Nonalcoholic Fatty Liver Disease

Abstract

The nonalcoholic fatty liver disease (NAFLD) is the liver disorder that is most common in Western countries; has a global prevalence of approximately 25%; and is strongly associated to obesity and metabolic syndrome. According to the Third National Health and Nutrition Examination Survey (NHANES III), the prevalence of NAFLD is more common in obese individuals with a prevalence of 39.4% than in lean individuals with a prevalence of 7.7%. Nonalcoholic fatty liver disease is the hepatic manifestation of the metabolic syndrome and is defined as the accumulation of fat in the liver. The NAFLD is defined by an accumulation of fat in liver with >5% of steatosis by histologic examination or by proton density fat fraction >5.6%. The diagnosis of NAFLD implies the exclusion of secondary causes like alcohol consumption. The NAFLD includes two different pathological conditions with different prognosis: the nonalcoholic fatty liver (NAFL) and the nonalcoholic steatohepatitis (NASH), the last one has a wide spectrum of severity.