Exercise, Arterial Stiffness, and Cerebral Vascular Function: Potential Impact on Brain Health

Associations of the 'weekend warrior' physical activity pattern with mild dementia: findings from the Mexico City Prospective Study

OBJECTIVES

To investigate associations of the 'weekend warrior' physical activity pattern with mild dementia.

METHODS

Participants in the Mexico City Prospective Study were surveyed from 1998 to 2004 and re-surveyed from 2015 to 2019. Participants were asked about leisure time physical activity at baseline. Those who exercised up to once or twice per week were termed 'weekend warriors' and those who exercised more often were termed 'regularly active'. A Mini Mental State Examination (MMSE) was used to assess mild dementia at re-survey. Cox models were adjusted for age, sex, education, income, blood pressure, smoking, body mass index, civil status, sleep, diet and alcohol at baseline. The attributable fraction was defined as the proportion of cases that would not exist if all adults were to exercise once or twice per week or more often.

RESULTS

The analysis included 10 033 adults of mean (SD) age 51 (10) years followed for 16 (2) years. There were 2400 cases when mild dementia was defined as a score of ≤22 on the MMSE. Compared with the group that reported no sport or exercise, the hazard ratio was 0.75 (95% CI 0.61 to 0.91) in the weekend warrior group, 0.89 (95% CI 0.78 to 1.02) in the regularly active group and 0.84 (95% CI 0.75 to 0.95) in the combined group. The attributable fraction was 13% (95% CI 5% to 21%). Similar results were observed when mild dementia was defined as a score of ≤23 on the MMSE.

CONCLUSIONS

This longitudinal analysis suggests that the weekend warrior physical activity pattern is associated with a reduced risk of mild dementia.

Long-term egg-protein hydrolysate consumption improves endothelial function: a randomized, double-blind, placebo-controlled trial in older adults with overweight or obesity

PURPOSE

The dietary egg-protein hydrolysate Newtricious (NWT)-03 has previously demonstrated improvements in blood pressure and metabolic profiles. However, the long-term effects on vascular function and cardiometabolic risk markers are unknown.

METHODS

Forty-four older (aged 60-75) adults with overweight/obesity experiencing elevated Subjective Cognitive Failures (SCF) were randomized into a 36-week, double-blind, placebo-controlled trial. Participants either consumed 5.7 g of an egg-protein hydrolysate (NWT-03) or maltodextrin placebo. Endothelial function (brachial artery flow-mediated vasodilation [FMD] and carotid artery reactivity [CAR] responses after a cold pressor test), arterial stiffness (carotid-to-femoral pulse wave velocity [PWVc-f]), retinal microvascular calibers, and cardiometabolic risk markers (insulin sensitivity using a 7-point oral glucose tolerance test, serum lipid profiles, and blood pressure) were evaluated.

RESULTS

FMD observed a non-significant trend towards a 0.3 percentage point (pp) increase in the intervention compared to the placebo group (95% CI: [0.0, 0.7]; p = 0.08), and a significant intervention effect was observed on CAR responses based on a 0.7 pp improvement after a cold pressor test (95% CI: [0.1, 1.3]; p = 0.03). No significant overall changes were observed for arterial stiffness as measured by PWVc-f. Retinal microvascular calibers and cardiometabolic parameters also did not change.

CONCLUSION

Long-term supplementation with 5.7 g of the egg-protein hydrolysate NWT-03 for 36 weeks improved vascular endothelial function in older adults with overweight/obesity experiencing elevated SCF, which may benefit cardiovascular disease risk. No overall changes in other vascular function markers, retinal microvascular calibers or cardiometabolic risk markers were observed.

CLINICAL TRIAL REGISTRATION

The study was registered at ClinicalTrials.gov in January 2021 as NCT04831203: https://clinicaltrials.gov/study/NCT04831203.

Acute Effects of Cadence-Controlled Walking on Cognition and Vascular Function in Physically Inactive Older Adults: A Randomized Crossover Study

BACKGROUND

Cadence-controlled walking may be a desirable approach for older adults to self-monitor exercise intensity and achieve physical activity guidelines. We examined the acute effects of cadence-controlled walking on cognition and vascular function in physically inactive older adults.

METHODS

In a randomized crossover design, 26 participants (65% females, 67.8 ± 11.3 years) underwent 30-min acute exercise (walking at 100 steps/min) and control (sitting) conditions. We measured cognition, central blood pressure (BP), and arterial stiffness before, and immediately, after each condition.

