From the Guidelines
Repeat blood work to verify elevation should be performed without delay, as recommended by the most recent guidelines 1. When verifying abnormal results, it's crucial to consider the specific test and the degree of abnormality. For example, if the A1C is above the diagnostic threshold, a repeat result should be performed promptly to confirm the diagnosis of diabetes.
- The timing of repeat testing may vary, but for critical values or significantly abnormal results, immediate repeat testing is often necessary.
- For moderately abnormal results, follow-up testing in 3-6 months may be appropriate, as recommended by the guidelines 1.
- It's essential to use the same laboratory and collection method for consistency and to maintain similar conditions (fasting status, time of day, medication timing) as the original test.
- The verification process is critical because laboratory errors, biological variations, and temporary physiological changes can all cause transient elevations.
- Multiple consistent abnormal results provide stronger evidence of a true medical condition requiring intervention, while a return to normal values may indicate a temporary fluctuation that doesn't require treatment.
- According to the guidelines, if two different tests (such as A1C and FPG) are both above the diagnostic threshold when analyzed from the same sample, the diagnosis of diabetes is confirmed, and no further testing is needed immediately 1.
From the FDA Drug Label
Elevations in Liver Enzyme Tests Persistent elevations in serum transaminases, defined as more than 3 times the ULN and occurring on 2 or more occasions, occurred in 0. 7% of patients who received atorvastatin calcium in clinical trials. Persistent transaminase elevations (≥3 x ULN twice within 4 to 10 days) occurred in 1.3% of individuals with atorvastatin calcium 80 mg and in 0. 2% of individuals with atorvastatin calcium 10 mg.
The blood work should be repeated to verify elevation within 4 to 10 days if the initial test shows persistent elevations in serum transaminases 2.
From the Research
Repeating Blood Work to Verify Elevation
- The decision to repeat blood work to verify elevation of liver enzymes should be based on the clinical context and the degree of elevation of the enzymes 3, 4.
- For mild elevations (< 5 × upper limit of normal), repeat testing may be done after a period of time to assess for persistence or resolution of the elevation 3.
- For moderate to severe elevations (> 5-< 15 × ULN or > 15 × ULN), further evaluation, including serologic testing, imaging, and potentially liver biopsy, should be undertaken to determine the underlying cause of the elevation 3, 4.
- The pattern of liver injury, whether hepatocellular or cholestatic, can guide the evaluation and help determine the need for repeat testing or further investigation 4.
- In patients taking statins, mild elevations of liver enzymes are common and may not require immediate discontinuation of the medication, but rather monitoring and repeat testing to assess for persistence or worsening of the elevation 5, 6.