Cryptogenic cirrhosis in the region where obesity is not prevalent

AIM: Recent studies have demonstrated that obesity is the common feature of cryptogenic cirrhosis (CC) and non-alcoholic steatohepatitis. However, there is little information on CC in the region where obesity is not prevalent. METHODS: The clinical features, and the liver-related morbidity and mortality of CC were analyzed in Japan where the prevalence of obesity is low. Among 652 cirrhotic patients, we identified 29 patients (4.4%) with CC. Of these, 24 CC patients who were followed up for more than 6 months were compared in a case-control study with age-, sex-, and Child-Pugh score-matched controls having cirrhosis of viral etiology. RESULTS: Obesity (BMI≥25 kg/m2), diabetes mellitus, and hypertriglyceridemia were more frequent, and the visceral fat area was larger in the CC patients than in the controls. The indices of insulin resistance were higher and the serum aminotransferase levels were lower in the CC patients than in the controls. Logistic regression analysis identified the elevated hemoglobin A1c, BMI ≥ 25 kg/m2, and normal aminotransferase levels as independent predictors of CC. Kaplan-Meier analysis demonstrated lower occurrence of hepatocellular carcinoma and higher survival rate in the CC than in the controls in contrast to the similar cumulative probability of liver-related morbidity between those groups. CONCLUSION: CC more frequently presents with the clinical features suggestive of non-alcoholic steatohepatitis compared with controls even in the region where obesity is not prevalent. The lower occurrence of hepatocellular carcinoma and higher survival rate may indicate an indolent clinical course in CC as compared with viral cirrhosis.