1. Division of Endocrinology and Metabolism, Department of Internal Medicine, Korea University Ansan Hospital, Korea University College of Medicine, Ansan, Korea.
2. Department of Biostatistics, College of Medicine, The Catholic University of Korea, Seoul, Korea.
3. Department of Neurology, Gangnam Severance Hospital, Yonsei University College of Medicine, Seoul, Korea.
4. Department of Family Medicine, Korea University Guro Hospital, Korea University College of Medicine, Seoul, Korea.
5. Division of Endocrinology and Metabolism, Department of Internal Medicine, Korea University Anam Hospital, Korea University College of Medicine, Seoul, Korea.
6. Division of Endocrinology and Metabolism, Department of Internal Medicine, Korea University Guro Hospital, Korea University College of Medicine, Seoul, Korea.