RESULTS

We observed significant Time × Condition interactions in the Flanker Inhibitory Control and Attention (Flanker) test and Dimensional Change Card Sort (DCCS) test scores, and in central systolic BP, central pulse pressure, and carotid to femoral pulse wave velocity (p < .05). The Flanker and DCCS scores significantly increased after walking (d = 0.4 and 0.5, respectively), but not after sitting. Central systolic BP, central pulse pressure, and carotid to femoral pulse wave velocity significantly increased after sitting but remained unchanged after acute walking (d = 0.4-0.2), with p-values < .05. After walking, significant correlations were observed between DCCS and diastolic BP and central pulse pressure change scores and change scores in central pulse wave velocity, Flanker, and DCCS (rs = -0.45 to -0.52).

CONCLUSION

These findings suggest that a single bout of cadence-controlled walking elicited an immediate improvement in cognition and might have mitigated increases in arterial stiffness and central BP observed in the seated control condition. Further research is needed to examine the association between cognition and vascular function following acute exercise compared to control conditions.

SIGNIFICANCE

Our findings may have practical implications for developing daily physical activity recommendations for improving the cognitive health for successful aging.

Sex-specific effects of intensity and dose of physical activity on BOLD-fMRI cerebrovascular reactivity and cerebral pulsatility

Cerebrovascular reactivity (CVR) and cerebral pulsatility (CP) are important indicators of cerebrovascular health and have been shown to be associated with physical activity (PA). Sex differences have been shown to influence the impact of PA on cerebrovascular health. However, the sex-specific effects of PA on CP and CVR, particularly in relation to intensity and dosage of PA, remains unknown. Thus, this cross-sectional study aimed to evaluate the sex-specific effects of different intensities and doses of PA on CVR and CP. The Human Connectome - Aging dataset was used, including 626 participants (350 females, 276 males) aged 36-85 (mean age: 58.8 ± 14.1 years). Females were stratified into premenopausal and postmenopausal groups to assess the potential influence of menopausal status. Novel tools based solely on resting state fMRI data were used to estimate both CVR and CP. The International Physical Activity Questionnaire was used to quantify weekly self-reported PA as metabolic equivalent of task. Results indicated that both sexes and menopausal subgroups revealed negative linear relationships between relative CVR and PA. Furthermore, females presented a unique non-linear relationship between relative CVR and total PA in the cerebral cortex. In females, there were also relationships with total and walking PA in occipital and cingulate regions. In males, we observed relationships between total or vigorous PA and CVR in parietal and cingulate regions. Sex-specific effects were also observed with CP, whereby females benefited across a greater number of regions and intensities than males, especially in the postmenopause group. Overall, males and females appear to benefit from different amounts and intensities of PA, with menopause status significantly influencing the effect of PA on cerebrovascular outcomes, underscoring the need for sex-specific recommendations in promoting cerebrovascular health.

Arterial Aging and Cerebrovascular Function: Impact of Aerobic Exercise Training in Older Adults

Advanced age is the major risk factor for dementia including Alzheimer's disease. The clinical effects of recently developed anti-amyloid therapy for Alzheimer's disease were modest and the long-term outcome is unknown. Thus, an in-depth understanding of the mechanisms of brain aging is essential to develop preventive interventions to maintain cognitive health in late life. Mounting evidence suggests that arterial aging manifested as increases in central arterial stiffness is associated closely with cerebrovascular dysfunction and brain aging while improvement of cerebrovascular function with aerobic exercise training contributes to brain health in older adults. We summarized evidence in this brief review that 1) increases in central arterial stiffness and arterial pulsation with age are associated with increases in cerebrovascular resistance, reduction in cerebral blood flow, and cerebrovascular dysfunction, 2) aerobic exercise training improves cerebral blood flow by modifying arterial aging as indicated by reductions in cerebrovascular resistance, central arterial stiffness, arterial pulsation, and improvement in cerebrovascular function, and 3) improvement in cerebral blood flow and cerebrovascular function with aerobic exercise training may lead to improvement in cognitive function. These findings highlight the associations between arterial aging and cerebrovascular function and the importance of aerobic exercise in maintaining brain health in older adults.

Effect of combined physical-cognitive training on the functional and cognitive capacity of older people with mild cognitive impairment: a randomized controlled trial

BACKGROUND

The increase in population aging highlights the growing prevalence of mild cognitive impairment, prompting the adoption of interventions that combine physical exercise and cognitive training to improve health and cognitive performance in older adults. The aim of this study was to analyze the efficacy of a combined program on physical and cognitive health in older people with cognitive impairment.

