Practical Use of Transient Elastography in Screening for Nonalcoholic Steatohepatitis in a Japanese Population

Background and Aims:Fatty infiltration of liver may induce insulin resistance(IR),and a proportion of patients with nonalcoholic fatty liver disease(NAFLD)is diagnosed with nonalcoholic steatohepatitis.Transient elastography is gaining popularity as a means of non-invasively determining both liver stiffness(fibrosis level)and degree of fatty infiltration,expressed as controlled attenuation parameter(CAP)value.Methods:The aims of this study were to investigate the association between IR and level of fatty liver,and to identify the group at a greater risk of nonalcoholic steatohepatitis using transient elastography and other noninvasive fibrosis markers.A total of 169 patients without chronic hepatitis B and C were analyzed.Results:The CAP value was significantly associated with IR(HOMA-IR≥2.5;AUROC=0.81),and the optimal cut-off to discriminate IR was 264 dB/m.The liver stiffness measurement and aspartate aminotransferase-to-platelet ratio index values were significantly higher for CAP≥264 than in CAP<264.The 9 patients among the overall 169 patients(5.3%)and among the 102 NAFLD patients(8.8%)who showed≥264 dB and≥7.0 kPa in transient elastography could represent good candidates for liver biopsy.Conclusions:Evaluation of NAFLD based on CAP values was useful in diagnosing IR.About 9%of NAFLD patients in a Japanese outpatient clinic with a few metabolic complications might be considered good candidates for liver biopsy to confirm nonalcoholic steatohepatitis.