Cardiorespiratory Fitness and Cognitive Function are Positively Related Among Participants with Mild and Subjective Cognitive Impairment

Effect of exercise detraining in cognitive functions of older adults: A systematic review

OBJECTIVE

Provide a synthesis of the current literature about the effects of detraining on cognitive functions in older adults.

METHODS

The PICOS acronym strategy was performed in PubMed/MEDLINE, Web of Science, Cochrane Library and PsycINFO database. The Preferred Reporting Items for Systematic Review and Meta-Analyses statement had been followed in the present study, in which the search was conducted on October 2023. The study selection consisted in original articles including older adults, detraining after training exercise period, use of tests or scales to measure cognitive function. The Downs and Black checklist had been used to assess the studies quality. Sample characteristics, type of previous training, detraining period, cognitive functions measurements and main results were extracted by 2 investigators.

RESULTS

From 1927 studies, 12 studies were included, being 11 studies identified via systematic research, and 1 study by citation search. Older adults, ranged from 60 to 87 years old, were assessed after detraining. The cognitive functions most evaluated were global cognition and executive functions. One study evaluated both cognitive outcome and cerebral blood flow. Most of the studies demonstrated a decline in the cognitive function after detraining.

CONCLUSION

Exercise detraining period, ranging from 10 days to 16 weeks, can effect negatively the cognitive function in older adults.

Validation of the mild cognitive impairment health literacy assessment scale (MCI-HLA scale) in middle-aged and older adults

OBJECTIVES

Health literacy (HL) is associated with early prevention of mild cognitive impairment (MCI), but a targeted comprehensive assessment tool is lacking. This study aims to psychometrically evaluate the MCI-HLA scale.

METHODS

This observational study was conducted in a tertiary-level hospital's physical examination center from October to December 2020. The middle-aged and older adults (N = 550, aged 41-80 years) completed the MCI-HLA questionnaire online. The validity of the MCI-HLA scale was assessed through content validity, exploratory factor analysis, confirmatory factor analysis (CFA), convergent validity, and discriminant validity. The internal reliability was measured using Cronbach's alpha, McDonald's Omega coefficient, and split-half reliability.

RESULTS

5 factors emerged, naming: Function (7 items), Knowledge (8 items), Practice (8 items), Attitude (4 items), and Motivation (3 items), explaining 72.42% of variance. The CFA revealed that five factors of the MCI-HLA scale fit well (χ2/df=4.076, RMSEA=0.078, SRMR=0.057, CFI=0.904, TLI=0.894). Good convergent validity was suggested by the Average Variance Extracted (AVE) values exceeding 0.50. Discriminant validity was demonstrated for all the square root AVE were higher than the correlation between the two factors. Internal consistency was high (Cronbach's alpha=0.875, McDonald's Omega coefficient=0.910, split-half reliability=0.949).

CONCLUSIONS

The MCI-HLA scale takes on high reliability and validity, suitable for assessing MCI-related health literacy in middle-aged and older adults. The MCI-HLA scale could enhance MCI health literacy assessment and supports tailored interventions for improved outcomes.

A decade of aging in healthy older adults: longitudinal findings on cerebrovascular and cognitive health

Research suggests an association between cerebrovascular health and cognitive decline, but previous work is limited by its cross-sectional nature or short (< 1-2 years) follow-up. Our aim was to examine, across 10 years of follow-up in healthy older adults, changes in cerebrovascular health and their relationship with subjective memory complaints as an early marker of cognitive decline. Between 2008 and 2010, twenty-eight healthy older adults (69 ± 4 years) underwent baseline blood pressure and transcranial Doppler measurements to assess middle cerebral artery blood velocity (MCAv), cerebrovascular resistance index (CVRi), and measures of cerebral autoregulation (CA). After 9-12 years of follow-up, these measurements were repeated, and presence of memory complaints was evaluated. Linear mixed-model analyses explored effects of aging on cerebrovascular parameters and whether memory complaints were associated with cerebrovascular changes. Across a median follow-up of 10.9 years, no changes in MCAv, CVRi, or CA were found. At baseline, these parameters were not different between subjects with (n = 15) versus without (n = 13) memory complaints. During follow-up, subjects with memory complaints showed larger decreases in MCAv (- 10% versus + 9%, P = 0.041) and increases in CVRi (+ 26% versus - 9%, P = 0.029) compared to other peers without memory complaints, but no distinct changes in CA parameters (P > 0.05). Although a decade of aging does not lead to deterioration in cerebral blood flow or autoregulation, our findings suggest that reductions in cerebral blood flow and increases in cerebrovascular resistance are associated with early subjective cognitive decline.

