THE FATTY LIVER AND THE AST:ALT RATIO A normal AST:ALT ratio should be <1. In patients with alcoholic liver disease, the AST:ALT ratio is >1 in 92% of patients, and >2 in 70%. AST:ALT scores >2 are, therefore, strongly suggestive of alcoholic liver disease and scores <1 more suggestive of NAFLD/NASH.
An elevated serum AST in relation to serum ALT (alanine aminotransferase) has been proposed as an indicator that alcohol has induced organ damage. Thus, when AST/ALT ratio is >1.5, this is considered as highly suggestive that alcohol is the cause of the patient's liver injury (Correia et al., 1981; Salaspuro, 1987).
Severe alcoholic hepatitis is marked by bilirubin levels over 10–15 mg/dL. Levels of aspartate aminotransferase (AST) are usually between 100 and 200 U/L and are almost always less than 400 U/L. Alanine aminotransferase (ALT) is usually approximately 25–50% the value of AST, somewhere in the range of 50–150 U/L.
The most common causes of elevated ALT levels in subjects undergoing health screening exams are alcohol intake, viral hepatitis, and NAFLD [18].
ALT levels greater than 15 times the normal range indicate severe acute liver cell injury and evaluation should be initiated immediately.
Your ALT level is considered high if it exceeds the normal range of 0 to 44 IU/L. Some laboratories may present a slightly different reference interval, but a test result of 55 IU/L or above could indicate liver problems.
Usually, the upper limit of ALT is 35 - 40 U/L. Moderate increase in ALT (such as 70 U/L) is seen in chronic hepatitis, chronic obstruction of bile ducts, heart damage, alcohol abuse, liver tumor, skeletal muscle damage. In any acute liver conditions, ALT is much more elevated.
An ALT test result of >100 IU/l is a clear indicator of serious liver disease, but a mildly elevated ALT result (30–100 IU/l) is often ascribed to the use of medication (for example statins) or alcohol, obesity, or, for lower ALT levels (<50 IU/l), considered as part of the normal distribution of test results.
In general, high levels of ALT may be a sign of liver damage from hepatitis, infection, cirrhosis, liver cancer, or other liver diseases. The damage may also be from a lack of blood flow to the liver or certain medicines or poisons.
Alcoholic Hepatitis
The predominance of AST over ALT in alcohol-related liver disease was first reported by Harinasuta et al. in 1967. Many authors have since described AST/ALT ratios greater than 1.5 or greater than 2.0 as being highly suggestive of alcoholic hepatitis.
If you stop drinking alcohol for 2 weeks, your liver should return to normal.
The researchers also found that even a single episode of binge drinking elevated the levels of the liver enzyme CYP2E1, which metabolizes alcohol into toxic by-products that can cause oxidative damage and other forms of tissue injury.
An AST/ALT ratio higher than one (where the AST is higher than ALT) means you may have cirrhosis. An AST/ALT ratio higher than 2:1 (where the AST is more than twice as high as the ALT) is a sign of alcoholic liver disease.
Alanine aminotransferase (ALT) is a liver enzyme, and high levels can indicate liver damage. Taking steps to lower ALT levels can help the liver recover. Lifestyle changes, such as a healthful diet and regular exercise, can all help to lower ALT levels.
Laboratory findings suggestive of cirrhosis:
Albumin < 3.8 mg/dL. AST > ALT (in non-alcoholic etiologies) INR > 1.2.
Typically the range for normal AST is reported between 10 to 40 units per liter and ALT between 7 to 56 units per liter. Mild elevations are generally considered to be 2-3 times higher than the normal range. In some conditions, these enzymes can be severely elevated, in the 1000s range.
High liver enzyme levels may be temporary, or they may be a sign of a medical condition like hepatitis or liver disease.
There is no consensus on cutoff point and maximum normal concentration of ALT, and a broad value range, between 26 and 66 IU/L, has been suggested in different studies[37]. Some studies have shown that risk of NAFLD increases as ALT rises to more than 19 and 30 in women and men, respectively.
There are many causes of mildly elevated ALT and AST levels. The most common causes are nonalcoholic fatty liver disease (NAFLD) and alcoholic liver disease. In NAFLD, the liver has more fatty tissue in it than normal. Regular or heavy alcohol use can also hurt the liver and increase liver enzymes.
Very high levels (>75 times upper reference limit) suggest ischaemic or toxic (poison or medicine-related) injury to the liver. Ischaemic liver damage is mostly seen in patients with other serious illnesses such as septicaemia or collapse.
A low level of ALT in the blood has no clinical significance. An abnormally high level generally indicates that the liver cells are damaged and releasing their contents into the bloodstream. High ALT levels (300 units per litre (U/L) or more) are often caused by acute viral hepatitis.
Measurement of serum ALT activity is a good indicator of hepatocyte injury. The best ALT discriminant value for recognizing acute hepatic injury is 300 U/L.
Although levels of ALT and AST can be extremely elevated (exceeding 2,000 U per L in cases of hepatocyte injury and necrosis related to drugs, toxins, ischemia, and hepatitis), elevations less than five times the upper limit of normal (i.e., about 250 U per L and below) are much more common in primary care medicine.