Obesity and NASH in Japan

Summary: Background: NASH is expected to be a major target disease in near future, although we are too short in information to realize NASH. In this study, we revealed the prevalence of fatty liver, which is a background disease of NASH, in Kyoto. Then we made histological diagnosis of NASH from chronic liver disorder with fatty liver. Materials and methods: By using the data obtained from medical check-up with more than 1000 subjects per year in Kyoto, the prevalence of fatty liver on ultrasound, serum ALT, body mass index (BMI) were compared between 1994 and 2004. Next 32 patients with elevated ALT and bright liver on ultrasound were biopsied in order to diagnose them as NASH or not. Biochemical, serological and hormonal parameters as well as adipocytokine profiles were also studied. Lastly, liver tissues from those patients were examined to compare the expression of peroxisome proliferator activator receptor (PPAR) alpha and gamma. Results: It was revealed that the prevalence of fatty liver increased from 12.9 to 34.7% over 10 years. The mean ALT and BMI also increased in this period. From 32 patients, 6 cases were excluded for alcohol, autoimmune hepatitis, and drug-induced liver injury, leaving 26 cases to enter the study. Among them, 12 and 8 patients showed grade 1 and grade 2 steatohepatitis, which were consistant with NASH. Various data were compared among simple steatosis, grade 1 steatohepatitis, and grade 2 steatohepatitis, but highly sensitive CRP was the sole parameter with statistical significance. PPAR alpha seems to be expressed higher in patients with steatohepatitis, although PPAR alpha did not show any significance. Conclusion: We found the prevalence of fatty liver was increasing over 10 years. The histological examination showed more patients with grade 1 or grade 2 steatohepatitis than expected, which means we might have much more NASH cases undiagnosed. We were unable to propose reliable diagnostic markers to diagnose NASH from this study. [Copyright &y& Elsevier]