1. Department of Endocrinology and Metabolism, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea
2. Department of Endocrinology and Metabolism, Catholic University of Korea, Seoul, Korea
3. Department of Endocrinology and Metabolism, Kyung Hee University, Seoul, Korea
4. Department of Endocrinology and Metabolism, Hallym University School of Medicine, Hallym University Sacred Heart, Seoul, Korea
5. Department of Endocrinology and Metabolism, Seoul National University College of Medicine, Seoul, Korea
6. Department of Endocrinology and Metabolism, Yonsei University College of Medicine, Seoul, Korea