Cardiorespiratory fitness and cognitive function in middle age: the CARDIA study

Cardiorespiratory fitness is associated with cognitive function in late adulthood: baseline findings from the IGNITE study

OBJECTIVES

To evaluate the association between cardiorespiratory fitness (CRF) and cognition in a large sample of older adults, and to examine clinical and demographic factors that might moderate these associations.

METHODS

CRF was measured with a graded exercise test performed on a motorised treadmill. A confirmatory factor analysis was conducted using data from a comprehensive neuropsychological battery to obtain latent factors reflecting core cognitive domains. Linear regression models evaluated the association between CRF and each of the cognitive composites, and potential moderators including demographic factors (age, sex, education), apolipoprotein E ε4 (APOE4) carriage, beta-blocker use and components of maximal effort criteria during CRF testing.

RESULTS

The sample consisted of 648 adults (mean (SD) age 69.88 (3.75)), including 461 women (71.1%). The highest oxygen consumption obtained during testing (VO2max) was mean (SD) = 21.68 (5.06) mL/kg/min. We derived a five-factor model composed of episodic memory, processing speed, working memory, executive function/attentional control and visuospatial function. Higher CRF was associated with better performance across all five cognitive domains after controlling for covariates. Age and APOE4 carriage did not moderate observed associations. The relationship between CRF and cognitive performance was greater in women, those with fewer years of education and those taking beta-blockers in the domains of processing speed (sex: β=-0.447; p=0.015; education: β=-0.863; p=0.018) and executive function/attentional control (sex: β=-0.417; p=0.022; education β=-0.759; p=0.034; beta-blocker use: β=0.305; p=0.047).

CONCLUSION

Higher CRF in older adulthood is associated with better cognitive performance across multiple domains susceptible to age-related cognitive decline. Sex, education and use of beta-blockers moderated observed associations within select cognitive domains.

Racial discrimination and cognitive function: An instrumental variable analysis

Racial inequities in cognitive function persist with mixed evidence regarding the impacts of racial discrimination on cognitive outcomes. We examined the association between experiences of racial discrimination within institutional settings, such as getting a job or housing, and multiple measures of cognitive function among middle-aged adults using analytic methods to strengthen the existing evidence base and provide potential points for intervention. We used cross-sectional data from 2895 participants in Wave 8 (Mage = 50.20, range: 43-55) and 2618 participants in Wave 9 (Mage = 55.20, range: 48-60) of the Coronary Artery Risk Development in Young Adults (CARDIA) study. Self-reported racial discrimination was operationalized using the Experiences of Discrimination Scale. Cognitive measures included were the Stroop Interference Test, Rey Auditory Verbal Learning Test, Digit Symbol Substitution Test, and the Montreal Cognitive Assessment. Analyses were conducted using ordinary least squares regression (OLS) and instrumental variable (IV) analysis using reflectance meter-measured skin color as the instrument. We find that increased experiences of racial discrimination are associated with poorer performance on cognitive assessments across OLS and IV analyses. For example, reporting one additional experience of racial discrimination was associated with approximately 0.50 SD lower auditory verbal learning scores using IV and 0.08 SD lower scores using OLS (Wave 8 IV 95% CI: -0.54, -0.41; OLS 95% CI: -0.10, -0.06). Such results in a relatively young sample yield insight into the potential implications of navigating a racialized society over one's life course in contributing to inequities in cognitive decline in older age.

The Hidden Dangers of Sedentary Living: Insights into Molecular, Cellular, and Systemic Mechanisms

With the aging of the global population, neurodegenerative diseases are emerging as a major public health issue. The adoption of a less sedentary lifestyle has been shown to have a beneficial effect on cognitive decline, but the molecular mechanisms responsible are less clear. Here we provide a detailed analysis of the complex molecular, cellular, and systemic mechanisms underlying age-related cognitive decline and how lifestyle choices influence these processes. A review of the evidence from animal models, human studies, and postmortem analyses emphasizes the importance of integrating physical exercise with cognitive, multisensory, and motor stimulation as part of a multifaceted approach to mitigating cognitive decline. We highlight the potential of these non-pharmacological interventions to address key aging hallmarks, such as genomic instability, telomere attrition, and neuroinflammation, and underscore the need for comprehensive and personalized strategies to promote cognitive resilience and healthy aging.

The frontal association area: exercise-induced brain plasticity in children and adolescents and implications for cognitive intervention practice

Objective

Explore the plasticity of the frontal associative areas in children and adolescents induced by exercise and potential moderating variables.

Methods

Computer searches of CNKI, WOS, PubMed and EBSCO databases were conducted, and statistical analyses were performed based on SPSS 25.0, Stata 12.0 and Ginger ALE 2.3 software after literature screening, data extraction and quality assessment were performed independently by two researchers.

Results

A total of 13 articles, including 425 participants aged 8.9∼16.8 years, were included. Frequency analysis revealed that exercise induced enhanced activation in frontal, parietal, occipital, limbic system and cerebellum (P < 0.01). Activation Likelihood Estimation (ALE) meta-analysis revealed that exercise altered the activation status of the frontal association (medial frontal gyrus, middle frontal gyrus, inferior frontal gyrus and precentral gyrus), cuneus, lingual gyrus, cingulate gyrus, parahippocampal gyrus, caudate nucleus and cerebellar apex, with the volume of activation in the frontal association accounting for 61.81% of the total activation cluster volume and an enhanced activation effect. Additionally, the study design, age, gender, nationality, cognitive tasks, as well as exercise intensity, intervention time, and type of exercise may be potential moderating variables. Particularly, sustained exercise induced a decrease in activation in the left parahippocampal gyrus, culmen, and lingual gyrus, while variable exercise induced an increase in activation in the left middle frontal gyrus.

Conclusion

Exercise-induced activation increase in the frontal associative areas of children and adolescents is dominant, especially longer periods of moderate-intensity variable exercise can induce more brain region activation. However, some of the included studies are cross-sectional, and the accuracy of the results still requires further verification.

Systematic review registration

https://www.crd.york.ac.uk/prospero/, identifier PROSPERO, CRD42022348781.

Associations of Polycystic Ovary Syndrome With Indicators of Brain Health at Midlife in the CARDIA Cohort

BACKGROUND AND OBJECTIVES

Polycystic ovary syndrome (PCOS) is a common reproductive disorder associated with an adverse cardiometabolic profile early in life. Increasing evidence links cardiovascular risk factors, such as diabetes and hypertension, to accelerated cognitive aging. However, less is known about PCOS and its relationship to brain health, particularly at midlife. Our goal was to investigate possible associations between PCOS and midlife cognitive function and brain MRI findings in an ongoing prospective study.

METHODS

We used data from the Coronary Artery Risk Development in Young Adults (CARDIA) study, a geographically diverse prospective cohort study of individuals who were 18-30 years at baseline (1985-1986) and followed for 30 years. We identified women with PCOS from an ancillary study (CARDIA Women's study (CWS); n = 1,163) as those with elevated androgen levels and/or hirsutism in conjunction with symptoms of oligomenorrhea. At year 30, participants completed cognitive testing, including the Montreal Cognitive Assessment, Rey Auditory Verbal Learning Test (RAVLT) (verbal learning and memory), Digit Symbol Substitution Test (processing speed and executive function), Stroop test (attention and cognitive control), and category and letter fluency tests (semantics and attention). A subset completed brain MRI to assess brain structure and white matter integrity. Multivariable linear regression models estimated the association between PCOS and outcomes, adjusting for age, race, education, and study center.

RESULTS

Of the 1163 women in CWS, 907 completed cognitive testing, and of these, 66 (7.1%) met criteria for PCOS (age 54.7 years). Women with and without PCOS were similar for age, BMI, smoking/drinking status, and income. At year 30, participants with PCOS performed lower (mean z score; 95% CI) on Stroop (-0.323 (-0.69 to -7.37); p = 0.008), RAVLT (-0.254 (-0.473 to -0.034); p = 0.002), and category fluency (-0.267 (-0.480 to -0.040); p = 0.02) tests. Of the 291 participants with MRI, 25 (8.5%) met PCOS criteria and demonstrated lower total white matter fractional anisotropy, a measure of white matter integrity (coefficient (95% CI) -0.013 (-0.021 to -0.005); p = 0.002), though not abnormal white matter.

