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Elevated body mass index and maintenance of cognitive function in late life: exploring underlying neural mechanisms

Background: Obesity is associated with vascular risk factors that in turn, may increase dementia risk. However, higher body mass index (BMI) in late life may be neuroprotective. The possible neural mechanisms underlying the benefit of higher BMI on cognition in older adults are largely unknown. Thus...

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Autores principales: Hsu, Chun Liang, Voss, Michelle W., Best, John R., Handy, Todd C., Madden, Kenneth, Bolandzadeh, Niousha, Liu-Ambrose, Teresa
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Frontiers Media S.A. 2015
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4539697/
https://www.ncbi.nlm.nih.gov/pubmed/26347646
http://dx.doi.org/10.3389/fnagi.2015.00155
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author Hsu, Chun Liang
Voss, Michelle W.
Best, John R.
Handy, Todd C.
Madden, Kenneth
Bolandzadeh, Niousha
Liu-Ambrose, Teresa
author_facet Hsu, Chun Liang
Voss, Michelle W.
Best, John R.
Handy, Todd C.
Madden, Kenneth
Bolandzadeh, Niousha
Liu-Ambrose, Teresa
author_sort Hsu, Chun Liang
collection PubMed
description Background: Obesity is associated with vascular risk factors that in turn, may increase dementia risk. However, higher body mass index (BMI) in late life may be neuroprotective. The possible neural mechanisms underlying the benefit of higher BMI on cognition in older adults are largely unknown. Thus, we used functional connectivity magnetic resonance imaging (fcMRI) to examine: (1) the relationship between BMI and functional brain connectivity; and (2) the mediating role of functional brain connectivity in the association between baseline BMI and change in cognitive function over a 12-month period. Methods:We conducted a 12-month, prospective study among 66 community-dwelling older adults, aged 70 to 80 years, who were categorized as: normal weight (BMI from 18.50 to 24.99); overweight (BMI from 25.00 to 29.99); and obese (BMI ≥ 30.00). At baseline, participants performed a finger-tapping task during fMRI scanning. Relevant neural networks were initially identified through independent component analysis (ICA) and subsequently examined through seed-based functional connectivity analysis. At baseline and 12-months, we measured three executive cognitive processes: (1) response inhibition; (2) set shifting; and (3) working memory. Results:Obese individuals showed lower task-related functional connectivity during finger tapping in the default mode network (DMN) compared with their healthy weight counterparts (p < 0.01). Lower task-related functional connectivity in the DMN at baseline was independently associated with better working memory performance at 12-months (p = 0.02). Finally, DMN functional connectivity during finger tapping significantly mediated the relationship between baseline BMI and working memory at 12-months (indirect effect: −0.155, 95% confidence interval [−0.313, −0.053]). Conclusions:These findings suggest that functional connectivity of the DMN may be an underlying mechanism by which higher BMI confers protective effects to cognition in late life.
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spelling pubmed-45396972015-09-07 Elevated body mass index and maintenance of cognitive function in late life: exploring underlying neural mechanisms Hsu, Chun Liang Voss, Michelle W. Best, John R. Handy, Todd C. Madden, Kenneth Bolandzadeh, Niousha Liu-Ambrose, Teresa Front Aging Neurosci Neuroscience Background: Obesity is associated with vascular risk factors that in turn, may increase dementia risk. However, higher body mass index (BMI) in late life may be neuroprotective. The possible neural mechanisms underlying the benefit of higher BMI on cognition in older adults are largely unknown. Thus, we used functional connectivity magnetic resonance imaging (fcMRI) to examine: (1) the relationship between BMI and functional brain connectivity; and (2) the mediating role of functional brain connectivity in the association between baseline BMI and change in cognitive function over a 12-month period. Methods:We conducted a 12-month, prospective study among 66 community-dwelling older adults, aged 70 to 80 years, who were categorized as: normal weight (BMI from 18.50 to 24.99); overweight (BMI from 25.00 to 29.99); and obese (BMI ≥ 30.00). At baseline, participants performed a finger-tapping task during fMRI scanning. Relevant neural networks were initially identified through independent component analysis (ICA) and subsequently examined through seed-based functional connectivity analysis. At baseline and 12-months, we measured three executive cognitive processes: (1) response inhibition; (2) set shifting; and (3) working memory. Results:Obese individuals showed lower task-related functional connectivity during finger tapping in the default mode network (DMN) compared with their healthy weight counterparts (p < 0.01). Lower task-related functional connectivity in the DMN at baseline was independently associated with better working memory performance at 12-months (p = 0.02). Finally, DMN functional connectivity during finger tapping significantly mediated the relationship between baseline BMI and working memory at 12-months (indirect effect: −0.155, 95% confidence interval [−0.313, −0.053]). Conclusions:These findings suggest that functional connectivity of the DMN may be an underlying mechanism by which higher BMI confers protective effects to cognition in late life. Frontiers Media S.A. 2015-08-18 /pmc/articles/PMC4539697/ /pubmed/26347646 http://dx.doi.org/10.3389/fnagi.2015.00155 Text en Copyright © 2015 Hsu, Voss, Best, Handy, Madden, Bolandzadeh and Liu-Ambrose. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
spellingShingle Neuroscience
Hsu, Chun Liang
Voss, Michelle W.
Best, John R.
Handy, Todd C.
Madden, Kenneth
Bolandzadeh, Niousha
Liu-Ambrose, Teresa
Elevated body mass index and maintenance of cognitive function in late life: exploring underlying neural mechanisms
title Elevated body mass index and maintenance of cognitive function in late life: exploring underlying neural mechanisms
title_full Elevated body mass index and maintenance of cognitive function in late life: exploring underlying neural mechanisms
title_fullStr Elevated body mass index and maintenance of cognitive function in late life: exploring underlying neural mechanisms
title_full_unstemmed Elevated body mass index and maintenance of cognitive function in late life: exploring underlying neural mechanisms
title_short Elevated body mass index and maintenance of cognitive function in late life: exploring underlying neural mechanisms
title_sort elevated body mass index and maintenance of cognitive function in late life: exploring underlying neural mechanisms
topic Neuroscience
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4539697/
https://www.ncbi.nlm.nih.gov/pubmed/26347646
http://dx.doi.org/10.3389/fnagi.2015.00155
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