title: Increased CSF levels of aromatic amino acids in hip fracture patients with delirium suggests higher monoaminergic activity.
abstract: To examine whether delirium in hip fracture patients was associated with changes in the levels of amino acids and/or monoamine metabolites in cerebrospinal fluid (CSF) and serum.
  
  
  
  In this prospective cohort study, 77 patients admitted with an acute hip fracture to Oslo University Hospital, Norway, were studied. The concentrations of amino acids in CSF and serum were determined by high performance liquid chromatography. The patients were assessed daily for delirium by the Confusion Assessment Method (pre-operatively and post-operative day 1-5 (all) or until discharge (delirious patients)). Pre-fracture dementia status was decided by an expert panel. Serum was collected pre-operatively and CSF immediately before spinal anesthesia.
  
  
  
  Fifty-three (71 %) hip fracture patients developed delirium. In hip fracture patients without dementia (n = 39), those with delirium had significantly higher CSF levels of tryptophan (40 % higher), tyrosine (60 % higher), phenylalanine (59 % higher) and the monoamine metabolite 5-hydroxyindoleacetate (23 % higher) compared to those without delirium. The same amino acids were also higher in CSF in delirious patients with dementia (n = 38). The correlations between serum and CSF amino acid levels were poor.
  
  
  
  Higher CSF levels of monoamine precursors in hip fracture patients with delirium suggest a higher monoaminergic activity in the central nervous system during delirium in this patient group.
authors.affiliation: Institute of Clinical Medicine, University of Oslo, Oslo, Norway. l.o.watne@gmail.com.|Oslo Delirium Research Group, Department of Geriatric Medicine, Oslo University Hospital, PO BOX 4950, Nydalen, N-0424, Oslo, Norway. l.o.watne@gmail.com.|Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway. l.o.watne@gmail.com.|Edinburgh Delirium Research Group, Geriatric Medicine, University of Edinburgh, Edinburgh, Scotland, UK. l.o.watne@gmail.com.
authors.forename: Leiv Otto
authors.initials: LO
authors.lastname: Watne
authors.affiliation: Institute of Clinical Medicine, University of Oslo, Oslo, Norway.|Oslo Delirium Research Group, Department of Geriatric Medicine, Oslo University Hospital, PO BOX 4950, Nydalen, N-0424, Oslo, Norway.
authors.forename: Ane-Victoria
authors.initials: AV
authors.lastname: Idland
authors.affiliation: Department of Clinical Chemistry, Erasmus MC, University Medical Center Rotterdam, Rotterdam, Netherlands.
authors.forename: Durk
authors.initials: D
authors.lastname: Fekkes
authors.affiliation: Institute of Clinical Medicine, University of Oslo, Oslo, Norway.|Department of Anesthesiology, Oslo University Hospital, Oslo, Norway.
authors.forename: Johan
authors.initials: J
authors.lastname: Raeder
authors.affiliation: Department of Orthopaedic Surgery, Oslo University Hospital, Oslo, Norway.
authors.forename: Frede
authors.initials: F
authors.lastname: Frihagen
authors.affiliation: Department of Medicine, Diakonhjemmet Hospital, Oslo, Norway.|Department of Clinical Science, University of Bergen, Bergen, Norway.
authors.forename: Anette Hylen
authors.initials: AH
authors.lastname: Ranhoff
authors.affiliation: Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway.
authors.forename: Farrukh Abbas
authors.initials: FA
authors.lastname: Chaudhry
authors.affiliation: Institute of Clinical Medicine, University of Oslo, Oslo, Norway.|Norwegian National Advisory Unit on Ageing and Health, Vestfold Health Trust, Tønsberg, Norway.
authors.forename: Knut
authors.initials: K
authors.lastname: Engedal
authors.affiliation: Institute of Clinical Medicine, University of Oslo, Oslo, Norway.|Oslo Delirium Research Group, Department of Geriatric Medicine, Oslo University Hospital, PO BOX 4950, Nydalen, N-0424, Oslo, Norway.
authors.forename: Torgeir Bruun
authors.initials: TB
authors.lastname: Wyller
authors.affiliation: Department of Complex Neurology and Neurohabilitation, Oslo University Hospital, N-0027, Oslo, Norway. bjornar.hassel@medisin.uio.no.|Norwegian Defense Research Establishment (FFI), Kjeller, Norway. bjornar.hassel@medisin.uio.no.
authors.forename: Bjørnar
authors.initials: B
authors.lastname: Hassel
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002853:Chromatography, Liquid / Q000379:methods; D003693:Delirium / Q000097:blood / Q000134:cerebrospinal fluid / Q000175:diagnosis / Q000209:etiology; D003704:Dementia / Q000150:complications / Q000175:diagnosis / Q000378:metabolism; D005260:Female; D006620:Hip Fractures / Q000097:blood / Q000134:cerebrospinal fluid / Q000150:complications / Q000601:surgery; D006801:Humans; D007211:Indoles / Q000378:metabolism*; D008297:Male; D009664:Norway; D010649:Phenylalanine / Q000378:metabolism*; D011300:Preoperative Care / Q000379:methods; D011446:Prospective Studies; D011569:Psychiatric Status Rating Scales; D015203:Reproducibility of Results; D014364:Tryptophan / Q000378:metabolism*; D014443:Tyrosine / Q000378:metabolism*
chemical_list: D007211:Indoles; D014443:Tyrosine; D010649:Phenylalanine; C024139:indole-3-lactic acid; D014364:Tryptophan