Non-Alcoholic Fatty Liver Disease: From patient to population

Non-alcoholic fatty liver disease (NAFLD) has become the most common chronic liver disease in Western countries, in parallel with epidemics in obesity and type 2 diabetes mellitus. NAFLD comprises a wide range of histological findings, extending from simple steatosis to nonalcoholic steatohepatitis (NASH) with inflammation, ballooning degeneration and advanced fibrosis , which may eventually progress to end-stage cirrhosis (Figure 1). From an etiological perspective NAFLD can be divided by primary or secondary causality. Primary NAFLD is strongly associated with insulin resistance and its phenotypic manifestations, including visceral obesity and type 2 diabetes mellitus. Secondary NAFLD is less frequent and is due to a variety of medical or surgical conditions or use of pharmacological agents (e.g. methotrexate, amiodarone). Historically, primary NAFLD can only be diagnosed when other causes of liver disease and excessive ethanol consumption have been excluded.