1. Division of Endocrinology and Metabolism, Department of Internal Medicine; Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
2. Center for Cohort Studies, Total Healthcare Center; Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
3. Department of Occupational and Environmental Medicine; Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
4. Department of Clinical Research Design and Evaluation, SAIHST, Sungkyunkwan University, Seoul, Republic of Korea.
5. Department of Family Medicine; Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.