Table 2.

‟Abnormally normal” labs in NAFLD

Laboratory test	Comments
Aminotransferases (AST, ALT)	• AST not specific for liver dysfunction* • Not well-correlated with histologic findings • Normal values vary by reference lab†, race, weight
Creatinine	• Estimated GFR (eGFR) problematic in non-Caucasian or African-American patients • eGFR may overestimate renal function in women and patients with sarcopenia
Hemoglobin A1c	• Accuracy impaired in patients with decompensated cirrhosis • Can be falsely elevated (iron-deficiency) or decreased (hemolytic) in anemic states‡
Alpha fetoprotein (AFP)	• Low PPV at common threshold of 20 ng/mL • Up to 30% of HCC tumors are non-secreters

^*AST also found in skeletal and cardiac muscle, red blood cells, bone.

^†Widely accepted upper limit of normal = 30 IU/L for men and 19 IU/L for women.

^‡Related to erythrocyte lifespan. AST: Aspartate aminotransferase; ALT: alanine aminotransferase; GFR: glomerular filtration rate; PPV: positive predictive value; HCC: hepatocellular carcinoma; NAFLD: nonalcoholic fatty liver disease.