title: Peripheral oxidative damage in mild cognitive impairment and mild Alzheimer's disease.
abstract: Oxidative stress has been shown to be a triggering event in the pathogenesis of Alzheimer's disease (AD). However, little evidence exists on the role of oxidative imbalance in Mild Cognitive Impairment (MCI), a group with a high risk of progression to AD. We therefore assessed the peripheral blood levels of a broad spectrum of non-enzymatic and enzymatic antioxidant defenses, as well as lipid and protein oxidation markers and nitrogen oxidative species in 85 MCI patients, 42 mild AD patients and 37 age-matched controls. In mild AD patients, the plasma levels of vitamin E were significantly decreased, while the plasma concentration of oxidized glutathione was increased in both MCI and mild AD patients. An increase in plasmatic and erythrocytes oxidative markers was also observed in MCI and mild AD patients as compared to controls. In both patients groups, increased levels of plasma antioxidants were found in females, whereas apolipoprotein E epsilon4 allele carriers showed higher indices of intracellular oxidative markers. Moreover, in MCI patients, cognitive function positively correlates with antioxidant levels. This study shows that most of the oxidative changes found in mild AD patients are already present in the MCI group, and that progression to AD might be accompanied by antioxidant depletion.
authors.affiliation: Laboratory of Neurochemistry, Neurology Department, Coimbra University Hospital, Coimbra, Portugal. ines.baldeiras@sapo.pt
authors.forename: Inês
authors.initials: I
authors.lastname: Baldeiras
authors.forename: Isabel
authors.initials: I
authors.lastname: Santana
authors.forename: Maria Teresa
authors.initials: MT
authors.lastname: Proença
authors.forename: Maria Helena
authors.initials: MH
authors.lastname: Garrucho
authors.forename: Rui
authors.initials: R
authors.lastname: Pascoal
authors.forename: Ana
authors.initials: A
authors.lastname: Rodrigues
authors.forename: Diana
authors.initials: D
authors.lastname: Duro
authors.forename: Catarina Resende
authors.initials: CR
authors.lastname: Oliveira
mesh_terms: D000368:Aged; D000544:Alzheimer Disease / Q000453:epidemiology* / Q000235:genetics / Q000378:metabolism; D001057:Apolipoproteins E / Q000235:genetics; D003072:Cognition Disorders / Q000175:diagnosis / Q000453:epidemiology*; D004912:Erythrocytes / Q000502:physiology; D005260:Female; D005838:Genotype; D019803:Glutathione Disulfide / Q000097:blood; D006801:Humans; D008297:Male; D009483:Neuropsychological Tests; D018384:Oxidative Stress / Q000502:physiology*; D012720:Severity of Illness Index; D014810:Vitamin E / Q000097:blood
chemical_list: D001057:Apolipoproteins E; D014810:Vitamin E; D019803:Glutathione Disulfide