intake of carbohydrates and fats at a low level and concentrating on eating more proteins instead. If we wish to keep our liver healthy, we should also avoid frying foods and consuming alcohol.

Products that support liver detox

A liver detox is a preventive measure that we should take only once a year to maintain a healthy liver.1 It should take ideally around eight weeks and we should base it on four to five small fresh meals during the day. The prepared food should be served raw if possible, steamed or cooked with a little amount of water.

Harmful factors for the liver

Learn about the factors which negatively affect your liver.

    1. https://www.mp.pl/medycynarodzinna/artykuly/120195,badania-czynnosci-watroby 

    2. Szajewska H et al. Badania diagnostyczne. Wątroba. Interna Szczeklika: Podręcznik chorób wewnętrznych. Medycyna Praktyczna. Kraków 2012: 832–836. 

    3. Milkiewicz P. Interpretacja badań laboratoryjnych w chorobach wątroby. Wielka Interna. Gastroenterology, part I, ed. A. Dąbrowski. Medical tribune Poland. Warsaw 2010: 467–471. 

    4. Unconjugated Bilirubin - Glossary | Laboratory, radiology, sleep and genetic | Biron, https://www.biron.com/en/glossary/unconjugated-bilirubin/ 

    5. Essentiale in the treatment of NAFLD, REPORT FROM THE QUANTITATIVE STUDY WITH PHYSICIANS FOR SANOFI, THE MODULE BASED ON PATIENTS’ MEDICAL RECORDS, April 2020. Data on file.