1. Division of Endocrinology and Metabolism, Department of Internal Medicine, Wonkwang University School of Medicine, Iksan, Korea.
2. Division of Endocrinology and Metabolism, Department of Internal Medicine, Wonkwang University Sanbon Hospital, Wonkwang University School of Medicine, Gunpo, Korea.
3. Department of Public Health, Wonkwang University School of Medicine, Iksan, Korea.
4. Division of Endocrinology and Metabolism, Department of Internal Medicine, Gachon University Gil Medical Center, Gachon University College of Medicine, Incheon, Korea.