title: Depression is associated with low plasma Abeta42 independently of cardiovascular disease in the homebound elderly.
abstract: BACKGROUND
  Depression often precedes the onset of Alzheimer's disease (AD) before the appearance of cognitive symptoms. Plasma Amyloid-beta peptide 42 (Abeta42) declines before and soon after the onset of AD, yet the relationship between plasma Abeta42 and depression is unclear.
  
  
  METHODS
  We used 515 homebound elders aged 60 and older in a population-based, cross-sectional study to investigate associations between plasma Abeta levels and depression with and without cardiovascular co-morbidities. Depression was evaluated by using the Center for Epidemiological Studies Depression (CES-D) scale. Plasma Abeta40 and Abeta42 were measured.
  
  
  RESULTS
  The elderly with depression had lower plasma Abeta42 (median: 15.3 vs. 18.9, p = 0.008) than those without depression. The CES-D score was inversely associated with plasma Abeta42 (p = 0.001) in subjects with no cardiovascular disease (CVD); however, in the presence of CVD, this association did not exist. Low plasma Abeta42 (OR = 0.41, p = 0.007) and the presence of CVD (OR = 1.84, p = 0.005) were independently associated with depression after adjusting for the confounders of age, stroke and apolipoprotein E4.
  
  
  CONCLUSIONS
  Depressive symptoms are associated with low plasma Abeta42 independently of CVD. Prospective studies are needed to determine whether depression associated with low plasma Abeta42 is a separate depression subtype that could predict the onset of AD.
authors.affiliation: Department of Psychiatry, Tufts-New England Medical Center, Tufts University School of Medicine, Boston, MA, USA. wqiu@tufts-nemc.org
authors.forename: Wei Qiao
authors.initials: WQ
authors.lastname: Qiu
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Sun
authors.forename: Dennis J
authors.initials: DJ
authors.lastname: Selkoe
authors.forename: D Mkaya
authors.initials: DM
authors.lastname: Mwamburi
authors.forename: Tina
authors.initials: T
authors.lastname: Huang
authors.forename: Refeeque
authors.initials: R
authors.lastname: Bhadela
authors.forename: Peter
authors.initials: P
authors.lastname: Bergethon
authors.forename: Tammy M
authors.initials: TM
authors.lastname: Scott
authors.forename: Paul
authors.initials: P
authors.lastname: Summergrad
authors.forename: Lixia
authors.initials: L
authors.lastname: Wang
authors.forename: Irwin
authors.initials: I
authors.lastname: Rosenberg
authors.forename: Marshal
authors.initials: M
authors.lastname: Folstein
mesh_terms: D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000097:blood* / Q000175:diagnosis / Q000453:epidemiology / Q000523:psychology; D016229:Amyloid beta-Peptides / Q000097:blood*; D002318:Cardiovascular Diseases / Q000097:blood* / Q000175:diagnosis / Q000453:epidemiology / Q000523:psychology; D015897:Comorbidity; D003430:Cross-Sectional Studies; D003866:Depressive Disorder / Q000097:blood* / Q000175:diagnosis / Q000453:epidemiology / Q000523:psychology; D005260:Female; D018577:Homebound Persons / Q000523:psychology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D010446:Peptide Fragments / Q000097:blood*; D012016:Reference Values; D014481:United States
chemical_list: D016229:Amyloid beta-Peptides; D010446:Peptide Fragments; C075222:amyloid beta-protein (1-42)