The association of the 24-hour activity cycle profiles with cognition in older adults with mild cognitive impairment: A cross-sectional study.

BACKGROUND: The relationship of cognition and the 24-hour activity cycles (24-HAC), encompassing physical activity, sedentary behaviour, and sleep, in older adults with mild cognitive impairment (MCI) remains uncertain. Distinct combinations of 24-HAC behaviours can characterize unique activity profiles and influence cognition. We aimed to characterize 24-HAC activity profiles in older adults with MCI and assess whether differences in cognition exist across profiles. METHODS: We conducted a cross-sectional analysis utilizing baseline data from three randomized controlled trials involving 253 community-dwelling older adults (55+ years) with MCI (no functional impairment, dementia diagnosis, and Montreal Cognitive Assessment score <26/30). Using MotionWatch8© wrist-worn actigraphy (+5 days), we captured the 24-HAC. Cognition was indexed by the Alzheimer's Disease Assessment Scale Cognitive Plus (ADAS-Cog-Plus). Compositional data and latent profile analyses identified distinct 24-HAC activity profiles. Analysis of covariance examined whether 24-HAC activity profiles differed in cognition. RESULTS: Four distinct activity profiles were identified. Profile 1 ("Average 24-HAC," n=108) engaged in all 24-HAC behaviours around the sample average. Profile 2 ("Active Chillers," n=64) depicted lower-than-average engagement in physical activity and higher-than-average sedentary behaviour. Profile 3 ("Physical Activity Masters," n=56) were the most active and the least sedentary. Profile 4 ("Sedentary Savants," n=25) were the least active and the most sedentary. Sleep was similar across profiles. There were no significant differences in ADAS-Cog-Plus scores between 24-HAC activity profiles (p>0.05). CONCLUSION: Older adults with MCI exhibited four 24-HAC activity profiles conforming to recommended physical activity and sleep guidelines. Nonetheless, cognition was similar across these profiles.

Aerobic exercise training effects on hippocampal volume in healthy older individuals: a meta-analysis of randomized controlled trials.

We conducted a meta-analysis of randomized controlled trials investigating the effects of aerobic exercise training (AET) lasting ≥ 4 weeks on hippocampal volume and cardiorespiratory fitness (CRF) in cognitively unimpaired, healthy older individuals. Random-effects robust variance estimation models were used to test differences between AET and controls, while meta-regressions tested associations between CRF and hippocampal volume changes. We included eight studies (N = 554) delivering fully supervised AET for 3 to 12 months (M = 7.8, SD = 4.5) with an average AET volume of 129.85 min/week (SD = 45.5) at moderate-to-vigorous intensity. There were no significant effects of AET on hippocampal volume (SMD = 0.10, 95% CI - 0.01 to 0.21, p = 0.073), but AET moderately improved CRF (SMD = 0.30, 95% CI 0.12 to 0.48, p = 0.005). Improvement in CRF was not associated with changes in hippocampal volume (bSE = 0.05, SE = 0.51, p = 0.923). From the limited number of studies, AET does not seem to impact hippocampal volume in cognitively unimpaired, healthy older individuals. Notable methodological limitations across investigations might mask the lack of effects.

Economic Evaluation of Exercise or Cognitive and Social Enrichment Activities for Improved Cognition After Stroke.

