The bidirectional relationship between brain structure and physical activity:A longitudinal analysis in the UK Biobank

Physical activity is a protective factor against brain atrophy, while loss of brain volume could also be a determinant of physical activity. Therefore, we aimed to explore the bidirectional association of physical activity with brain structures in middle-aged and older adults from the UK Biobank. Overall, 3027 participants (62.45 ± 7.27 years old, 51.3% females) had data at two time points. Hippocampal volume was associated with total (β=0.048, pFDR=0.016) and household (β=0.075, pFDR&lt;0.001) physical activity. Global fractional anisotropy (β=0.042, pFDR=0.028) was also associated with household physical activity. In the opposite direction, walking was negatively associated with white matter volume (β=-0.026, pFDR=0.008). All these associations were confirmed by the linear mixed models. Interestingly, sports at baseline were linked to hippocampal and frontal cortex volumes at follow-up but these associations disappeared after adjusting for multiple comparisons (pall&gt;0.104). In conclusion, we found more consistent evidence that a healthier brain structure predicted higher physical activity levels than for the inverse, more established relationship.</p

Levels of Physical Activity at Age 10 Years and Brain Morphology Changes from Ages 10 to 14 Years

Importance: Physical activity may promote healthy brain development in children, but previous research was predominantly cross-sectional and included small samples, providing limited knowledge. Objective:To investigate the longitudinal associations of physical activity with brain morphology changes. Design, Setting, and Participants: A 4-year longitudinal population-based cohort study in Rotterdam, the Netherlands, embedded in Generation R, a cohort from fetal life onward. From the women enrolled during pregnancy, children who had repeated measures of brain structure at ages 10 (range 8 to 12) years and 14 (range 13 to 15) years were included. Data were collected from March 2013 to November 2015 (baseline) and from October 2016 to January 2020 (follow-up). Data were analyzed from April to December 2022. Exposure: At age 10 years, both the child and their primary caregiver reported the child's levels of physical activity with regard to sport participation, outdoor play, and total physical activity. Primary analyses were based on an average multi-informant report. Main outcomes and measures: Brain morphology was quantified by magnetic resonance imaging. Hypothesized regions of interest were the bilateral amygdala and hippocampal volumes. Global brain measures were studied to test the specificity of the hypothesis. Results: Data were available for 1088 children (566 girls [52%]; 693 [64%] Dutch). Their mean (SD) age at baseline was 10.1 (0.6) years. For amygdala volume change, positive associations with multi-informant reports of total physical activity (β = 2.6; 95% CI, 0.3-4.9) were found. Total physical activity was associated with hippocampal volume increases only when reported by the child (β = 3.1; 95% CI, 0.4-5.8). No robust associations with global brain measures were found. Conclusions and relevance: In this cohort study of 1088 children, more physical activity at 10 years was consistently associated with an increase in amygdala volume in children aged 10 to 14 years. Physical activity and increases in hippocampal volume were found using child reports of physical activity only. These findings suggest physical activity in late childhood was prospectively associated with volumetric changes in specific subcortical structures, but not to global brain development, from late childhood to early adolescence. These findings may inform the design of future public health interventions to best facilitate neurodevelopment with physical activity..</p

Mechanisms linking physical activity with psychiatric symptoms across the lifespan:A protocol for a systematic review

INTRODUCTION: Persistent psychiatric symptomatology during childhood and adolescence predicts vulnerability to experience mental illness in adulthood. Physical activity is well-known to provide mental health benefits across the lifespan. However, the underlying mechanisms linking physical activity and psychiatric symptoms remain underexplored. In this context, we aim to systematically synthesise evidence focused on the mechanisms through which physical activity might reduce psychiatric symptoms across all ages. METHODS AND ANALYSIS: With the aid of a biomedical information specialist, we will develop a systematic search strategy based on the predetermined research question in the following electronic databases: MEDLINE, Embase, Web of Science, Cochrane and PsycINFO. Two independent reviewers will screen and select studies, extract data and assess the risk of bias. In case of inability to reach a consensus, a third person will be consulted. We will not apply any language restriction, and we will perform a qualitative synthesis of our findings as we anticipate that studies are scarce and heterogeneous. ETHICS AND DISSEMINATION: Only data that have already been published will be included. Then, ethical approval is not required. Findings will be published in a peer-reviewed journal and presented at conferences. Additionally, we will communicate our findings to healthcare providers and other sections of society (eg, through regular channels, including social media). PROSPERO REGISTRATION NUMBER: CRD42021239440

