[1] Korea Univ, Guro Hosp, Dept Internal Med, Div Nephrol, Seoul, South Korea
[2] Yonsei Univ, Coll Med, Dept Internal Med, Div Nephrol,Inst Kidney Dis, Seoul, South Korea
[3] Chonnam Natl Univ, Dept Internal Med, Div Nephrol, Med Sch, Gwangju, South Korea
[4] Catholic Univ Korea, Seoul St Marys Hosp, Dept Internal Med, Div Nephrol, Seoul, South Korea
[5] Seoul Natl Univ Hosp, Dept Internal Med, Div Nephrol, Seoul, South Korea
[6] Inje Univ, Busan Paik Hosp, Dept Internal Med, Div Cardiol, Busan, South Korea
[7] Korea Univ, Coll Med, Dept Internal Med, Div Nephrol,Guro Hosp, Gurodong Ro 148, Seoul 08308, South Korea