The Interplay between Alcoholic Liver Disease, Obesity, and the Metabolic Syndrome

BACKGROUND: Fatty liver may be the result of several factors. The two main contributors are nonalcoholic fatty liver disease (NAFLD) and alcoholic liver disease (ALD). SUMMARY: NAFLD is the hepatic manifestation of the metabolic syndrome (MetS) and is the major cause of chronic liver disease worldwide as a result of the obesity epidemic. ALD is also a common cause of chronic liver disease. Obesity is a major contributory factor to MetS and is also common in individuals who consume large amounts of alcohol. There is a similar hepatic pathology and both can result in severe fibrosis, cirrhosis, and its complications including hepatocellular carcinoma. This review discusses the etiology, pathogenesis, and genetics of both NAFLD and ALD and their interaction. It is necessary to understand this better in order to prevent and treat these important causes of liver disease worldwide. KEY MESSAGE: Obesity, MetS, and alcohol consumption are linked to the development and progression of fatty liver disease. The coexistence of these factors in many patients requires a reassessment of many aspects of treatment of fatty liver disease.