Mechanisms Linking Physical Activity with Psychiatric Symptoms Across the Lifespan:A Systematic Review

Background: Physical activity has been suggested as a protective factor against psychiatric symptoms. While numerous studies have focused on the magnitude of physical activity’s effect on psychiatric symptoms, few have examined the potential mechanisms. Objective: The current review aimed to synthesize scientific evidence of the mechanisms through which physical activity might reduce psychiatric symptoms across the lifespan. Methods: We included articles that were published before March 2022 from five electronic databases (MEDLINE, Web of Science, PsycINFO, Embase, and Cochrane). A qualitative synthesis of studies was conducted. The risk of bias assessment was performed using The Joanna Briggs Institute Critical Appraisal Tool for Systematic Reviews. Studies were included if they explored the possible mechanisms through which physical activity influences psychiatric symptoms (i.e., internalizing and externalizing symptoms) across the lifespan. Results: A total of 22 articles were included (three randomized controlled trials, four non-randomized controlled trials, three prospective longitudinal studies, and 12 cross-sectional studies). Overall, most of the studies focused on children, adolescents, and young adults. Our findings showed that self-esteem, self-concept, and self-efficacy were the only consistent paths through which physical activity influences psychiatric symptoms (specifically depressive and anxiety symptoms) across the lifespan. There were insufficient studies to determine the role of neurobiological mechanisms. Conclusions: Overall, future physical activity interventions with the purpose of improving mental health should consider these mechanisms (self-esteem, self-concept, self-efficacy) to develop more effective interventions. Clinical Trial Registration: The protocol of this study was registered in the PROSPERO database (registration number CRD42021239440) and published in April 2022.</p

Inflammatory biomarkers and brain health indicators in children with overweight and obesity: The ActiveBrains project

INTRODUCTION: Chronic inflammation plays an important role on the pathogenesis of several cardiovascular and metabolic diseases, as well as on brain function and behaviour. The aim of the present study was to examine the associations between inflammatory biomarkers and a wide range of brain health indicators (i.e., academic performance, executive function, behavioural and emotional functioning, and brain volume) in children with overweight/obesity. METHODS: A total of 107 children (10.0 ± 1.1 years, 41% girls) from the ActiveBrains project were included in the analysis. Five inflammatory biomarkers were analysed in plasma: white blood cell (WBC) count, interleukin-6 (IL-6), interleukin-1beta, tumor necrosis factor-alpha (TNF-alpha), and C-reactive protein (CRP). Academic performance was assessed by Woodcock-Munoz Tests of Achievement. Executive function was assessed through the Design Fluency Test for cognitive flexibility, the Stroop test for cognitive inhibition, and the Delayed Non-Match-to-Sample task for working memory. Behavioural and emotional functioning was evaluated through the Behavior Assessment System for Children (BASC) questionnaire. Total and regional brain volume was assessed by magnetic resonance imaging. RESULTS: IL-6 was inversely associated with adaptive skills (beta = -0.228; p = 0.030), while TNF-alpha was related to mathematics (beta = -0.198; p = 0.034). In addition, CRP was positively associated with externalizing (beta = 0.246; p = 0.046) and internalizing problems (beta = 0.234; p = 0.039), as well as the behavioural symptoms index (beta = 0.236; p = 0.047). However, these significant associations disappeared after multiple comparisons correction. Inflammatory biomarkers were not associated with executive function and total brain volumes. Regarding regional brain analyses, WBC was positively associated with gray matter volume in the left middle temporal gyrus (beta = 0.387; p < 0.001, k = 44), and CRP was positively associated with gray matter volume in the right superior temporal gyrus (beta = 0.439; p < 0.001, k = 29). Additionally, when adjusting by total brain volume, CRP was positively associated with gray matter volume in the right supplementary motor cortex (beta = 0.453; p < 0.001, k = 51). Moreover, both, IL-6 (beta = 0.366; p < 0.001, k = 81) and TNF-alpha (beta = 0.368; p < 0.001, k = 62) were positively associated with white matter volume around the right inferior frontal gyrus pars opercularis, while CRP was inversely associated with white matter volume around the left superior frontal gyrus (beta = -0.482; p < 0.001, k = 82). After adjusting by total brain volume, CRP was also inversely associated with white matter volume in 3 additional clusters (beta ranging from -0.473 to -0.404; p < 0.001, k = 87). CONCLUSIONS: Inflammation was slightly associated with brain health (i.e., academic performance, behavioural and emotional functioning and regional brain volume) in children with overweight or obesity. Further larger longitudinal and interventional studies are warranted to elucidate the short-term and long-term effect of systemic low-grade inflammation on children's brain health