DISCUSSION

Our results suggest that women with PCOS have lower cognitive performance and lower white matter integrity at midlife. Additional research is needed to confirm these findings and to determine potential mechanistic pathways including potential modifiable factors.

Integrating Lifestyle Factor Science into Neuropsychological Practice: A National Academy of Neuropsychology Education Paper

OBJECTIVE

The primary aim of this paper is to review evidence and clinical implications related to lifestyle activities associated with promoting brain and cognitive health. Our review targets four key lifestyle factors: physical activity and exercise, social engagement, cognitively stimulating activity, and consuming Mediterranean-style diets.

METHOD

We conducted a critical review of the lifestyle factor literature in the four domains listed earlier. We contextualize this literature review by translating findings, when possible, into evidence-based recommendations to consider when providing neuropsychological services.

RESULTS

There is significant current evidence supporting the role of physical activity and exercise, social engagement, cognitively stimulating activity, and consuming Mediterranean-style diets on positive brain and cognitive health outcomes. While some null findings are present in all four areas reviewed, the weight of the evidence supports the notion that engaging in these activities may promote brain and cognitive functioning.

CONCLUSIONS

Clinical neuropsychologists can have confidence in recommending engagement in physical activity, social activity, and cognitively stimulating activity, and adhering to a Mediterranean-style diet to promote brain and cognitive health. We discuss limitations in existing lifestyle factor research and future directions to enhance the existing evidence base, including additional research with historically underrepresented groups and individuals with neurological conditions.

The Impact of Cognitive, Physical, and Psychological Stressors on Subsequent Cognitive Performance

OBJECTIVE

To quantify the impact of performing challenging cognitive, physical and psychological tasks on subsequent cognitive performance, and whether differences in performance are predicted by psychological variables.

BACKGROUND

Successful performance in many occupations depends on resilient cognition: the degree to which cognitive functions can withstand, or are resilient to, the effects of stress. Several studies have examined the effect of individual stressors on cognition; however, the capacity to compare different types of stress across studies is limited.

METHOD

Fifty-eight participants completed cognitive, physical, psychological and control interventions, immediately preceded, and followed, by a battery of cognitive tasks. Self-efficacy and cognitive appraisal were reported at baseline. Perceived stress was recorded post-intervention. Subjective workload was recorded for each cognitive battery and intervention.

RESULTS

Cognitive performance was impaired by the cognitive, physical and psychological interventions, with the greatest effect following the cognitive intervention. The subjective workload reported for the post-intervention cognitive battery was higher following the cognitive and physical interventions. Neither self-efficacy, cognitive appraisal, perceived stress nor subjective workload of the intervention strongly predicted post-intervention performance.

CONCLUSION

Given the differences among interventions and cognitive domains, it appears that challenges to resilient cognition are broad and varied, and the mechanism(s) by which impairment occurs is complex.

APPLICATION

Considering the increase in subjective workload for the post-intervention cognitive battery, a combination of subjective and objective measures of cognitive performance monitoring should be considered.

Basal forebrain functional connectivity as a mediator of associations between cardiorespiratory fitness and cognition in healthy older women

Age-related cholinergic dysfunction within the basal forebrain (BF) is one of the key hallmarks for age-related cognitive decline. Given that higher cardiorespiratory fitness (CRF) induces neuroprotective effects that may differ by sex, we investigated the moderating effects of sex on the associations between CRF, BF cholinergic function, and cognitive function in older adults. 176 older adults (68.5 years) were included from the Nathan Kline Institute Rockland Sample. Functional connectivity (rsFC) of the BF subregions including the medial septal nucleus/diagonal band of Broca (MS/DB) and nucleus basalis of Meynert (NBM) were computed from resting-sate functional MRI. Modified Astrand-Ryhming submaximal cycle ergometer protocol was used to estimate CRF. Trail making task and inhibition performance during the color word interference test from the Delis-Kaplan Executive Function System and Rey Auditory Verbal Learning Test were used to examine cognitive function. Linear regression models were used to assess the associations between CRF, BF rsFC, and cognitive performance after controlling for age, sex, and years of education. Subsequently, we measured the associations between the variables in men and women separately to investigate the sex differences. There was an association between higher CRF and greater rsFC between the NBM and right middle frontal gyrus in older men and women. There were significant associations between CRF, NBM rsFC, and trail making task number-letter switching performance only in women. In women, greater NBM rsFC mediated the association between higher CRF and better trail making task number-letter switching performance. These findings provide evidence that greater NBM rsFC, particularly in older women, may be an underlying neural mechanism for the relationship between higher CRF and better executive function.

Physical activity interventions have a moderate effect in increasing physical activity in university students-a meta-analysis

INTRODUCTION

The transition to college is associated with changes in physical activity. This meta-analysis aims to quantify the effect of interventions on increasing physical activity in healthy university students.

METHODS

We conducted a literature search (up to 2/3/2020) to identify randomized controlled trials with healthy undergraduate or graduate students enrolled in a college degree program. Moderator analyses were conducted to examine the effects of intervention modality delivery (delivered in-person or remotely) and the type of outcome measure (self-report or objective measures).

RESULTS

18 publications were included. Interventions had a medium effect on physical activity (Cohen's d = 0.52). Moderator analyses revealed no differences.

CONCLUSION

Suggestions of how to improve the quality of physical activity intervention studies in college students are given. The moderate effect size of physical activity interventions in college students highlights the importance of developing and testing new interventions to promote physical activity in emerging adults.

Supplemental data for this article can be accessed online at https://doi.org/10.1080/07448481.2021.1998070 .

The interrelationship between physical activity intensity, cardiorespiratory fitness, and executive function in middle-aged adults: An observational study of office workers

Background

Previous evidence supports a beneficial effect of physical activity on executive function across the whole lifespan. Yet, the interrelationships of the intensities of physical activity, cardiorespiratory fitness, and executive function require further investigation in adults.

Aim

Using unfiltered accelerometry data and high-resolution intensity classification, we sought to estimate the associations of physical activity with cardiorespiratory fitness and executive function in adult office workers.

Methods

We included 343 full-time office workers (mean age: 42.41 years, range of age: 36-49 years). Executive function was assessed using Stroop, Trail making tests (part-B), and 2-back tests, and a composite score was produced to reflect the general executive function performance. Physical activity was assessed using the Actigraph GT3X+-monitor, worn by each participant for seven days at the hip. Raw accelerometry data were processed by the 10 Hz frequency extended method and divided into 22 intensity bins and sleep time. Cardiorespiratory fitness was estimated using the submaximal Ekblom-Bak cycle ergometer test. Data were analyzed using partial least squares regressions.

Results

In adults, cardiorespiratory fitness was closely correlated with a wide range of absolute physical activity intensity patterns. A higher level of executive function in adults was associated with both higher absolute physical activity intensities and cardiorespiratory fitness, which was independent of age, sex, and education levels. A very weak association between intensities, fitness, and executive function was observed in high-fit adults. Among low-fit adults, although a positive association started already toward the upper end of moderate intensity, there still appeared to be an association between intensities, cardiorespiratory fitness, and executive function. That is, cardiorespiratory fitness may mediate the association between absolute physical activity intensities and executive function up to a certain level.

Conclusion

The maintenance of executive function in adulthood was related to both physical activity intensities and cardiorespiratory fitness, while their interrelationship was not equal across fitness levels. It is highly recommended to consider the cardiorespiratory fitness level in future studies that focus on executive functions in aging as well when designing individualized physical activity training programs.

Cardiorespiratory fitness and cognition in persons at risk for Alzheimer's disease

Introduction

This study examined the relationship between cardiorespiratory fitness (CRF) and longitudinal cognitive functioning in a cohort enriched with risk factors for Alzheimer's disease (AD).

Methods

A total of 155 enrollees in the Wisconsin Registry for Alzheimer's Prevention completed repeat comprehensive neuropsychological evaluations that assessed six cognitive domains. Peak oxygen consumption (VO2peak) was the primary measure of CRF. Random effects regression was used to investigate the effect of CRF on cognitive trajectories.

Results

Higher CRF was associated with slower decline in the cognitive domains of verbal learning and memory (P < .01) and visual learning and memory (P < .042). Secondary analyses indicated that these effects were stronger among men than women, and for noncarriers of the apolipoprotein E ε4 allele.

Discussion

Higher CRF was associated with a slower rate of the decline in episodic memory that occurs as a natural consequence of aging in a cohort enriched with risk factors for AD.

