1. Division of Endocrinology and Metabolism, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
2. Huh's Diabetes Center and 21st Century Diabetes and Vascular Research Institute, Seoul, Korea.
3. Division of Endocrinology and Metabolism, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.
4. Department of Endocrinology and Metabolism, Ajou University School of Medicine, Suwon, Korea.
5. Department of Internal Medicine, CHA University School of Medicine, Seongnam, Korea.
6. Department of Epidemiology and Health Promotion, Institute for Health Promotion, Yonsei University Graduate School of Public Health, Seoul, Korea.
7. Department of Internal Medicine, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Korea.