From U Sydney: Exercise and non-alcoholic fatty liver disease

http://www.ncbi.nlm.nih.gov/pubmed/22414768

J Hepatol. 2012 Mar 10. [Epub ahead of print]

Exercise and non-alcoholic fatty liver disease: a systematic review and meta-analysis.

Keating SE, Hackett DA, George J, Johnson NA.

Source

Discipline of Exercise and Sport Science, University of Sydney, Australia.

Abstract

BACKGROUND & AIMS:

Exercise is an integral component of lifestyle intervention aimed at weight loss, but an independent benefit of exercise in NAFLD has also been suggested.

METHODS:

We aimed to evaluate the efficacy of aerobic exercise and/or progressive resistance training for the modulation of liver fat and alanine aminotransferase (ALT) levels in adults. Relevant databases were searched to August 2011 for controlled trials which compared regular exercise versus a non-exercise control on change in liver fat and/or ALT.

RESULTS:

Of the 16,822 studies from the initial search, 12 were included. There was a significant pooled effect size (ES) for the comparison between exercise therapy versus control (ES = -0.37, 95% CI: -0.06 to -0.69; P=0.02), but only when interventions which compared combined exercise and diet versus diet-alone and achieved substantial weight loss were omitted. The benefit of exercise on liver fat occurred with minimal or no weight loss. There was no effect of exercise alone versus control on ALT (ES = -0.15, 95% CI: 0.14 to -0.45; P=0.32).

CONCLUSIONS:

Individual reports of exercise interventions often have low sample sizes and insufficient power to detect clinically meaningful hepatic benefits. By pooling current research we show clear evidence for a benefit of exercise therapy on liver fat but not ALT levels. This benefit is apparent with minimal or no weight loss and at exercise levels below currentexercise recommendations for obesity management. Given the paucity of current treatment options, exercise provides a valid, low-cost therapy for disorders characterised by fatty liver.