title: Insulin-like growth factor-I and insulin-like growth factor binding protein-3 in Alzheimer's disease.
abstract: BACKGROUND
  Few large studies have been conducted to assess the relationship between circulating IGF and late-life cognition.
  
  
  OBJECTIVE
  The aim of the study was to assess the relationship between IGF-I and IGF binding protein-3 (IGFBP-3) serum levels and cognitive impairment, including Alzheimer's disease (AD).
  
  
  METHODS
  In this multicentric cross-sectional study, 694 elderly subjects (218 men, 476 women; 78.6 ± 6.7 yr old) were included; 481 had memory complaints and were diagnosed, after comprehensive cognitive assessment, with AD (n = 224) or mild cognitive impairment (MCI) (n = 257). The control group was comprised of 213 subjects without memory complaint and with normal cognition (recruited among patients' caregivers). IGF-I and IGFBP-3 serum levels were determined by ELISA.
  
  
  RESULTS
  IGF-I and IGFBP-3 serum levels were significantly associated with cognitive status in men (IGF-I, 137 ± 69 ng/ml for AD vs. 178 ± 88 ng/ml for MCI and 172 ± 91 ng/ml for controls, P = 0.01; IGFBP-3, 3675 ± 1542 ng/ml for AD vs. 4143 ± 1828 ng/ml for MCI and 4488 ± 1893 ng/ml for controls, P = 0.04). In women, IGFBP-3 was significantly associated with cognitive status (3781 ± 1351 ng/ml for AD vs. 4190 ± 1408 ng/ml for MCI and 4390 ± 1552 ng/ml for controls; P < 0.001), but no significant differences between groups for IGF-I occurred. After adjustment for confounding variables (age, educational level, body mass index, diabetes, apolipoprotein E ε4 status), logistic regression indicated that IGF-I [odds ratio (95% confidence interval) = 0.48 (0.26-0.88)] and IGFBP-3 [odds ratio (95% confidence interval) = 0.71 (0.52-0.97)] serum levels were independently associated with AD in men, but not in women.
  
  
  CONCLUSIONS
  We report a significant association between low IGF-I and IGFBP-3 serum levels and AD in men, but not in women.
authors.affiliation: Assistance Publique-Hôpitaux de Paris, Broca Hospital, Department of Geriatrics, 54-56 rue Pascal, 75013 Paris, France. emmanuelle.duron@brc.aphp.fr
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Duron
authors.forename: Benoît
authors.initials: B
authors.lastname: Funalot
authors.forename: Nadège
authors.initials: N
authors.lastname: Brunel
authors.forename: Joel
authors.initials: J
authors.lastname: Coste
authors.forename: Laurent
authors.initials: L
authors.lastname: Quinquis
authors.forename: Cécile
authors.initials: C
authors.lastname: Viollet
authors.forename: Joel
authors.initials: J
authors.lastname: Belmin
authors.forename: Pierre
authors.initials: P
authors.lastname: Jouanny
authors.forename: Florence
authors.initials: F
authors.lastname: Pasquier
authors.forename: Jean-Marc
authors.initials: JM
authors.lastname: Treluyer
authors.forename: Jacques
authors.initials: J
authors.lastname: Epelbaum
authors.forename: Yves
authors.initials: Y
authors.lastname: le Bouc
authors.forename: Olivier
authors.initials: O
authors.lastname: Hanon
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000097:blood* / Q000209:etiology / Q000235:genetics / Q000503:physiopathology; D001057:Apolipoproteins E / Q000235:genetics; D003071:Cognition / Q000502:physiology; D003430:Cross-Sectional Studies; D005260:Female; D005838:Genotype; D006801:Humans; D018972:Insulin-Like Growth Factor Binding Protein 3 / Q000097:blood* / Q000378:metabolism; D007334:Insulin-Like Growth Factor I / Q000032:analysis / Q000378:metabolism*; D008297:Male; D008568:Memory / Q000502:physiology; D009483:Neuropsychological Tests
chemical_list: D001057:Apolipoproteins E; D018972:Insulin-Like Growth Factor Binding Protein 3; D007334:Insulin-Like Growth Factor I