Aerobic Fitness Is Associated with Cerebral μ-Opioid Receptor Activation in Healthy Humans

INTRODUCTION

Central μ-opioid receptors (MORs) modulate affective responses to physical exercise. Individuals with higher aerobic fitness report greater exercise-induced mood improvements than those with lower fitness, but the link between cardiorespiratory fitness and the MOR system remains unresolved. Here we tested whether maximal oxygen uptake (V̇O2peak) and physical activity level are associated with cerebral MOR availability and whether these phenotypes predict endogenous opioid release after a session of exercise.

METHODS

We studied 64 healthy lean men who performed a maximal incremental cycling test for V̇O2peak determination, completed a questionnaire assessing moderate-to-vigorous physical activity (MVPA; in minutes per week), and underwent positron emission tomography with [11C]carfentanil, a specific radioligand for MOR. A subset of 24 subjects underwent additional positron emission tomography scan also after a 1-h session of moderate-intensity exercise and 12 of them also after a bout of high-intensity interval training.

RESULTS

Higher self-reported MVPA level predicted greater opioid release after high-intensity interval training, and both V̇O2peak and MVPA level were associated with a larger decrease in cerebral MOR binding after aerobic exercise in the ventral striatum, orbitofrontal cortex, and insula. That is, more trained individuals showed greater opioid release acutely after exercise in brain regions especially relevant for reward and cognitive processing. Fitness was not associated with MOR availability.

CONCLUSIONS

We conclude that regular exercise training and higher aerobic fitness may induce neuroadaptation within the MOR system, which might contribute to improved emotional and behavioral responses associated with long-term exercise.

Lifestyle Matters: Effects of Habitual Physical Activity on Driving Skills in Older Age

Research on multitasking driving has suggested age-related deterioration in driving performance. It has been shown that physical and cognitive functioning, which are related to driving performance and decline with aging, are positively associated with physical activity behavior. This study aimed to explore whether driving performance decline becomes severe with advancing age and whether physical activity behavior modifies age-related deterioration in driving performance. A total of one hundred forty-one healthy adults were categorized into three groups based on their age; old-old (74.21 ± 2.33 years), young-old (66.53 ± 1.50 years), and young adults (23.25 ± 2.82 years). Participants completed a realistic multitasking driving task. Physical activity and cardiorespiratory fitness levels were evaluated. Older groups drove more slowly and laterally than young adults, and old-old adults drove slower than young-old ones across the whole driving course. Physical activity level did not interact with the aging effect on driving performance, whereas cardiovascular fitness interacted. Higher-fitness young-old and young adults drove faster than higher-fitness old-old adults. Higher-fitness old adults drove more laterally than higher-fitness young adults. The present study demonstrated a gradual decline in driving performance in old adults, and cardiorespiratory fitness interacted with the aging effect on driving performance. Future research on the interaction of aging and physical activity behavior on driving performance in different age groups is of great value and may help deepen our knowledge.

Mean arterial pressure, fitness, and executive function in middle age and older adults

Previous literature suggests that higher fitness is related to better executive function in older adulthood, but the mechanisms underlying this association are poorly understood. While many studies have focused on these associations in older adulthood, recent evidence suggests the importance of cardiorespiratory fitness (CRF) and long-term blood pressure control on cognitive functioning. The purpose of the current study was to examine whether mean arterial pressure (MAP) mediated the association between CRF and executive function in middle age and older adults. Participants were adults (age 40+) without any self-reported psychiatric and neurological disorders or cognitive impairment from the Nathan Kline Institute Rockland Sample (N = 224, M age = 56). CRF was defined by V̇O2max estimated via a bike test, neuropsychological testing was used to examine executive functioning, and MAP was calculated from systolic and diastolic blood pressure recordings. Mediation models were analyzed controlling for age, sex, and education. Results indicated that higher CRF was associated with better inhibition (B = -0.0048, t = -2.16, p = 0.03) and there was a significant indirect effect of greater CRF on better inhibition through lower MAP (B = -0.0011; CI [-0.0026, -0.0002]). There were additional significant indirect effects of greater CRF and better fluency (B = 0.0028; CI [.0009, 0.0053]) and planning (B = 0.0037; CI [.0014, 0.0074]) through lower MAP. This suggests that MAP may be an underlaying physiological mechanism by which CRF influences executive function in mid- and older adulthood.

Endurance and gait speed relationships with mild cognitive impairment and dementia

INTRODUCTION

Slower mobility is associated with mild cognitive impairment (MCI) and dementia. We examined the interaction of endurance with gait speed on prevalent MCI and dementia.

METHODS

Cross-sectional multinomial regression in the ARIC cohort (n = 2844 participants; 71 to 94 years; 44% men; 18% Black persons) with cognitive status (normal/MCI/dementia), 4 m gait speed, and endurance (2 minute walk [2MW]).

RESULTS

Faster gait speed (up to but not above 1 m/s) and better 2MW were separately associated with lower dementia risk. Good performance in both (2MW = 200 m, gait speed = 1.2 m/s) was associated with 99% lower dementia (Relative Prevalence Ratio [RPR] = 0.01 [95% CI: 0.0 to 0.06]) and 73% lower MCI, RPR = 0.27 (0.15 to 0.48) compared to poor performance in both (2MW = 100 m, gait speed = 0.8 m/s). Models incorporating a gait speed-by-2MW interaction term outperformed gait speed-only models (P < .001).

DISCUSSION

Gait speed relationships with dementia diminish at faster gait speeds. Combining endurance with gait speed may yield more sensitive markers of MCI and dementia than gait speed alone.

Evidence for exercise-related plasticity in functional and structural neural network connectivity

The number of studies investigating exercise and cardiorespiratory fitness (CRF)-related changes in the functional and structural organization of brain networks continues to rise. Functional and structural connectivity are critical biomarkers for brain health and many exercise-related benefits on the brain are better represented by network dynamics. Here, we reviewed the neuroimaging literature to better understand how exercise or CRF may facilitate and maintain the efficiency and integrity of functional and structural aspects of brain networks in both younger and older adults. Converging evidence suggests that increased exercise performance and CRF modulate functional connectivity of the brain in a way that corresponds to behavioral changes such as cognitive and motor performance improvements. Similarly, greater physical activity levels and CRF are associated with better cognitive and motor function, which may be brought about by enhanced structural network integrity. This review will provide a comprehensive understanding of trends in exercise-network studies as well as future directions based on the gaps in knowledge that are currently present in the literature.

Temporal trends in step test performance for Chinese adults between 2000 and 2014

BACKGROUD/OBJECTIVE

Cardiorespiratory endurance is an excellent marker of functional endurance and health among adults. The aim of this study was to estimate temporal trends in step test performance for Chinese adults between 2000 and 2014.

METHODS

Apparently healthy adults aged 20-59 years were included. Nationally representative step test data (n = 603,977) from 2000, 2005, 2010, and 2014 were reported descriptively by the China Physical Fitness Surveillance Center. Temporal trends in means were estimated at the sex-age level for all adults and separate location/occupation groups using sample-weighted linear regression, with trends in distributional characteristics described visually and estimated as the ratio of coefficients of variation (CVs).

RESULTS

Collectively, there was a negligible improvement in mean step test performance of 0.12 standardized effect sizes (95% confidence interval (95%CI): 0.11-0.13). Negligible to small improvements were observed for all age, sex, location, and occupation groups. Variability declined substantially over time (ratio of CVs (95%CI): 0.86 (0.86-0.86)), with negligible to large improvements in those below the 10th percentile, and negligible to moderate declines in those above the 90th percentile.

CONCLUSION

There have been negligible to large improvements in step test performance for low to average performing Chinese adults since 2000, which may be meaningful to public health because low endurance is an important risk factor for all-cause mortality.

Associations Between Cardiorespiratory Fitness, Cardiovascular Risk, and Cognition Are Mediated by Structural Brain Health in Midlife

Background

Evidence in older adults suggests that higher cardiorespiratory fitness and lower cardiovascular risk are associated with greater cognition. However, given that changes in the brain that lead to cognitive decline begin decades before the onset of symptoms, understanding the mechanisms by which modifiable cardiovascular factors are associated with brain health in midlife is critical and can lead to the development of strategies to promote and maintain brain health as we age.

