1. Department of Internal Medicine, Pusan National University Hospital, Pusan National University School of Medicine, Busan, Korea.
2. Biomedical Research Institute, Pusan National University Hospital, Pusan National University School of Medicine, Busan. Korea.
3. Kim Yong Ki Internal Medicine Clinic, Busan, Korea.
4. Department of Internal Medicine, Seoul St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Korea.
5. Department of Internal Medicine, Hallym University Kangdong Sacred Heart Hospital, Hallym University College of Medicine, Seoul, Korea.
6. Department of Endocrinology and Metabolism, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea.
7. Department of Internal Medicine, Ewha Womans University School of Medicine, Seoul, Korea.
8. Department of Internal Medicine, Chonbuk National University Medical School, Jeonju, Korea.