[1] Yonsei Univ, Coll Med, Inst Kidney Dis Res, Dept Internal Med, Yonsei Ro 50, Seoul, South Korea
[2] Univ Ulsan, Coll Med, Asan Med Ctr, Div Nephrol,Dept Internal Med, Seoul, South Korea
[3] Ilsan Hosp, Natl Hlth Insurance Serv Med Ctr, Dept Internal Med, Goyangshi, Gyeonggi Do, South Korea
[4] Korea Univ, Coll Med, Dept Internal Med, Seoul, South Korea
[5] Seoul Natl Univ, Coll Med, Dept Prevent Med, Seoul, South Korea
[6] Chonnam Natl Univ, Sch Med, Div Nephrol, Gwangju, South Korea
[7] Inje Univ, Busan Paik Hosp, Internal Med, Div Nephrol, Pusan, South Korea
[8] Eulji Univ, Nowon Eulji Med Ctr, Dept Internal Med, Seoul, South Korea
[9] Seoul Natl Univ, Coll Med, Dept Internal Med, Seoul, South Korea