Methods and Results

In 501 middle‐aged (aged 40–65 years) adult participants of the BBHI (Barcelona Brain Health Initiative), we found differential associations among cardiorespiratory fitness, cardiovascular risk, and cognition and cortical thickness. Higher cardiorespiratory fitness was significantly associated with better visuospatial abilities and frontal loading abstract problem solving (β=3.16, P=0.049) in the older middle‐aged group (aged 55–65 years). In contrast, cardiovascular risk was negatively associated with better visuospatial reasoning and problem‐solving abilities (β=−0.046, P=0.002), flexibility (β=−0.054, P<0.001), processing speed (β=−0.115, P<0.001), and memory (β=−0.120, P<0.001). Cortical thickness in frontal regions mediated the relationship between cardiorespiratory fitness and cognition, whereas cortical thickness in a disperse network spanning multiple cortical regions across both hemispheres mediated the relationship between cardiovascular risk and cognition.

Conclusions

The relationships between modifiable cardiovascular factors, cardiorespiratory fitness, and cardiovascular risk, and cognition are present in healthy middle‐aged adults. These relationships are also mediated by brain structure highlighting a potential mechanistic pathway through which higher cardiorespiratory fitness and lower cardiovascular risk can positively impact cognitive function in midlife.

The Coronary Artery Risk Development In Young Adults (CARDIA) Study: JACC Focus Seminar 8/8

The CARDIA (Coronary Artery Risk Development in Young Adults) study began in 1985 to 1986 with enrollment of 5,115 Black or White men and women ages 18 to 30 years from 4 US communities. Over 35 years, CARDIA has contributed fundamentally to our understanding of the contemporary epidemiology and life course of cardiovascular health and disease, as well as pulmonary, renal, neurological, and other manifestations of aging. CARDIA has established associations between the neighborhood environment and the evolution of lifestyle behaviors with biological risk factors, subclinical disease, and early clinical events. CARDIA has also identified the nature and major determinants of Black-White differences in the development of cardiovascular risk. CARDIA will continue to be a unique resource for understanding determinants, mechanisms, and outcomes of cardiovascular health and disease across the life course, leveraging ongoing pan-omics work from genomics to metabolomics that will define mechanistic pathways involved in cardiometabolic aging.

Epigenetic rewiring of skeletal muscle enhancers after exercise training supports a role in whole-body function and human health

Objectives

Regular physical exercise improves health by reducing the risk of a plethora of chronic disorders. We hypothesized that endurance exercise training remodels the activity of gene enhancers in skeletal muscle and that this remodeling contributes to the beneficial effects of exercise on human health.

Methods and results

By studying changes in histone modifications, we mapped the genome-wide positions and activities of enhancers in skeletal muscle biopsies collected from young sedentary men before and after 6 weeks of endurance exercise. We identified extensive remodeling of enhancer activities after exercise training, with a large subset of the remodeled enhancers located in the proximity of genes transcriptionally regulated after exercise. By overlapping the position of enhancers with genetic variants, we identified an enrichment of disease-associated genetic variants within the exercise-remodeled enhancers.

Conclusion

Our data provide evidence of a functional link between epigenetic rewiring of enhancers to control their activity after exercise training and the modulation of disease risk in humans.

•

Exercise training changes in skeletal muscle gene expression is enriched for secreted factors.

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The activity of skeletal muscle enhancers undergoes substantial remodeling after exercise training.

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Skeletal muscle enhancer activity and gene transcription are strongly associated.

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Exercise training-remodeled enhancer regions are enriched for GWAS SNPs associated with human traits and diseases.

The presence of emphysema on chest imaging and mid-life cognition

Background

Airflow obstruction is associated with cognitive dysfunction but studies have not assessed how emphysema, a structural phenotype of lung disease, might be associated with cognitive function independent from pulmonary function measured by spirometry. We aimed to determine the relationship between the presence of visually detectable emphysema on chest computed tomography (CT) imaging and cognitive function.

Methods

We examined 2491 participants, mean age of 50 years, from the Coronary Artery Risk Development in Young Adults study who were assessed for the presence of emphysema on chest CT imaging and had cognitive function measured 5 years later with a battery of six cognitive tests.

Results

Of those assessed, 172 (7%) had emphysema. After adjusting for age, sex, height, study centre, race, body mass index, education and smoking, visual emphysema was significantly associated with worse performance on most cognitive tests. Compared to those without emphysema, participants with emphysema performed worse on cognitive testing: 0.39 sd units lower (95% CI -0.53- -0.25) on the Montreal Cognitive Assessment, 0.27 sd units lower (95% CI -0.42- -0.12) on the Rey Auditory Verbal Learning Test, 0.29 sd units lower (95% CI -0.43- -0.14) on the Digit Symbol Substitution Test and 0.25 sd units lower (95% CI -0.42- -0.09) on letter fluency. Further adjustment for forced expiratory volume in 1 s (FEV₁), peak FEV₁ and annualised FEV₁ decline did not attenuate these associations.

Conclusions

The presence of emphysema on chest CT is associated with worse cognitive function, independent of airflow obstruction. These data suggest that emphysema may be a novel risk factor for cognitive impairment.

Associations between Cognition and Hand Function in Older People Diagnosed with Mild Cognitive Impairment or Dementia

Background/Aims

The aim of this study was to examine the associations between different cognitive domains and hand function in older people diagnosed with mild cognitive impairment (MCI) or dementia.

Methods

This study is cross-sectional, including 98 community-living older people aged ≥65 years with MCI or dementia. Assessments of hand function included grip strength, the Finger Tapping Test, and the Grooved Pegboard. Cognitive assessments were the Mini-Mental State Examination, the Clock Drawing Test, and Trail Making Tests A and B, as well as a 10-word List Learning Test. Statistical analyses were based on descriptive statistics and univariable and multivariable analyses.

Results

Sixty participants were diagnosed with MCI and 38 were diagnosed with dementia. The mean age was 78.8 years (SD 7.4). Analyses of hand function, cognitive tests, and demographic factors showed an association between cognitive tests, in particular executive function (EF), and hand function.

Conclusions

The findings indicated an association between physical and cognitive function. Among the cognitive domains, declines in EF were most related to a reduced physical function.

Benefits and promotion of physical activity in rheumatoid arthritis

PURPOSE OF REVIEW

The aim of this article is to describe the benefits of physical activity and exercise on rheumatoid arthritis disease activity, functioning, and symptoms; and offer recommendations for promotion of physical activity and exercise among people with rheumatoid arthritis.

RECENT FINDINGS

In addition to well-known benefits of exercise such as improving cardiovascular health and metabolic syndrome and reducing obesity, exercise has consistently shown rheumatoid arthritis-specific benefits. Exercise and increases in physical activity improve clinically measured disease activity, reduce symptoms such as fatigue and pain, and improve function and mental health. In spite of these benefits, most people with rheumatoid arthritis are inactive. Patient barriers to engaging in physical activity may include fears of joint damage, rheumatoid arthritis symptoms, and lack of understanding that physical activity improves the symptoms that may be barriers. However, the greatest barrier to healthy levels of physical activity among individuals with rheumatoid arthritis appears to be the lack of direction from healthcare providers.

SUMMARY

Exercise is safe and highly beneficial for people with rheumatoid arthritis. Because receiving recommendations from healthcare providers may be the factor most strongly associated with engaging in physical activity or exercise, providers are encouraged to give patients positive messages about the benefits of physical activity and the extremely low risks of harm.

The gut microbiome-derived metabolite trimethylamine N-oxide modulates neuroinflammation and cognitive function with aging

Aging is associated with declines in cognitive performance, which are mediated in part by neuroinflammation, characterized by astrocyte activation and higher levels of pro-inflammatory cytokines; however, the upstream drivers are unknown. We investigated the potential role of the gut microbiome-derived metabolite trimethylamine N-oxide (TMAO) in modulating neuroinflammation and cognitive function with aging. Study 1: In middle-aged and older humans (65 ± 7 years), plasma TMAO levels were inversely related to performance on NIH Toolbox Cognition Battery tests of memory and fluid cognition (both r² = 0.07, p < 0.05). Study 2: In mice, TMAO concentrations in plasma and the brain increased in parallel with aging (r² = 0.60), suggesting TMAO crosses the blood-brain barrier. The greater TMAO concentrations in old mice (27 months) were associated with higher brain pro-inflammatory cytokines and markers of astrocyte activation vs. young adult mice (6 months). Study 3: To determine if TMAO independently induces an "aging-like" decline in cognitive function, young mice (6 months) were supplemented with TMAO in chow for 6 months. Compared with controls, TMAO-supplemented mice performed worse on the novel object recognition test, indicating impaired memory and learning, and had increased neuroinflammation and markers of astrocyte activation. Study 4: Human astrocytes cultured with TMAO vs. control media exhibited changes in cellular morphology and protein markers consistent with astrocyte activation, indicating TMAO directly acts on these cells. Our results provide translational insight into a novel pathway that modulates neuroinflammation and cognitive function with aging, and suggest that TMAO might be a promising target for prevention of neuroinflammation and cognitive decline with aging.

