1 Center for Liver Diseases, Department of Medicine, Inova Fairfax Medical Campus, Falls Church, VA. United States.
2 Betty and Guy Beatty Center for Integrated Research, Inova Health System, Falls Church, VA. United States.
3 Center for Outcomes Research in Liver Diseases, Washington, DC. United States.
Nonalcoholic fatty liver disease (NAFLD) is rapidly becoming the most common cause of chronic liver disease worldwide. This is primarily driven by the global epidemic of obesity and diabetes as well as the ageing of the general population. Most of the data regarding the epidemiology of NAFLD is published from the studies originating in the U.S. The overall prevalence of NAFLD in the United States is estimated to be 24%. In the U.S., Hispanic Americans have a higher prevalence of NAFLD, whereas African Americans have lower prevalence of NAFLD. The exact contributions of genetic and environmental factors on these differences in the prevalence rates have not been determined. From the spectrum of NAFLD, patients with non-alcoholic steatohepatitis (NASH) are at the highest risk of progression to cirrhosis and hepatocellular carcinoma (HCC). The most recent data regarding progression of NASH suggest a complex pattern of progression and regression of fibrosis. Factors influencing the progression and regression of NASH have not been fully described.