METHODS

A 12-week randomized controlled clinical trial involving 95 participants (aged 72.12 ± 4.25 years), 47 individuals participated in a control group (CG) that only underwent cognitive stimulation, while 48 individuals were in an experimental group (EG) that participated in a combined program. Balance was measured using the Tinetti scale, upper body strength was assessed with the arm curl test, lower body strength was evaluated with the 30-s chair stand test, flexibility was tested using the back scratch test and chair sit-and-reach test, physical function was measured with the Timed Up and Go test, cognitive function was assessed using the Mini Mental State Examination, cognitive impairment was evaluated with the Montreal Cognitive Assessment, verbal fluency was tested with the Isaac test, and executive functions were assessed using the Trail Making Test.

RESULTS

The results of the study show significant improvements in both physical and cognitive aspects, such as balance, gait, upper and lower body strength, flexibility, physical function, cognitive function, cognitive impairment, verbal fluency, and executive functions in the group that carried out the intervention compared to the control group.

CONCLUSION

A combined program for older individuals with mild cognitive impairment leads to enhancements in physical and cognitive health. These improvements underscore the importance of integrating physical exercise with cognitive training as an effective strategy for enhancing overall health and quality of life in older adults.

TRIAL REGISTRATION

NCT05503641.

Lower middle cerebral artery blood velocity during low-volume high-intensity interval exercise in chronic stroke

High-intensity interval training (HIIE) may present unique challenges to the cerebrovascular system in individuals post-stroke. We hypothesized lower middle cerebral artery blood velocity (MCAv) in individuals post-stroke: 1) during 10 minutes of HIIE, 2) immediately following HIIE, and 3) 30 minutes after HIIE, compared to age- and sex-matched controls (CON). We used a recumbent stepper submaximal exercise test to determine workloads for high-intensity and active recovery. Our low volume HIIE protocol consisted of 1-minute intervals for 10 minutes. During HIIE, we measured MCAv, mean arterial pressure (MAP), heart rate (HR), and end tidal carbon dioxide (PETCO2). We assessed carotid-femoral pulse wave velocity as a measure of arterial stiffness. Fifty participants completed the study (25 post-stroke, 76% ischemic, 32% moderate disability). Individuals post-stroke had lower MCAv during HIIE compared to CON (p = 0.03), which remained 30 minutes after HIIE. Individuals post-stroke had greater arterial stiffness (p = 0.01) which was moderately associated with a smaller MCAv responsiveness during HIIE (r = -0.44). No differences were found for MAP, HR, and PETCO2. This study suggests individuals post-stroke had a lower MCAv during HIIE compared to their peers, which remained during recovery up to 30 minutes. Arterial stiffness may contribute to the lower cerebrovascular responsiveness post-stroke.

Current perspectives on prevention of vascular cognitive impairment and promotion of vascular brain health

INTRODUCTION

The true global burden of vascular cognitive impairment (VCI) is unknown. Reducing risk factors for stroke and cardiovascular disease would inevitably curtail VCI.

AREAS COVERED

The authors review current diagnosis, epidemiology, and risk factors for VCI. VCI increases in older age and by inheritance of known genetic traits. They emphasize modifiable risk factors identified by the 2020 Lancet Dementia Commission. The most profound risks for VCI also include lower education, cardiometabolic factors, and compromised cognitive reserve. Finally, they discuss pharmacological and non-pharmacological interventions.

EXPERT OPINION

By virtue of the high frequencies of stroke and cardiovascular disease the global prevalence of VCI is expectedly higher than prevalent neurodegenerative disorders causing dementia. Since ~ 90% of the global burden of stroke can be attributed to modifiable risk factors, a formidable opportunity arises to reduce the burden of not only stroke but VCI outcomes including progression from mild to the major in form of vascular dementia. Strict control of vascular risk factors and secondary prevention of cerebrovascular disease via pharmacological interventions will impact on burden of VCI. Non-pharmacological measures by adopting healthy diets and encouraging physical and cognitive activities and urging multidomain approaches are important for prevention of VCI and preservation of vascular brain health.

Interaction Between Arteriosclerosis and Amyloid-β on Cognitive Function

BACKGROUND

Dementia is a multifactorial disease, with Alzheimer's disease (AD) and vascular pathology often co-occurring in many individuals with dementia. Yet, the interplay between AD and vascular pathology in cognitive decline is largely undetermined.