The effects of an exercise intervention on neuroelectric activity and executive function in children with overweight/obesity:The ActiveBrains randomized controlled trial

Objective: To investigate whether a 20-week aerobic and resistance exercise program induces changes in brain current density underlying working memory and inhibitory control in children with overweight/obesity. Methods: A total of 67 children (10.00 ± 1.10 years) were randomized into an exercise or control group. Electroencephalography (EEG)-based current density (μA/mm2) was estimated using standardized low-resolution brain electromagnetic tomography (sLORETA) during a working memory task (Delayed non-matched-to-sample task, DNMS) and inhibitory control task (Modified flanker task, MFT). In DNMS, participants had to memorize four stimuli (Pokemons) and then select between two of them, one of which had not been previously shown. In MFT, participants had to indicate whether the centered cow (i.e., target) of five faced the right or left. Results: The exercise group had significantly greater increases in brain activation in comparison with the control group during the encoding phase of DNMS, particularly during retention of second stimuli in temporal and frontal areas (peak t = from 3.4 to 3.8, cluster size [k] = from 11 to 39), during the retention of the third stimuli in frontal areas (peak t = from 3.7 to 3.9, k = from 15 to 26), and during the retention of the fourth stimuli in temporal and occipital areas (peak t = from 2.7 to 4.3, k = from 13 to 101). In MFT, the exercise group presented a lower current density change in the middle frontal gyrus (peak t = −4.1, k = 5). No significant change was observed between groups for behavioral performance (p ≥ 0.05). Conclusion: A 20-week exercise program modulates brain activity which might provide a positive influence on working memory and inhibitory control in children with overweight/obesity.</p

Effectiveness of Exercise on Fatigue and Sleep Quality in Fibromyalgia: A Systematic Review and Meta-analysis of Randomized Trials

Objectives: To determine the effects of exercise on fatigue and sleep quality in fibromyalgia (primary aim) and to identify which type of exercise is the most effective in achieving these outcomes (secondary aim). Data Sources: PubMed and Web of Science were searched from inception until October 18, 2018. Study Selection: Eligible studies contained information on population (fibromyalgia), intervention (exercise), and outcomes (fatigue or sleep). Randomized controlled trials (RCT) testing the effectiveness of exercise compared with usual care and randomized trials (RT) comparing the effectiveness of 2 different exercise interventions were included for the primary and secondary aims of the present review, respectively. Two independent researchers performed the search, screening, and final eligibility of the articles. Of 696 studies identified, 17 RCTs (nZ1003) were included for fatigue and 12 RCTs (nZ731) for sleep. Furthermore, 21 RTs compared the effectiveness of different exercise interventions (nZ1254). Data Extraction: Two independent researchers extracted the key information from each eligible study. Data Synthesis: Separate random-effect meta-analyses were performed to examine the effects from RCTs and from RTs (primary and secondary aims). Standardized mean differences (SMD) effect sizes were calculated using Hedges’ adjusted g. Effect sizes of 0.2, 0.4, and 0.8 were considered small, moderate, and large. Compared with usual care, exercise had moderate effects on fatigue and a small effect on sleep quality (SMD, e0.47; 95% confidence interval [CI], e0.67 to e0.27; P<.001 and SMD, e0.17; 95% CI, e0.32 to e0.01; PZ.04). RTs in which fatigue was the primary outcome were the most beneficial for lowering fatigue. Additionally, meditative exercise programs were the most effective for improving sleep quality. Conclusions: Exercise is moderately effective for lowering fatigue and has small effects on enhancing sleep quality in fibromyalgia. Meditative exercise programs may be considered for improving sleep quality in fibromyalgi

Physical activity and amyloid beta in middle-aged and older adults:A systematic review and meta-analysis

