Significant variation of traditional markers of liver injury after a half-marathon run

Background: While the promotion of health-related fitness is thereby widespread, less focus is currently being given on the biological influence that physical activity might exert on results of laboratory testing. As such, this study was undertaken to assess the kinetics of liver injury markers following physical exercise. Design and methods: Total and direct bilirubin as well as the activity of biochemical markers of liver injury including aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), gamma-glutamyl transpeptidase (GGT) and creatine kinase (CK), were measured before and after a half-marathon. Results: Significant increases occurred for GGT, AST, LDH, CK, total and direct bilirubin immediately after the run. AST, LDH, CK, total and direct bilirubin were still increased 24 h thereafter, whereas GGT decreased after 6 h. None of the athletes exceed the upper reference limit for ALT, ALP and GGT, whereas significant variations were instead observed for LDH, AST, CK, total and direct bilirubin. Conclusions: Taken together, the results of our prospective investigation clearly attest that an acute bulk of aerobic physical exercise, such as a half-marathon, might produce significant changes in the activity of traditional biomarkers of liver injury, which should be carefully considered when investigating physically active individuals undergoing laboratory testing.