Recent advances in nonalcholic fatty liver disease.
OBJECTIVE
The purpose of this review is to summarize recent advances in defining the clinical features, pathophysiology, natural history, and treatment of nonalcoholic fatty liver disease.


RESULTS
Nonalcoholic fatty liver disease is present in approximately 30% of the US population. A histologic grading and staging system has been developed and validated. Nonalcoholic fatty liver disease increases the risk of developing the metabolic syndrome. The presence and severity of nonalcoholic fatty liver disease correlates with the severity of obesity, fat distribution, age, and presence of other features of the metabolic syndrome. Fifteen to 20% of subjects with nonalcoholic steatohepatitis develop cirrhosis. Hepatic steatosis is associated with an increase in both free fatty acid delivery to the liver for re-esterification and increased de-novo lipogenesis. Several mechanisms of hepatocyte injury and death including free fatty acid toxicity, increased free cholesterol, cytokine-mediated injury and activation of the unfolded protein response have been defined. While many therapeutic targets have been identified and pilot studies performed, a definitive treatment for nonalcoholic steatohepatitis remains to be established.


CONCLUSIONS
Nonalcoholic fatty liver disease is a widely prevalent disease that is critically linked to insulin resistance and the metabolic syndrome. While much new information on the pathogenesis and natural history of nonalcoholic steatohepatitis is available, an effective therapy remains to be established.
Greenfield
Victoria
V
Divisoipn of Gastroenterology, Hepatology and Nutrition, Department of Internal Medicine, Virginia Commonwealth University School of Medicine, Richmond, Virginia, USA.
Cheung
Onpan
O
Sanyal
Arun J
AJ
D005234:Fatty Liver / Q000175:diagnosis / Q000503:physiopathology* / Q000628:therapy; D022781:Hepatocytes / Q000473:pathology; D006801:Humans; D007249:Inflammation / Q000503:physiopathology; D007333:Insulin Resistance / Q000502:physiology; D008103:Liver Cirrhosis / Q000503:physiopathology