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The stiffness of large arteries and increased pulsatility can have an impact on the brain white matter (WM) microstructure, however those mechanisms are still poorly understood. The aim of this study was to investigate the association between central artery stiffness, axonal and myelin integrity in 54 cognitively unimpaired elderly subjects (65–75 years old). The neuronal fiber integrity of brain WM was assessed using diffusion tensor metrics and magnetization transfer imaging as measures of axonal organization (Fractional anisotropy, Radial diffusivity) and state of myelination (Myelin volume fraction). Central artery stiffness was measured by carotid-femoral pulse wave velocity (cfPWV). Statistical analyses included 4 regions (the corpus callosum, the internal capsule, the corona radiata and the superior longitudinal fasciculus) which have been previously denoted as vulnerable to increased central artery stiffness. cfPWV was significantly associated with fractional anisotropy and radial diffusivity (p < 0.05, corrected for multiple comparisons) but not with myelin volume fraction. Findings from this study also show that improved executive function performance correlates with Fractional anisotropy positively (p < 0.05 corrected) as well as with myelin volume fraction and radial diffusivity negatively (p < 0.05 corrected). These findings suggest that arterial stiffness is associated with axon degeneration rather than demyelination. Controlling arterial stiffness may play a role in maintaining the health of WM axons in the aging brain.

Everyday activities like walking and talking can put an older adult at risk for a fall if they have difficulty dividing their attention between motor and cognitive tasks. Training studies have demonstrated that both cognitive and physical training regimens can improve motor and cognitive task performance. Few studies have examined the benefits of combined training (cognitive and physical) and whether or not this type of combined training would transfer to walking or balancing dual-tasks. This study examines the dual-task benefits of combined training in a sample of sedentary older adults. Seventy-two older adults (≥60 years) were randomly assigned to one of four training groups: Aerobic + Cognitive training (CT), Aerobic + Computer lessons (CL), Stretch + CT and Stretch + CL. It was expected that the Aerobic + CT group would demonstrate the largest benefits and that the active placebo control (Stretch + CL) would show the least benefits after training. Walking and standing balance were paired with an auditory n-back with two levels of difficulty (0- and 1-back). Dual-task walking and balance were assessed with: walk speed (m/s), cognitive accuracy (% correct) and several mediolateral sway measures for pre- to post-test improvements. All groups demonstrated improvements in walk speed from pre- ( = 1.33 m/s) to post-test ( = 1.42 m/s, < 0.001) and in accuracy from pre- ( = 97.57%) to post-test ( = 98.57%, = 0.005).They also increased their walk speed in the more difficult 1-back ( = 1.38 m/s) in comparison to the 0-back ( = 1.36 m/s, < 0.001) but reduced their accuracy in the 1-back ( = 96.39%) in comparison to the 0-back ( = 99.92%, < 0.001). Three out of the five mediolateral sway variables (Peak, SD, RMS) demonstrated significant reductions in sway from pre to post test ( < 0.05). With the exception of a group difference between Aerobic + CT and Stretch + CT in accuracy, there were no significant group differences after training. Results suggest that there can be dual-task benefits from training but that in this sedentary sample Aerobic + CT training was not more beneficial than other types of combined training.

Physical exercise and cognitive training have been shown to enhance cognition among older adults. However, few studies have looked at the potential synergetic effects of combining physical and cognitive training in a single study. Prior trials on combined training have led to interesting yet equivocal results. The aim of this study was to examine the effects of combined physical and cognitive interventions on physical fitness and neuropsychological performance in healthy older adults. Seventy-six participants were randomly assigned to one of four training combinations using a 2×2 factorial design. The physical intervention was a mixed aerobic and resistance training program, and the cognitive intervention was a dual-task (DT) training program. Stretching and toning exercises and computer lessons were used as active control conditions. Physical and cognitive measures were collected pre- and postintervention. All groups showed equivalent improvements in measures of functional mobility. The aerobic-strength condition led to larger effect size in lower body strength, independently of cognitive training. All groups showed improved speed of processing and inhibition abilities, but only participants who took part in the DT training, independently of physical training, showed increased task-switching abilities. The level of functional mobility after intervention was significantly associated with task-switching abilities. Combined training did not yield synergetic effects. However, DT training did lead to transfer effects on executive performance in neuropsychological tests. Both aerobic-resistance training and stretching-toning exercises can improve functional mobility in older adults.

