From the Guidelines
Elevated AST levels should be addressed by identifying and treating the underlying cause, with the most recent and highest quality study suggesting that common causes include alcohol consumption, medications, viral hepatitis, fatty liver disease, and autoimmune conditions 1. To address elevated AST, it is essential to first identify the underlying cause, as the treatment approach varies depending on the etiology.
- Common causes of elevated AST include:
- Alcohol consumption
- Medications (such as acetaminophen, statins, or antibiotics)
- Viral hepatitis
- Fatty liver disease
- Autoimmune conditions If alcohol is the cause, complete abstinence is recommended. For medication-induced elevation, the offending drug should be discontinued if possible. For viral hepatitis, antiviral medications may be prescribed depending on the specific virus. Non-alcoholic fatty liver disease requires lifestyle modifications, including weight loss of 7-10% of body weight, regular exercise (150 minutes weekly of moderate activity), and a Mediterranean diet low in processed foods and sugars 1. Additional testing is often necessary, including a complete liver panel (ALT, alkaline phosphatase, bilirubin), hepatitis serologies, and imaging studies like ultrasound.
- The severity of abnormal aminotransferase can be classified as mild, moderate, or severe, with moderate and severe cases requiring prompt evaluation and treatment 1. AST elevation is significant because it reflects the release of this enzyme from damaged liver cells, though it can also come from muscle, heart, or kidney tissue damage, which is why context and additional testing are important for proper diagnosis and treatment 1.
From the Research
Elevated AST
Elevated AST (aspartate aminotransferase) levels can be an indicator of liver damage or disease. The following points highlight the relationship between AST and liver health:
- AST is present in liver tissue, as well as in cardiac and skeletal muscle and in erythrocytes, making ALT (alanine aminotransferase) a more specific marker for liver damage 2
- Elevated serum transaminase levels, including AST, can be caused by various factors, and a differential diagnostic work-up is necessary to determine the underlying cause 2
- In patients with primary biliary cirrhosis, ursodeoxycholic acid treatment can decrease serum bilirubin concentration and activity of serum alkaline phosphatases, but its effect on AST levels is not explicitly stated in the available studies 3, 4, 5
- Biochemical response to ursodeoxycholic acid, including reduction in alkaline phosphatase levels, can predict survival in primary biliary cirrhosis patients, but the specific impact on AST levels is not mentioned 6
Relationship between AST and Liver Disease
The relationship between AST and liver disease is complex, and elevated AST levels can be caused by various factors, including:
- Liver damage or disease, such as primary biliary cirrhosis 3, 4, 5
- Cardiac or skeletal muscle damage 2
- Other medical conditions, such as myocardial infarction 2
- It is essential to consider the clinical context and perform a thorough diagnostic work-up to determine the underlying cause of elevated AST levels 2
Treatment and Management
The treatment and management of elevated AST levels depend on the underlying cause. In patients with primary biliary cirrhosis, ursodeoxycholic acid treatment can improve liver biochemistry measures and histological progression, but its effect on AST levels is not explicitly stated in the available studies 3, 4, 5, 6