title: Plasma selenium over time and cognitive decline in the elderly.
abstract: BACKGROUND
  Because brain oxidative stress is a cause of cognitive impairment, selenium, which is an antioxidant, may protect against cognitive decline. The aim of the study was to examine whether declining selenium levels over time are associated with cognitive decline in a cohort of community-dwelling French elderly.
  
  
  METHODS
  During 1991-1993, 1389 subjects (age 60-71 years) were recruited into a 9-year longitudinal study with 6 waves of follow-up. Cognitive functions were evaluated by neuropsychologic tests. To take into account the entire set of cognitive measurements and the within-subject correlations between measures, we analyzed mixed linear and logistic models to study associations between selenium change and cognitive decline.
  
  
  RESULTS
  After controlling for potential confounders, cognitive decline was associated with decreases of plasma selenium over time. Among subjects who had a decrease in their plasma selenium levels, the greater the decrease in plasma selenium, the higher the probability of cognitive decline. Among subjects who had an increase in their plasma selenium levels, cognitive decline was greater in subjects with the smallest selenium increase. There was no association between short-term (2-year) selenium change and cognitive changes.
  
  
  CONCLUSIONS
  Selenium status decreases with age and may contribute to declines in neuropsychologic functions among aging people.
authors.affiliation: Inserm E361 Université Montpellier1, Montpellier, France. akbaraly@montp.inserm.fr
authors.forename: Tasnime N
authors.initials: TN
authors.lastname: Akbaraly
authors.forename: N Tasnime
authors.initials: NT
authors.lastname: Akbaraly
authors.forename: Isabelle
authors.initials: I
authors.lastname: Hininger-Favier
authors.forename: Isabelle
authors.initials: I
authors.lastname: Carrière
authors.forename: Josiane
authors.initials: J
authors.lastname: Arnaud
authors.forename: Veronique
authors.initials: V
authors.lastname: Gourlet
authors.forename: Anne-Marie
authors.initials: AM
authors.lastname: Roussel
authors.forename: Claudine
authors.initials: C
authors.lastname: Berr
mesh_terms: D000367:Age Factors; D000368:Aged; D003071:Cognition; D003072:Cognition Disorders / Q000097:blood* / Q000453:epidemiology; D015331:Cohort Studies; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D012643:Selenium / Q000378:metabolism*
chemical_list: D012643:Selenium