title: Markers of inflammation and cognitive decline in an African-Caribbean population.
abstract: BACKGROUND
  Inflammatory processes may play an important role in cognitive decline and dementia. We investigated the prospective association between levels of three markers of inflammation, plasma interleukin-6 (IL-6), serum C-reactive protein (CRP), serum amyloid A (SAA), and cognitive decline in an African-Caribbean community population.
  
  
  METHODS
  Of 290 participants aged 55-75 years at baseline sampled from Primary Care registration lists in south London, 216 (75%) were re-interviewed after 3 years. Baseline plasma concentrations of IL-6, CRP and SAA were ascertained through immunoassays. A battery of psychometric tests was administered on both occasions and decline in both individual tests and a composite outcome was analysed.
  
  
  RESULTS
  After adjustment for potential confounding factors, raised levels of IL-6 (>3.1 pg/ml) were associated with cognitive decline in the total sample (odds ratio 2.9, 95% CI 1.1-7.5), but no associations were found for CRP or SAA. Raised IL-6 was most strongly associated with decline in orientation and immediate verbal recall tasks, with weaker associations for delayed recall and psychomotor speed.
  
  
  CONCLUSIONS
  Raised IL-6 but not CRP predicted cognitive decline in this population Inflammatory changes associated with cognitive decline may be specific to particular causal pathways.
authors.affiliation: King's College London, Institute of Psychiatry, London, UK.
authors.forename: Vesna
authors.initials: V
authors.lastname: Jordanova
authors.forename: Robert
authors.initials: R
authors.lastname: Stewart
authors.forename: Emma
authors.initials: E
authors.lastname: Davies
authors.forename: Roy
authors.initials: R
authors.lastname: Sherwood
authors.forename: Martin
authors.initials: M
authors.lastname: Prince
mesh_terms: D000368:Aged; D015415:Biomarkers / Q000378:metabolism; D044383:Black People; D002097:C-Reactive Protein / Q000378:metabolism*; D017691:Caribbean Region / Q000208:ethnology; D003072:Cognition Disorders / Q000175:diagnosis* / Q000208:ethnology; D004812:Epidemiologic Methods; D005260:Female; D006801:Humans; D015850:Interleukin-6 / Q000097:blood*; D008131:London / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D000685:Serum Amyloid A Protein / Q000378:metabolism*
chemical_list: D015415:Biomarkers; D015850:Interleukin-6; D000685:Serum Amyloid A Protein; D002097:C-Reactive Protein