Sex differences in exercise efficacy: Is midlife a critical window for promoting healthy cognitive aging?

Dementia is one of the most pressing health care issues of this century. As no curative treatment for dementia exists, research efforts are growing to identify effective lifestyle interventions to prevent or delay onset. One such promising strategy that promotes cognitive and brain health is engaging in physical exercise. However, current exercise recommendations are imprecise. To advance the potential of exercise as a preventative and treatment strategy, important questions regarding moderators (ie, biological sex and age) are being addressed in the literature. Biological sex is recognized as an important variable to consider in exercise efficacy on brain health, with females showing greater cognitive gains. This may be related to sex differences in underlying mechanisms. Here, we argue to better understand the sex differences in exercise efficacy, the timing of exercise intervention should also be considered. Specifically, we present the hypothesis that midlife in females is a critical window for the implementation of exercise as an early intervention to promote brain health and prevent dementia. Further, we speculate that exercise interventions targeting midlife will be of critical importance for the female brain, as females exit this period of the lifespan at greater risk for cognitive impairment. Given the potential sex differences in dementia risk and prevalence, it is imperative to assess potential sex differences in exercise efficacy as an early intervention during midlife.

Protocol of Aerobic Exercise and Cognitive Health (REACH): A Pilot Study

A growing body of evidence supports that aerobic exercise can decrease the risk of future cognitive impairment and Alzheimer's disease (AD). There is a pressing need to rigorously determine whether cognitively normal yet at-risk individuals stand to benefit from the protective effects of exercise. The present study will test the feasibility of an aerobic exercise intervention in such a population and inform the design of a larger-scale randomized, controlled trial examining the effect of aerobic exercise on biomarkers of AD in late-middle-aged, at-risk individuals. This was a single-site, 1 : 1 block-randomized, parallel, two-arm trial. Cognitively normal participants aged 45-80 with documentation of familial and genetic AD risk factors were randomly assigned to one of two interventions. The Usual Physical Activity group was provided educational materials about exercise. The Enhanced Physical Activity intervention delivered 26 weeks of individualized and supervised aerobic exercise. Exercise duration and intensity were incrementally increased to 150 min/week and 70-80% of heart rate reserve, respectively. Retention and adherence were measured to assess study feasibility. In addition, pre- and post- intervention differences between the two arms were evaluated for cardiorespiratory fitness, physical activity, brain glucose metabolism, cerebral structure, vascular health, memory, executive function, and mood. Data from randomized controlled trials of exercise training are needed to identify the proper exercise prescription for reducing accumulation of AD biomarkers in cognitively normal individuals. The current trial will contribute to filling that gap while informing the design of large-scale trials.

Accelerometer-determined physical activity and cognitive function in middle-aged and older adults from two generations of the Framingham Heart Study

INTRODUCTION

Physical activity (PA) may play a role in maintenance of cognitive function in both middle and older ages and prevention of outcomes such as dementia and Alzheimer's disease.

METHODS

Cross-sectional regression analyses were performed in Framingham Heart Study Third Generation (n = 1861) and Offspring (n = 909) cohort participants assessing the association of accelerometry-measured PA with cognitive function, adjusting for age, sex, accelerometer wear time, education, occupational status/PA, and smoking status.

RESULTS

In each cohort, achieving just 10-21.4 min/day moderate-to-vigorous PA related to better executive function (P < .02); and just 10 min/day moderate-to-vigorous PA was associated with better verbal memory in middle-aged adults in the Third Generation cohort (P = .02). In older adults of the Offspring cohort, total PA (measured in steps/day) was associated with better executive function (P < .02).

DISCUSSION

PA at levels lower than the current PA Guidelines (just 10 min/day moderate-to-vigorous PA and total PA including lower intensity PA) were associated with better cognitive function.

Feasibility of a 6-month pilot randomised controlled trial of resistance training on cognition and brain health in Canadian older adults at-risk for diabetes: study protocol

INTRODUCTION

Type 2 diabetes (T2D) is associated with cognitive deficits and increased risk of dementia, and thus individuals at high risk for T2D (ie, those who are overweight or prediabetic) are also at greater risk for cognitive decline. Aerobic exercise is known to preserve and improve cognitive function, but the effects of resistance training (RT) are much less known in older adults. Moreover, research on the effects of RT on cognition and brain health (structure and function) in older adults at-risk for diabetes is limited. To address this question, a 6-month RT intervention is needed. Importantly, before conducting a full-scale randomised controlled trial (RCT), we are conducting a feasibility pilot study to assess potential recruitment rates, adherence and retention in this specific population.

METHODS AND ANALYSIS

We are conducting a 6-month, thrice-weekly RT RCT. Participants (aged 60-80; sedentary; fasting plasma glucose of 6.1-7.0 mmol/L or body mass index ≥25) are randomised into one of two groups: (1) RT or (2) balance and tone (control). Based on other exercise trials using a similar population, we will consider our trial feasible if we have adherence and retention at 70%. Recruitment rate will be measured as time it takes to enrol 20 participants. To assess behavioural and MRI data, we will report descriptive statistics and estimation using a 95% CI.

ETHICS AND DISSEMINATION

Our study has received ethics approval from the Health Sciences Research Ethics Board at Western University. As this is a small pilot study, data will only be made available to other researchers on request. Results from this study will be disseminated via academic publication.

TRIAL REGISTRATION NUMBER

NCT03254381.

Improvements in functional and cognitive status following short-term pulmonary rehabilitation in COPD lung transplant recipients: a pilot study

BACKGROUND

Pulmonary rehabilitation (PR) following lung transplantation (LTx) is considered part of the optimal treatment in chronic obstructive pulmonary disease (COPD) for favourable post-operative outcomes. We investigated the effects of a PR intervention in the post-transplant phase with regard to lung function, exercise responses and cognitive function in COPD LTx recipients.

METHODS

24 COPD LTx recipients (mean±sd forced expiratory volume in 1 s 75±22% predicted) were assigned to a comprehensive 3-week inpatient PR programme. Changes from PR admission to discharge in lung function variables, 6-min walk test-derived outcomes and cognitive function were assessed and examined for several factors. The magnitude of changes was interpreted by effect size (ES).

RESULTS

In response to the PR intervention, LTx recipients had improved lung function with regard to diffusing capacity of the lung for carbon monoxide (+4.3%; p=0.012) and static hyperinflation (residual volume/total lung capacity -2.3%; p=0.017), increased exercise capacity (6-min walk test +86 m; p<0.001), and had small to large improvements (ES range 0.23-1.00; all p≤0.34) in 50% of the administered cognitive tests. Learning skills and memory ability presented the greatest benefits (ES composite scores 0.62 and 0.31, respectively), which remained similar after stratification by single or bilateral LTx and sex.

CONCLUSIONS

PR is an effective treatment for LTx recipients in the post-transplant phase, improving lung function, exercise responses, and domains of cognitive function of learning, memory and psychomotor speed. PR may facilitate the course of post-operative treatment and should be recommended in LTx.

Impact of Preeclampsia on Long-Term Cognitive Function

Preeclampsia increases a woman's risk of stroke and leads to short-term cognitive complaints. Our objective was to assess the impact of preeclampsia on long-term cognitive performance. This is a retrospective cohort study using data from the Coronary Artery Risk Development in Young Adults cohort of healthy individuals (18-30 years) recruited from the general population in 3 cities in the United States, followed for 25 years (1985-2010). Psychomotor speed (Digit Symbol Substitution Test), executive function (Stroop Test), and memory (Rey Auditory Verbal Learning Test) were contrasted between women with and without preeclampsia using multivariate linear regression. We included 568 parous women (193 with preeclampsia and 375 with normotensive pregnancy) without baseline neurological disease or depression matched according to delivery period. Approximately 18 years after delivery, preeclamptic women scored significantly lower on Digit Symbol Substitution Test than women with normotensive pregnancy (73.21±14.79 versus 75.87±15.22; P=0.047) and on the third trial of Stroop Test (correct answers: 38.85±3.62 versus 39.42±1.87; P=0.014; completion time: 44.02±10.48 versus 41.62±10.61 seconds; P=0.01), but there were no differences in Rey Auditory Verbal Learning Test. These differences were attenuated after adjustment for age, body mass index, hypertension, education, and depression. Similar differences in neurocognitive scores were noted between women with other hypertensive disorders of pregnancy and normotensive pregnancy. Hypertension in pregnancy does not seem to be independently associated with neurocognitive impairment later in life.

