[1] Chungnam Natl Univ, Dept Otorhinolaryngol Head & Neck Surg, Coll Med, Daejeon 35015, South Korea
[2] Chungnam Natl Univ, Dept Otorhinolaryngol Head & Neck Surg, Sejong Hosp, Sejong 30099, South Korea
[3] Daegu Catholic Univ, Dept Internal Med, Sch Med, Daegu 42472, South Korea
[4] Chungnam Natl Univ Hosp, Dept Otorhinolaryngol Head & Neck Surg, Daejeon 35015, South Korea
[5] Chungnam Natl Univ Hosp, Dept Internal Med, Div Endocrinol & Metab, Daejeon 35015, South Korea
[6] Sungkyunkwan Univ, Dept Med, Div Endocrinol & Metab, Sch Med, Seoul 16419, South Korea
[7] Konyang Univ Hosp, Dept Internal Med, Daejeon 35365, South Korea
[8] Inje Univ, Dept Surg, Busan Paik Hosp, Busan 47392, South Korea
[9] Ulsan Univ, Dept Surg, Coll Med, Seoul 05505, South Korea
[10] Eulji Univ, Dept Internal Med, Coll Med, Daejeon 34824, South Korea
[11] Seoul Natl Univ, Dept Internal Med, Coll Med, Seoul 03080, South Korea