Importance: Cognitive impairment is prevalent in survivors of stroke, affecting approximately 30% of individuals. Physical exercise and cognitive and social enrichment activities can enhance cognitive function in patients with chronic stroke, but their cost-effectiveness compared with a balance and tone program is uncertain. Objective: To conduct a cost-effectiveness and cost-utility analysis of multicomponent exercise or cognitive and social enrichment activities compared with a balance and tone program. Design, Setting, and Participants: This economic evaluation used a Canadian health care systems perspective and the Vitality study, a randomized clinical trial aimed at improving cognition after stroke with a 6-month intervention and a subsequent 6-month follow-up (ie, 12 months). The economic evaluation covered the duration of the Vitality trial, between June 6, 2014, and February 26, 2019. Participants were community-dwelling adults aged 55 years and older who experienced a stroke at least 12 months prior to study enrollment in the Vancouver metropolitan area, British Columbia, Canada. Data were analyzed from June 1, 2022, to March 31, 2023. Interventions: Participants were randomly assigned to twice-weekly classes for 1 of the 3 groups: multicomponent exercise program, cognitive and social enrichment activities program, or a balance and tone program (control). Main Outcomes and Measures: The primary measures for the economic evaluation included cost-effectiveness (incremental costs per mean change in cognitive function, evaluated using the Alzheimer Disease Assessment Scale-Cognitive-Plus), cost-utility (incremental cost per quality-adjusted life-year gained), intervention costs, and health care costs. Since cognitive benefits 6 months after intervention cessation were not observed in the primary randomized clinical trial, an economic evaluation at 12 months was not performed. Results: Among 120 participants (mean [SD] age, 71 [9] years; 74 [62%] male), 34 were randomized to the multicomponent exercise program, 34 were randomized to the social and cognitive enrichment activities program, and 52 were randomized to the balance and tone control program. At the end of the 6-month intervention, the cost per mean change in Alzheimer Disease Assessment Scale-Cognitive-Plus score demonstrated that exercise was more effective and costlier compared with the control group in terms of cognitive improvement with an incremental cost-effectiveness ratio of CAD -$8823. The cost per quality-adjusted life-year gained for both interventions was negligible, with exercise less costly (mean [SD] incremental cost, CAD -$32 [$258]) and cognitive and social enrichment more costly than the control group (mean [SD] incremental cost, CAD $1018 [$378]). The balance and tone program had the lowest delivery cost (CAD $777), and the exercise group had the lowest health care resource utilization (mean [SD] $1261 [$1188]) per person. Conclusions and Relevance: The findings of this economic evaluation suggest that exercise demonstrated potential for cost-effectiveness to improve cognitive function in older adults with chronic stroke during a 6-month intervention.

Supporting physical activity for mobility in older adults with mobility limitations (SuPA Mobility): study protocol for a randomized controlled trial.

BACKGROUND: Limited mobility in older adults consistently predicts both morbidity and mortality. As individuals age, the rates of mobility disability increase from 1.0% in people aged 15-24 to 20.6% in adults over 65 years of age. Physical activity can effectively improve mobility in older adults, yet many older adults do not engage in sufficient physical activity. Evidence shows that increasing physical activity by 50 min of moderate intensity physical activity in sedentary older adults with mobility limitations can improve mobility and reduce the incidence of mobility disability. To maximize the healthy life span of older adults, it is necessary to find effective and efficient interventions that can be delivered widely to prevent mobility limitations, increase physical activity participation, and improve quality of life in older adults. We propose a randomized controlled trial to assess the effect of a physical activity health coaching intervention on mobility in older adults with mobility limitations. METHODS: This randomized controlled trial among 290 (145 per group) community-dwelling older adults with mobility limitations, aged 70-89 years old, will compare the effect of a physical activity health coaching intervention versus a general healthy aging education program on mobility, as assessed with the Short Physical Performance Battery. The physical activity health coaching intervention will be delivered by exercise individuals who are trained in Brief Action Planning. The coaches will use evidence-based behavior change techniques including goal-setting, action planning, self-monitoring, and feedback to improve participation in physical activity by a known dose of 50 min per week. There will be a total of 9 health coaching or education sessions delivered over 26 weeks with a subsequent 26-week follow-up period, wherein both groups will receive the same duration and frequency of study visits and activities. DISCUSSION: The consequences of limited mobility pose a significant burden on the quality of life of older adults. Our trial is novel in that it investigates implementing a dose of physical activity that is known to improve mobility in older adults utilizing a health coaching intervention. TRIAL REGISTRATION: ClinicalTrials.gov Protocol Registration System: NCT05978336; registered on 28 July 2023.

A Wrinkle in Measuring Time Use for Cognitive Health: How should We Measure Physical Activity, Sedentary Behaviour and Sleep?

