1. Department of Internal Medicine, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seoul, Korea.
2. Department of Endocrinology and Metabolism, Ajou University School of Medicine, Suwon, Korea.
3. Department of Internal Medicine, Kyung Hee University, East-West Neo Medical Center, Seoul, Korea.
4. Department of Internal Medicine, Uijeognbu St. Mary's Hospital, Catholic University Medical College, Uijeongbu, Korea.
5. Department of Internal Medicine, Yonsei University Wonju College of Medicine, Wonju, Korea.
6. Department of Internal Medicine, Cheju National University Hospital, Cheju National University School of Medicine, Jeju, Korea.
7. Department of Internal Medicine, Yeungnam University College of Medicine, Yeungnam University Hospital, Daegu, Korea.
8. Department of Internal Medicine, Pusan Paik Hospital, College of Medicine, Inje University, Busan, Korea.
9. Department of Internal Medicine, Chonbuk National University Hospital, Jeonju, Korea.
10. Department of Internal Medicine, Chung-Ang University Hospital, College of Medicine, Chung-Ang University, Seoul, Korea.
11. Department of Internal Medicine, Dongsan Hospital, Keimyung University School of Medicine, Daegu, Korea.
12. Department of Internal Medicine, St. Vincent's Hospital, Catholic University Medical College, Suwon, Korea.
13. Department of Internal Medicine, Kyungpook National University Hospital, School of Medicine, Kyungpook National University, Daegu, Korea.