1. Division of Endocrinology and Metabolism, Department of Internal Medicine, Yeouido St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.
2. Division of Endocrinology and Metabolism, Department of Internal Medicine, St. Vincent's Hospital, College of Medicine, The Catholic University of Korea, Suwon, Korea.
3. Division of Endocrinology and Metabolism, Department of Internal Medicine, Soonchunhyang University Bucheon Hospital, Soonchunhyang University College of Medicine, Bucheon, Korea.
4. Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.
5. Division of Endocrinology and Metabolism, Department of Internal Medicine, Inje University Ilsan Paik Hospital, Inje University College of Medicine, Goyang, Korea.
6. Division of Endocrinology and Metabolism, Department of Internal Medicine, CHA Bundang Medical Center, CHA University, Seongnam, Korea.
7. Gwangmyeong Sungae Hospital, Gwangmyeong, Korea.
8. Division of Endocrinology and Metabolism, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
9. Department of Endocrinology and Metabolism, Kyung Hee University School of Medicine, Seoul, Korea.
10. Department of Internal Medicine, Seoul Metropolitan Government Seoul National University Boramae Medical Center, Seoul National University College of Medicine, Seoul, Korea.
11. Department of Internal Medicine, Korea University College of Medicine, Ansan, Korea.
12. Division of Endocrinology and Metabolism, Department of Internal Medicine, Chosun University College of Medicine, Gwangju, Korea.
13. Sejong St. Mary's Diabetes and Endocrine Clinic, Sejong, Korea.
14. Division of Endocrinology and Metabolism, Department of Internal Medicine, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea.
15. Department of Internal Medicine, Soonchunhyang University Cheonan Hospital, Soonchunhyang University College of Medicine, Cheonan, Korea.
16. Department of Endocrinology and Metabolism, Hanyang University Guri Hospital, Hanyang University College of Medicine, Guri, Korea.
17. Department of Endocrinology and Metabolism, Ajou University School of Medicine, Suwon, Korea.
18. Department of Molecular Medicine and Biopharmaceutical Sciences, Graduate School of Convergence Science and Technology, Seoul National University, Seoul, Korea.
19. Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea.