1. Department of Internal Medicine, Seoul National University College of Medicine, Seongnam, Korea
2. Division of Endocrinology and Metabolism, Department of Internal Medicine, Seoul National University Bundang Hospital, Seongnam, Korea
3. Division of Gastroenterology and Hepatology, Department of Internal Medicine, SMG-SNU Boramae Medical Center, Seoul, Korea
4. Division of Endocrinology and Metabolism, Department of Internal Medicine, SMG-SNU Boramae Medical Center, Seoul, Korea
5. Department of Preventive Medicine, Ajou University School of Medicine, Suwon, Korea