Determinants of verbal fluency trajectories among older adults from the English Longitudinal Study of Aging

BACKGROUND

Prevalence of dementia and cognitive impairment increase creating the need for identifying modifiable risk factors to reduce their burden. The aim of this study was to identify latent groups following similar trajectories in cognitive performance assessed with the verbal fluency test, as well as their determinants.

METHODS

Data from English Longitudinal Study of Aging (ELSA) were studied. Latent groups of similar course through a 6-year period in the outcome variable (verbal fluency) were investigated, along with their determinants, using Group Based Trajectory Modeling (GBTM).

RESULTS

Four latent groups of verbal fluency trajectories were revealed. Education was the strongest predictor for a favorable trajectory, while cardiovascular disease and depression symptoms were associated with lower within each trajectory.

CONCLUSION

Cardiovascular diseases and depressive symptoms are associated with a worse course of verbal fluency through aging, implying that they might serve as targets for interventions to prevent cognitive decline in the aging population. Contrarily, higher level of education is associated with a more favorable course through aging.

Influence of a 12-Month Structured Exercise Program on the Micronutrient-Cognitive Fitness-Physical Association Profiles in Mild Cognitive Impairment

Background

Preventive lifestyle strategies have shown promise to slow down or prevent age-related cognitive decline. However, evidence on the reciprocal longitudinal relationships between nutrition biomarkers and cognitive and physical performance is lacking. Studying nutritional, cognitive, and physical profiles over time may help to overcome this knowledge gap.

Objective

To investigate the relationship of plasma levels of the robust nutritional- and antioxidant defense-related biomarkers carotenoids and tocopherols with both indicators of cognitive and physical performance in persons with mild cognitive impairment (MCI) participating in a structured exercise program.

Methods

Data from 40 participants with MCI of the NeuroExercise study were analyzed. Participants had undergone a blood withdrawal for the analysis of plasma concentrations of six carotenoids, two tocopherols and retinol prior to and after one-year of structured exercise. All participants had undergone a broad spectrum of cognitive and physical performance tests.

Results

Significant associations between lipophilic micronutrients and cognitive/physical measures were observed that were previously found to play a role in cognitive and physical frailty. In particular, lutein, zeaxanthin, and lycopene are confirmed as robust, reliable, and stable indicators of nutritional defense. Importantly, these micronutrients were associated with cognitive measures prior to the physical training program and to a more prominent extent with indicators of motoric function after the physical exercise program.

Conclusion

Specific profiles of lipophilic micronutrients are associated to cognitive performance measures and, especially after a structured exercise program, to indicators of physical performance.

Mediating role of cognitive status on performance in the two-minute step test and its normative data among Malaysian community-dwelling older persons

INTRODUCTION

The two-minute step test (2MST) has been used to estimate cardiorespiratory fitness and optimum scores are needed for performing activities of daily living with ease among older persons. However, there is limited information on the mediating role of cognitive impairment on 2MST performance and the 2MST normative data. Hence, we aim to identify the mediating role of cognitive status on performance in the 2MST among community-dwelling older adults and to establish the normative values of the 2MST.

METHODS

Participants aged 60 years and above were recruited through multistage random sampling from four states in Malaysia. The participants performed the 2MST using standard protocols. Mean comparison was done using an independent sample t-test or one-way analysis of variance. The 2MST normative values were then outlined descriptively.

