1. Division of Endocrinology and Metabolism, Department of Internal Medicine, Kyungpook National University Hospital, School of Medicine, Kyungpook National University, Daegu, Korea.
2. Department of Internal Medicine, Yeungnam University College of Medicine, Daegu, Korea.
3. Division of Pulmonary and Critical Care Medicine, Department of Internal Medicine, Kyungpook National University Hospital, School of Medicine, Kyungpook National University, Daegu, Korea.