Recent update on pathogenesis of nonalcoholic fatty liver disease

Recently, the prevalence of nonalcoholic fatty liver disease (NAFLD) is increasing in Korean population. NAFLD includes a spectrum of hepatic pathology from simple steatosis in its most benign form, to nonalcoholic steatohepatitis (NASH) and/or cirrhosis. NAFLD has a strong association with type 2 diabetes and obesity, and thus it is now recognized to represent the hepatic manifestation of metabolic syndrome. The pathogenesis of simple steatosis occurrence and its progression to NASH is not entirely elucidated and multi-factorial. Liver fat accumulation is mainly induced by insulin resistance and increased free fatty acids, and then NASH is developed by oxidative stress, lipid peroxidation, mitochondrial dysfunction, gut-derived endotoxin, and cytokine/adipokine interplay. Genetic factors and environmental factors such as exercise and high fat and high fructose diet also participate in the development of NAFLD. This review is focused to summarize the up-to-date understanding of NAFLD pathogenesis