The natural history and risk factors for progression of non-alcoholic fatty liver disease and steatohepatitis.

Nonalcoholic fatty liver disease (NAFLD) is a condition of increasing incidence in western Countries seldom associated to other diseases of high prevalence in general population (i.e. diabetes and obesity). NAFLD ranges from simple fatty liver to steatohepatitis (NASH), which may lead to cryptogenic cirrhosis and in some cases hepatocellular carcinoma (HCC). Natural history of NAFLD in humans is poorly understood and progression of liver disease seems to be due to interaction between hosting (i.e. genetic, gut flora, insulin resistance) and environmental factors (social and eating behaviours) that should be responsible of increased oxidative stress within hepatocytes. Even if we need non-invasive markers able to describe the progression of liver disease, only meaning of liver biopsy is useful to characterize the stigmata of worsening such as inflammation and fibrosis.