When and how to evaluate mildly elevated liver enzymes in apparently healthy patients

Because 1% to 9% of people without symptoms have elevated liver enzymes, extensive evaluation of all abnormal test results would expose many patients to undue risks and expenses. On the other hand, failure to evaluate minor liver enzyme elevations could mean missing the early diagnosis of potentially treatable disorders. This review discusses likely causes of elevated aminotransferase, alkaline phosphatase, and gamma-glutamyl transferase levels and provides algorithms for evaluating high liver enzyme values in apparently healthy patients in the primary care setting. Key points Nonalcoholic fatty liver disease is the most common cause of asymptomatic elevated aminotransferase levels. Suspect alcoholic liver disease when the aminotransferases are elevated and the aspartate aminotransferase level is two to three times higher than the alanine aminotransferase level, especially when gamma-glutamyl transferase levels are elevated. If medications or alcohol is a suspected cause of elevated aminotransferase levels, remeasure the levels after 6 to 8 weeks of abstinence.