Epidemiology: Pathogenesis, and Diagnostic Strategy of Diabetic Liver Disease in Japan.

Type 2 diabetes (T2D) is closely associated with nonalcoholic fatty liver disease (NAFLD). Nonalcoholic steatohepatitis (NASH), a severe form of NAFLD, can lead to cirrhosis, hepatocellular carcinoma (HCC), and hepatic decompensation. Patients with T2D have twice the risk of HCC incidence compared with those without T2D. Because the hepatic fibrosis grade is the main determinant of mortality in patients with NAFLD, identifying patients with advanced fibrosis using non-invasive tests (NITs) or imaging modalities is crucial. Globally, the fibrosis-4 index (FIB-4 index), NAFLD fibrosis score, and enhanced liver fibrosis test have been established to evaluate hepatic fibrosis. Two-step algorithms using FIB-4 index as first triaging tool are globally accepted. It remains unknown which kinds of NITs or elastography are best as the second step tool. In Japan, type IV collagen 7s or the CA-fibrosis index (comprising type IV collagen 7s and aspartate aminotransferase (AST)) is believed to precisely predict advanced fibrosis in NAFLD. Patients with NAFLD who have high non-invasive test results should be screened for HCC or esophageal varices. Risk factors of rapid fibrosis progression in NAFLD includes age, severe obesity, presence of T2D, menopause in women, and a patatin-like phospholipase domain containing the 3 GG genotype. Patients with NAFLD who have these risk factors should be intensively treated with lifestyle modification or pharmacotherapies for preventing liver-related mortality.

Assessment of transient elastography in Japanese patients with non-alcoholic fatty liver disease.

AIM: Transient elastography (TE) is a non-invasive method for predicting liver fibrosis. However, there are limited data regarding the performance of TE in Japanese patients with non-alcoholic fatty liver disease (NAFLD). We aimed to evaluate the association between liver stiffness measurement (LSM) by TE and liver fibrosis stage, and define a cut-off value for predicting liver fibrosis. METHODS: A total of 171 Japanese patients with biopsy-proven NAFLD underwent LSM using TE with FibroScan. The area under the receiver operating characteristic curve of LSM and other non-invasive markers of liver fibrosis were compared to determine the most accurate method of predicting liver fibrosis. RESULTS: Liver stiffness measurement significantly correlated with fibrosis stage (P < 0.001). The areas under the receiver operating characteristic curve of LSM for fibrosis stage ≥1 and ≥3 was 0.85 and 0.91, respectively and were higher than those of the aspartate aminotransferase/alanine aminotransferase ratio, aspartate aminotransferase to platelet ratio index, fibrosis-4 index, and NAFLD fibrosis score. The best cut-off values of LSM fibrosis stage ≥1 and ≥3 were 7.2 kPa (sensitivity 78.5%, specificity 78.3%) and 10.0 kPa (sensitivity 89.5%, specificity 87.6%), respectively. The combination of LSM (≥10 kPa) and type IV collagen 7 s (≥6.0 ng/mL) had a specificity of 97.6% for advanced fibrosis. The LSM in patients with high alanine aminotransferase levels or high body mass index was associated with false positive results regarding advanced fibrosis. CONCLUSIONS: In NAFLD patients, TE has excellent utility for the assessment of liver fibrosis, particularly for advanced stage cases. The cut-off value of LSM by TE for predicting liver fibrosis stage ≥3 is 10.0 kPa in Japanese NAFLD patients.