1. Division of Endocrinology, Department of Internal Medicine, Kwandong University College of Medicine, Myongji Hospital, Goyang, Korea.
2. Department of Preventive Medicine and Public Health, Ajou University School of Medicine, Suwon, Korea.
3. Department of Endocrinology and Metabolism, Ajou University School of Medicine, Suwon, Korea.
4. Department of Endocrinology and Metabolism, Kyung Hee University School of Medicine, Seoul, Korea.
5. Department of Internal Medicine, Hanyang University College of Medicine, Seoul, Korea.
6. Department of Internal Medicine, Inha University College of Medicine, Incheon, Korea.
7. Department of Internal Medicine, Korea University College of Medicine, Seoul, Korea.