1. Division of Endocrinology & Metabolism, Department of Internal Medicine, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea.
2. Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.
3. Department of Internal Medicine, Pusan National University School of Medicine, Busan, Korea.
4. Department of Internal Medicine, Chonbuk National University Hospital, Jeonju, Korea.
5. Department of Internal Medicine, University of Ulsan College of Medicine, Seoul, Korea.
6. Department of Internal Medicine, Seoul National University College of Medicine, Seoul, Korea.
7. Department of Internal Medicine, The Catholic University of Korea College of Medicine, Seoul, Korea.
8. Department of Internal Medicine, WCU Program, Kyungpook National University School of Medicine, Daegu, Korea.