The clinical significance of hepatic steatosis remains controversial. Long known to be common,^1,2 fatty liver was once dismissed as an innocuous condition, particularly when discovered incidentally in individuals with normal serum aminotransferases.^3–5 However, as discussed subsequently, emerging evidence challenges this old assumption by demonstrating strong associations between hepatic steatosis and other potentially life threatening diseases.

Reports that some alcohol abusers and non-alcoholic individuals with fatty livers eventually develop cirrhosis and succumb to “typical” complications of advanced liver disease are certainly concerning.^3,4,6–11 Moreover, evidence suggests a detrimental interaction between hepatic steatosis and other types of chronic hepatitis because several studies have identified fatty liver as an independent predictor of progressive liver fibrosis in patients with chronic hepatitis C,^12–14 and at least one study demonstrated that hepatic steatosis conveys an independent risk for hepatocellular carcinoma in this population.¹⁵ Hepatic steatosis is also associated with a poor response to antiviral therapy¹³ although this may be because it is strongly associated with obesity, which independently decreases the efficacy of hepatitis C treatment.¹⁶ In any case, there is no longer any doubt that having a fatty liver increases an individual’s risk for advanced liver disease.

In addition, fatty liver is …