RESULTS

Older age groups (60-69 years: 65.4 ± 21.9 times; 70-79 years: 61.7 ± 22.9 times; ≥80 years: 51.6 ± 24.5 times) had significantly lower levels of 2MST performance (p < 0.001). Women (56.6 ± 20.9 times) and participants with mild cognitive impairment (MCI) (58.7 ± 21.7 times) also had significantly lower levels of 2MST performance (p < 0.001) compared with men (69.1 ± 20.7 times) and participants with normal cognition (63.7 ± 21.6 times). Cognitive status had a significant mediation effect for age and sex on 2MST performance (p < 0.001). Therefore, the 2MST normative values were stratified according to cognitive status, sex, and age groups.

CONCLUSION

Validation of these findings in a larger number of older populations with MCI may provide directions for cardiorespiratory fitness training to be emphasised among older persons with MCI. Geriatr Gerontol Int 2022; ••: ••-••.

Exploring the Associations between Functional Capacity, Cognitive Function and Well-Being in Older Adults

Background: The present study aimed to explore the associations between functional capacity and global cognition, executive function and well-being in older adults. Methods: Ninety-seven older adults (age 80.6 ± 8.2 years) were examined for global cognitive function (Mini-Mental State Examination), executive function (symbol cancellation test), functional capacity (sit-to-stand tests, 6 min walk test, timed up-and-go test and handgrip strength test) and well-being (quality of life, fatigue levels, sleep quality and daily sleepiness). Adjusted partial correlations were computed to examine the associations between variables. Mediation analyses were conducted to evaluate whether functional capacity would mediate the relationships between age and cognitive or executive function. Results: Greater levels of functional capacity were associated with better performance in cognitive and executive function tests (p < 0.05). Mediation analyses revealed that functional capacity partially mediated the effects of age on global cognition and executive function (indirect effect: β = −0.11, 95% CI = −0.20 to −0.03; β = 0.34, 95% CI = 0.13 to 0.57, respectively). Increased levels of functional capacity were also associated with higher quality of life (p < 0.05, r = 0.32 to 0.41), lower fatigue levels (p < 0.05, r = 0.23 to 0.37), and better sleep quality (p < 0.05, r = 0.23 to 0.24). Conclusions: Functional capacity can mediate the effects of age on global cognition and executive function in older adults and greater levels of functional capacity are associated with improved quality of life, better sleep quality, and lower fatigue levels.

Cerebrovascular function and its association with systemic artery function and stiffness in older adults with and without mild cognitive impairment

PURPOSE

Our aim was to compare cerebrovascular and systemic vascular function between older adults with and without mild cognitive impairment (MCI), and to determine which measures of vascular function best predict the presence of MCI.

METHODS

In 41 adults with MCI and 33 adults without MCI (control) we compared middle cerebral artery velocity (MCAv) and cerebrovascular pulsatility index (PI) at rest, cerebrovascular reactivity to CO₂, and responsiveness to changes in blood pressure (%∆MCAv/%∆MAP). Systemic vascular function was assessed by flow-mediated dilation (FMD) and stiffness by pulse wave velocity (PWV).

RESULTS

Cerebrovascular PI was higher in MCI compared with control (mean ± SD: 1.17 ± 0.27 vs. 1.04 ± 0.21), and MCI exhibited a lower %∆MCAv/%∆MAP (1.26 ± 0.44 vs. 1.50 ± 0.55%). Absolute (p = 0.76) and relative cerebrovascular reactivity to CO₂ (p = 0.34) was similar between MCI and control. When age was included as a covariate the significant difference in cerebral PI between groups was lost. PWV was higher (13.2 ± 2.2 vs. 11.3 ± 2.5 m s^-1) and FMD% (4.41 ± 1.70 vs. 5.43 ± 2.15%) was lower in MCI compared with control. FMD% was positively associated with PI across the cohort. Logistic regression analysis indicated that FMD and PWV significantly discriminated between MCI and controls, independent of age, whereas the inclusion of cerebrovascular measures did not improve the predictive accuracy of the model.

