| [ Summary ] |
Over the past forty years, there has been a rapid increase in the frequency of obesity in the Japanese population. This has resulted in an abrupt increase in life-style related diseases and metabolic syndromes. Nonalcoholic fatty liver disease (NAFLD), a hepatic manifestation of metabolic syndrome, is now present in approximately 10% of the population and parallels the frequency of central adiposity, obesity, insulin resistance, hypertension and type 2 diabetes. Nonalcoholic steatohepatitis (NASH) is the most progressive form of NAFLD, which is present in 1% of the Japanese population. There is a latent progression to liver cirrhosis and hepatocellular carcinoma (HCC). Many cases of cryptogenic cirrhosis are likely NASH in the endstage. Some of these cases have been seen to develop HCC very recently. While HCC, related to NAFLD, currently accounts for only 2% of primary liver tumors, this may soon increase. Strong links are noted in the pathogenic concepts for NAFLD / NASH, overnutrition and underactivity, insulin resistance, and genetic factors. There is a need to verify the factors involved in the transition of steatosis to NASH and cholesterol metabolism, oxidative stress, cytokines, and other proinflammatory mediators. |