AST

Definition

AST, or aspartate aminotransferase, is an enzyme found primarily in the liver and heart that is used as a biomarker to assess liver and heart health. It is a key term that is relevant in the context of understanding the mechanisms and effects of various lipid-lowering medications as well as the monitoring of masculinizing hormone therapy.

5 Must Know Facts For Your Next Test

1. Elevated AST levels can indicate liver injury or damage, as the enzyme is released into the bloodstream when liver cells are damaged.
2. AST levels are often monitored in patients taking statin medications, as statins can potentially cause liver toxicity and increased AST levels.
3. PCSK9 inhibitors, another class of lipid-lowering drugs, are generally associated with a lower risk of liver enzyme elevations compared to statins.
4. Bile acid sequestrants, fibrates, and niacin may also cause increases in AST levels, requiring monitoring during treatment.
5. In the context of masculinizing hormone therapy, AST levels are monitored to assess liver function and potential adverse effects of the exogenous testosterone administration.

Review Questions

• Explain the role of AST as a biomarker in the context of statin (HMG-CoA reductase inhibitor) and PCSK9 inhibitor therapy.
  • AST is an important biomarker used to monitor for potential liver toxicity in patients taking statins and PCSK9 inhibitors. Statins can occasionally cause increases in AST levels, indicating liver damage, and therefore AST is regularly tested to ensure the liver is not being adversely affected by statin therapy. In contrast, PCSK9 inhibitors are generally associated with a lower risk of liver enzyme elevations compared to statins, but AST levels are still monitored to detect any potential hepatotoxicity.
• Describe how AST levels may be impacted by treatment with bile acid sequestrants, fibrates, and niacin.
  • Bile acid sequestrants, fibrates, and niacin are other classes of lipid-lowering medications that can potentially cause increases in AST levels. Similar to statins, these drugs may lead to hepatotoxicity and liver injury, resulting in the release of AST into the bloodstream. Therefore, healthcare providers closely monitor AST levels in patients taking these medications to detect any signs of liver damage and make appropriate adjustments to the treatment plan if necessary.
• Analyze the importance of monitoring AST levels in the context of masculinizing hormone therapy.
  • In the context of masculinizing hormone therapy, AST levels are closely monitored to assess liver function and potential adverse effects of the exogenous testosterone administration. Elevated AST can indicate liver damage or dysfunction, which is a possible side effect of testosterone therapy. By regularly testing AST levels, healthcare providers can identify any issues early and make necessary adjustments to the treatment regimen to mitigate the risk of hepatotoxicity and ensure the safe and effective management of masculinizing hormone therapy.

Related terms

Transaminases: A class of enzymes that catalyze the transfer of amino groups between amino acids and α-keto acids, including AST and ALT.

Hepatotoxicity: Liver damage or dysfunction caused by exposure to drugs, chemicals, or other substances.

Myopathy: A muscular disease or disorder that results in muscle weakness or degeneration.