Impact of fibrosis on liver-related event incidence in nonalcoholic fatty liver disease: A multicenter observational study

AimThere are few reports on the prognosis of liver-related events in Japanese patients with nonalcoholic fatty liver disease (NAFLD). We undertook an observational study to compare the prognosis between fibrotic and nonfibrotic groups in Japanese NAFLD patients. MethodsPrognosis in 393 NAFLD patients who underwent liver biopsy between April 2013 and April 2015 at multiple centers were investigated. The time to onset of liver-related events, cardiovascular events, development of extrahepatic cancers, and death were compared between the pathologically fibrotic nonalcoholic steatohepatitis (NASH) group and nonalcoholic fatty liver (NAFL) + nonfibrotic NASH group. A similar analysis was carried out based on the fibrotic classification diagnosed using four noninvasive fibrosis prediction models. ResultsThe mean age and body mass index at the time of liver biopsy was 55.7 years old and 28.04 kg/m(2), respectively The cumulative incidence of liver-related events at 1080 days after liver biopsy was 5.79% in the pathologically fibrotic NASH group and 0% in the NAFL + nonfibrotic NASH group, with a significant difference (p = 0.0334). The cumulative incidence of liver-related events was significantly higher in the positive group for the prediction model than in the negative group in all four models (all p values were <0.0001). There was no significant difference between the pathologically fibrotic NASH group and NAFL + nonfibrotic NASH group in terms of cumulative incidence of cardiovascular events, development of extrahepatic cancers, and death. ConclusionsThe incidence of liver-related events was significantly higher in the fibrotic NASH group than that of the NAFL + nonfibrotic NASH group in Japanese NAFLD patients.