title: Endocrine and inflammatory markers as predictors of frailty.
abstract: OBJECTIVE
  To examine the association of serum concentrations of 25-hydroxyvitamin D [25(OH)D], interleukin-6 (IL-6), C-reactive protein (CRP) and IGF-1 with prevalent and incident frailty.
  
  
  METHODS
  The Longitudinal Aging Study Amsterdam (LASA), a prospective cohort study with 3-yearly measurement cycles. Setting General population-based sample.
  
  
  METHODS
  The respondents were men and women aged 65 and over, who participated at T1 (1995/1996, N = 1720) and T2 (1998/1999, N = 1509). Blood samples were obtained at T1 (N = 1271). Measurements The presence of frailty at T1 and 3-year incidence of frailty. Frailty is defined as the presence of three out of nine frailty indicators.
  
  
  RESULTS
  At T1, 242 (19.0%) of all respondents were frail. Those who were frail at T1 had higher CRP and lower 25(OH)D levels. Serum 25(OH)D remained associated with frailty after adjustment for potential confounders with an odd ratios (OR) of 2.60 [95% confidence interval (95% CI) 1.60-4.21] for 25(OH)D < 25 nmol/l and 1.72 (95% CI 1.19-2.47) for 25(OH)D 25-50 nmol/l vs. high levels of 25(OH)D. Of the nonfrail at T1, 125 respondents (14.1%) became frail at T2. After adjustment, moderately elevated CRP levels (3-10 microg/ml) (OR 1.69, 95% CI 1.09-2.63) and low 25(OH)D (OR 2.04, 95% CI 1.01-4.13) were associated with incident frailty. No consistent associations were observed for IL-6 and IGF-1.
  
  
  CONCLUSIONS
  Low 25(OH)D levels were strongly associated with prevalent and incident frailty; moderately elevated levels of CRP were associated with incident frailty.
authors.affiliation: Institute for Research in Extramural Medicine (EMGO Institute), VU University Medical Centre, Amsterdam, the Netherlands. m.puts@vumc.nl
authors.forename: Martine T E
authors.initials: MT
authors.lastname: Puts
authors.forename: Marjolein
authors.initials: M
authors.lastname: Visser
authors.forename: Jos W R
authors.initials: JW
authors.lastname: Twisk
authors.forename: Dorly J H
authors.initials: DJ
authors.lastname: Deeg
authors.forename: Paul
authors.initials: P
authors.lastname: Lips
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D002097:C-Reactive Protein / Q000032:analysis; D003430:Cross-Sectional Studies; D005260:Female; D016330:Frail Elderly; D006801:Humans; D007334:Insulin-Like Growth Factor I / Q000032:analysis; D015850:Interleukin-6 / Q000097:blood; D008137:Longitudinal Studies; D008297:Male; D016017:Odds Ratio; D011237:Predictive Value of Tests; D014807:Vitamin D / Q000031:analogs & derivatives / Q000097:blood
chemical_list: D015415:Biomarkers; D015850:Interleukin-6; D014807:Vitamin D; D007334:Insulin-Like Growth Factor I; D002097:C-Reactive Protein; C104450:25-hydroxyvitamin D