1. Division of Endocrinology and Metabolism, Department of Internal Medicine, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Korea.
2. Division of Endocrinology and Metabolism, Department of Internal Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea.
3. Division of Endocrinology and Metabolism, Department of Internal Medicine, Seoul Metropolitan Government Borame Medical Center, Seoul National University College of Medicine, Seoul, Korea.