Background: One of the pathological hallmarks distinguishing Alzheimer's disease from other dementias is the accumulation of amyloid beta (Aβ). Higher physical activity is associated with decreased dementia risk, and one potential path could be through Aβ levels modulation. We aimed to explore the relationship between physical activity and Aβ in middle-aged and older adults. Methods: A systematic search of PubMed, Web of Science, PsycINFO, Cochrane Central Register of Controlled Trials, and SPORTDiscus was performed from inception to the 28th of April 2022. Studies were eligible if they included physical activity and Aβ data in adults aged 45 years or older. Multi-level meta-analyses of intervention and observational studies were performed to examine the role of physical activity in modulating Aβ levels. Results: In total, 37 articles were included (8 randomized controlled trials, 3 non-randomized controlled trials, 4 prospective longitudinal studies, and 22 cross-sectional studies). The overall effect size of physical activity interventions on changes in blood Aβ was medium (pooled standardized mean difference = –0.69, 95% confidence interval (95%CI): –1.41 to 0.03; I2 = 74.6%). However, these results were not statistically significant, and there were not enough studies to explore the effects of physical activity on cerebrospinal fluid (CSF) and brain Aβ. Data from observational studies were examined based on measurements of Aβ in the brain using positron emission tomography scans, CSF, and blood. Higher physical activity was positively associated with Aβ only in the CSF (Estimate r = 0.12; 95%CI: 0.05–0.18; I2 = 38%). Conclusion: Physical activity might moderately reduce blood Aβ in middle-aged and older adults. However, results were only near statistical significance and might be interpreted with caution given the methodological limitations observed in some of the included studies. In observational studies, higher levels of physical activity were positively associated with Aβ only in CSF. Therefore, further research is needed to understand the modulating role of physical activity in the brain, CSF, and blood Aβ, as well as its implication for cognitive health.</p

Physical activity and amyloid beta in middle-aged and older adults:A systematic review and meta-analysis

Background: One of the pathological hallmarks distinguishing Alzheimer's disease from other dementias is the accumulation of amyloid beta (Aβ). Higher physical activity is associated with decreased dementia risk, and one potential path could be through Aβ levels modulation. We aimed to explore the relationship between physical activity and Aβ in middle-aged and older adults. Methods: A systematic search of PubMed, Web of Science, PsycINFO, Cochrane Central Register of Controlled Trials, and SPORTDiscus was performed from inception to the 28th of April 2022. Studies were eligible if they included physical activity and Aβ data in adults aged 45 years or older. Multi-level meta-analyses of intervention and observational studies were performed to examine the role of physical activity in modulating Aβ levels. Results: In total, 37 articles were included (8 randomized controlled trials, 3 non-randomized controlled trials, 4 prospective longitudinal studies, and 22 cross-sectional studies). The overall effect size of physical activity interventions on changes in blood Aβ was medium (pooled standardized mean difference = –0.69, 95% confidence interval (95%CI): –1.41 to 0.03; I2 = 74.6%). However, these results were not statistically significant, and there were not enough studies to explore the effects of physical activity on cerebrospinal fluid (CSF) and brain Aβ. Data from observational studies were examined based on measurements of Aβ in the brain using positron emission tomography scans, CSF, and blood. Higher physical activity was positively associated with Aβ only in the CSF (Estimate r = 0.12; 95%CI: 0.05–0.18; I2 = 38%). Conclusion: Physical activity might moderately reduce blood Aβ in middle-aged and older adults. However, results were only near statistical significance and might be interpreted with caution given the methodological limitations observed in some of the included studies. In observational studies, higher levels of physical activity were positively associated with Aβ only in CSF. Therefore, further research is needed to understand the modulating role of physical activity in the brain, CSF, and blood Aβ, as well as its implication for cognitive health.</p

Associations of physical activity and screen time with white matter microstructure in children from the general population

Physical activity and sedentary behaviors have been linked to a variety of general health benefits and problems. However, few studies have examined how physical activity during childhood is related to brain development, with the majority of work to date focusing on cardio-metabolic health. This study examines the association between physical activity and screen time with white matter microstructure in the general pediatric population. In a sample of 2532 children (10.12 ± 0.58 years; 50.04% boys) from the Generation R Study, a population-based cohort in Rotterdam, the Netherlands, we assessed physical activity and screen time using parent-reported questionnaires. Magnetic resonance imaging of white matter microstructure was conducted using diffusion tensor imaging. Total physical activity was positively associated with global fractional anisotropy (β = 0.057, 95% CI = 0.016, 0.098, p = 0.007) and negatively associated with global mean diffusivity (β = −0.079, 95% CI = −0.120, −0.038, p 0.05). This study provides new evidence that physical activity is modestly associated with white matter microstructure in children. In contrast, complementing other recent evidence on cognition, screen time was not associated with white matter microstructure. Causal inferences from these modest associations must be interpreted cautiously in the absence of longitudinal data. However, these data still offer a promising avenue for future work to explore to what extent physical activity may promote healthy white matter development