title: Inflammatory markers and cognition in well-functioning African-American and white elders.
abstract: BACKGROUND
  Several lines of evidence suggest that inflammatory mechanisms contribute to AD.
  
  
  OBJECTIVE
  To examine whether several markers of inflammation are associated with cognitive decline in African-American and white well-functioning elders.
  
  
  METHODS
  The authors studied 3,031 African-American and white men and women (mean age 74 years) enrolled in the Health, Aging, and Body Composition Study. Serum levels of interleukin-6 (IL-6) and C-reactive protein (CRP) and plasma levels of tumor necrosis factor-alpha (TNFalpha) were measured at baseline; cognition was assessed with the Modified Mini-Mental State Examination (3MS) at baseline and at follow-up. Cognitive decline was defined as a decline of >5 points.
  
  
  RESULTS
  In age-adjusted analyses, participants in the highest tertile of IL-6 or CRP performed nearly 2 points lower (worse) on baseline and follow-up 3MS (p < 0.001 for all) and declined by almost 1 point over the >2 years (p = 0.01 for IL-6 and p = 0.04 for CRP) compared with those in the lowest tertile. After multivariate adjustment, 3MS scores among participants in the highest tertile of IL-6 and CRP were similar at baseline but remained significantly lower at follow-up (p < or = 0.05 for both). Those in the highest inflammatory marker tertile were also more likely to have cognitive decline compared with the lowest tertile for IL-6 (26 vs 20%; age-adjusted odds ratio [OR] = 1.34; 95% CI 1.06 to 1.69) and for CRP (24 vs 19%; OR = 1.41; 95% CI 1.10 to 1.79) but not for TNFalpha (23 vs 21%; OR = 1.12; 95% CI 0.88 to 1.43). There was no significant interaction between race and inflammatory marker or between nonsteroidal anti-inflammatory drug use and inflammatory marker on cognition.
  
  
  CONCLUSIONS
  Serum markers of inflammation, especially IL-6 and CRP, are prospectively associated with cognitive decline in well-functioning elders. These findings support the hypothesis that inflammation contributes to cognitive decline in the elderly.
authors.affiliation: Department of Psychiatry, University of California, San Francisco 94121, USA. kyaffe@itsa.ucsf.edu
authors.forename: K
authors.initials: K
authors.lastname: Yaffe
authors.forename: K
authors.initials: K
authors.lastname: Lindquist
authors.forename: B W
authors.initials: BW
authors.lastname: Penninx
authors.forename: E M
authors.initials: EM
authors.lastname: Simonsick
authors.forename: M
authors.initials: M
authors.lastname: Pahor
authors.forename: S
authors.initials: S
authors.lastname: Kritchevsky
authors.forename: L
authors.initials: L
authors.lastname: Launer
authors.forename: L
authors.initials: L
authors.lastname: Kuller
authors.forename: S
authors.initials: S
authors.lastname: Rubin
authors.forename: T
authors.initials: T
authors.lastname: Harris
mesh_terms: D001741:Black or African American / Q000706:statistics & numerical data*; D000367:Age Factors; D000368:Aged; D000375:Aging / Q000502:physiology; D015415:Biomarkers / Q000032:analysis; D002097:C-Reactive Protein / Q000032:analysis*; D003071:Cognition / Q000502:physiology*; D015331:Cohort Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015850:Interleukin-6 / Q000097:blood*; D016013:Likelihood Functions; D008297:Male; D015999:Multivariate Analysis; D009483:Neuropsychological Tests / Q000706:statistics & numerical data; D016017:Odds Ratio; D011446:Prospective Studies; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis*; D044465:White People / Q000706:statistics & numerical data*
chemical_list: D015415:Biomarkers; D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha; D002097:C-Reactive Protein