The signs and symptoms of potential liver disease are often encountered in clinical practice. The 42-year-old asymptomatic man with an aspartate aminotransferase level of 96 U/L, the 35-year-old woman with itching and an alkaline phosphatase level of 182 U/L, and the obese woman with right-upper-quadrant pain and minimal aminotransferase elevation may all show up in the busy office of the primary care physician. These patients require further evaluation, and some may need a gastroenterology consultation.
Abnormal liver test results are also common, with or without further evidence of liver disease. Aminotransferase elevation occurs in approximately 8% of Americans, with men (9.3%) more likely to have abnormalities than women (6.6%).[1,2,3] Men (especially Native American men) are also more likely to have underlying chronic liver disease, including hepatitis C with or without alcoholic liver disease, alcoholic liver disease, nonalcoholic fatty liver disease (NAFLD), and hepatitis B.[5,6] NAFLD is often the most likely diagnosis when abnormal liver tests are encountered in adults in the absence of overt signs of advanced liver disease.
Patients with abnormal liver tests pose clinical challenges in diagnosis. The presence of elevated aminotransferase and gamma glutamyltranspeptidase (GGT) serum levels can indicate a greater likelihood of finding a cause for the liver injury. In the absence of signs of chronic liver disease, factors such as ethanol, medications, nutritional issues, female sex, or NAFLD will account for most causes of abnormal liver test results.[9,10]
If there are no physical signs of chronic liver disease in patients with mild increases of aminotransferase or alkaline phosphatase, it may be best to simply retest the patient in 3-5 months. If more than 1 liver test result is abnormal or test values are moderately or markedly elevated, the patient should be evaluated immediately. A careful history and physical examination coupled with a thoughtful laboratory and radiologic evaluation will often provide a likely diagnosis.
Medscape Gastroenterology © 2009 Medscape, LLC
Cite this: Rowen K. Zetterman. Evaluating the Patient With Abnormal Liver Tests - Medscape - Oct 08, 2009.