title: Plasma antioxidants and brain glucose metabolism in elderly subjects with cognitive complaints.
abstract: OBJECTIVE
  The role of oxidative stress is increasingly recognized in cognitive disorders of the elderly, notably Alzheimer's disease (AD). In these subjects brain(18)F-FDG PET is regarded as a reliable biomarker of neurodegeneration. We hypothesized that oxidative stress could play a role in impairing brain glucose utilization in elderly subjects with increasing severity of cognitive disturbance.
  
  
  METHODS
  The study group comprised 85 subjects with cognitive disturbance of increasing degrees of severity including 23 subjects with subjective cognitive impairment (SCI), 28 patients with mild cognitive impairment and 34 patients with mild AD. In all subjects brain FDG PET was performed and plasma activities of extracellular superoxide dismutase (eSOD), catalase and glutathione peroxidase were measured. Voxel-based analysis (SPM8) was used to compare FDG PET between groups and to evaluate correlations between plasma antioxidants and glucose metabolism in the whole group of subjects, correcting for age and Mini-Mental State Examination score.
  
  
  RESULTS
  Brain glucose metabolism progressively decreased in the bilateral posterior temporoparietal and cingulate cortices across the three groups, from SCI to mild AD. eSOD activity was positively correlated with glucose metabolism in a large area of the left temporal lobe including the superior, middle and inferior temporal gyri and the fusiform gyrus.
  
  
  CONCLUSIONS
  These results suggest a role of oxidative stress in the impairment of glucose utilization in the left temporal lobe structures in elderly patients with cognitive abnormalities, including AD and conditions predisposing to AD. Further studies exploring the oxidative stress-energy metabolism axis are considered worthwhile in larger groups of these patients in order to identify pivotal pathophysiological mechanisms and innovative therapeutic opportunities.
authors.affiliation: Clinical Neurology, Department of Neuroscience (DINOGMI), University of Genoa and IRCCS San Martino-IST, Largo P. Daneo, 3, 16132, Genoa, Italy.
authors.forename: Agnese
authors.initials: A
authors.lastname: Picco
authors.forename: M Cristina
authors.initials: MC
authors.lastname: Polidori
authors.forename: Michela
authors.initials: M
authors.lastname: Ferrara
authors.forename: Roberta
authors.initials: R
authors.lastname: Cecchetti
authors.forename: Dario
authors.initials: D
authors.lastname: Arnaldi
authors.forename: Mauro
authors.initials: M
authors.lastname: Baglioni
authors.forename: Silvia
authors.initials: S
authors.lastname: Morbelli
authors.forename: Patrizia
authors.initials: P
authors.lastname: Bastiani
authors.forename: Irene
authors.initials: I
authors.lastname: Bossert
authors.forename: Giuliana
authors.initials: G
authors.lastname: Fiorucci
authors.forename: Andrea
authors.initials: A
authors.lastname: Brugnolo
authors.forename: Massimo Eugenio
authors.initials: ME
authors.lastname: Dottorini
authors.forename: Flavio
authors.initials: F
authors.lastname: Nobili
authors.forename: Patrizia
authors.initials: P
authors.lastname: Mecocci
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000097:blood / Q000000981:diagnostic imaging*; D001921:Brain / Q000000981:diagnostic imaging* / Q000378:metabolism; D002374:Catalase / Q000097:blood; D060825:Cognitive Dysfunction / Q000097:blood / Q000000981:diagnostic imaging*; D005260:Female; D019788:Fluorodeoxyglucose F18; D005947:Glucose / Q000378:metabolism*; D005979:Glutathione Peroxidase / Q000097:blood; D006801:Humans; D008297:Male; D008875:Middle Aged; D018384:Oxidative Stress; D049268:Positron-Emission Tomography; D019275:Radiopharmaceuticals; D013482:Superoxide Dismutase / Q000097:blood
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D005947:Glucose