Epidemiology of Nonalcoholic Fatty Liver Disease / 대한내과학회지

ABSTRACT

Nonalcoholic fatty liver disease (NAFLD) is recognized as the most common liver disease with an estimated prevalence of 20-30% in the Western world and 16-33% in Korea. NAFLD encompasses a broad spectrum of hepatic dysfunction ranging from nonalcoholic fatty liver (NAFL) to nonalcoholic steatohepatitis (NASH), cirrhosis, and hepatocellular carcinoma. The increasing prevalence of NAFLD is particularly worrying because patients appear to have higher non-liver-related and liver-related death, as compared to the general population. Given its well-known association with metabolic comorbidities, NAFLD is commonly associated with obesity, type II diabetes, dyslipidemia, and metabolic syndrome. The natural history of NAFLD remains unclear due to its indolent clinical course and the lack of well-designed prospective studies. The prognosis of NAFLD depends on the histological subtype, while NASH may be associated with liver fibrosis and cirrhosis and may progress to hepatocellular carcinoma. The overall and liver-related mortality are increased in patients with NASH, as compared to NAFL and the general population. NAFLD is strongly associated with cardiovascular disease and type 2 diabetes, so it should also be considered a metabolic liver disease. Further long-term studies of the natural course of NAFLD are warranted.