CONCLUSION

These findings raise the possibility that early changes in systemic vascular stiffness and endothelial function may contribute to altered cerebrovascular haemodynamics and impaired cognitive function, and present potential targets for prevention and treatment strategies in people with MCI.

Association Between Physical Activity and Risk of Disabling Dementia in Japan

IMPORTANCE

The associations of daily total physical activity and total moderate to vigorous physical activity (MVPA) with dementia are still unclear.

OBJECTIVE

To investigate the association between daily total physical activity and subsequent risk of disabling dementia in large-scale, extended follow-up prospective study.

DESIGN, SETTING, AND PARTICIPANTS

This prospective cohort study used data from questionnaires collected between 2000 and 2003 from 8 areas from the Japan Public Health Center-based Prospective Disabling Dementia Study. Participants included adults aged 50 to 79 years in with available follow-up data on disabling dementia. Data analysis was performed from February 1, 2019, to July 31, 2021.

EXPOSURES

Daily total physical activity, total MVPA, and leisure-time MVPA.

MAIN OUTCOMES AND MEASURES

The main outcome was incidence of disabling dementia during the dementia ascertainment period between 2006 and 2016, based on the national long-term care insurance system. Risks of dementia in association with daily total physical activity, total MVPA, and leisure time MVPA were calculated using multivariable adjusted hazard ratios (aHRs).

RESULTS

Among 43 896 participants (mean [SD] age, 61.0 [7.5] years; 23 659 [53.9%] women), 5010 participants were newly diagnosed with disabling dementia during a mean (SD) of 9.5 (2.8) years in the dementia ascertainment period. In the highest daily total physical activity group, compared with the lowest activity group, risk of dementia was lower in men (aHR, 0.75 [95% CI, 0.66-0.85]; P for trend < .001) and women (aHR, 0.75 [95% CI, 0.67-0.84]; P for trend < .001). Similar inverse associations were observed in men and women for total MVPA (men: aHR, 0.74 [95% CI, 0.65-0.84]; P for trend < .001; women: aHR, 0.74 [95% CI, 0.66-0.83]; P for trend < .001) and leisure-time MVPA (men: aHR, 0.59 [95% CI, 0.53-0.67]; P for trend < .001; women: aHR, 0.70 [95% CI, 0.63-0.78]; P for trend < .001). However, these inverse associations disappeared when participants diagnosed with disabling dementia within 7 years of the starting point were excluded in men (aHR, 0.93 [95%CI, 0.77-1.12]) and within 8 years were excluded in women (aHR, 0.86 [95%CI, 0.71-1.04]). The association remained significant among men in the highest vs lowest group of leisure-time MVPA, after excluding participants diagnosed within the first 9 years (aHR, 0.72 [95% CI, 0.56-0.92]; P for trend = .004).

CONCLUSIONS AND RELEVANCE

This cohort study examined associations of daily total physical activity and total MVPA with risk of disabling dementia. The findings suggest that a high level of leisure-time MVPA was associated with decreased risk of disabling dementia in men.

Social networks moderate the association between physical fitness and cognitive function among community-dwelling older adults: a population-based study

BACKGROUND

Physical fitness declines with age. Low levels of physical fitness appear to be a risk factor of cognitive impairment. Literature elucidates social networking as a potential moderator for the relationship between physical fitness and cognitive impairment. Present study aimed to examine the relationship between physical fitness and cognitive function among community-dwelling older Malaysians, and if social network moderates said relationship.

METHODS

Data of 2322 representative community-dwelling older adults were obtained from the first wave of the "Longitudinal Study on Neuroprotective Model for Healthy Longevity" national survey. Cognitive function, physical fitness and social network was assessed through Malay-version of Mini-Mental State Examination, 2-min step test and Lubben Social Network Scale-6 respectively. Moderated hierarchical multiple regression was employed to investigate if social networks moderate the relationship between physical fitness and cognitive function.

RESULTS

A positive association between physical fitness and cognitive function were found upon controlling for covariates. Moderated hierarchical multiple regression revealed social networks to be a moderator of the association between physical fitness and cognitive function. When physical fitness was low, those with small social network revealed lowest cognitive function.

