Cognitive decline is associated with systemic oxidative stress: The EVA study

OBJECTIVE: To determine whether systemic oxidative stress status is associa ted with cognitive decline. DESIGN: A longitudinal population-based study. SETTING: A cohort study of older subjects in Nantes, France. PARTICIPANTS: A total of 1166 high cognitive functioning subjects aged 60 t o 70 in the Etude du Vieillissement Arteriel (EVA) cohort with a 4 year fol low-up. MEASUREMENTS: Subjects completed a baseline interview and a global cognitiv e test (Mini-Mental Status Examination (MMSE)). Blood samples were obtained at baseline to determine plasma levels of selenium, carotenoids, thiobarbi turic acid reactant substances (TBARS), an indicator of lipoperoxidation, a nd red blood cell vitamin E. Risk of cognitive decline, defined as a loss o f 3 points in MMSE score between baseline and the 4 year follow-up, was ass essed by oxidative stress level. RESULTS: Subjects with the highest levels of TEARS show an increased risk o f cognitive decline (adjusted odds ratio (OR) = 2.25; confidence interval ( CI) 95% = 1.26-4.02). This result is reinforced in the lower antioxidant st atus subgroup. Subjects with low levels of selenium have an increased risk of cognitive decline (OR = 1.58; CI 95% = 1.08-2.31) after adjustment for v arious confounding factors. CONCLUSIONS: These results suggest that increased levels of oxidative stres s and/or antioxidant deficiencies may pose risk factors for cognitive decli ne. The direct implication of oxidative stress in vascular and neurodegener ative mechanisms that lead to cognitive impairment should be further explor ed.