OBJECTIVE

The aim of the present study was to examine the joint effect of arteriosclerosis and AD pathology on cognition in the general population without dementia.

METHODS

We determined the interaction between blood-based AD biomarkers and CT-defined arteriosclerosis on cognition in 2,229 dementia-free participants of the population-based Rotterdam Study (mean age: 68.9 years, 52% women) cross-sectionally.

RESULTS

Amyloid-β (Aβ)42 and arterial calcification were associated with cognitive performance. After further adjustment for confounders in a model that combined all biomarkers, only arterial calcification remained independently associated with cognition. There was a significant interaction between arterial calcification and Aβ42 and between arterial calcification and the ratio of Aβ42/40. Yet, estimates attenuated, and interactions were no longer statistically significant after adjustment for cardio metabolic risk factors.

CONCLUSIONS

Arteriosclerosis and AD display additive interaction-effects on cognition in the general population, that are due in part to cardio metabolic risk factors. These findings suggest that joint assessment of arteriosclerosis and AD pathology is important for understanding of disease etiology in individuals with cognitive impairment.

Prestroke physical activity is associated with admission haematoma volume and the clinical outcome of intracerebral haemorrhage

BACKGROUND

Prestroke physical activity (PA) has been linked to improved outcomes after intracerebral haemorrhage (ICH), but its association with ICH volume is unknown. We aimed to investigate associations of prestroke PA with location-specific haematoma volume and the clinical outcome of ICH.

METHODS

All patients with primary ICH, admitted to three hospitals between 2014 and 2019, were included. Patients performing light PA ≥4 hour/week the year before stroke were considered physically active. Haematoma volumes were assessed from admission brain imaging. Adjusted associations were estimated using multivariate linear and logistic regression models. Haematoma volume was explored as mediator to the relationship between prestroke PA and mild stroke severity (0-4 points on the National Institutes of Health Stroke Scale), a good 1-week functional status (0-3 points on the modified Rankin Scale) and 90-day survival. Average direct effects (ADE) and average causal mediation effects (ACME) were computed.

RESULTS

Of 686 primary ICH cases, 349 were deep, 240 lobar and 97 infratentorial. Prestroke PA predicted smaller haematoma volumes in deep ICH (β=-0.36, SE=0.09, p<0.001) and lobar ICH (β=-0.23, SE=0.09, p=0.016). Prestroke PA was also associated with mild stroke severity (OR 2.53, 95% CI 1.59 to 4.01), a good 1-week functional status (OR 2.12, 95% CI 1.37 to 3.30) and 90-day survival (OR 3.48, 95% CI 2.06 to 5.91). Haematoma volume partly mediated the relationships between PA and stroke severity (ADE 0.08, p=0.004; ACME 0.10, p<0.001), 1-week functional status (ADE 0.07, p=0.03; ACME 0.10, p<0.001) and 90-day survival (ADE 0.14, p<0.001; ACME 0.05, p<0.001).

CONCLUSIONS

Light PA ≥4 hour/week prior to ICH was associated with smaller haematoma volumes in deep and lobar locations. Physically active patients with ICH had a higher likelihood of mild stroke, a good 1-week functional status and 90-day survival, in part mediated by smaller haematoma volumes on admission.

Walking energetics and white matter hyperintensities in mid-to-late adulthood

INTRODUCTION

White matter hyperintensities (WMHs) increase with age and contribute to cognitive and motor function decline. Energy costs for mobility worsen with age, as the energetic cost of walking increases and energetic capacity declines. We examined the cross-sectional associations of multiple measures of walking energetics with WMHs in mid- to late-aged adults.

METHODS

A total of 601 cognitively unimpaired adults (mean age 66.9 ± 15.3 years, 54% women) underwent brain magnetic resonance imaging scans and completed standardized slow- and peak-paced walking assessments with metabolic measurement (V̇O2). T1-weighted scans and fluid-attenuated inversion recovery images were used to quantify WMHs. Separate multivariable linear regression models examined associations adjusted for covariates.

RESULTS

Lower slow-paced V̇O2 (B = 0.07; P = 0.030), higher peak-paced V̇O2 (B = -0.10; P = 0.007), and lower cost-to-capacity ratio (B = .12; P < 0.0001) were all associated with lower WMH volumes.

