With the increase of lifestyle-related diseases, metabolic syndrome has clearly increased in recent years. Fatty liver, which is the manifestation of metabolic syndrome in the liver, has received little attention because it is not the actual cause of death. However, with the developing increase of metabolic syndrome, non-alcoholic fatty liver disease(NAFLD), especially nonalcoholic steatohepatits(NASH), has increased, and has received much attention. In chronic liver disease, liver cirrhosis develops, finally leading to liver failure. The most serious chronic liver disease is progression to liver cancer. Once hepatic fibrosis develops, the hepatic carcinogenic rate has been increased. Hepatic carcinogenic rate has been reported to reach 8%per year in hepatitis type C-related liver cirrhosis. Although little has been reported about NASH-related liver cancer, NASH-related hepatic carcinogenic rate reached to about 2. 6%per year. In this review, we will describe the epidemiology, gender differences, risk factors and pathogenesis of NASH-related liver cancer.
Approximately 10% non-alcoholic fatty liver disease (NAFLD) cases progress to non-alcoholic steatohepatitis (NASH). Liver biopsy, the gold standard for diagnosing NASH and associated liver fibrosis, is invasive with a risk of life-threatening complications. Therefore, reliable non-invasive biomarkers for predicting NASH are required to prevent unnecessary liver biopsies. We evaluated the performance of two non-invasive fibrosis markers, Mac-2 binding protein glycosylation isomer (M2BPGi) and the FIB-4 index for predicting the fibrosis staging, NAFLD activity scoring (NAS) index, and NASH. We also analyzed the correlation between the two markers. The sensitivities, specificities, positive predictive values (PPV), and negative predictive values of the FIB-4 index, M2BPGi, and a combination of both markers for NASH diagnosis were evaluated. The M2BPGi and FIB-4 index showed a good performance in diagnosing NASH, the fibrosis stage, and the NAS index in NAFLD patients. While both markers were well-correlated with each other in most cases, no correlation was found in some patients. Compared with the FIB-4 index or the M2BPGi alone, a combination of the two showed a higher specificity, PPV, and accuracy for NASH diagnosis. The M2BPGi and the FIB-4 index are easily accessible and reliable liver fibrosis markers. Diseases other than liver disease may cause dissociation between the two markers, causing failure to predict NASH. However, the combination of both markers can compensate for their disadvantages. Because the PPV of the combination was relatively high, patients who test positive for both markers should undergo liver biopsy for NASH diagnosis.
Bile acid has attracted attention as a signal transmission molecule in energy metabolism. Although a high-fat diet (HFD) or obesity is known to increase hepatic fat content and alter bile acid composition, the changes in bile acid composition due to HFD or obesity remain to be elucidated. We sought to examine the bile acid composition in high fat diet-induced non-alcoholic fatty liver disease (NAFLD) in obese diabetic rats. Eight-week-old male spontaneously diabetic Torii fatty (SDTF) rats or control rats were fed an HFD. Twelve weeks post the commencement of HFD, serum and hepatic bile acid compositions and serum GLP-1 levels, which is stimulated by the secondary bile acid deoxycholic acid (DCA), were measured. The correlation between the bile acid composition and serum GLP-1 levels was also examined. While serum and hepatic levels of cholic acid (CA), a primary bile acid, tended to decrease in HFD-fed control rats, they were significantly decreased in HFD-fed SDTF rats. Hepatic CYP8B1, which plays a role in CA synthesis, the mRNA levels were significantly decreased in HFD-fed control and SDTF rats. In contrast, while serum and hepatic DCA levels were not changed in HFD-fed control rats, they were decreased in HFD-fed SDTF rats. Hepatic DCA/CA did not change in HFD-fed SDTF rats, but significantly increased in HFD-fed control rats. While serum GLP-1 levels were not changed in SDTF rats, they were significantly increased in HFD-fed control rats. Hepatic DCA/CA tended to correlate with serum GLP-1 levels, which tended to negatively correlate with the hepatic triglyceride content in SDTF rats. These results indicate that relatively increased DCA might contribute to an increase in serum GLP-1 levels, which inhibits hepatic steatosis in NAFLD.
