1. Division of Endocrinology and Metabolism, Department of Internal Medicine, Sejong General Hospital, Bucheon, Korea.
2. Division of Endocrinology and Metabolism, Department of Internal Medicine, Eulji General Hospital, Eulji University School of Medicine, Seoul, Korea.
3. Division of Endocrinology and Metabolism, Department of Internal Medicine, College of Medicine, The Catholic University of Korea, Seoul, Korea.