Lifetime physical activity and late-life cognitive function: the Rancho Bernardo study

BACKGROUND

physical activity in older age has been associated with better cognitive function, but the role of earlier life physical activity is less well understood.

OBJECTIVE

determine associations between physical activity throughout the lifespan and cognitive function in older age.

DESIGN

cross-sectional study.

SETTING

the Rancho Bernardo Study of Healthy Aging in southern California.

SUBJECTS

A total of 1,826 community-dwelling men and women (60-99 years) who attended a research visit in 1988-92.

METHODS

participants underwent cognitive testing at older age, and reported physical activity as a teenager, at age 30 years, 50 years and currently. For each time-point, participants were classified as regularly active (3+ times/week) or inactive.

RESULTS

regular physical activity was associated with better cognitive function, with physical activity at older ages showing the strongest associations. Physical activity in older age was associated with better global cognitive function, executive function and episodic memory, regardless of intensity. Intense physical activity in teenage years was associated with better late-life global cognitive function in women. Teenage physical activity interacted with older age physical activity on executive function; those active at both periods performed better than those active at only one period. Similar patterns of associations were observed after excluding individuals with poor health.

CONCLUSIONS

regular physical activity in older age, regardless of intensity, is associated with better cognitive function. Physical activity in teenage years may enhance cognitive reserve to protect against age-related decline in executive function. Further research is needed to assess the effect of physical activity across the lifespan on healthy brain ageing.

Impact of Baseline Features and Risk Factor Control on Cognitive Function in the Stenting and Aggressive Medical Management for Preventing Recurrent Stroke in Intracranial Stenosis Trial

BACKGROUND

Cerebrovascular disease is an important cause of cognitive impairment. The aim of this study is to report the relationship between cognitive function and risk factors at baseline and during follow-up in the Stenting and Aggressive Medical Management for Preventing Recurrent stroke in Intracranial Stenosis (SAMMPRIS) trial.

METHODS

Subjects in the SAMMPRIS trial were included in this study. In order to have an assessment of cognitive function independent of stroke, patients with a stroke as a qualifying event whose deficits included aphasia or neglect were excluded from these analyses as were those with a cerebrovascular event during follow-up. The Montreal Cognitive Assessment (MoCA) score was used to assess cognitive impairment at baseline, 4 months, 12 months and closeout. Cognitive impairment was defined as MoCA < 26. A multivariate analysis was performed to determine what risk factors were independent predictors of cognitive function at baseline, 12 months and closeout. Among patients randomized to aggressive medical management only, the percentage of patients with cognitive impairment was compared between patients in versus out of target for each risk factor at 12 months and closeout.

RESULTS

Of the 451 patients in SAMMPRIS, 371 patients met the inclusion criteria. MoCA < 26 was present in 55% at baseline. Older age and physical inactivity were associated with cognitive impairment at baseline. Older age, non-white race, lower baseline body mass index, and baseline cognitive impairment were associated with cognitive impairment at 12 months. In the aggressive medical management group, at 12 months, physical inactivity during follow-up was the strongest risk factor associated with cognitive impairment.

CONCLUSION

Cognitive impairment is common in patients with severe symptomatic intracranial atherosclerosis. Physical inactivity at baseline and during follow-up is a strong predictor of cognitive impairment.

Exercise Improves Vascular Function, but does this Translate to the Brain?

The number of adults with Alzheimer’s disease (AD) or related dementia is expected to increase exponentially. Interventions aimed to reduce the risk and progression of AD and dementia are critical to the prevention and treatment of this devastating disease. Aging and cardiovascular disease risk factors are associated with reduced vascular function, which can have important clinical implications, including brain health. The age-associated increase in blood pressure and impairment in vascular function may be attenuated or even reversed through lifestyle behaviors. Greater volumes of habitual exercise and higher cardiorespiratory fitness are associated with beneficial effects on vascular health and cognition. Exercise and cardiorespiratory fitness may be most important during midlife, as physical activity and cardiorespiratory fitness during the middle-aged years are associated with future cognitive function. The extent to which exercise, and more specifically aerobic exercise, influences the cerebral circulation is not well established. In this review, we present our working hypothesis showing how cerebrovascular function may be a mediating factor underlying the association between exercise and cognition, as well as discuss recent studies evaluating the effect of exercise interventions on the cerebral circulation.

Migration and cognitive function: a conceptual framework for Global Health Research

BACKGROUND

Migration is a fundamental demographic process that has been observed globally. It is suggested that migration is an issue of global health importance that can have an immediate and lasting impact on an individual's health and well-being. There is now an increasing body of evidence linking migration with cognitive function in older adults. In this paper, we synthesized the current evidence to develop a general conceptual framework to understand the factors contributing to the association between migration and cognitive function.

METHODS

A comprehensive review of the literature was conducted on the associations between migration and cognition among middle-aged and older adults.

RESULTS

Five potential mechanisms were identified from the literature: 1) socioeconomic status-including education, occupation, and income; 2) psychosocial factors-including social networks, social support, social stressors, and discrimination; 3) behavioral factors-including smoking, drinking, and health service utilization; 4) physical and psychological health status-including chronic conditions, physical function, and depression; and 5) environmental factors-including both physical and social environment. Several underlying factors were also identified-including early-life conditions, gender, and genetic factors.

CONCLUSIONS

The factors linking migration and cognitive function are multidimensional and complex. This conceptual framework highlights potential implications for global health policies and planning on healthy aging and migrant health. Additional studies are needed to further examine these mechanisms to extend and refine our general conceptual framework.

Sedentary Behavior at Work and Cognitive Functioning: A Systematic Review

Background: It is now well-established that sedentarity has a negative impact on the physiological functioning and health of humans, whereas very little is known about the psychological repercussions, especially in cognitive functioning. Yet, studying the cognitive effects of the sedentary lifestyle is particularly relevant in the short term for productivity and in the long term for cognitive health (accelerated aging). This systematic review therefore aims to make an inventory of the potential cognitive effects of sedentarity at the workplace. Methods: Pubmed, PsycINFO, Cochrane, Web of Science, and Scopus were searched for English-language peer-reviewed articles published between January 1, 2000 and December 31, 2017 to identify studies including sedentary behavior and objective measures from cognitive domains (cognitive inhibition, cognitive flexibility, working memory, etc.). To carry out this systematic review, the 3 keywords "Sedentary" and "Cognition" and "Work" (and their derivatives) had to appear in the title or in the summary of the paper. Results: Of the 13 papers that met the inclusion criteria, 9 were short-term interventions, 3 medium-term interventions, and 1 long-term intervention. Nine of them reported non-significant results. Two studies study reported deterioration in cognitive performance. Two reported an improvement in performance in cognitive tasks with one study with overweight adults and the only one study with a long-term intervention. However, these studies intend to reduce sedentary behavior, but do not allow answering the question of the potential cognitive effects of the sedentary lifestyle. Conclusion: These data suggest that sedentary behavior is not associated with changes in cognitive performance in interventions that intend to reduce sedentary behavior. Then, and given the trend toward increased time in sedentary behavior, long-term prospective studies of high methodological quality are recommended to clarify the relationships between sedentary behavior and the cognitive functioning. Our systematic review identifies also the need for retrospective, longitudinal, or epidemiologic studies. It also recognizes the need to standardize methodology for collecting, defining, and reporting sedentary behavior and the need to standardize the cognitive tests used. The relationship between sedentary behavior and cognitive functioning remaining uncertain, further studies are warranted for which 8 recommendations are proposed.

