skip to main content

DOE PAGESDOE PAGES

Title: Sedentary behavior associated with reduced medial temporal lobe thickness in middle-aged and older adults

Atrophy of the medial temporal lobe (MTL) occurs with aging, resulting in impaired episodic memory. Aerobic fitness is positively correlated with total hippocampal volume, a heavily studied memory-critical region within the MTL. However, research on associations between sedentary behavior and MTL subregion integrity is limited. Here we explore associations between thickness of the MTL and its subregions (namely CA1, CA23DG, fusiform gyrus, subiculum, parahippocampal, perirhinal and entorhinal cortex,), physical activity, and sedentary behavior. We assessed 35 non-demented middle-aged and older adults (25 women, 10 men; 45–75 years) using the International Physical Activity Questionnaire for older adults, which quantifies physical activity levels in MET-equivalent units and asks about the average number of hours spent sitting per day. All participants had high resolution MRI scans performed on a Siemens Allegra 3T MRI scanner, which allows for detailed investigation of the MTL. Controlling for age, total MTL thickness correlated inversely with hours of sitting/day (r = -0.37, p = 0.03). In MTL subregion analysis, parahippocampal (r = -0.45, p = 0.007), entorhinal (r = -0.33, p = 0.05) cortical and subiculum (r = -0.36, p = .04) thicknesses correlated inversely with hours of sitting/day. No significant correlations were observed between physical activity levelsmore » and MTL thickness. Though preliminary, our results suggest that more sedentary non-demented individuals have less MTL thickness. Future studies should include longitudinal analyses and explore mechanisms, as well as the efficacy of decreasing sedentary behaviors to reverse this association.« less
Authors:
ORCiD logo [1] ;  [2] ;  [3] ;  [1] ;  [1]
  1. Univ. of California, Los Angeles, CA (United States). Semel Inst. for Neuroscience and Human Behavior
  2. Univ. of California, Los Angeles, CA (United States). Center for Cognitive Neurosciences
  3. Univ. of Adelaide, SA (Australia). Discipline of Psychiatry
Publication Date:
Grant/Contract Number:
FC03-87ER60615; MH077650; AT003480; P01-AG024831; AG13308; P50 AG 16570; MH/AG58156; AG10123; M01-RR00865; 5P30AG028748; UL1TR000124
Type:
Accepted Manuscript
Journal Name:
PLoS ONE
Additional Journal Information:
Journal Volume: 13; Journal Issue: 4; Journal ID: ISSN 1932-6203
Publisher:
Public Library of Science
Research Org:
Univ. of California, Los Angeles, CA (United States)
Sponsoring Org:
USDOE; National Inst. of Health (NIH) (United States)
Country of Publication:
United States
Language:
English
Subject:
60 APPLIED LIFE SCIENCES; physical activity; elderly; Alzheimer's disease; behavior; central nervous system; magnetic resonance imaging; entorhinal cortex; temporal lobe
OSTI Identifier:
1505148

Siddarth, Prabha, Burggren, Alison C., Eyre, Harris A., Small, Gary W., and Merrill, David A.. Sedentary behavior associated with reduced medial temporal lobe thickness in middle-aged and older adults. United States: N. p., Web. doi:10.1371/journal.pone.0195549.
Siddarth, Prabha, Burggren, Alison C., Eyre, Harris A., Small, Gary W., & Merrill, David A.. Sedentary behavior associated with reduced medial temporal lobe thickness in middle-aged and older adults. United States. doi:10.1371/journal.pone.0195549.
Siddarth, Prabha, Burggren, Alison C., Eyre, Harris A., Small, Gary W., and Merrill, David A.. 2018. "Sedentary behavior associated with reduced medial temporal lobe thickness in middle-aged and older adults". United States. doi:10.1371/journal.pone.0195549. https://www.osti.gov/servlets/purl/1505148.
@article{osti_1505148,
title = {Sedentary behavior associated with reduced medial temporal lobe thickness in middle-aged and older adults},
author = {Siddarth, Prabha and Burggren, Alison C. and Eyre, Harris A. and Small, Gary W. and Merrill, David A.},
abstractNote = {Atrophy of the medial temporal lobe (MTL) occurs with aging, resulting in impaired episodic memory. Aerobic fitness is positively correlated with total hippocampal volume, a heavily studied memory-critical region within the MTL. However, research on associations between sedentary behavior and MTL subregion integrity is limited. Here we explore associations between thickness of the MTL and its subregions (namely CA1, CA23DG, fusiform gyrus, subiculum, parahippocampal, perirhinal and entorhinal cortex,), physical activity, and sedentary behavior. We assessed 35 non-demented middle-aged and older adults (25 women, 10 men; 45–75 years) using the International Physical Activity Questionnaire for older adults, which quantifies physical activity levels in MET-equivalent units and asks about the average number of hours spent sitting per day. All participants had high resolution MRI scans performed on a Siemens Allegra 3T MRI scanner, which allows for detailed investigation of the MTL. Controlling for age, total MTL thickness correlated inversely with hours of sitting/day (r = -0.37, p = 0.03). In MTL subregion analysis, parahippocampal (r = -0.45, p = 0.007), entorhinal (r = -0.33, p = 0.05) cortical and subiculum (r = -0.36, p = .04) thicknesses correlated inversely with hours of sitting/day. No significant correlations were observed between physical activity levels and MTL thickness. Though preliminary, our results suggest that more sedentary non-demented individuals have less MTL thickness. Future studies should include longitudinal analyses and explore mechanisms, as well as the efficacy of decreasing sedentary behaviors to reverse this association.},
doi = {10.1371/journal.pone.0195549},
journal = {PLoS ONE},
number = 4,
volume = 13,
place = {United States},
year = {2018},
month = {4}
}