CONCLUSIONS

Social networks moderated the relationship between physical fitness and cognitive function as older adults with low levels of physical fitness and small social networks revealed lowest cognitive function. Therefore, community support or peer-based interventions among physically unfit older adults should be implemented to promote cognitive function.

Assessment of the Relationship Between Executive Function and Cardiorespiratory Fitness in Healthy Older Adults

Associations between cardiorespiratory fitness and brain health in healthy older adults have been reported using a variety of cardiorespiratory fitness estimates (CRFe). Using commonly used methods to determine CRF, we assessed the relationship between CRFe and executive function performance. Healthy older adults (n = 60, mean age 68 years, 77% women), underwent three CRF tests: a Maximal Graded Exercise Test performed on a cycle ergometer, the Rockport Fitness Walking Test, and a Non-Exercise Prediction Equation. Executive function was assessed by a computerized cognitive assessment using an N-Back task (updating cost) and a Stroop task (interference cost, global and local switch cost). Multiple hierarchical regression analyses were conducted to assess the relationship between different CRFe and executive function performance. Regardless of age and education, cardiorespiratory fitness estimated from the Maximal Graded Exercise Test and the Rockport Fitness Walking Test was significantly associated with the global switch cost. All CRFe were associated with the interference cost. No association was observed between CRFe and local switching costs or the updating costs. In the present study, not all subcomponents of executive function were related to CRFe. Interestingly, the executive functions that were associated with CRFe are those that are known to be the most affected by aging.

Achieving brain clearance and preventing neurodegenerative diseases-A glymphatic perspective

Age-related neurodegenerative diseases are a growing burden to society, and many are sporadic, meaning that the environment, diet and lifestyle play significant roles. Cerebrospinal fluid (CSF)-mediated clearing of brain waste products via perivascular pathways, named the glymphatic system, is receiving increasing interest, as it offers unexplored perspectives on understanding neurodegenerative diseases. The glymphatic system is involved in clearance of metabolic by-products such as amyloid-β from the brain, and its function is believed to lower the risk of developing some of the most common neurodegenerative diseases. Here, we present magnetic resonance imaging (MRI) data on the heart cycle's control of CSF flow in humans which corroborates findings from animal studies. We also review the importance of sleep, diet, vascular health for glymphatic clearance and find that these factors are also known players in brain longevity.

Determinants of Processing Speed Trajectories among Middle Aged or Older Adults, and Their Association with Chronic Illnesses: The English Longitudinal Study of Aging

The aim of this study was to identify latent groups of similar trajectories in processing speed through aging, as well as factors that are associated with these trajectories. In the context of the Ageing Trajectories of Health: Longitudinal Opportunities and Synergies (ATHLOS) project, data from the English Longitudinal Study of Aging (ELSA) (n = 12099) were analyzed. Latent groups of similar trajectories in the processing scores as well as their predictors and covariates were investigated, using group-based trajectory models (GBTM). The coefficient estimates for potential group predictors correspond to parameters of multinomial logit functions that are integrated in the model. Potential predictors included sex, level of education, marital status, level of household wealth, level of physical activity, and history of smoking, while time-varying covariates included incidence of cardiovascular disease (CVD), diabetes mellitus, depressive symptoms, and sleep disturbances. Four trajectories were identified and named after their baseline scores and shapes: High (4.4%), Middle/Stable (31.5%), Low/Stable (44.5%), and Low Decline (19.6%). Female sex, higher levels of education, mild level of physical activity, having been married, and higher level of wealth were associated with a higher probability of belonging to any of the higher groups compared to the Low/Decline that was set as reference, while presence of CVD, diabetes mellitus, and depressive symptoms were associated with lower processing speed scores within most trajectories. All the aforementioned factors might be valid targets for interventions to reduce the burden of age-related cognitive impairment.