Executive control processes are associated with individual fitness outcomes following regular exercise training: blood lactate profile curves and neuroimaging findings

Cardiovascular training has been associated with neuroimaging correlates of executive control functions (ECF) in seniors and children/adolescents, while complementary studies in middle-aged populations are lacking. Ascribing a prominent role to cardiorespiratory fitness improvements, most studies concentrated on training-induced gains in maximal oxygen uptake (VO₂max), although other fitness indices may provide complementary information. Here, we investigated the impact of long-term sub-maximal exercise training on interference control, considering individual training-induced shifts in blood lactate profile curves (BLC) and VO₂max. Twenty-three middle-aged sedentary males (M = 49 years) underwent a six-month exercise program (intervention group, IG). Additionally, 14 individuals without exercise training were recruited (control group, CG, M = 52 years). Interference control was assessed before and after the intervention, using a functional magnetic resonance imaging (fMRI) flanker paradigm. Task performance and brain activations showed no significant group-by-time interactions. However, regression analyses in the IG revealed significant associations between individual fitness gains and brain activation changes in frontal regions, which were not evident for VO₂max, but for BLC. In conclusion, training-induced plasticity of ECF-related brain activity can be observed in late middle adulthood, but depends on individual fitness gains. For moderate training intensities, BLC shifts may provide sensitive markers for training-induced adaptations linked to ECF-related brain function.

Aerobic Exercise: Evidence for a Direct Brain Effect to Slow Parkinson Disease Progression

No medications are proven to slow the progression of Parkinson disease (PD). Of special concern with longer-standing PD is cognitive decline, as well as motor symptoms unresponsive to dopamine replacement therapy. Not fully recognized is the substantial accumulating evidence that long-term aerobic exercise may attenuate PD progression. Randomized controlled trial proof will not be forthcoming due to many complicating methodological factors. However, extensive and diverse avenues of scientific investigation converge to argue that aerobic exercise and cardiovascular fitness directly influence cerebral mechanisms mediating PD progression. To objectively assess the evidence for a PD exercise benefit, a comprehensive PubMed literature search was conducted, with an unbiased focus on exercise influences on parkinsonism, cognition, brain structure, and brain function. This aggregate literature provides a compelling argument for regular aerobic-type exercise and cardiovascular fitness attenuating PD progression.

Increased Myo-Inositol in Primary Motor Cortex of Contact Sports Athletes without a History of Concussion

The objective of the study was to determine whether repetitive hits to the head at a subclinical level are associated with structural and functional brain abnormalities and whether these effects are influenced by high levels of fitness associated with intense physical activity. Seventy-two college students were recruited: 24 nonathletic, 24 athletes practicing a varsity contact sport, and 24 athletes practicing a varsity noncontact sport. They were recruited for a neuropsychological evaluation and a magnetic resonance imaging session that included magnetic resonance spectroscopy of primary motor cortex (M1) and prefrontal cortex and susceptibility-weighted imaging. There was no evidence for reduced cognitive performance or presence of micro bleeds in contact sports athletes. Abnormalities in contact sports athletes were found for myo-inositol concentration (mIns) in M1, where levels were significantly higher compared with noncontact sports athletes (p = 0.016) and nonathletes (p = 0.029). In prefrontal cortex, glutamate + glutamine (Glx) was significantly reduced in contact sports athletes compared with noncontact sports athletes (p = 0.016), and a similar reduction was observed for gamma-aminobutyric acid (GABA) levels (p = 0.005). Varsity contact sports are associated with area-specific alterations in mIns concentration in the primary motor cortex. In the prefrontal cortex, high levels of fitness could modulate the effects of head impact exposure on prefrontal metabolite concentration. Indeed, although athletes in contact and noncontact sports show different neurometabolic profiles, they do not differ from sedentary controls.

Cognitive function in patients with stable coronary heart disease: Related cerebrovascular and cardiovascular responses

Chronic exercise has been shown to prevent or slow age-related decline in cognitive functions in otherwise healthy, asymptomatic individuals. We sought to assess cognitive function in a stable coronary heart disease (CHD) sample and its relationship to cerebral oxygenation-perfusion, cardiac hemodynamic responses, and V˙O2 peak compared to age-matched and young healthy control subjects. Twenty-two young healthy controls (YHC), 20 age-matched old healthy controls (OHC) and 25 patients with stable CHD were recruited. Cognitive function assessment included short term—working memory, perceptual abilities, processing speed, cognitive inhibition and flexibility and long-term verbal memory. Maximal cardiopulmonary function (gas exchange analysis), cardiac hemodynamic (impedance cardiography) and left frontal cerebral oxygenation-perfusion (near-infra red spectroscopy) were measured during and after a maximal incremental ergocycle test. Compared to OHC and CHD, YHC had higher V˙O2 peak, maximal cardiac index (CI max), cerebral oxygenation-perfusion (ΔO₂ Hb, ΔtHb: exercise and recovery) and cognitive function (for all items) (P<0.05). Compared to OHC, CHD patients had lower V˙O2 peak, CI max, cerebral oxygenation-perfusion (during recovery) and short term—working memory, processing speed, cognitive inhibition and flexibility and long-term verbal memory (P<0.05). V˙O2 peak and CI max were related to exercise cerebral oxygenation-perfusion and cognitive function (P<0.005). Cerebral oxygenation-perfusion (exercise) was related to cognitive function (P<0.005). Stable CHD patients have a worse cognitive function, a similar cerebral oxygenation/perfusion during exercise but reduced one during recovery vs. their aged-matched healthy counterparts. In the all sample, cognitive functions correlated with V˙O2 peak, CI max and cerebral oxygenation-perfusion.

The positive cognitive impact of aerobic fitness is associated with peripheral inflammatory and brain-derived neurotrophic biomarkers in young adults

There is ample evidence for supporting the positive impact of aerobic fitness on cognitive function, but little is known about the physiological mechanisms. The objective of this study was to investigate whether the positive cognitive impact of aerobic fitness is associated with inflammatory and neurotrophic peripheral biomarkers in young adults aged 18 to 29years (n=87). For the objective assessment of aerobic fitness, we measured maximal oxygen uptake (VO₂max) as a parametric measure of cardiorespiratory capacity. We demonstrated that young adults with the higher levels of VO₂max performed better on computerized cognitive tasks assessing sustained attention and working memory. This positive VO₂max-cognitive performance association existed independently of confounders (e.g., years of education, intelligence scores) but was significantly dependent on resting peripheral blood levels of inflammatory (C-reactive protein, CRP) and neurotrophic (brain-derived neurotrophic factor, BDNF) biomarkers. Statistical models showed that CRP was a mediator of the effect of VO₂max on working memory. Further, BDNF was a moderator of the effect of VO₂max on working memory. These mediating and moderating effects occurred in individuals with higher levels of aerobic fitness. The results suggest that higher aerobic fitness, as measured by VO₂max, is associated with enhanced cognitive functioning and favorable resting peripheral levels of inflammatory and brain-derived neurotrophic biomarkers in young adults.

Cardiorespiratory fitness, cognition and brain structure after TIA or minor ischemic stroke

Background It is not known whether cardiorespiratory fitness is associated with better cognitive performance and brain structure in patients with a TIA or minor ischemic stroke. Aims To examine the association between cardiorespiratory fitness, cognition and brain structure in patients with a TIA and minor stroke. Methods The study population consisted of patients with a TIA or minor stroke with a baseline measurement of the peak oxygen consumption, a MRI scan of brain and neuropsychological assessment. Composite z-scores were calculated for the cognitive domains attention, memory and executive functioning. White matter hyperintensities, microbleeds and lacunes were rated visually. The mean apparent diffusion coefficient was measured in regions of interest in frontal and occipital white matter and in the centrum semiovale as a marker of white matter structure. Normalized brain volumes were estimated by use of Statistical Parametric Mapping. Results In 84 included patients, linear regression analysis adjusted for age, sex and education showed that a higher peak oxygen consumption was associated with higher cognitive z-scores, a larger grey matter volume (B = 0.15 (95% CI 0.05; 0.26)) and a lower mean apparent diffusion coefficient (B = -.004 (95% CI -.007; -.001)). We found no association between the peak oxygen consumption and severe white matter hyperintensities, microbleeds, lacunes and total brain volume. Conclusions These data suggest that cardiorespiratory fitness is associated with better cognitive performance, greater grey matter volume and greater integrity of the white matter in patients with a TIA or minor ischemic stroke. Further prospective trials are necessary to define the effect of cardiorespiratory fitness on cognition and brain structure in patients with TIA or minor stroke.