DISCUSSION

The cost-to-capacity ratio, which describes the percentage of capacity required for ambulation, was the walking energetic measure most strongly associated with WMHs.

Cross-sectional associations between short and mid-term blood pressure variability, cognition, and vascular stiffness in older adults

Background

High blood pressure variability (BPV), particularly in older age, appears to be an independent risk factor for incident dementia. The current study aimed to investigate the association between different BPV measures (short- and mid-term BPV including circadian patterns) and cognitive functioning as well as vascular stiffness measures to better understand the role that BPV plays in cognitive impairment.

Methods

70 older adults (60-80-year-olds) without dementia completed a cognitive test battery and had their blood pressure (BP) assessed via a 24-hour ambulatory BP monitor (divided into sleep and wake for short-term BPV) and 4-day morning and evening home-based BP monitor (for day-to-day BPV). Arterial stiffness was evaluated via pulse wave analysis and pulse wave velocity (PWV) and cerebrovascular pulsatility was assessed via transcranial doppler sonography of the middle cerebral arteries.

Results

High systolic as well as diastolic short- and mid-term BPV were associated with poorer cognitive functioning, independent of the mean BP. Higher short-term BPV was associated with poorer attention and psychomotor speed, whilst day-to-day BPV was negatively linked with executive functioning. Circadian BP patterns (dipping and morning BP surge) showed no significant relationships with cognition after adjusting for covariates. Higher systolic short-term BPV was associated with higher arterial stiffness (PWV) and higher diastolic day-to-day BPV was linked with lower arterial stiffness. No significant associations between BPV measures and cerebrovascular pulsatility were present.

Conclusion

High BPV, independently of the mean BP, is associated with lower cognitive performance and increased arterial stiffness in older adults without clinically-relevant cognitive impairment. This highlights the role of systolic and diastolic BPV as a potential early clinical marker for cognitive impairment.

Role of light walking pace on cognition: Findings from the Maine-Syracuse Longitudinal Study

Moderate- to vigorous intensities of physical activity are recommended for health promotion, including brain health. Regular physical activity is considered a modifiable factor to delay -perhaps prevent- onset of dementias such as Alzheimer's disease. Little is known about the benefits of light physical activity. We analyzed data from a 998 community-dwelling, cognitively unimpaired participants from the Maine-Syracuse Longitudinal Study (MSLS) and investigated the role of light physical activity, defined by walking pace, across two time points. Results revealed light levels of walking pace were associated with higher performance at the first timepoint and less decline by time 2 in the domains of verbal abstract reasoning and visual scanning and tracking, which includes both processing speed and executive function skills. When examining change over time (N = 583), increasing walking pace was associated with less decline at time two for the domains of visual scanning and tracking, working memory, visual spatial ability, and working memory, but not verbal abstract reasoning. These findings highlight the relevance of light physical activity and the need to investigate its contribution to cognitive function. From a public health perspective, this may encourage more adults to adopt a light level of exercise and still reap health benefits.

Brain function effects of exercise interventions for cognitive decline: a systematic review and meta-analysis

Introduction

Exercise is recognized as a modifiable lifestyle factor that can mitigate cognitive decline and dementia risk. While the benefits of exercise on cognitive aging have been reported on extensively, neuronal effects in adults experiencing cognitive decline have not been systematically synthesized. The aim of this systematic review was to assess the effects of exercise on cognition and brain function in people with cognitive decline associated with dementia risk.

Method

A systematic search was conducted for randomized controlled trials of ≥ 4 weeks exercise (aerobic, resistance, or mind-body) that assessed cognition and brain function using neuroimaging and neurophysiological measures in people with subjective or objective cognitive decline. Study characteristics and brain function effects were narratively synthesized, while domain-specific cognitive performance was subjected to meta-analysis. Study quality was also assessed.

Results

5,204 records were identified and 12 unique trials met the eligibility criteria, representing 646 adults classified with cognitive frailty, mild or vascular cognitive impairment. Most interventions involved 40-minute sessions conducted 3 times/week. Exercise improved global cognition (g = -0.417, 95% CI, -0.694 to -0.140, p = 0.003, I2 = 43.56%), executive function (g = -0.391, 95% CI, -0.651 to -0.131, p = 0.003, I2 = 13.28%), but not processing speed or general short-term memory (both p >0.05). Across fMRI and ERP studies, significant neuronal adaptations were found with exercise cf. control throughout the brain and were linked with improved global cognition, memory, and executive function. Cerebral blood flow was also found to improve with 24 weeks of exercise, but was not linked with cognitive changes.