It is well established that sex differences exist in the manifestation of vascular diseases. Arterial stiffness (AS) has been associated with changes in cerebrovascular reactivity (CVR) and cognitive decline in aging. Specifically, older adults with increased AS show a decline on executive function (EF) tasks. Interestingly, the relationship between AS and CVR is more complex, where some studies show decreased CVR with increased AS, and others demonstrate preserved CVR despite higher AS. Here, we investigated the possible role of sex on these hemodynamic relationships. Acquisitions were completed in 48 older adults. Pseudo-continuous arterial spin labeling (pCASL) data were collected during a hypercapnia challenge. Aortic pulse wave velocity (PWV) data was acquired using cine phase contrast velocity series. Cognitive function was assessed with a comprehensive neuropsychological battery, and a composite score for EF was calculated using four cognitive tests from the neuropsychological battery. A moderation model test revealed that sex moderated the relationship between PWV and CVR and PWV and EF, but not between CVR and EF. Together, our results indicate that the relationships between central stiffness, cerebral hemodynamics and cognition are in part mediated by sex.

Older adults are at risk of multiple chronic diseases, most of which could be prevented by engaging in regular physical activity. Frailty is a state of increased vulnerability to diseases. Worsening symptoms of frailty, such as decrease in physical functionality, can compromise health-related quality of life (HR-QOL). Previous findings suggest that frailty moderates the relationship between physical activity and HR-QOL, yet intervention findings are limited, particularly in dose-response analyses. Hence, this study was conducted to test if lower-dose physical activity (120 minutes/week) would provide the same benefits in health outcomes (physical functionality and HR-QOL) as higher-dose physical activity (180 minutes/week). Participants (n=110) were older adults comprising higher-dose, lower-dose, and control groups who were combined from recent randomized controlled trials. Experimental groups participated in a multimodal exercise program in a supervised laboratory setting for 12 weeks. The higher-dose group showed a significant improvement in physical functionality ( =0.23, =0.03) and in overall HR-QOL ( =0.44, =0.001) including its subcategories over the control group. A group × frailty interaction revealed that frail individuals significantly improved in capacity HR-QOL when they exercised at a higher dose ( (1, 49)=4.57, =0.038). This study identifies a positive, predictive relationship between exercise duration and health outcomes (HR-QOL dimensions and frailty) among older adults. Frail individuals in the higher-dose group demonstrated significant recovery of capacity HR-QOL, thus reflecting improvement in their daily activities.

Background Spontaneous walking speed (SWS) is one of the most important indicators of health in older adults. Studies have shown benefits of physical trainings on SWS in older adults but the impact of cognitive training and multidomain interventions remains understudied. Aims This original study aimed at comparing the impact of aerobic/resistance exercise, computerized cognitive training and the combination of both interventions compared with active control conditions on SWS in healthy older adults. Methods Ninety community-dwelling older adults were randomly assigned to four different combinations composed of two active interventions: physical aerobic/resistance and cognitive dual-task trainings, and two active control conditions: stretching exercises and computer lessons. The four combinations were the following: (1) aerobic/resistance and cognitive dual task ( n  = 28), (2) aerobic/resistance and computer lessons ( n  = 21), (3) stretching exercises and cognitive dual task and ( n  = 23), (4) stretching exercises and computer lessons ( n  = 18). Training sessions were held three times/week for three months. SWS for 30 s was assessed before and after the intervention. Results Repeated-measures ANOVA showed a main effect of time and a significant three-way interaction suggesting differential improvement in SWS according to training combinations. A clinical meaningful improvement in SWS was observed in groups 1–3 (0.08–0.14 m/s; effect sizes: small to moderate) but not in the active control group 4. Discussion Results of this study suggest that aerobic/resistance exercise and computerized dual-task training are two non-pharmacological interventions by which SWS, a functional vital sign, can be clinically improved in older adults. Conclusion This original study pointed out different tools to prevent functional decline in older people.

Many studies have suggested that physical exercise training improves cognition and more selectively executive functions. There is a growing interest to clarify the neurophysiological mechanisms that underlie this effect. The aim of the current study was to evaluate the neurophysiological changes in cerebral oxygenation associated with physical fitness level and executive functions. In this study, 22 younger and 36 older women underwent a maximal graded continuous test (i.e., [Formula: see text]O2max ) in order to classify them into a fitness group (higher vs. lower fit). All participants completed neuropsychological paper and pencil testing and a computerized Stroop task (which contained executive and non-executive conditions) in which the change in prefrontal cortex oxygenation was evaluated with near infrared spectroscopy (NIRS). Our findings revealed a Fitness × Condition interaction (p < 0.05) such that higher fit women scored better on measures of executive functions than lower fit women. In comparison to lower fit women, higher fit women had faster reaction times in the Executive condition of the computerized Stroop task. No significant effect was observed in the non-executive condition of the test and no interactions were found with age. In measures of cerebral oxygenation (ΔHbT and ΔHbO2), we found a main effect of fitness on cerebral oxygenation during the Stroop task such that only high fit women demonstrated a significant increase in the right inferior frontal gyrus. Higher fit individuals who demonstrate better cardiorespiratory functions (as measured by [Formula: see text]O2max ) show faster reaction times and greater cerebral oxygenation in the right inferior frontal gyrus than women with lower fitness levels. The lack of interaction with age, suggests that good cardiorespiratory functions can have a positive impact on cognition, regardless of age.