Relationships between cardiorespiratory fitness, hippocampal volume, and episodic memory in a population at risk for Alzheimer's disease

INTRODUCTION

Cardiorespiratory fitness (CRF) has been shown to be related to brain health in older adults. In individuals at risk for developing Alzheimer's disease (AD), CRF may be a modifiable risk factor that could attenuate anticipated declines in brain volume and episodic memory. The objective of this study was to determine the association between CRF and both hippocampal volume and episodic memory in a cohort of cognitively healthy older adults with familial and/or genetic risk for Alzheimer's disease (AD).

METHODS

Eighty-six enrollees from the Wisconsin Registry for Alzheimer's Prevention participated in this study. Participants performed a graded maximal exercise test, underwent a T-1 anatomical magnetic resonance imaging scan, and completed the Rey Auditory Verbal Learning Test (RAVLT).

RESULTS

There were no significant relationships between CRF and HV or RAVLT memory scores for the entire sample. When the sample was explored on the basis of gender, CRF was significantly associated with hippocampal volume for women. For men, significant positive associations were observed between CRF and RAVLT memory scores.

SUMMARY

These results suggest that CRF may be protective against both hippocampal volume and episodic memory decline in older adults at risk for AD, but that the relationships may be gender specific.

Chronotropic Response and Cognitive Function in a Cohort at Risk for Alzheimer's Disease

The objective of this study was to examine the association of chronotropic response (CR) and heart rate (HR) recovery- two indices of cardiovascular function within the context of a graded exercise test- with cognitive performance in a cognitively healthy, late-middle-aged cohort at risk for Alzheimer's disease (AD). Ninety participants (age = 63.52±5.86 years; 65.6% female) from the Wisconsin Registry for Alzheimer's Prevention participated in this study. They underwent graded exercise testing and a comprehensive neuropsychological assessment that assessed the following four cognitive domains: Immediate Memory, Verbal & Learning Memory, Working Memory, and Speed & Flexibility. Regression analyses, adjusted for age, sex, and education, were used to examine the association between CR, HR recovery, and cognition. We found significant associations between CR and cognitive performance in the domains of Immediate Memory, Verbal Learning & Memory, and Speed & Flexibility. In contrast, HR recovery was not significantly associated with cognitive function. The association between CR and cognition persisted even after controlling for HR recovery. Together, these findings indicatethat, in a cognitively normal, late-middle-aged cohort, CR is a stronger correlate of cognitive performance than HR recovery. Overall, this study reinforces the idea that cardiovascular health plays an important role in cognitive function, specifically in a cohort at risk for AD; and that interventions that promote vascular health may be a viable pathway to preventing or slowing cognitive decline due to AD.

Polygenic Risk of Schizophrenia and Cognition in a Population-Based Survey of Older Adults

Cognitive impairment is a common feature of the major psychotic disorders, with deficits often present in at risk individuals and unaffected first-degree relatives. Previous studies have suggested that polygenic risk scores (PRS) for schizophrenia (SCZ) are associated with cognitive deficits, but there has been little examination of this association in longitudinal datasets, or comparison with other disorders. We used mixed models to study the association between PRS for 4 adult onset psychiatric disorders with cross-sectional cognitive performance and longitudinal cognitive decline in 8616 older adults from the Health and Retirement Study (HRS), followed for an average of 10 years. PRS were computed for SCZ, bipolar disorder (BD), Major Depressive Disorder (MDD), and Alzheimer's disease (ALZ). SCZ PRS associated with decreased cognitive function (z = -3.00, P = .001, ΔR (2) = 0.04%), which was largely driven by an association with impaired attention and orientation (z = -3.33, P = 4.3×10(-4), ΔR (2) = 0.08%). We found no effect of BD or MDD PRS on cognition, in contrast to a robust effect of the APOE4/TOMM40 locus (z = -5.05, P = 2.2×10(-7), ΔR (2) = 0.36%), which was primarily associated with impaired verbal memory (z = -5.15, P = 1.3×10(-7), ΔR (2) = 0.21%). APOE4/TOMM40 locus and the ALZ PRS, but not the PRS for SCZ, were associated with greater cognitive decline. In summary, using a large, representative sample of older adults, we found evidence for different degrees of association between polygenic risk for SCZ and genetic risk factors for ALZ on cognitive function and decline, highlighting potential differences in the pathophysiology of cognitive deficits seen in SCZ and ALZ.

Invited Commentary: Lessons for Research on Cognitive Aging From a Study of Children

As the population ages, the burden of disease from cognitive decline and dementing illness is rising. In the absence of treatments to reverse cognitive decline, prevention is a public health priority. Physical fitness and physical activity have emerged as prevention targets based on evidence of "neuroprotective" benefits in observational studies. However, observational studies linking active lifestyle with successful cognitive aging might be subject to bias from "neuroselection," in which adults with better cognitive functioning are more likely to engage in healthy behaviors and avoid unhealthy ones. In their analysis of longitudinal data on several thousand children from the United Kingdom's Millennium Cohort Study, Aggio et al. (Am J Epidemiol. 2016;183(12):1075-1082) revealed that this pattern of neuroselection is already apparent in childhood. However, they also report data that suggest there are cognitive benefits to engaging in certain types of active behaviors over and above this selection. Their findings argue for greater attention to confounding by neuroselection in research on cognitive aging, and they suggest the possibility that early interventions to promote certain health behaviors may instill a virtuous cycle with benefits that accumulate across the lifespan.

Midlife exercise blood pressure, heart rate, and fitness relate to brain volume 2 decades later

OBJECTIVE

To determine whether poor cardiovascular (CV) fitness and exaggerated exercise blood pressure (BP) and heart rate (HR) were associated with worse brain morphology in later life.

METHODS

Framingham Offspring participants (n = 1,094, 53.9% female) free from dementia and CV disease (CVD) underwent an exercise treadmill test at a mean age of 40 ± 9 years. A second treadmill test and MRI scans of the brain were administered 2 decades later at mean age of 58 ± 8 years.

RESULTS

Poor CV fitness and greater diastolic BP and HR response to exercise at baseline were associated with a smaller total cerebral brain volume (TCBV) almost 2 decades later (all p < 0.05) in multivariable adjusted models; the effect of 1 SD lower fitness was equivalent to approximately 1 additional year of brain aging in individuals free of CVD. In participants with prehypertension or hypertension at baseline, exercise systolic BP was also associated with smaller TCBV (p < 0.05).

CONCLUSION

Our results suggest that lower CV fitness and exaggerated exercise BP and HR responses in middle-aged adults are associated with smaller brain volume nearly 2 decades later. Promotion of midlife CV fitness may be an important step towards ensuring healthy brain aging.

Fitness and cognition in the elderly: The Austrian Stroke Prevention Study

OBJECTIVE

To investigate whether greater cardiorespiratory fitness is associated with better global and domain-specific cognitive function.

METHODS

We investigated 877 participants (aged 65 ± 7 years, 55% women) of the Austrian Stroke Prevention Study. For cardiorespiratory fitness, the maximum oxygen consumption (V̇o2max) was calculated based on weight and maximum and resting heart rate on a treadmill test (mL·kg(-1)·min(-1)). A test battery assessing memory (Bäumler's Lern-und Gedächtnistest), executive function (Wisconsin Card Sorting Test, Trail Making Test-Part B, Digit Span Backward, Alters Konzentrationstest, a computerized complex reaction time task) and motor skills (Purdue Pegboard Test) was administered. Summary measures for cognitive domains and for global cognition were calculated. White matter lesions, lacunes, and brain atrophy were assessed using MRI.

RESULTS

Higher V̇o2max was associated with better global (B = 0.024; p = 0.000) and domain-specific cognitive function (memory B = 0.026, p = 0.000; executive function B = 0.009, p = 0.003; motor skills B = 0.012, p = 0.018) after adjustment for age, sex, education years, and Ca(2+) channel antagonists or β-blockers. White matter lesions, lacunes, or brain atrophy did not mediate the effect (p > 0.05 for all mediators). The interactions of V̇o2max with age, overweight, and APOE ε4 on cognition were not statistically significant (p > 0.05 for all interaction terms) with the exception of a modulating effect of body mass index on V̇o2max in the memory domain.

CONCLUSIONS

Higher V̇o2max is associated with better global cognitive function and with better performance in the cognitive domains of memory, executive function, and motor skills in the middle-aged and elderly. The association is not mediated by the presence of white matter lesions, lacunes, and brain atrophy.