title: Neopterin: a potential biomarker for delirium in elderly patients.
abstract: OBJECTIVE
  The diagnosis of delirium is not supported by specific biomarkers. In a previous study, high neopterin levels were found in patients with a postoperative delirium. In the present study, we investigated levels of neopterin, interleukin-6 (IL-6) and insulin-like growth factor-1 (IGF-1) in acutely ill admitted elderly patients with and without a delirium.
  
  
  METHODS
  Plasma/serum levels of neopterin, IL-6 and IGF-1 were determined in patients aged ≥65 years admitted to the wards of Internal Medicine and Geriatrics. Differences in biomarker levels between patients with and without a delirium were investigated by the analysis of variance in models adjusted for age, gender, comorbidities and eGFR (when appropriate).
  
  
  RESULTS
  Eighty-six patients were included; 23 of them with a delirium. In adjusted models, higher mean levels of neopterin (70.5 vs. 45.9 nmol/l, p = 0.009) and IL-6 (43.1 vs. 18.5 pg/ml, p = 0.034) and lower mean levels of IGF-1 (6.3 vs. 9.3 nmol/l, p = 0.007) were found in patients with a delirium compared to those without.
  
  
  CONCLUSIONS
  The findings of this study suggest that neopterin might be a potential biomarker for delirium which, through oxidative stress and activation of the immune system, may play a role in the pathophysiology of delirium.
authors.affiliation: Section of Geriatric Medicine, Department of Internal Medicine, Erasmus University Medical Center, Rotterdam, The Netherlands.
authors.forename: Angelique
authors.initials: A
authors.lastname: Egberts
authors.forename: Eline H A
authors.initials: EH
authors.lastname: Wijnbeld
authors.forename: Durk
authors.initials: D
authors.lastname: Fekkes
authors.forename: Milly A
authors.initials: MA
authors.lastname: van der Ploeg
authors.forename: Gijsbertus
authors.initials: G
authors.lastname: Ziere
authors.forename: Herbert
authors.initials: H
authors.lastname: Hooijkaas
authors.forename: Tischa J M
authors.initials: TJ
authors.lastname: van der Cammen
authors.forename: Francesco U S
authors.initials: FU
authors.lastname: Mattace-Raso
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015415:Biomarkers / Q000097:blood; D003693:Delirium / Q000097:blood*; D005260:Female; D006801:Humans; D018970:Insulin-Like Growth Factor Binding Protein 1 / Q000097:blood; D015850:Interleukin-6 / Q000097:blood; D008297:Male; D019798:Neopterin / Q000097:blood*; D018384:Oxidative Stress / Q000502:physiology
chemical_list: D015415:Biomarkers; D018970:Insulin-Like Growth Factor Binding Protein 1; D015850:Interleukin-6; D019798:Neopterin