Physical activity is prospectively associated with adolescent nonalcoholic fatty liver disease

OBJECTIVES: To assess whether objectively-measured physical activity at mean ages 12 and 14y are prospectively associated with ultrasound scan liver fat and stiffness, alanine aminotransferase (ALT), aspartate aminotransferase (AST) and gamma-glutamyl transferase (GGT)) assessed at mean age 17.8y.

METHODS: Participants were from the Avon Longitudinal Study of Parents and Children. Total physical activity (counts per minute [CPM]) and minutes of moderate to vigorous physical activity (MVPA) were measured using Actigraph accelerometers at mean ages 12 and 14y.

RESULTS: Greater total physical activity and MVPA at ages 12 and 14y were associated with lower odds of liver fat and lower GGT levels at mean age 17.8y, e.g. per 15 minute increase in daily MVPA at age 12y, the confounder adjusted odds ratio of liver fat was 0.47 (95%CI: 0.27-0.84). Associations attenuated after additional adjustment for fat mass as a potential confounder (e.g. per 15 minute increase in daily MVPA at age 12y the odds ratio of liver fat attenuated to 0.65 [95%CI: 0.35-1.21]) or a potential mediator (e.g. per 15 minute increase in daily MVPA at age 12y the odds ratio of liver fat attenuated to 0.59 [95%CI: 0.32-1.09]). Results did not further attenuate after additional adjustment for insulin resistance. There was some evidence that greater total physical activity and MVPA at age 12y were associated with higher AST levels.

CONCLUSIONS: Adolescents who were more active in childhood have lower odds of fatty liver and lower GGT levels. These findings are likely to be, at least in part, explained by adiposity.This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives 4.0 License, where it is permissible to download and share the work, provided it is properly cited. The work cannot be changed in any way or used commercially. http://creativecommons.org/licenses/by-nc-nd/4.0.