Changes to Biceps and Supraspinatus Tendons in Response to a Progressive Maximal Treadmill-Based Propulsion Aerobic Fitness Test in Manual Wheelchair Users: A Quantitative Musculoskeletal Ultrasound Study

Objective

To investigate if the completion of a recently developed treadmill-based wheelchair propulsion maximal progressive workload incremental test alters the integrity of the long head of the biceps and supraspinatus tendons using musculoskeletal ultrasound imaging biomarkers.

Method

Fifteen manual wheelchair users completed the incremental test. Ultrasound images of the long head of the biceps and supraspinatus tendons were recorded before, immediately after, and 48 hours after the completion of the test using a standardized protocol. Geometric, composition, and texture-related ultrasound biomarkers characterized tendon integrity.

Results

Participants propelled during 10.2 ± 2.9 minutes with the majority (N = 13/15) having reached at least the eighth stage of the test (speed = 0.8 m/s; slope = 3.6°). All ultrasound biomarkers characterizing tendon integrity, measured in the longitudinal and transversal planes for both tendons, were similar (p = 0.063 to 1.000) across measurement times.

Conclusion

The performance of the motorized treadmill wheelchair propulsion test to assess aerobic fitness produced no changes to ultrasound biomarkers of the biceps or supraspinatus tendons. Hence, there was no ultrasound imaging evidence of a maladaptive response due to overstimulation in these tendons immediately after and 48 hours after the performance of the test.

NeuroExercise: The Effect of a 12-Month Exercise Intervention on Cognition in Mild Cognitive Impairment-A Multicenter Randomized Controlled Trial

Exercise intervention studies in mild cognitive impairment (MCI), a prodromal stage of Alzheimer's disease (AD), have demonstrated inconsistent yet promising results. Addressing the limitations of previous studies, this trial investigated the effects of a 12-month structured exercise program on the progression of MCI. The NeuroExercise study is a multicenter randomized controlled trial across three European countries (Ireland, Netherlands, Germany). Hundred and eighty-three individuals with amnestic MCI were included and were randomized to a 12-month exercise intervention (3 units of 45 min) of either aerobic exercise (AE; n = 60), stretching and toning exercise (ST; n = 65) or to a non-exercise control group (CG; n = 58). The primary outcome, cognitive performance, was determined by an extensive neuropsychological test battery. For the primary complete case (CC) analyses, between-group differences were analyzed with analysis of covariance under two conditions: (1) the exercise group (EG = combined AE and ST groups) compared to the CG and (2) AE compared to ST. Primary analysis of the full cohort (n = 166, 71.5 years; 51.8% females) revealed no between-group differences in composite cognitive score [mean difference (95% CI)], 0.12 [(−0.03, 0.27), p = 0.13] or in any cognitive domain or quality of life. VO₂ peak was significantly higher in the EG compared to the CG after 12 months [−1.76 (−3.39, −0.10), p = 0.04]. Comparing the two intervention groups revealed a higher VO₂peak level in the aerobic exercise compared to the stretching and toning group, but no differences for the other outcomes. A 12-month exercise intervention did not change cognitive performance in individuals with amnestic MCI in comparison to a non-exercise CG. An intervention effect on physical fitness was found, which may be an important moderator for long term disease progression and warrants long-term follow-up investigations.

Clinical Trial Registration:https://clinicaltrials.gov/ct2/show/NCT02913053, identifier: NCT02913053.

Acute exercise increases circulating IGF-1 in Alzheimer's disease patients, but not in older adults without dementia

OBJECTIVES

Increased Insulin-like growth factor I (IGF-1) has been associated with improvement of cognitive function in response to exercise. Evidences indicate a role for IGF-1 in beta-amyloid clearance and reducing hyperphosphorylation tau in Alzheimer's disease (AD). There is a need to investigate the IGF-1 response to exercise in AD patients due to well-known potential effects of exercise on IGF-1. The aim of this study was to examine circulating IGF-1 levels in AD patients and older adults without dementia after acute exercise and to verify the associations among cardiorespiratory fitness, cognition and IGF-1 levels.

