title: Memory decline in Down syndrome and its relationship to iPF2alpha, a urinary marker of oxidative stress.
abstract: BACKGROUND
  Lipid peroxidation may be a marker of free-radical-mediated injury associated with Alzheimer's disease (AD). We aimed to investigate whether changes in lipid peroxidation is associated with cognitive decline in individuals with Down syndrome over a 4-year period.
  
  
  METHODS
  Thirty-two adults with DS participated in a longitudinal study with urinary isoprostane 8,12-iso-iPF2alpha (iPF2alpha) assays at baseline and four years follow-up. Informants rated their functional ability and memory function and the adults with DS attempted assessments of language skills and memory. Twenty-six individuals completed assessments of memory (Modified Memory Object Task, MOMT), adaptive behavior (ABAS), and receptive vocabulary (British Picture vocabulary, BPVS) at both time-points.
  
  
  RESULTS
  Overall change in iPF2alpha level was negatively correlated with change in the MOMT score (Spearman's Rho =  -0.576, p = 0.006), i.e., increased lipid peroxidation was correlated with worse memory functioning over time. An increase of ≥ 0.02 ng/mg creatinine iPF2α had good sensitivity (85.7%), positive predictive value (75%,), specificity (85.7%) and negative predictive value (92.3%) for memory decline.
  
  
  CONCLUSIONS
  Change in iPF2alpha over time may have potential as a biomarker for memory decline in Down syndrome and potentially also help to track progression of MCI to AD in the general population.
authors.affiliation: University College London, Division of Psychiatry, London, United Kingdom.
authors.forename: Panagiotis
authors.initials: P
authors.lastname: Zis
authors.affiliation: Division of Pharmacy and Pharmaceutical Sciences, School of Applied Sciences University of Huddersfield, Queensgate, Huddersfield, United Kingdom.
authors.forename: Patrick
authors.initials: P
authors.lastname: McHugh
authors.affiliation: University College London, Molecular Psychiatry Laboratory, London, United Kingdom.
authors.forename: Andrew
authors.initials: A
authors.lastname: McQuillin
authors.affiliation: Department of Pharmacology and Center for Translational Medicine, Temple University, Philadelphia, Pennsylvania, United States of America.
authors.forename: Domenico
authors.initials: D
authors.lastname: Praticò
authors.affiliation: Enfield Integrated Learning Disability Team, Enfield, United Kingdom.
authors.forename: Mark
authors.initials: M
authors.lastname: Dickinson
authors.affiliation: University College London, Division of Psychiatry, London, United Kingdom.
authors.forename: Sima
authors.initials: S
authors.lastname: Shende
authors.affiliation: University College London, Division of Psychiatry, London, United Kingdom.
authors.forename: Zuzana
authors.initials: Z
authors.lastname: Walker
authors.affiliation: University College London, Division of Psychiatry, London, United Kingdom.
authors.forename: Andre
authors.initials: A
authors.lastname: Strydom
mesh_terms: D000293:Adolescent; D000328:Adult; D015415:Biomarkers / Q000652:urine; D003071:Cognition; D015237:Dinoprost / Q000031:analogs & derivatives* / Q000652:urine; D004314:Down Syndrome / Q000150:complications* / Q000652:urine*; D004789:Enzyme Activation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008569:Memory Disorders / Q000175:diagnosis / Q000209:etiology* / Q000652:urine*; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D011594:Psychometrics; D055815:Young Adult
chemical_list: D015415:Biomarkers; C075750:8-epi-prostaglandin F2alpha; D015237:Dinoprost