One new case of dementia is detected every 4 seconds and no effective drug therapy exists. Effective behavioural strategies to promote healthy cognitive ageing are thus essential. Three behaviours related to cognitive health which we all engage in daily are physical activity, sedentary behaviour and sleep. These time-use activity behaviours are linked to cognitive health in a complex and dynamic relationship not yet fully elucidated. Understanding how each of these behaviours is related to each other and cognitive health will help determine the most practical and effective lifestyle strategies for promoting healthy cognitive ageing. In this review, we discuss methods and analytical approaches to best investigate how these time-use activity behaviours are related to cognitive health. We highlight four key recommendations for examining these relationships such that researchers should include measures which (1) are psychometrically appropriate; (2) can specifically answer the research question; (3) include objective and subjective estimates of the behaviour and (4) choose an analytical method for modelling the relationships of time-use activity behaviours with cognitive health which is appropriate for their research question.

Cost-effectiveness of exercise versus multimodal interventions that include exercise to prevent falls among community-dwelling older adults: A systematic review and meta-analysis.

OBJECTIVE: To compare the cost-effectiveness of exercise as a unimodal intervention versus multimodal interventions that included exercise in conjunction with other falls prevention strategies to prevent falls among community-dwelling older adults. DESIGN: Systematic review and meta-analysis. DATA SOURCES: MEDLINE, EMBASE, NHS EED, and CINAHL (1 January 1946 to June 2022). ELIGIBILITY CRITERIA: Economic evaluations of fall prevention strategies that included exercise delivered as a unimodal intervention or a multimodal intervention that included exercise in conjunction with other falls prevention strategies among community-dwelling adults aged 60 years and over. RESULTS: Eighteen studies were included in this review: 9 unimodal, 6 multimodal, and 3 that included exercise delivered as both a unimodal and a multimodal intervention. In the cost-effectiveness analyses, 61.5 % (n = 8/13) of exercise-only unimodal interventions demonstrated cost-effectiveness, compared with 33.3 % (n = 2/6) of multimodal interventions. In the cost-utility analyses, 60 % (n = 6/10) of unimodal interventions compared with zero multimodal interventions (n = 0/4) demonstrated cost-effectiveness. Sixteen studies (25,017 participants) were included in our meta-analysis. Incremental costs were $128 [-$661, $1644] (2021 US dollars) for exercise-only unimodal interventions and $786 [-$72, $1644] for multimodal interventions. Estimated incremental quality-adjusted life-years was 0.09 [-0.37, 0.55] for exercise-only unimodal interventions and 0.00 [-0.04, 0.04] for multimodal interventions. Both exercise-only and multimodal interventions had an estimated 28 % reduction in falls versus the control, with incidence rate ratios for exercise-only unimodal interventions of 0.72 [0.62, 0.83] and for multimodal interventions of 0.72 [0.25, 2.09]. CONCLUSION: Exercise delivered as a unimodal intervention, particularly resistance training, provided the best value for money for fall prevention. Multimodal interventions that included exercise did not demonstrate additional benefits in terms of costs, quality of life, or fall prevention compared with exercise-only unimodal interventions. This finding may be due to the smaller number of multimodal interventions available. REVIEW REGISTRATION: PROSPERO CRD42022295561. REGISTRATION TITLE: Comparing the cost-effectiveness of multimodal versus unimodal interventions that include exercise to prevent falls among community-dwelling older adults: A systematic review.

Effect of Exercise Training or Complex Mental and Social Activities on Cognitive Function in Adults With Chronic Stroke: A Randomized Clinical Trial.

