Association Between Accelerometer-Derived Physical Activity Measurements and Brain Structure

Abstract

Background and Objectives:While there is growing evidence that physical activity promotes neuronal health, studies examining the relation between physical activity and brain morphology remain inconclusive. We therefore examined whether objectively-quantified physical activity is related to brain volume, cortical thickness and grey matter density in a large cohort study. Additionally, we assessed molecular pathways that may underlie the effects of physical activity on brain morphology.Methods:We used cross-sectional baseline data from 2,550 eligible participants (57.6% women; mean age: 54.7 years, range: 30–94 years) of a prospective cohort study. Physical activity dose (metabolic equivalent hours and step counts) and intensity (sedentary, light-intensity and moderate-to-vigorous intensity activities) were recorded with accelerometers. Brain volumetric, grey matter density and cortical thickness measures were obtained from 3T MRI scans using FreeSurfer and Statistical Parametric Mapping. The relation of physical activity (independent variable) and brain structure (outcome) was examined with polynomial multivariable regression, while adjusting for age, sex, intracranial volume, education and smoking. Using gene expression profiles from the Allen Brain Atlas, we extracted molecular signatures associated with the effects of physical activity on brain morphology.Results:Physical activity dose and intensity were independently associated with larger brain volumes, grey matter density and cortical thickness of several brain regions. The effects of physical activity on brain volume were most pronounced at low physical activity quantities and differed between men and women and across age. For example, more time spent in moderate-to-vigorous intensity activities was associated with greater total grey matter volume, but the relation leveled off with more activity (standardized ß [95% confidence intervals]: 1.37 [0.35, 2.39] and -0.70 [-1.25, -0.15] for the linear and quadratic terms, respectively). The strongest effects of physical activity were observed in motor regions and cortical regions enriched for genes involved in mitochondrial respiration.Discussion:Our findings suggest that physical activity benefits brain health, with the strongest effects in motor regions and regions with a high oxidative demand. While young adults may particularly profit from additional high-intensity activities, older adults may already benefit from light-intensity activities. Physical activity and reduced sedentary time may be critical in the prevention of age-associated brain atrophy and neurodegenerative diseases.

Physical activity is associated with slower epigenetic ageing—Findings from the Rhineland study

“…Gene enrichment analysis of the nearest genes across the CpG sites demonstrated that genes, whose methylation levels were most strongly associated with physical activity, were enriched in pathways related to regulation of vascular endothelial function as well as pathways related to nervous system function and health (including synaptic signalling, sensory development and perception, as well as cell proliferation and interaction). These results thus suggest that physical activity may particularly affect neuronal signalling, thereby pointing to a novel molecular basis for previous findings suggesting that physical activity is beneficial for brain function (Silverman & Deuster, 2014;World Health Organization, 2020), an effect that is particularly evident in brain regions with a high oxidative demand (Fox et al, 2022). Larger EWAS of physical activity are required for the identification of additional molecular mechanisms through which physical activity exerts its beneficial health effects.…”

25-hydroxyvitamin D level is associated with greater grip strength across adult life span: a population-based cohort study

“…This study used cross-sectional baseline data from the first 3000 participants (age range: 30–95 years ( n = 50–95 years) of the Rhineland Study, an ongoing population-based cohort study in Bonn, Germany ( 23 ). Participants were recruited from March 2016 to March 2019.…”

“…Physical activity was continuously recorded with activPAL3 accelerometers across 7 days. We calculated average daily energy expenditure (in metabolic equivalent hours, MET hours) weighted by sensor wear time as described previously (23).…”

The Case for Light Physical Activity and Brain Health

“…Although the study by Fox et al 3 contributes to our understanding of the neuroprotective effects of physical activity, it has some limitations. Its cross-sectional design precludes conclusions about causality.…”

“…Findings examining the associations between physical activity and exercise interventions on brain volume change in older adults have largely been mixed, 6,7 likely owing to the inability to disentangle distinct components of physical activity because of limited power and little uniformity in the regions of interest examined. The study by Fox et al 3 found a preferential impact of physical activity on motor regions, which are often not explored in research on brain health.…”