1. Division of Endocrinology and Metabolism, Department of Internal Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
2. Division of Endocrinology and Metabolism, Department of Internal Medicine, Samsung Changwon Hospital, Sungkyunkwan University School of Medicine, Changwon, Korea.
3. Division of Endocrinology and Metabolism, Department of Internal Medicine, Andong Sungso hospital, Andong, Korea.
4. Division of Endocrinology and Metabolism, Department of Internal Medicine, Dong-A Medical Center, Dong-A University College of Medicine, Busan, Korea.
5. Division of Endocrinology and Metabolism, Department of Internal Medicine, Gachon University Gil Medical Center, Gachon University of Medicine and Science, Incheon, Korea.