Dynamic Changes and Risk Factors of Fibrosis and Steatosis Progression in Nonalcoholic Fatty Liver Disease

Inclusion Criteria: * 1\. 18-70 years of age, 2. liver biopsy proven non alcoholic fatty liver disease. 3. Agree to be followed up regularly; 4. Signature of written informed consent. Exclusion Criteria: * 1\. Patients with other liver diseases including viral hepatitis, alcoholic liver diseases, autoimmune liver diseases, drug induced liver diseases, genetic metabolic liver disease. 2\. Patients undergone bariatric surgery. 3. HIV infected patients. 4. Pregnant women. 5. Patients with severe diseases with expected survival less than 2 years. 6. Patients had followings before liver biopsy: 1. Hepatocellular carcinoma or suspected liver cancer, 2. Decompensated cirrhosis: including ascites, hepatic encephalopathy, esophageal varices bleeding or other complications of decompensated cirrhosis or hepatocelluar carcinoma; 3. Other malignancy, 4. Undergone liver transplantation surgery. 7.Patients with any other reasons not suitable for the study.