Discussion

The cognitive improvements associated with exercise are likely driven by increased metabolic activity, cerebrovascular mechanisms, and neuroplasticity throughout the brain. Our paper shows the promise in, and need for, high-quality trials integrating cognitive and brain function measures to elucidate the functional relationship between exercise and brain health in populations with a high risk of dementia.

Systematic review registration

PROSPERO, identifier: CRD42022291843.

Vascular function and cognition in persons with multiple sclerosis: Preliminary examination

BACKGROUND

Cognitive dysfunction is one of the most common consequences of multiple sclerosis (MS). Recent studies have noted a high incidence of vascular comorbidity that might be associated with cognitive decline among persons with MS. However, there is a lack of evidence on vascular biomarkers (e.g., arterial stiffness indices) that are associated with cognition in MS. The current study characterized differences in vascular function between persons with MS and healthy controls, and examined the association between vascular and cognitive function in persons with MS compared with healthy controls.

RESULTS

The MS group had significantly worse cognitive performance and higher cfPWV than healthy controls. There were significant bivariate correlations between the Symbol Digit Modalities Test (SDMT) score with AIx75 (r_s = -0.45) and cfPWV (r_s = 0.30) in the MS sample, but not in healthy controls. Regression analyses further indicated a nonlinear association between cfPWV and the SDMT in the MS sample (p-values for β coefficients < 0.05; adjusted R² = 0.10). No significant associations were observed among other cognitive and vascular outcomes.

CONCLUSION

Our findings suggest significant associations between arterial stiffness and cognitive processing speed in MS. This preliminary examination provides initial, cross-sectional support for future population-based research on cognitive and vascular function in persons with MS. Such results may be clinically important for developing interventions that focus on regulating vascular dysfunction as an early treatment for preventing cognitive impairment in the MS population.

Effect of Baduanjin exercise on cerebral blood flow and cognitive frailty in the community older adults with cognitive frailty: A randomized controlled trial

Objectives

Regular Baduanjin exercise training has been shown to be beneficial to the physical and cognitive health of older adults, but the underlying mechanisms remain to be investigated. This study examined the influence of Baduanjin on cerebral hemodynamics in community-dwelling older adults with cognitive frailty.

Design

Randomized controlled trial.

Methods

A total of 102 eligible participants were randomly allocated into the Baduanjin exercise intervention group (BEG) or usual physical activity control group (CG) for 24 weeks. Cerebral hemodynamic parameters of bilateral middle/anterior cerebral artery and basilar artery, cognitive ability and physical frailty were assessed using Transcranial Doppler (TCD), Montreal Cognitive Assessment (MoCA) and Edmonton Frailty Scale (EFS) at baseline and 24 weeks post-intervention.

Results

After 24 weeks intervention, the changes in peak systolic velocity (PSV), mean blood flow velocity (MBFV), and end diastolic velocity (EDV) in the right middle cerebral artery and basilar artery were better in the BEG than in the CG; the increase in MoCA scores and the decrease in EFS scores were significantly higher in the BEG than in the CG. Moreover, the interaction of exercise and time on those variables showed obvious significance.

Conclusions

The 24 weeks Baduanjin exercise training had a positive beneficial effect on cerebral blood flow in community-dwelling older adults with cognitive frailty. This may be a potential mechanism by which Baduanjin exercise improves the cognitive frailty in older adults.

Trial registration

Chinese Clinical Trial Registry, ChiCTR1800020341.

Date of registration

December 25, 2018, http://www.chictr.org.cn/showproj.aspx?proj=29846.

Acute Effects of the Interval and Duration of Intermittent Exercise on Arterial Stiffness in Young Men

We proved the hypothesis that intermittent exercise would have a better effect on arterial stiffness by shortening the duration of intervals and increasing the number of bouts. Twenty healthy male college students (20.4 ± 0.4 years) were randomly assigned to a quiet control (CON), 30 min continuous exercise (CE), long-interval intermittent exercise with long intervals (IELL), long-interval intermittent exercise with short intervals (IELS), and short-interval intermittent exercise with short intervals (IESS). The intensity was set to 45% of the heart rate reserve. The brachial-ankle pulse wave (baPWV) was measured at baseline (BL), 0 min post-exercise, 20 min post-exercise, 40 min post-exercise, and 60 min post-exercise. BaPWV changes (⊿baPWV) from the BL in the same tests were used for the analysis. ⊿baPWV did not change significantly in the CON. ⊿baPWV decreased significantly at 0, 20, and 40 min in all exercise tests. ⊿baPWV decreased significantly at 60 min in IELS and IESS. At 60 min, the ⊿baPWV of IELS and IESS was still significantly lower than that of CON and CE, and the ⊿baPWV of IESS was still significantly lower than that of IELS. Hence, shortening the intervals of intermittent exercise and increasing the number of repetitions may enhance the effect of improving arterial stiffness.

