aDepartment of Internal Medicine, Eulji General Hospital, Seoul, KoreabDepartment of Surgery, Yonsei University College of Medicine, Seoul, KoreacDepartment of Internal Medicine, Seoul National University College of Medicine, Seoul, KoreadDepartment of Surgery, Seoul National University College of Medicine, Seoul, KoreaeDepartment of Otorhinolaryngology-Head and Neck Surgery, Seoul National University College of Medicine, Seoul, KoreafDepartment of Internal Medicine, Chung-Ang University College of Medicine, Seoul, Korea