1. Division of Foregut Surgery, Korea University College of Medicine, Seoul, South Korea
2. Center for Obesity and Metabolic Diseases, Korea University Anam Hospital, Seoul, South Korea
3. Department of Statistics, Daegu University, Gyeongbuk, South Korea
4. Department of Medicine, Korea University College of Medicine, Seoul, South Korea
5. Clinical and Translational Epidemiology Unit, Massachusetts General Hospital, Boston, MA, United States
6. BK21 FOUR Community-Based Intelligent Novel Drug Discovery Education Unit, College of Pharmacy and Research Institute of Pharmaceutical Sciences, Kyungpook National University, Daegu, South Korea