Muscular exercise can cause highly pathological liver function tests in healthy men.
Level 4 - case-series / case-control
Prospective uncontrolled before-and-after interventional study
PubMed 17764474 · doi:10.1111/j.1365-2125.2007.03001.x
What was done
Fifteen healthy men accustomed to moderate physical activity (excluding weightlifting) completed a 1-hour weightlifting protocol. Blood samples were collected at repeated intervals over 7 days post-exercise and at a follow-up visit 10–12 days post-exercise to evaluate aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LD), gamma-glutamyl transferase (gamma GT), alkaline phosphatase (ALP), bilirubin, creatine kinase (CK), and myoglobin.
What was found
Five out of the eight measured parameters (AST, ALT, LD, CK, and myoglobin) increased significantly post-exercise (P < 0.01) and remained elevated for at least 7 days. Bilirubin, gamma GT, and ALP remained within the normal range. Specific baseline or peak numeric values were not reported in the abstract.
Why it matters
Strenuous weightlifting can cause substantial, week-long elevations in standard liver transaminases in healthy individuals. Recognizing exercise-induced enzyme leakage prevents misdiagnosing asymptomatic transaminitis as drug-induced hepatotoxicity or liver disease during clinical trials and routine practice.
Limits
The study was very small (n = 15) and included only healthy men unaccustomed to weightlifting, limiting generalizability to women or resistance-trained individuals. It lacked a non-exercising control group, and the abstract omitted specific quantitative values and confidence intervals.
Cited by
- partial The greatest amount of AST (aspartate aminotransferase) in the human body is found in skeletal muscle, which frequently leads to elevated serum AST levels in individuals with high muscle mass.