From the Guidelines
Your ALT level of 16 U/L is normal, as it falls within the reference range of less than 50 U/L, indicating that your liver is functioning properly without signs of significant inflammation or damage. ALT is an enzyme primarily found in liver cells, and blood levels are measured to assess liver health 1. When liver cells are damaged or diseased, ALT leaks into the bloodstream, causing elevated levels. According to the most recent study 1, normal ALT levels are 29 to 33 IU/L in men and 19 to 25 IU/L in women, and your result is well within the normal range.
Key Points to Consider
- ALT is commonly included in routine blood work to screen for liver problems, and it's often measured alongside other liver enzymes like AST (aspartate aminotransferase) 1.
- Various factors can affect ALT levels, including medications, alcohol consumption, obesity, and viral hepatitis 1.
- Maintaining a healthy lifestyle with moderate alcohol intake, regular exercise, and a balanced diet helps support liver health and keep ALT levels within normal range.
- The interpretation of all abnormal liver chemistries must be taken in the clinical context of a given patient, including a detailed history, inventory of medications, and a physical examination 1.
Recommendation
No specific action is needed regarding this test result, but it is essential to continue maintaining a healthy lifestyle to support liver health. If you have any concerns or risk factors for liver disease, it is crucial to discuss them with your healthcare provider 1.
From the Research
Alanine Aminotransferase (ALT) Levels
- The given ALT level is 16 U/L, which is within the reference range of <50 U/L 2, 3.
- ALT is a biomarker for liver damage, and it is considered the most specific marker for liver damage compared to aspartate aminotransferase (AST) 2.
- Elevated ALT levels have been associated with increased liver-related mortality, and a true healthy normal ALT level ranges from 29 to 33 IU/l for males and 19 to 25 IU/l for females 3.
Evaluation of Abnormal Liver Chemistries
- The evaluation of hepatocellular injury, which is defined as disproportionate elevation of AST and ALT levels, includes testing for viral hepatitis A, B, and C, assessment for nonalcoholic fatty liver disease and alcoholic liver disease, and screening for hereditary hemochromatosis, autoimmune hepatitis, Wilson's disease, and alpha-1 antitrypsin deficiency 3.
- A liver biopsy may be considered when serologic testing and imaging fails to elucidate a diagnosis, to stage a condition, or when multiple diagnoses are possible 3.
- Percutaneous ultrasound-guided liver biopsy has been considered the reference standard in distinguishing the degree of liver disease, with low rates of major and minor complications 4.