Importance: A stroke doubles one's risk for dementia. How to promote cognitive function among persons with chronic stroke is unclear. Objective: To evaluate the effect of exercise (EX) or cognitive and social enrichment activities (ENRICH) on cognitive function in adults with chronic stroke. Design, Setting, and Participants: This was a 3-group parallel, single-blinded, single-site, proof-of-concept randomized clinical trial at a research center in Vancouver, British Columbia, Canada. Participants included community-dwelling adults with chronic stroke, aged 55 years and older, able to walk 6 meters, and without dementia. The trial included a 6-month intervention and a 6-month follow-up. Randomization occurred from June 6, 2014, to February 26, 2019. Measurement occurred at baseline, 6 months, and 12 months. Data were analyzed from January to November 2021. Interventions: Participants were randomly allocated to twice-weekly supervised classes of: (1) EX, a multicomponent exercise program; (2) ENRICH, a program of cognitive and social enrichment activities; or (3) balance and tone (BAT), a control group that included stretches and light-intensity exercises. Main Outcomes and Measures: The primary outcome was the Alzheimer Disease Assessment Scale-Cognitive-Plus (ADAS-Cog-Plus), which included the 13-item ADAS-Cog, Trail Making Test Parts A and B, Digit Span Forward and Backward, Animal Fluency, and Vegetable Fluency. Results: One-hundred and twenty participants, with a mean (range) of 1.2 (1-4) strokes, a mean (SD) of 66.5 (53.8) months since the most recent stroke, mean (SD) baseline age of 70 (8) years, mean (SD) baseline ADAS-Cog-Plus of 0.22 (0.81), and 74 (62%) male participants, were randomized to EX (34 participants), ENRICH (34 participants), or BAT (52 participants). Seventeen withdrew during the 6-month intervention and another 7 during the 6-month follow-up. Including all 120 participants, at the end of the 6-month intervention, EX significantly improved ADAS-Cog-Plus performance compared with BAT (estimated mean difference: -0.24; 95% CI, -0.43 to -0.04; P = .02). This difference did not persist at the 6-month follow-up (estimated mean difference: -0.08; 95% CI, -0.29 to 0.12; P = .43). For the 13-item ADAS-Cog, the EX group improved by 5.65 points over the 6-month intervention (95% CI, 2.74 to 8.57 points; P < .001), exceeding the minimally clinical difference of 3.0 points. Conclusions and Relevance: These findings suggest that exercise can induce clinically important improvements in cognitive function in adults with chronic stroke. Future studies need to replicate current findings and to understand training parameters, moderators, and mediators to maximize benefits. Trial Registration: ClinicalTrials.gov identifier: NCT01916486.

Can "Rover" help with mental health during the COVID-19 pandemic? Results from the Canadian Longitudinal Study on Aging (CLSA).

COVID-19 has negatively affected the mental health and well-being of adults, and thus it is important to examine potential factors which may influence mental health during the pandemic. We thus examined the association between pet ownership and depression/anxiety symptoms based on mental health disorder status during the COVID-19 pandemic. We included 12,068 cognitively healthy participants (45-86 years at study entry) from the Canadian Longitudinal Study on Aging (CLSA) comprehensive cohort who completed the first follow-up ([FU1]; 2015-2018), and COVID-19 Survey entry (April-May 2020) and exit (September-December 2020). Participants self-reported at FU1 if they owned a pet (yes/no). Participants were dichotomized as with or without a mental health disorder based on self-reported diagnosis of depression, anxiety, or mood disorders at baseline assessment (2011-2015) or FU1. Depressive symptoms were indexed using the 10-item Center for Epidemiological Studies Depression Scale (CESD-10) at FU1, and COVID-19 entry/exit surveys. Anxiety symptoms were assessed using the General Anxiety Disorder Questionnaire (GAD-7) at COVID-19 entry/exit surveys. Final models adjusted for age, sex, body mass index, income, education, living status, smoking status, relationship status, and alcohol intake. Forty-percent of participants owned a pet at FU1. Among those without a mental health disorder, there were no significant differences in CESD-10 between participants who owned pets compared with those without pets. For people with a mental health disorder, pet owners had higher CESD-10 (estimated mean difference range: 0.56-1.02 points; p < 0.05) and GAD-7 scores (estimated mean difference range: 0.28-0.57 points; p < 0.05) at both COVID-19 entry and exit surveys. Among people with mental health disorders, pet ownership was associated with poor mental health symptoms during April 2020 to December 2020 of the COVID-19 pandemic.

International depiction of the cost of functional independence limitations among older adults living in the community: a systematic review and cost-of-impairment study.

