Objectively measured physical activity is associated with dorsolateral prefrontal cortex volume in older adults
Joseph M. Northey,
Ben Rattray,
Kate L. Pumpa,
Disa J. Pryor,
Mark A. Fraser,
Marnie E. Shaw,
Kaarin J. Anstey,
Nicolas Cherbuin
Affiliations
Joseph M. Northey
UC Research Institute for Sport and Exercise, University of Canberra, ACT, 2617, Australia; Discipline of Sport and Exercise Science, Faculty of Health, University of Canberra, ACT, 2617, Australia; Centre for Research on Ageing, Health and Wellbeing, Australian National University, ACT, 2601, Australia; Corresponding author. UC Research Institute for Sport and Exercise, Building 29, University Drive, Bruce, ACT, 2617, Australia.
Ben Rattray
UC Research Institute for Sport and Exercise, University of Canberra, ACT, 2617, Australia; Discipline of Sport and Exercise Science, Faculty of Health, University of Canberra, ACT, 2617, Australia; Centre for Research on Ageing, Health and Wellbeing, Australian National University, ACT, 2601, Australia
Kate L. Pumpa
UC Research Institute for Sport and Exercise, University of Canberra, ACT, 2617, Australia; Discipline of Sport and Exercise Science, Faculty of Health, University of Canberra, ACT, 2617, Australia
Disa J. Pryor
Discipline of Sport and Exercise Science, Faculty of Health, University of Canberra, ACT, 2617, Australia
Mark A. Fraser
Centre for Research on Ageing, Health and Wellbeing, Australian National University, ACT, 2601, Australia
Marnie E. Shaw
College of Engineering and Computer Science, The Australian National University, ACT, 2601, Australia
Kaarin J. Anstey
Centre for Research on Ageing, Health and Wellbeing, Australian National University, ACT, 2601, Australia; School of Psychology, University of New South Wales, NSW, 2031, Australia; Neuroscience Research Australia, NSW, 2013, Australia
Nicolas Cherbuin
Centre for Research on Ageing, Health and Wellbeing, Australian National University, ACT, 2601, Australia
Background: Epidemiological studies suggest physical activity (PA) can slow or prevent both cognitive decline and age-related atrophy in frontal and hippocampal gray matter volumes. However, much of this evidence is based on self-reported measures of PA. Methods: PA was measured objectively with a SenseWear™ Armband to examine the cross-sectional associations between the duration of light, moderate and vigorous intensity PA with gray matter volume in the dorsolateral prefrontal cortex (DLPFC) and hippocampus in 167 (female: 43%) cognitively healthy older adults aged 73 to 78. Results: The duration of objective moderate to vigorous intensity physical activity (MVPA) was associated with a greater volume of the right DLPFC (β = 0.16; p = 0.04). In addition, objective moderate-intensity PA alone was also associated with greater volume of the left (β = 0.17; p = 0.03) and right (β = 0.19; p = 0.01) DLPFC after controlling for covariates and adjustment for multiple comparisons. In contrast, there were no significant associations between light- or vigorous-intensity PA and gray matter volumes (all p > 0.05). No associations between PA and cognitive performance were detected, and self-reported PA was not associated with any of the outcomes investigated. Conclusions: These findings suggest that an intensity-dependent relationship may exist, whereby a greater duration of MVPA, perhaps driven by moderate-intensity PA, is associated with preserved gray matter volume in frontal regions of the brain. Future research should investigate the mechanisms of this dose-effect and determine whether greater brain volumes associated with objective PA convey protective effects against cognitive decline.
