Physical activity, sedentary time, and liver enzymes in adolescents: the HELENA study

Abstract

Background: To examine the association between physical activity (PA) and liver enzyme levels in adolescents from nine European countries.

Methods: The study comprised 718 adolescents (397 girls). PA was measured by accelerometry and expressed as total PA (counts/min), and time (min/d) engaged in moderate to vigorous intensity PA (MVPA). Time spent sedentary was also objectively measured. We measured serum levels of alanine aspartate aminotransferase (AST), alanine aminotransferase (ALT), and γ-glutamyltransferase (GGT), and the AST/ALT ratio was computed.

Results: There was an association between MVPA and AST and AST/ALT (age, sex, and center-adjusted β = 0.096, 95% confidence interval (CI): 0.016 to 0.118; and β = 0.090, 95% CI: 0.006 to 0.112, respectively). Meeting the PA recommendations (60 min/d of MVPA) was significantly associated with higher AST and AST/ALT, which persisted after further adjusting for sedentary time and waist circumference. Sedentary time was not associated with any of the studied liver enzyme levels.

Conclusion: Meeting the current PA recommendations of 60 min/d of MVPA is associated with higher levels of AST and AST/ALT regardless of time spent sedentary as well as total and central body fat in European adolescents.