BackgroundHalf of the people with fear of falling (FoF) are non-fallers, and the reason why some people considered non-fallers are afraid of falling is unknown, but reduced mobility or cognition, or both concurrently must be considered as potential risk factors.AimThe study aimed to determine if mobility and/or cognitive abilities could identify people with a history of falls in older adults with FoF.MethodsTwenty-six older adults with FoF participated in this study. Full cognitive and mobility assessments were performed assessing global cognitive impairments (MoCA score < 26), executive functions, memory, processing speed, visuospatial skills, mobility impairment (TUG time > 13.5 s), gait, balance and physical capacity. Information about falls occurring during the year prior to the inclusion was collected. Logistic regression analyses were performed to explore the association between falls and cognitive and mobility abilities.ResultsNo significant differences in age, sex, level of education or body mass index were detected between fallers and non-fallers. Cognitive impairments (MoCA score < 26) distinguished between fallers and non-fallers (p = 0.038; R2 = 0.247). Among specific cognitive functions, visuospatial skills distinguished between fallers and non-fallers (p = 0.027; R2 = 0.258). Mobility impairments (TUG time > 13.5 s), gait, balance and physical capacity were not related to past falls.Discussion/conclusionIn older adults with FoF, global cognitive deficits detected by the MoCA are important factors related to falls and more particularly visuospatial skills seem to be among the most implicated functions. These functions could be targeted in multifactorial interventions.

PurposeExercise has been shown to have various proximal and distal benefits among older adults such as improving physical fitness, cognitive functioning, and health-related quality of life (HR-QOL). Despite this evidence, limited research has investigated pathway change of these outcomes. The primary purpose of this study was to test if older adults who improved in physical fitness measures from engaging in multicomponent exercise training for 12 weeks predicted change in proximal (cognitive functioning) and distal (HR-QOL) outcomes, respectively.MethodsParticipants (n = 110) were healthy, older adults (M = 72, SD = 7.24) that comprised an exercise-intervention and control group. The intervention consisted of exercising in a supervised laboratory setting for 12 weeks.ResultsStructural equation modeling revealed group type to predict change in physical performance and the maximum walking test with comparable effect sizes. Physical performance in turn predicted improvement in processing speed (β = 0.23, p = 0.013) executive functioning (β = 0.26, p = 0.006), and HR-QOL (β = 0.13, p = 0.031). However, only executive functioning was found to significantly predict HR-QOL (β = 0.49, p < 0.001) over processing speed (p > 0.05).ConclusionsBetween two fitness measures, the physical performance test demonstrated better predictive validity in proximal and distal health outcomes. In addition to physical fitness, older adults who engage in multi-component exercise sessions regularly can improve their executive functioning, which in turn enhances their HR-QOL.

Aging is accompanied by decreased grey matter volume (GMV), cerebral blood flow (CBF), and cerebrovascular reactivity (CVR), where the latter tends to decline the earliest in aging. Enhanced fitness in aging has been related to preservation of GMV and CBF, and in some cases CVR, although there are contradictory relationships reported between CVR and fitness. Therefore, to gain a better understanding of the complex interplay with fitness and GMV, CBF and CVR, it is necessary to study them concurrently. Here, we aimed to disentangle the interactions between these outcomes in healthy older adults. MRI acquisitions collected anatomical, CBF and CVR information in all participants, as well as VO2max. Results revealed decreased CVR was associated with increased fitness throughout large areas of the cerebral cortex. Within these regions it was found that lower fitness was associated with higher CBF and a slower hemodynamic response to hypercapnia. Overall, results indicate that the relationship between age, cerebral health and cerebral hemodynamics are complex. Future studies should collect other physiological outcomes in parallel with quantitative imaging, such as measures of carbon dioxide sensitivity and autoregulation, to further understand the intricacy of the effects fitness has on the aging brain, and how this may bias quantitative measures of cerebral health.