The burden of mild cognitive impairment attributable to physical inactivity in Colombia

BACKGROUND

Mild cognitive impairment often precedes dementia. The purpose of this analysis was to estimate the population attributable fraction for physical activity in Colombia, which is the reduction in cases that would occur if all participants were physically active.

METHODS

The sample included 20,174 men and women aged 70.04 ± 7.68 years (mean ± SD) from the National Survey of Health, Wellbeing and Ageing. Trained interviewers administered a shorter version of the mini-mental state examination and mild cognitive impairment was defined as a score of 12 or less out of 19. Logistic regression models were fitted and population attributable fractions for physical activity were calculated. All analyses were adjusted for age, sex, height, education, income, civil status, smoking, and alcohol drinking.

RESULTS

The prevalence of physical activity was approximately 50% when defined as walking between 9 and 20 blocks at least three times per week. Theoretically, 19% of cases of mild cognitive impairment would be eliminated if all adults were to walk (95% confidence interval: 16%, 22%). The prevalence was approximately 20% when defined as taking part in vigorous sport or exercise at least three times per week. Theoretically, 23% of cases of mild cognitive impairment would be eliminated if all adults were to take part in vigorous sport or exercise (16%, 30%). Similar results were observed after removing those who reported mental health problems.

CONCLUSION

Physical activity, whether walking or vigorous sport and exercise, has the potential to substantially reduce the burden of mild cognitive impairment in Colombia.

Associations of body mass index and sarcopenia with screen-detected mild cognitive impairment in older adults in Colombia

Background and objective

More research is required to understand associations of body mass index (BMI) and sarcopenia with cognition, especially in Latin America. The objective of this study was to investigate associations of BMI and sarcopenia with mild cognitive impairment in Colombia.

Design, setting, and participants

Data were from the National Survey of Health, Wellbeing and Aging in Colombia (SABE Colombia, in Spanish). Community-dwelling adults aged 60 years or older were invited to participate.

Methods

Trained interviewers administered a shorter version of the mini-mental state examination and mild cognitive impairment was defined as a score of 12 or less out of 19. Body mass index was defined using standard cut-offs. Sarcopenia was defined as low grip strength or slow chair stands. Logistic regression models were adjusted for age, sex, height, education, income, civil status, smoking, and alcohol drinking.

Results

The prevalence of mild cognitive impairment was 20% in 23,694 participants in SABE Colombia and 17% in 5,760 participants in the sub-sample in which sarcopenia was assessed. Overweight and obesity were associated with decreased risk of mild cognitive impairment and sarcopenia was associated with increased risk. Sarcopenia was a risk factor for mild cognitive impairment in those with normal BMI (adjusted model included 4,911 men and women). Compared with those with normal BMI and without sarcopenia, the odds ratio for mild cognitive impairment was 1.84 in those with normal BMI and sarcopenia (95% confidence interval: 1.25, 2.71). Sarcopenia was also a risk factor in those with obesity but did not present a greater risk than sarcopenia alone. Compared with those with normal BMI and without sarcopenia, the odds ratio was 1.62 in those with obesity and sarcopenia (95% confidence interval: 1.07, 2.48). Sarcopenia was not a risk factor for mild cognitive impairment in those with overweight. Similar results were observed when reference values from Colombia were used to set cut-offs for grip strength. Similar results were also observed in cross-validation models, which suggests the results are robust.

Conclusion

This is the first study of the combined associations of sarcopenia and obesity with cognition in Colombia. The results suggest that sarcopenia is the major predictor of screen-detected mild cognitive impairment in older adults, not overweight or obesity.

Exploration of cerebral hemodynamic pathways through which large artery function affects neurovascular coupling in young women

Background

The interactions between large artery function and neurovascular coupling (NVC) are emerging as important contributors to cognitive health. Women are disproportionally affected by Alzheimer's disease and related dementia later in life. Understanding large artery correlates of NVC in young women may help with preservation of cognitive health with advancing age.

