1. Department of Endocrinology and Metabolism, Kyung Hee University School of Medicine, Seoul, Korea
2. Department of Medical Statistics, Catholic University College of Medicine, Seoul, Korea
3. Division of Endocrinology and Metabolism, Department of Internal Medicine, Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea
4. Department of Family Medicine, Korea University College of Medicine, Seoul, Korea
5. Division of Endocrinology and Metabolism, Department of Internal Medicine, Bucheon St. Mary’s Hospital, College of Medicine, The Catholic University of Korea, Bucheon, Korea