Association between heavy metal exposure and poor working memory and possible mediation effect of antioxidant defenses during aging

Association between heavy metal exposure and poor working memory and possible mediation effect of antioxidant defenses during aging

Author Souza-Talarico, Juliana Nery Google Scholar
Marcourakis, Tania Google Scholar
Barbosa, Fernando, Jr. Google Scholar
Moraes Barros, Silvia Berlanga Google Scholar
Rivelli, Diogo Pineda Google Scholar
Pompeia, Sabine Autor UNIFESP Google Scholar
Caramelli, Paulo Google Scholar
Plusquellec, Pierrich Google Scholar
Lupien, Sonia J. Google Scholar
Catucci, Raphael Fernandes Google Scholar
Alves, Andrea Regiani Google Scholar
Suchecki, Deborah Autor UNIFESP Google Scholar
Abstract Background: Inverse associations have been observed between memory performance and blood concentrations of cadmium (Cd) and lead (Pb). Low antioxidant cell activity has also been linked to decline in memory due to aging. However, it has not yet been established whether the heavy metal-memory relationship is mediated by differences in antioxidant activity. Methods: We examined Cd and Pb levels, as well as oxidative stress parameters, in blood samples from 125 older adults (age range 50-82 years). The Counting Span Test (CST) was used to evaluate working memory capacity (WMC). The Monte Carlo Method for Assessing Mediation (MCMAM) was used to analyze the mediation role of antioxidant activity in the heavy metals-memory association. Results: High blood Cd (BCd) concentration alone, and in combination with elevated blood Pb (BPb) concentration, was associated with poor WMC (p = 0.001) and low enzymatic antioxidant defenses (p = 0.006). The variance in WMC accounted for by BCd or by BCd combine with BPb was 20.6% and 18.6%, respectively. The MCMAM revealed that the influence of BCd and BPb concentrations on WMC was mediated by low antioxidant capacity (confidence interval -CI: 0.072 to -0.064 for BCd

CI: -0.062 to -0.045 for BPb). Conclusion: These findings showed Pb and Cd blood concentration in older adults, even at levels below the current recommended threshold, was negatively associated with WMC and that this relationship may be partly mediated by low antioxidant defenses. Knowledge on the environmental factors that negatively influence brain and cognition during aging can help inform public policy strategies to prevent and control the adverse effects of environmental contaminant exposure during aging. (C) 2016 Elsevier B.V. All rights reserved.
Keywords Cadmium
Oxidative stress
Working memory capacity
Emerging country economy
xmlui.dri2xhtml.METS-1.0.item-coverage Amsterdam
Language English
Sponsor Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
Grant number FAPESP: 2009/13911-6
CNPq: 303449/2015-2
Date 2017
Published in Science Of The Total Environment. Amsterdam, v. 575, p. 750-757, 2017.
ISSN 0048-9697 (Sherpa/Romeo, impact factor)
Publisher Elsevier Science Bv
Extent 750-757
Access rights Closed access
Type Article
Web of Science ID WOS:000390373400074

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