BACKGROUND: Functional independence limitations restrict older adult self-sufficiency and can reduce quality of life. This systematic review and cost of impairment study examined the costs of functional independence limitations among community dwelling older adults to society, the health care system, and the person. METHODS: Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines this systematic review included community dwelling older adults aged 60 years and older with functional independence limitations. Databases (Cochrane Database of Systematic Reviews, EconLit, NHS EED, Embase, CINAHL, AgeLine, and MEDLINE) were searched between 1990 and June 2020. Two reviewers extracted information on study characteristics and cost outcomes including mean annual costs of functional independence limitations per person for each cost perspective (2020 US prices). Quality was assessed using the Consolidated Health Economic Evaluation Reporting Standards (CHEERS) checklist. RESULTS: 85 studies were included. The mean annual total costs per person (2020 US prices) were: $27,380.74 (95% CI: [$4075.53, $50,685.96]) for societal, $24,195.52 (95% CI: [$9679.77, $38,711.27]) for health care system, and $7455.49 (95% CI: [$2271.45, $12,639.53]) for personal. Individuals with cognitive markers of functional independence limitations accounts for the largest mean costs per person across all perspectives. Variations across studies included: cost perspective, measures quantifying functional independence limitations, cost items reported, and time horizon. CONCLUSIONS: This study sheds light on the importance of targeting cognitive markers of functional independence limitations as they accounted for the greatest costs across all economic perspectives.

Objective Sleep Quality and the Underlying Functional Neural Correlates Among Older Adults with Possible Mild Cognitive Impairment.

BACKGROUND: Poor sleep quality is common among older individuals with mild cognitive impairment (MCI) and may be a consequence of functional alterations in the brain; yet few studies have investigated the underlying neural correlates of actigraphy-measured sleep quality in this cohort. OBJECTIVE: The objective of this study was to examine the relationship between brain networks and sleep quality measured by actigraphy. METHODS: In this cross-sectional analysis, sleep efficiency and sleep fragmentation were estimated using Motionwatch8 (MW8) over a period of 14 days in 36 community-dwelling older adults with possible MCI aged 65-85 years. All 36 participants underwent resting-state functional magnetic resonance imaging (fMRI) scanning. Independent associations between network connectivity and MW8 measures of sleep quality were determined using general linear modeling via FSL. Networks examined included the somatosensory network (SMN), frontoparietal network (FPN), and default mode network (DMN). RESULTS: Across the 36 participants (mean age 71.8 years; SD = 5.2 years), mean Montreal Cognitive Assessment score was 22.5 (SD = 2.7) and Mini-Mental State Examination score was 28.3 (SD = 1.5). Mean sleep efficiency and fragmentation index was 80.1% (SD = 10.0) and 31.8 (SD = 10.4) respectively. Higher sleep fragmentation was significantly correlated with increased connectivity between the SMN and insula, the SMN and posterior cingulate, as well as FPN and primary motor area (FDR-corrected, p < 0.004). CONCLUSION: Functional connectivity between brain regions involved in attentional and somatosensory processes may be associated with disrupted sleep in older adults with MCI.

Reshaping the path of mild cognitive impairment by refining exercise prescription: a study protocol of a randomized controlled trial to understand the "what," "for whom," and "how" of exercise to promote cognitive function.

BACKGROUND: Targeted exercise training is a promising strategy for promoting cognitive function and preventing dementia in older age. Despite the utility of exercise as an intervention, variation still exists in exercise-induced cognitive gains and questions remain regarding the type of training (i.e., what), as well as moderators (i.e., for whom) and mechanisms (i.e., how) of benefit. Both aerobic training (AT) and resistance training (RT) enhance cognitive function in older adults without cognitive impairment; however, the vast majority of trials have focused exclusively on AT. Thus, more research is needed on RT, as well as on the combination of AT and RT, in older adults with mild cognitive impairment (MCI), a prodromal stage of dementia. Therefore, we aim to conduct a 6-month, 2 × 2 factorial randomized controlled trial in older adults with MCI to assess the individual effects of AT and RT, and the combined effect of AT and RT on cognitive function and to determine the possible underlying biological mechanisms. METHODS: Two hundred and sixteen community-dwelling adults, aged 65 to 85 years, with MCI from metropolitan Vancouver will be recruited to participate in this study. Randomization will be stratified by biological sex and participants will be randomly allocated to one of the four experimental groups: (1) 4×/week balance and tone (BAT; i.e., active control); (2) combined 2×/week AT + 2×/week RT; (3) 2×/week AT + 2×/week BAT; or (4) 2×/week RT + 2×/week BAT. The primary outcome is cognitive function as measured by the Alzheimer's Disease Assessment Scale-Cognitive-Plus. Secondary outcomes include cognitive function, health-related quality of life, physical function, actigraphy measures, questionnaires, and falls. Outcomes will be measured at baseline, 6 months (i.e., trial completion), and 18 months (i.e., 12-month follow-up). DISCUSSION: Establishing the efficacy of different types and combinations of exercise training to minimize cognitive decline will advance our ability to prescribe exercise as "medicine" to treat MCI and delay the onset and progression of dementia. This trial is extremely timely as cognitive impairment and dementia pose a growing threat to global public health. TRIAL REGISTRATION: ClinicalTrials.gov NCT02737878 . Registered on April 14, 2016.

