[1] Peking Union Med Coll, Grad Sch, Beijing, Peoples R China
[2] Chinese Acad Med Sci, Beijing, Peoples R China
[3] Beijing Hosp, Natl Ctr Gerontol, Beijing, Peoples R China
[4] Beijing Inst Geriatr, Key Lab Geriatr, Beijing, Peoples R China
[5] Minist Hlth, Beijing Hosp, Beijing, Peoples R China