[1] Chungnam Natl Univ Hosp, Dept Internal Med, Div Gastroenterol & Hepatol, 282 Munwha Ro, Daejeon, South Korea
[2] Chungnam Natl Univ, Sch Med, Dept Internal Med, 266 Munwha Ro, Daejeon, South Korea
[3] Chungnam Natl Univ, Sch Med, 266 Munwha Ro, Daejeon, South Korea