Do the relationships of physical activity and total sleep time with cognitive function vary by age and biological sex? A cross-sectional analysis of the Canadian Longitudinal Study on Aging.

OBJECTIVES: Physical activity (PA) and total sleep time (TST) are each associated with cognition; however, whether these relationships vary by age and biological sex is unclear. We examined the relationships of PA or TST with cognition, and whether age and sex moderated these relationships, using baseline data from the Canadian Longitudinal Study on Aging (CLSA; 2010-2015). STUDY DESIGN: A cross-sectional analysis of participants from the Comprehensive cohort of the CLSA with complete PA and sleep data (n = 20,307; age range 45-86 years). MAIN OUTCOME MEASURES: PA and TST were measured using the Physical Activity Scale for the Elderly (PASE) and self-reported TST over the past month. Cognition was indexed using a three-factor structural equation model (i.e., memory, executive function, and verbal fluency). RESULTS: Non-linear restricted cubic spline models indicated that PA and TST explained statistically significant (p < 0.01) but modest variance of each cognitive domain (<1 % of 23-24 % variance). Age and sex did not moderate associations of PA with any cognitive domain. However, age and sex moderated relationships of TST with cognition, whereby: 1) associations of TST with memory decreased with age for males and females; and 2) males and females had different age-associated relationships of TST with executive function and verbal fluency. CONCLUSIONS: PA and TST modestly contribute to multiple domains of cognition across middle and older adulthood. Importantly, the association of PA with cognition does not appear to vary across middle or older adulthood, nor does it vary by biological sex; however, TST appears to have a complex relationship with multiple domains of cognition which is both age- and sex-dependent.

The association of sleep and cortical thickness in mild cognitive impairment.

We investigated whether device-measured sleep parameters are associated with cortical thickness in older adults with probable mild cognitive impairment (MCI). We performed a cross-sectional, exploratory analysis of sleep and structural MRI data. Sleep data were collected with MotionWatch8© actigraphy over 7 days. We computed average and variability for sleep duration, sleep efficiency, and fragmentation index. T1-weighted MRI scans were used to measure cortical thickness in FreeSurfer. We employed surface-based analysis to determine the association between sleep measures and cortical thickness, adjusting for age, sex, Montreal Cognitive Assessment (MoCA) score, and sleep medication use. Our sample included 113 participants (age = 73.1 [5.7], female = 72 [63.7 %]). Higher fragmentation index variability predicted lower cortical thickness in the left superior frontal gyrus (cluster size = 970.9 mm2, cluster-wise p = 0.017, cortical thickness range = 2.1 mm2 to 3.0 mm2), adjusting for age, sex, MoCA, and sleep medication. Our results suggest that higher variability in sleep fragmentation, an indicator of irregular sleep pattern, is linked to lower cortical thickness. Future longitudinal studies are needed to determine the directionality of these associations.

Can exercise training promote better sleep and reduced fatigue in people with chronic stroke? A systematic review.

