1. Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea.
2. Division of Endocrinology and Metabolism, Department of Internal Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
3. Department of Endocrinology and Metabolism, Kyung Hee University School of Medicine, Seoul, Korea.
4. Division of Endocrinology and Metabolism, Department of Internal Medicine, Korea University College of Medicine, Seoul, Korea.
5. Department of Internal Medicine, Seoul Metropolitan Government Boramae Medical Center, Seoul National University College of Medicine, Seoul, Korea.
6. Department of Internal Medicine, Gwangmyeong Sungae Hospital, Gwangmyeong, Korea.
7. Division of Endocrinology and Metabolism, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.
8. Division of Endocrinology and Metabolism, Department of Internal Medicine, Chungnam National University School of Medicine, Daejeon, Korea.
9. Division of Endocrinology and Metabolism, Department of Internal Medicine, Chosun University College of Medicine, Gwangju, Korea.