title: Selenium level and cognitive function in rural elderly Chinese.
abstract: Selenium is a trace element associated with antioxidant activity and is considered to be a protective agent against free radicals through enhanced enzyme activity. Studies on selenium and cognitive function or Alzheimer's disease have yielded inconsistent results. A cross-sectional survey of 2,000 rural Chinese aged 65 years or older from two provinces in the People's Republic of China was conducted from December 2003 to May 2005 by use of the Community Screening Instrument for Dementia, the Consortium to Establish a Registry for Alzheimer's Disease (CERAD) Word List Learning Test, the Indiana University Story Recall Test, the Animal Fluency Test, and the Indiana University Token Test. Over 70% of the study participants have lived in the same village since birth. Nail samples were collected and analyzed for selenium contents. Analysis-of-covariance models were used to estimate the association between quintile selenium levels measured in nail samples and cognitive test scores, with adjustment for other covariates. Lower selenium levels measured in nail samples were significantly associated with lower cognitive scores (p < 0.0087 for all tests) except the Animal Fluency Test (p = 0.4378). A dose-response effect of selenium quintiles was also seen for those significant associations. Results in this geographically stable cohort support the hypothesis that a lifelong low selenium level is associated with lower cognitive function.
authors.affiliation: Department of Medicine, School of Medicine, Indiana University, Indianapolis, IN, USA. sgao@iupui.edu
authors.forename: Sujuan
authors.initials: S
authors.lastname: Gao
authors.forename: Yinlong
authors.initials: Y
authors.lastname: Jin
authors.forename: Kathleen S
authors.initials: KS
authors.lastname: Hall
authors.forename: Chaoke
authors.initials: C
authors.lastname: Liang
authors.forename: Frederick W
authors.initials: FW
authors.lastname: Unverzagt
authors.forename: Rongdi
authors.initials: R
authors.lastname: Ji
authors.forename: Jill R
authors.initials: JR
authors.lastname: Murrell
authors.forename: Jingxiang
authors.initials: J
authors.lastname: Cao
authors.forename: Jianzhao
authors.initials: J
authors.lastname: Shen
authors.forename: Feng
authors.initials: F
authors.lastname: Ma
authors.forename: Janetta
authors.initials: J
authors.lastname: Matesan
authors.forename: Bo
authors.initials: B
authors.lastname: Ying
authors.forename: Yibin
authors.initials: Y
authors.lastname: Cheng
authors.forename: Jianchao
authors.initials: J
authors.lastname: Bian
authors.forename: Ping
authors.initials: P
authors.lastname: Li
authors.forename: Hugh C
authors.initials: HC
authors.lastname: Hendrie
mesh_terms: D000368:Aged; D002681:China / Q000453:epidemiology; D003071:Cognition / Q000502:physiology*; D003072:Cognition Disorders / Q000453:epidemiology* / Q000378:metabolism; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D009262:Nails / Q000378:metabolism; D012643:Selenium / Q000378:metabolism*
chemical_list: D012643:Selenium