How Variable Are Liver Enzyme Results?

How should an abnormal result from a “routine” serum liver enzyme test be interpreted? Researchers studied data from a national cross-sectional sample of 1864 U.S. adults who had liver tests performed twice (mean, 17.5 days apart). About half the patients reported having consumed ≥12 alcoholic drinks in the past year, 3% had positive hepatitis C antibody tests, and 0.5% had positive hepatitis B surface antigen tests.

Initial aspartate transaminase (AST) levels were high in 6% of the people and remained elevated in 64%. Similarly, ALT levels were initially elevated in 6% and remained elevated in 68%. Of the 18% of people with initially elevated γ-glutamyl transferase (GGT) levels, they remained elevated in 88%. Of the 12% of people with initi…