[1] Chinese Acad Med Sci, Beijing Hosp, Inst Geriat Med, Natl Ctr Gerontol,Dept Rheumatol, Beijing, Peoples R China
[2] Capital Med Univ, Beijing Friendship Hosp, Natl Clin Res Ctr Digest Dis,Dept Gastroenterol, Beijing Digest Dis Ctr,Beijing Key Lab Precancerou, Beijing, Peoples R China
[3] Peking Union Med Coll Hosp, Beijing, Peoples R China
[4] Chinese Acad Med Sci, Beijing Hosp, Beijing Inst Geriat,Natl Ctr Gerontol, Inst Geriatr Med,Key Lab Geriat, BeijingBeijing 100730, Peoples R China