Nonalcoholic Fatty Liver

Excerpt

Non-alcoholic fatty liver disease (NAFLD) is a broad term used to cover a spectrum of conditions that are characterized by evidence of hepatic steatosis on imaging or histology (macro-vesicular steatosis), and absence of secondary causes of hepatic steatosis such as significant alcohol consumption, chronic use of medications that can cause hepatic steatosis or hereditary disorders. The definition of significant alcohol consumption has not been consistent. For non-alcoholic steatohepatitis (NASH) clinical trials, it has been defined as ongoing or recent consumption of more than 14 standard drinks on average per week in women and more than 21 standard drinks on average per week in men. Non-alcoholic fatty liver disease is most often diagnosed incidentally on imaging or when it presents with complications. The prevalence of NAFLD in Western countries is around 20 to 30%. NAFLD is considered to be the liver manifestation of metabolic syndrome. 50 to 70% of people with diabetes are found to have NAFLD.

NAFLD has several phases of progression, which include simple steatosis, steatohepatitis, fibrosis, cirrhosis, and ultimately could even progress to hepatocellular carcinoma. The disease has a benign course; it is a silent liver disease when the only histological finding is steatosis. The presence of hepatic injury with inflammation with or without fibrosis constitutes non-alcoholic steatohepatitis (NASH). Please refer to the chapters on hepatitis and non-alcoholic steatohepatitis under the transplant hepatology section for a detailed discussion of this topic.