title: INSULIN-LIKE GROWTH FACTOR-1 AND ANEMIA IN OLDER SUBJECTS: THE INCHIANTI STUDY.
abstract: OBJECTIVE
  Recent studies indicate a role for the age-related decline of anabolic hormones, especially testosterone, in the onset of "anemia of aging." Some of testosterone's erythropoietic activities are mediated by insulin-like growth factor (IGF)-1, which also seems to have independent erythropoietic effects. However, the associations among IGF-1, anemia, and hemoglobin (Hb) have not been adequately investigated in older populations.
  
  
  METHODS
  We used data from a representative sample of 953 subjects ≥65 years who participated in the InCHIANTI (Invecchiare in Chianti) Study and were not on growth hormone (GH) or erythropoietin therapy and were not diagnosed with hematologic malignancies or other cancers. Anemia was defined according to the World Health Organization (WHO) criteria by Hb level ≤13 g/dL in males and ≤12 g/dL in females. Backward multiple regression analyses including age, IGF binding protein (IGFBP)-3, testosterone, comorbidities, inflammatory markers, and anemia-related measures were used to address the relationship between IGF-1 and Hb and between IGF-1 and anemia in both sexes.
  
  
  RESULTS
  We found that 46/410 (11.2%) males and 71/543 (13.0%) females were defined as anemic. After adjustment for age, anemic males (100 ± 54 vs. 130 ± 56, P<.001) and females (89.1 ± 48 vs. 110 ± 52, P = .001) exhibited lower IGF-1 levels than their nonanemic counterparts. IGF-1 levels were independently and negatively associated with anemia in males (β ± SE = -0.0005 ± 0.0002, P = .04) but not in females (β ± SE = -0.0002 ± 0.0002, P = .40). In both males (β ± SE = 0.002 ± 0.001, P = .03) and females (β ± SE = 0.002 ± 0.0009, P = .03), IGF-1 levels were independently and positively associated with Hb levels.
  
  
  CONCLUSIONS
  In older males but not in females, IGF-1 levels are negatively associated with anemia. IGF-1 levels are independent and positive determinants of Hb concentration in both sexes.
authors.forename: Francesca
authors.initials: F
authors.lastname: De Vita
authors.forename: Marcello
authors.initials: M
authors.lastname: Maggio
authors.forename: Fulvio
authors.initials: F
authors.lastname: Lauretani
authors.forename: Lara
authors.initials: L
authors.lastname: Crucitti
authors.forename: Stefania
authors.initials: S
authors.lastname: Bandinelli
authors.forename: Federica
authors.initials: F
authors.lastname: Mammarella
authors.forename: Francesco
authors.initials: F
authors.lastname: Landi
authors.forename: Luigi
authors.initials: L
authors.lastname: Ferrucci
authors.forename: Gian Paolo
authors.initials: GP
authors.lastname: Ceda
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000740:Anemia / Q000097:blood* / Q000453:epidemiology; D015897:Comorbidity; D005260:Female; D019382:Human Growth Hormone / Q000097:blood; D006801:Humans; D007249:Inflammation / Q000097:blood / Q000453:epidemiology; D018972:Insulin-Like Growth Factor Binding Protein 3; D007334:Insulin-Like Growth Factor I / Q000032:analysis* / Q000378:metabolism; D007501:Iron / Q000097:blood; D007558:Italy / Q000453:epidemiology; D008297:Male; D051436:Renal Insufficiency, Chronic / Q000097:blood / Q000453:epidemiology; D013739:Testosterone / Q000097:blood
chemical_list: D018972:Insulin-Like Growth Factor Binding Protein 3; D019382:Human Growth Hormone; D013739:Testosterone; D007334:Insulin-Like Growth Factor I; D007501:Iron