Objective Physical Activity Accumulation and Brain Volume in Older Adults: An MRI and Whole-Brain Volume Study

Abstract

A decrease in brain volume (i.e., brain atrophy) is a marker of cognitive health in older adults. Insufficient weekly accumulation of moderate and vigorous physical activity (MVPA) has been associated with lower brain volume. As this association has been established for a small number of brain areas and structures and atrophy rates seem to be nonuniform between them, more comprehensive analyses are warranted. We compared the volume of 71 brain areas and structures in 45 older adults who met and did not meet objectively measured MVPA recommendations. In addition, we used multiple regression models to determine whether cardiorespiratory fitness (VO2PEAK), MVPA and health-related risk factors could affect the atrophy of brain areas and structures. An accelerometer (GT9-X ActiGraph®) was worn for 7 days. Participants were then classified into two groups: <150 minutes MVPA (< 150'MVPA) (n=20) and ≥150 minutes MVPA (≥ 150'MVPA) (n=25) per week. Older adults who accumulated ≥ 150'MVPA per week had significantly higher absolute and relative (% of intracranial volume) volumes of 39 and 9 brain areas and structures, respectively, than those who accumulated < 150'MVPA per week. Higher VO2PEAK seems to be a key predictor of the atrophy of brain areas and structures. In conclusion, meeting weekly physical activity recommendations seems to have a widespread effect on preserving the volume of more than 30 brain areas and structures in older adults. VO2PEAK seems to be the most frequent and important predictor of brain volume preservation.

Cross-sectional associations between 24-hour time-use composition, grey matter volume and cognitive function in healthy older adults

“…As this study was the first to investigate associations between 24-hour time-use composition and grey matter volume, it is challenging to contextualize the findings with previous research. However, the findings of our correlation analyses contradict several previous studies in older adults which did report significant associations between grey matter volume and physical activity (4,6,7,11), sedentary behaviour (15) or sleep (19,20) when considered independently.…”

“…On balance, a much wider range of time-use profiles were included in their study and it could be that the observed relationships between volumetric outcomes and activity levels were driven by extreme cases (e.g., highest quintiles relative to lowest) (4). Similarly, other studies that have reported associations between physical activity or sleep and grey matter volume observed differences between extreme sub-groups only (i.e., lowest VS. highest quintile of physical activity) (6,19).…”

“…Comparatively, previous studies which have reported relationships between independent time-use behaviours and grey matter volume outcomes have mostly used self-report measures of duration (19) or validated questionnaires such as the Pittsburgh Sleep Quality Index (20), PAI (4), or activity compendiums (11). Moreover, studies which have used accelerometry to derive activity patterns have not taken a 24-hour approach, and have quantified physical activity outcomes using different metrics including total physical activity (irrespective of intensity) (7) or classification into low and high levels of MVPA (6). Taken together, the variability in measures used to capture activity patterns, as well as the absence of studies that have taken a 24-hour compositional approach, limits the comparability of the current study to previous studies.…”

“…Physical activity has been identified as a modifiable risk factor for dementia in older adulthood (3) and is positively associated with both brain volume and cognitive function in healthy older adults. Cross-sectional and longitudinal magnetic resonance imaging (MRI) studies suggest that older adults who engage in higher levels of PA have greater global brain volume (4)(5)(6)(7)(8) and greater volume in medial temporal (9,10) and frontal regions (11). Similarly there is evidence that habitual physical activity is positively associated with cognitive function in healthy older adults across several cognitive domains (12).…”

Association Between 24-Hour Movement Behavior and Cognitive Function in Brazilian Middle-Aged and Older Adults: Findings From the ELSA-Brasil

“…The guideline for daily movement behavior implies the existence of an optimal combination of movement behaviors (e.g., high LPA and MVPA, low SB, and adequate sleep; Rollo et al, 2020 ). For example, higher time spent in MVPA has been associated with greater brain volume, circulating levels of brain-derived neurotrophic factor, and synaptic plasticity ( Hillman et al, 2008 ; Neves et al, 2022 ), ultimately resulting in improved cognitive function and reduced risk of dementia ( Petermann-Rocha et al, 2021 ; Rojer et al, 2021 ). However, our results suggest that tailored physical activity promotion strategies should consider the distribution of movement behaviors in the 24 hr to achieve optimal results.…”