METHOD

Seventy-four older adults (40 older adults without dementia and 34 AD patients) participated in this study. The outcomes included IGF-1 plasma levels and performance in the submaximal exercise stress test. Secondary outcomes included cognitive functions, depressive symptoms, level of physical activity, insulin-resistance, and cholesterol. All participants performed the incremental test on a treadmill and IGF-1 was collected before and after the exercise.

RESULTS

A tendency to the difference of baseline IGF-1 plasma levels between the groups was found. After the acute exercise AD patients also presented higher levels of circulating IGF-1 compared to the Older adults without dementia. Correlations among cardiorespiratory fitness and cognitive functions were found.

CONCLUSION

The findings suggest that AD patients and older adults respond differently to acute exercise in terms of circulating IGF-1 levels. This response seems to indicate either an IGF-1 resistance or a compensatory exercise-induced to lower IGF-1 levels in AD patients. Cardiorespiratory fitness is associated with global cognition, executive function, attention and information processing speed.

The Effect of Different Exercise Modes on Domain-Specific Cognitive Function in Patients Suffering from Parkinson's Disease: A Systematic Review of Randomized Controlled Trials

BACKGROUND

Supervised exercise training alleviates motor symptoms in people with Parkinson's disease (PD). However, the efficacy of exercise to improve nonmotor symptoms such as cognitive function is less well known.

OBJECTIVE

To systematically review evidence on the efficacy of different exercise modes (coordination exercise, resistance exercise, aerobic exercise) on domain-specific cognitive function in patients with PD.

METHODS

Parallel-group randomized controlled trials published before March 2018 were included. Primary outcome measures included global cognitive function and its subdomains, and the Unified Parkinson's Disease Rating Scale was included as a secondary outcome. Methodological quality was assessed using the Physiotherapy Evidence Database scale.

RESULTS

The literature search yielded 2,000 articles, of which 11 met inclusion criteria. 508 patients (mean age 68±4 years) were included with a disease severity from 1 to 4 on the Hoehn & Yahr stage scale. Overall study quality was modest (mean 6±2, range 3-8/10). In 5 trials a significant between-group effect size (ES) was identified for tests of specific cognitive domains, including a positive effect of aerobic exercise on memory (ES = 2.42) and executive function (ES = 1.54), and of combined resistance and coordination exercise on global cognitive function (ES = 1.54). Two trials found a significant ES for coordination exercise (ES = 0.84-1.88), which led to improved executive function compared with that of non-exercising control subjects.

CONCLUSION

All modes of exercise are associated with improved cognitive function in individuals with PD. Aerobic exercise tended to best improve memory; however, a clear effect of exercise mode was not identified.

Modelling Modifiable Predictors of Age-Related Cognitive Decline: Exercise, Aortic Stiffness, and the Importance of Physical Fitness

BACKGROUND

Previous modelling found that fitness and aortic stiffness both independently predicted spatial working memory (SWM) performance in older people. There is also evidence that greater engagement in moderate intensity exercise contributes to better cognitive performance, potentially working through improving fitness and aortic stiffness.

OBJECTIVE

To investigate the effect of exercise on the previously established relationships between fitness, aortic stiffness, and SWM, and whether these associations differ between older adults of higher and lower fitness.

METHODS

One hundred and two residents of independent living facilities, aged 60-90 (M = 77.5, SD = 6.9) participated in the study. Measures included computerized cognitive assessment, the Six-Minute Walk fitness test, the CHAMPS physical activity questionnaire, and aortic pulse wave analysis. Multiple structural equation models were used to test hypotheses.

RESULTS

Overall, exercise levels had a small additional effect in predicting SWM, working exclusively through fitness, although this was only true for those of lower than average fitness. Additionally, it was found that while fitness was the most important factor in predicting SWM in those of lower fitness, aortic stiffness was the strongest predictor in those of higher fitness.

CONCLUSION

Fitness and aortic stiffness are strong predictors of cognition in older people, and greater engagement in exercise predicted better cognition in those who were of lower fitness. Fitter older people may benefit more from interventions which target aortic stiffness in order to preserve cognitive performance as they age, while those who are less fit may benefit most from improving fitness first, including through increased physical activity.

