Alanine Aminotransferase as an Independent Predictor of Incident Nonalcoholic Fatty Liver Disease

Abstract

We read with interest the recent article by Chang et al. (1) reporting that higher serum alanine aminotransferase (ALT) concentrations, within the reference interval, independently predicted the incidence of nonalcoholic fatty liver disease (NAFLD) during a mean follow-up of 2.5 years in a large cohort of apparently healthy Korean men. Several prospective studies have previously shown that increased ALT concentrations, even within the reference interval, also predict the future development of type 2 diabetes (2) and cardiovascular events (3) independently of other known risk factors. In all of these studies, however, increased ALT concentrations have been used as a surrogate marker of NAFLD. Indeed, increased liver enzymes are usually thought to be a consequence (and not a cause) of liver injury in …