1. Department of Internal Medicine, Keimyung University School of Medicine, Daegu, Korea.
2. Department of Internal Medicine, Hallym University College of Medicine, Seoul, Korea.
3. Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea.
4. Department of Internal Medicine, National Medical Center, Seoul, Korea.
5. Department of Internal Medicine, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea.
6. Department of Internal Medicine, Inje University College of Medicine, Busan Paik Hospital, Busan, Korea.
7. Department of Internal Medicine, Chonnam National University Medical School, Gwangju, Korea.
8. Department of Biomedical Sciences, Korea University College of Medicine, Seoul, Korea.
9. Department of Internal Medicine, Seoul Metropolitan Government-Seoul National University Boramae Medical Center, Seoul, Korea.