1. National Hospital Organization Kurihama Medical and Addiction Center Yokosuka Japan
2. Division of Gastroenterology and Hepatology, Department of Internal MedicineKeio University School of Medicine Tokyo Japan
3. Division of Gastroenterology and Hepatology, Department of Internal MedicineNational Defense Medical College Tokorozawa Japan
4. Department of Health PromotionNational Institute of Public Health Wako Japan