Elevated LFTs: To Repeat or Not to Repeat?

Lilian White, MD
Posted on February 3, 2025

Elevated liver function tests (LFTs) are reported in 10%–20% of the population, making this laboratory abnormality a common finding for family physicians. The most common cause of elevated LFTs, accounting for approximately one-third of cases, is metabolic-associated steatotic liver disease (MASLD). Other causes include liver disease because of alcohol use, chronic hepatitis C or B, hereditary hemochromatosis, drug-induced liver injury, and (more rarely) alpha-1 antitrypsin deficiency, autoimmune hepatitis, Wilson disease, and extrahepatic causes (e.g., celiac disease, hyperthyroidism). Elevated LFTs are associated with an increased risk of all-cause mortality.

American Family Physician recently published a review article on the subject, Mildly Elevated Liver Transaminase Levels: Causes and Evaluation. Because of lack of robust studies on the optimal approach to elevated LFTs, current recommendations are largely based on expert consensus.

A study involving nearly 2,000 patients found that with repeat laboratory testing, more than 30% of adults with initially elevated LFTs had normal LFTs after an average of 17 days. Another study found that 84% of patients with elevated LFTs had persistent elevations on repeat testing 1 month later; however, less than 5% of these patients had specific disease of the liver, such as hepatitis or hemochromatosis; MASLD and excessive alcohol use were the most common causes. Based on these studies, 16%–30% of patients will have resolution of elevated LFTs on repeat testing. Therefore, repeating LFTs before an in-depth workup may reduce unnecessary testing for patients with transient elevations.

A gamma-glutamyl transferase (GGT) level can be helpful in assessing suspected liver injury due to alcohol use, with a sensitivity and specificity of approximately 60%. However, GGT is not specific for alcohol-induced liver injury and may also be elevated in renal failure, myocardial infarction, and diabetes, among other conditions.

For mildly elevated LFTs (two to three times the upper limit of normal), a repeat test in four weeks is recommended by the recent AFP article, along with a focused history and physical. If LFTs continue to be mildly elevated, further laboratory evaluation focuses on markers of liver function (eg, prothrombin time, platelet count) and the differential diagnosis. Similarly, the American College of Gastroenterology guideline recommends repeating LFTs in cases of mild elevation, but a preferred time to repeat the test is not suggested.

Patients with higher laboratory elevations and multiple laboratory abnormalities are more likely to have follow-up testing for elevated LFTs. Nevertheless, it is crucial to follow up on even mildly elevated LFTs because the degree of elevation does not correlate with the severity of underlying liver disease.