1. Department of Gastroenterology and Metabology , Ehime University Graduate School of Medicine , Toon , Ehime 791-0295 , Japan
2. Department of Internal Medicine, Matsuyama Shimin Hospital , Matsuyama , Ehime , Japan
3. Department of Epidemiology and Preventive Medicine , Ehime University Graduate School of Medicine , Toon , Japan
4. Epidemiology and Medical Statistics Unit, Translational Research Center , Ehime University Hospital , Toon , Japan
5. Department of Internal Medicine , Yawatahama General City Hospital , Yawatahama , Japan
6. Department of Internal Medicine , Saiseikai Matsuyama Hospital , Matsuyama , Japan
7. Department of Lifestyle-related Medicine and Endocrinology , Ehime University Graduate School of Medicine , Toon , Japan
8. Department of Gastroenterology and Metabology , Ehime University Graduate School of Medicine , Shitsukawa, Toon , Ehime , Japan