An Overview of the Cardiorespiratory Hypothesis and Its Potential Contribution to the Care of Neurodegenerative Disease in Africa

One hypothesis that could explain the beneficial effects of physical exercise on cognitive function is the cardiorespiratory hypothesis. This hypothesis proposes that improved cognitive functioning may be in part a result of the physiological processes that occur after physical exercise such as: Increased cerebral perfusion and regional cerebral blood flow. These processes ensure increased oxygenation and glucose transportation to the brain, which together can improve cognitive function. The objective of this narrative review is to examine the contribution of this hypothesis in the care of African older adults with neurodegenerative conditions (i.e., dementia (Alzheimer’s disease)) or with mild cognitive impairments. Although studies in developed countries have examined people of African descent (i.e., with African Americans), only the limited findings presented in this review reflect how these conditions are also important for the African continent. This review revealed that no studies have examined the effects of cardiorespiratory fitness on neurodegenerative disease in Africa. African nations, like many other developing countries, have an aging population that is growing and will face an increased risk of neurodegenerative declines. It is therefore imperative that new research projects be developed to explore the role of the cardiorespiratory fitness in neurodegenerative disease prevention in African nations.

Validation of a widely used heart rate monitor to track steps in older adults

BACKGROUND

Activity tracking devices gain popularity in research, which is due to their multiple features (e.g. heart rate monitor, step count) and easy handling. Nevertheless, many devices used for research are lacking validation of specific features. This study aimed to assess the validity of the Polar M400© activity tracker to count steps in older adults and, therefore, compared it to a previously validated pedometer (Omron Walking Style©) and observed step count.

METHODS

Thirty-two older adults (mean age: 74.8±5.9 years) walked at a self-selected, normal gait speed on a tartan track for 200 meters while wearing the activity tracker and the pedometer. Additionally, steps were counted manually. Data was analysed using Kruskal-Wallis test and Lin's concordance coefficient. Furthermore, Bland Altman plots were employed to evaluate accuracy of the activity tracker.

RESULTS

Kruskal-Wallis test revealed significant differences between the step count of the activity tracker and the pedometer (P=0.011) but no further differences were observed. Lin's concordance showed a moderate correlation between activity tracker and pedometer (rc=0.561) and between pedometer and observed step count (rc=0.690). A high correlation was detected between activity tracker and observed step count (rc=0.802). Bland Altman plots revealed good accuracy of the activity tracker.

CONCLUSIONS

The Polar M400© activity tracker accurately assesses steps during walking in older adults. Nevertheless, a slight overestimation compared to the pedometer was observed, which should be considered when using the activity tracker for tracking steps over a longer period of time.

Associations of Lipophilic Micronutrients with Physical and Cognitive Fitness in Persons with Mild Cognitive Impairment

Age-associated cognitive impairment in general and dementia in particular are a global concern. Preventive lifestyle strategies are highly used but there is a lack of information on the reciprocal relationships between nutrition biomarkers and measures of both cognitive and physical performance. To fill this gap of knowledge, the relationship between plasma levels of the robust nutrition- and antioxidant defense-related biomarkers carotenoid and tocopherols and both indicators of cognitive and physical performance was investigated in a group of persons with mild cognitive impairment participating in the NeuroExercise Study at the German Sport University in Cologne, Germany. In 56 participants with full dataset, significant correlations independently of fruit and vegetable intake were found between plasma levels of β-cryptoxanthin and Timed Up&Go test (p < 0.05), γ-tocopherol and number of daily steps (p < 0.01), as well as between four out of six measured carotenoids—lutein; zeaxanthin; β-cryptoxanthin and β-carotene—and the computerized CogState International Shopping List subtest (p < 0.01). In light of the increasing attention towards the nutritional cognitive neuroscience of carotenoids, computerized measures of cognitive performance might be further implemented in future studies investigating the effects of lifestyle interventions against cognitive and physical impairment.