From the Guidelines
Your AST level of 13 U/L is normal, as it falls within the reference range of less than 35 U/L, and no action or intervention is needed for this result. This is based on the most recent evidence from the Journal of the American College of Radiology, 1. AST is an enzyme found primarily in the liver, heart, and muscles. When these tissues are damaged, AST is released into the bloodstream, causing elevated levels. Your normal result suggests your liver and other tissues containing this enzyme are functioning properly.
Key Points to Consider
- AST is typically measured alongside other liver enzymes like ALT to assess liver health, as noted in 1.
- The interpretation of all abnormal liver chemistries must be taken in the clinical context of a given patient, as stated in 1.
- While this individual result is reassuring, liver function is best evaluated as part of a complete panel of tests rather than by a single value.
- The severity of abnormal aminotransferase can be classified, and mild increases are often associated with nonalcoholic fatty liver disease (NAFLD) and alcohol-induced liver disease, as discussed in 1.
Recommendations
- Continue with your regular healthcare check-ups and follow any other recommendations from your healthcare provider based on your overall health assessment.
- Be aware that a normal AST level does not completely exclude the presence of hepatic disease, and any symptoms or concerns should be discussed with your healthcare provider, as indicated in 1.
From the Research
Aspartate Aminotransferase (AST) Levels
- The given AST level is 13 U/L, which is within the reference range of <35 U/L 2.
- AST is a biomarker for liver damage, but it is not specific to the liver as it is also present in cardiac and skeletal muscle and in erythrocytes 2.
- Elevated AST levels can be caused by various factors, including liver disorders, myocardial infarction, and obesity 2, 3.
Relationship with Alanine Aminotransferase (ALT)
- The ratio of AST to ALT (AST/ALT) is often used to diagnose liver disease, with a ratio greater than 2.0 indicating alcoholic liver disease and a ratio less than 1.0 indicating chronic hepatitis or chronic cholestatic syndromes 4.
- The AST/ALT ratio can also be used to assess the severity of liver disease, with higher ratios indicating more severe disease 4, 5.
- However, the AST/ALT ratio may not be a reliable indicator of liver disease in certain cases, such as in the presence of cirrhosis 4.
Cardiovascular Disease Risk Assessment
- The AST/ALT ratio has been associated with an increased risk of cardiovascular disease (CVD) in men, but not in women 5.
- Including the AST/ALT ratio in established CVD risk prediction tools may not improve their performance, but it may have clinical utility in certain subgroups 5.