From the Guidelines
Before initiating statin therapy, baseline liver function tests (LFTs) should be obtained, specifically alanine aminotransferase (ALT) and aspartate aminotransferase (AST), as recommended by the 2018 AHA/ACC/AACVPR/AAPA/ABC/ACPM/ADA/AGS/APhA/ASPC/NLA/PCNA guideline on the management of blood cholesterol 1.
Importance of Baseline LFTs
Baseline LFTs are essential to assess liver health before starting statin therapy. These tests help identify pre-existing liver conditions that might affect statin metabolism. According to the guideline, in patients treated with statins, it is recommended to measure liver transaminases (aspartate aminotransferase, alanine aminotransferase) as well as total bilirubin and alkaline phosphatase (hepatic panel) if there are symptoms suggesting hepatotoxicity 1.
Monitoring and Safety Checks
In patients at increased ASCVD risk with chronic, stable liver disease (including non-alcoholic fatty liver disease), it is reasonable to use statins after obtaining baseline measurements and determining a schedule of monitoring and safety checks 1. However, routine measurements of creatine kinase and transaminase levels are not useful in patients treated with statins 1.
Key Considerations
- Baseline LFTs should include ALT and AST to assess liver health before initiating statin therapy.
- Mild elevations in baseline LFTs (less than 3 times the upper limit of normal) do not typically represent a contraindication to initiating statin therapy, but patients should be carefully monitored.
- Patients with active liver disease or unexplained persistent elevations in transaminases may require additional evaluation or consideration of alternative lipid-lowering strategies.
- After starting statins, patients should be educated about reporting symptoms like unusual fatigue, loss of appetite, right upper quadrant pain, dark urine, or jaundice.
Recommendations
- Obtain baseline LFTs, including ALT and AST, before initiating statin therapy.
- Monitor patients with mild elevations in baseline LFTs closely.
- Consider alternative lipid-lowering strategies for patients with active liver disease or unexplained persistent elevations in transaminases.
- Educate patients about potential symptoms of hepatotoxicity and the importance of reporting them promptly.
From the Research
Liver Function Tests Before Initiating Statin Therapy
The following liver function tests are recommended before starting statin therapy:
- Baseline liver enzyme testing, including alanine aminotransferase (ALT) and aspartate aminotransferase (AST) 2, 3
- Liver function tests should also be performed 12 weeks after initiation, with any dose increase, and periodically for long-term maintenance therapy 3
Specific Liver Enzymes to Monitor
The liver enzymes that should be monitored before and during statin therapy include:
- Alanine aminotransferase (ALT) 2, 4, 3, 5
- Aspartate aminotransferase (AST) 4, 3, 5
- Gamma-glutamyl transpeptidase (GGT) 5
Interpretation of Liver Enzyme Results
Mild elevations of ALT or AST (<3 times the upper limit of normal [ULN]) following statin therapy do not appear to lead to significant liver toxicity over time 3 Statin initiators with elevated ALT had no meaningfully increased risk of severe acute liver injury (SALI) compared to those with normal ALT 2 A more intensive statin-based lipid-lowering therapy was associated with a similar occurrence of serious alteration of liver tests compared to less intensive or placebo treatments 4