From the Research
The Indian guidelines for Aspartate Aminotransferase (AST) reporting are based on the study of serum levels of AST in healthy populations, with normal levels considered to be ≤40 IU/L, although this cutoff is widely used for adults and may not be applicable to newborns 1.
Key Points
- The normal range for AST levels in adults is considered to be ≤40 IU/L, but this may vary depending on the population being studied 1.
- A study of newborns in India found that serum AST levels up to 52 IU/L can be considered normal for babies with a birth weight of ≥2000 g or gestational age of ≥34 weeks 1.
- Another study of healthy blood donors in western India found that mean AST levels were 23.4 ± 9.9 IU/L for males and 19.1 ± 9.8 IU/L for females, with AST levels increasing with body mass index (BMI) and waist-to-hip ratio (WHR) 2.
- The American College of Gastroenterology (ACG) clinical guideline for the evaluation of abnormal liver chemistries recommends that AST levels be considered in the context of other liver tests, such as ALT and alkaline phosphatase, to determine the presence of hepatocellular or cholestatic injury 3.
Recommendations
- AST levels should be interpreted in the context of other liver tests and clinical factors, such as BMI and WHR, to determine the presence of liver disease 2, 3.
- The normal range for AST levels may vary depending on the population being studied, and clinicians should consider the specific characteristics of their patients when interpreting AST results 1, 2.
- Further studies are needed to determine the optimal cutoff values for AST levels in different populations, including newborns and adults with varying BMIs and WHRs 1, 2.