Stéatopathies hépatiques non alcooliques

Non alcoholic fatty liver disease (NAFLD) is part of a spectrum of liver damage, ranging from simple steatosis to advanced fibrosis and cirrhosis similar to those of alcoholic liver disease but in the absence of significant alcohol intake. Non alcoholic steatohepatitis (NASH) is characterised by liver fatty infiltration with various degrees of inflammation, necrosis, and fibrosis. NAFLD is one of the most common causes of abnormal liver tests and NASH has been proposed as a possible cause of cryptogenic cirrhosis and hepatocellular carcinoma. The prevalence of NAFLD ranges from 10% to 24% among western general populations, whereas that of NASH is about 3%. Insulin resistance is regarded as a hallmark and a causal factor of NAFLD. Several etiologic mechanisms have been proposed as causal factors of NAFLD, including increased afflux of free fatty acids to the liver, reduced free fatty acid-oxidation, and increased lipid-peroxidation. NAFLD is associated with several underlying medical disorders: most commonly type 2 diabetes, dyslipidemia, and obesity. The diagnosis of NAFLD, rarely proposed by clinicians, is generally made when the liver biopsy reveals unexplained abnormalities. Once alcoholic abuse is ruled out, the diagnosis of NAFLD raises two questions: what is the cause? and what is the prognosis ? Although most patients have a benign disease that does not progress, others may develop fibrosis or even cirrhosis. There is no established treatment for NAFLD. Treatment is usually directed toward optimising body weight. The role of pharmacologic agents remains to be established.