1. Division of Endocrinology; Department of Internal Medicine; National Health Insurance Service; Ilsan Hospital; Seoul Korea
2. Department of Medicine; Graduate School of Yonsei University; Seoul Korea
3. Division of Endocrinology and Metabolism; Department of Internal Medicine; Severance Hospital; Yonsei University College of Medicine; Seoul Korea
4. Severance Executive Healthcare Clinic; Severance Hospital; Yonsei University Health System; Seoul Korea