Purpose

To explore the association between large artery function, NVC and cognitive performance in young women.

Methods

Vascular measurements were made in 61 women (21 ± 4 yrs) at rest and during a cognitive challenge (Stroop task). Transcranial Doppler was used to measure left middle cerebral artery (MCA) maximum velocity (Vmax), mean velocity (Vmean), and pulsatility index (PI). NVC was determined as MCA blood velocity reactivity to the Stroop task. Large artery function was determined using carotid-femoral pulse wave velocity (cfPWV) as a proxy measure of aortic stiffness and carotid ultrasound-derived measures of compliance and reactivity (diameter change to the Stroop task). Cognitive function was assessed separately using a computerized neurocognitive battery that included appraisal of response speed, executive function, information processing efficiency, memory, attention/concentration, and impulsivity.

Results

MCA Vmax reactivity was positively associated with executive function (β = 0.26, 95% CI 0.01–0.10); MCA Vmean reactivity was negatively associated with response speed (β = −0.33, 95% CI −0.19 to −0.02) and positively with memory score (β = 0.28, 95% CI 0.01–0.19). MCA PI reactivity was negatively associated with attention performance (β = −0.29, 95% CI −14.9 to −1.0). Path analyses identified significant paths (p &lt; 0.05) between carotid compliance and carotid diameter reactivity to select domains of cognitive function through MCA reactivity.

Conclusions

NVC was associated with cognitive function in young women. Carotid artery function assessed as carotid compliance and carotid reactivity may contribute to optimal NVC in young women through increased blood flow delivery and reduced blood flow pulsatility.

Sex-specific effects of cardiorespiratory fitness on age-related differences in cerebral hemodynamics

There is a positive association between cardiorespiratory fitness and cognitive health, but the interaction between cardiorespiratory fitness and aging on cerebral hemodynamics is unclear. These potential interactions are further influenced by sex differences. The purpose of this study was to determine the sex-specific relationships between cardiorespiratory fitness, age, and cerebral hemodynamics in humans. Measurements of unilateral middle cerebral artery blood velocity (MCAv) and cerebral pulsatility index obtained using transcranial Doppler ultrasound and cardiorespiratory fitness [maximal oxygen consumption (V̇o2max)] obtained from maximal incremental exercise tests were retrieved from study records at three institutions. A total of 153 healthy participants were included in the analysis (age = 42 ± 20 yr, range = 18-83 yr). There was no association between V̇o2max and MCAv in all participants (P = 0.20). The association between V̇o2max and MCAv was positive in women, but no longer significant after age adjustment (univariate: P = 0.01; age-adjusted: P = 0.45). In addition, there was no association between V̇o2max and MCAv in men (univariate: P = 0.25, age-adjusted: P = 0.57). For V̇o2max and cerebral pulsatility index, there were significant negative associations in all participants (P < 0.001), in men (P < 0.001) and women (P < 0.001). This association remained significant when adjusting for age in women only (P = 0.03). In summary, higher cardiorespiratory fitness was associated with a lower cerebral pulsatility index in all participants, and the significance remained only in women when adjusting for age. Future studies are needed to determine the sex-specific impact of cardiorespiratory fitness improvements on cerebrovascular health.NEW & NOTEWORTHY We present data pooled from three institutions to study the impact of age, sex, and cardiorespiratory fitness on cerebral hemodynamics. Cardiorespiratory fitness was positively associated with middle cerebral artery blood velocity in women, but not in men. Furthermore, cardiorespiratory fitness was inversely associated with cerebral pulsatility index in both men and women, which remained significant in women when adjusting for age. These data suggest a sex-specific impact of cardiorespiratory fitness on resting cerebral hemodynamics.

Truly Cross-fit: The Association of Exercise and Clinical Outcomes: Introduction to a JINS Special Section

We introduce a JINS special section inspired by a symposium presented at INS 2020 in Denver. The symposium was entitled Truly Cross-fit: The Association of Exercise and Cognitive Reserve. The collection of papers herein spans diverse methods, a range of developmental and clinical conditions, and a variety of outcomes all reflecting on the association of exercise and cognition-related outcomes. Taken together, the studies in this Special Section direct us to the variety of dimensions to be considered in understanding this association including what mode, intensity, duration, and timing of physical activity and aspects of age, sex, genetics, baseline characteristics, and disease status moderate these findings. We hope this Special Section will not only provide a framing for important future research on exercise and clinical outcomes but also inspiration to pursue them.