Poor sleep and chronic fatigue are common in people with chronic stroke (i.e. ≥ 6 months post-stroke). Exercise training is a viable, low-cost therapy for promoting sleep and reducing fatigue; however, the effects of exercise on sleep and fatigue in people with chronic stroke are unclear. Thus, we conducted a systematic review ascertaining the effects of exercise on sleep and fatigue in people with chronic stroke. We systematically searched EMBASE, MEDLINE, AgeLine, the Cochrane Database of Systematic Reviews, CINAHL, SPORTDiscus, SCOPUS, and reference lists of relevant reviews for articles that examined the effects of exercise on sleep or fatigue in chronic stroke. Search results were limited to adults ≥ 18 years, randomized controlled trials, non-randomized trials, and pre-post studies, which were published in English and examined the effects of exercise on sleep or fatigue in people with chronic stroke. We extracted study characteristics and information on the measurement of sleep and fatigue, and assessed study quality and risk of bias using the CONSORT criteria and Cochrane risk-of-bias tool, respectively. We found two studies that examined the effects of exercise on sleep, and two that examined the effects of exercise on fatigue. All studies reported positive effects of exercise training on sleep and fatigue; however, there were concerns of bias and study quality in all studies. There is preliminary evidence that exercise promotes sleep and reduces fatigue in people with chronic stroke; however, the extent to which exercise impacts these health parameters is unclear.

Effects of exercise training on the cognitive function of older adults with different types of dementia: a systematic review and meta-analysis.

OBJECTIVES: To assess the effect of exercise training on the cognitive function of older adults living with different types of dementia, as well as potential moderators of exercise efficacy. DESIGN: Systematic review and meta-analysis. DATA SOURCES: Cochrane Central, PsycINFO, Embase, Medline and CINAHL. ELIGIBILITY CRITERIA: Peer-reviewed, randomised controlled trials, in English (1990-present), which examined the effects of exercise training on the cognitive function of older adults living with dementia. STUDY APPRAISAL AND SYNTHESIS: Risk of bias and study quality were assessed (Cochrane Risk of Bias Tool 2.0 and Physiotherapy Evidence Database Scale). We performed random-effects models using robust variance estimation and tested moderators using the approximate Hotelling-Zhang test. RESULTS: Twenty-eight studies (n=2158) were included in the qualitative review and 25 in the meta-analysis. For all-cause dementia, a small effect of exercise training on cognitive function was observed (g=0.19; 95% CI 0.05 to 0.33; p=0.009). Type of dementia and exercise training characteristics did not moderate the effects of exercise training on cognitive function (p>0.05). Adherence to the intervention moderated the cognitive outcome effect size such that greater mean adherence was associated with greater cognitive outcome effect sizes (b=0.02; SE=0.01; p=0.005). CONCLUSION: Exercise training showed small benefits for the cognitive function of older adults living with all-cause dementia. More research and standardised reporting of exercise training characteristics can strengthen the evidence for what works best for which types of dementia. PROSPERO REGISTRATION NUMBER: CRD42020198716.

Study protocol for the BRAIN Training Trial: a randomised controlled trial of Balance, Resistance, And INterval training on cognitive function in older adults with mild cognitive impairment.

INTRODUCTION: Epidemiological evidence suggests that both poor cardiovascular fitness and low muscle mass or strength markedly increase the rate of cognitive decline and incident dementia in older adults. Results from exercise trials for the improvement of cognition in older adults with mild cognitive impairment (MCI) have reported mixed results. This is possibly due to insufficient exercise intensities. The aim of the Balance, Resistance, And INterval (BRAIN) Training Trial is to determine the effects of two forms of exercise, high-intensity aerobic interval training (HIIT) and high-intensity power training (POWER) each compared with a sham exercise control group on cognition in older adults with MCI. METHODS AND ANALYSIS: One hundred and sixty community-dwelling older (≥ 60 years) people with MCI have been randomised into the trial. Interventions are delivered supervised 2-3 days per week for 12 months. The primary outcome measured at baseline, 6 and 12 months is performance on a cognitive composite score measuring the executive domain calculated from a combination of computerised (NeuroTrax) and paper-and-pencil tests. Analyses will be performed via repeated measures linear mixed models and generalised linear mixed models of baseline, 6-month and 12-month time points, adjusted for baseline values and covariates selected a priori. Mixed models will be constructed to determine the interaction of GROUP × TIME. ETHICS AND DISSEMINATION: Ethical approval was obtained from the University of Sydney (HREC Ref.2017/368), University of Queensland (HREC Ref. 2017/HE000853), University of British Columbia (H16-03309), and Vancouver Coastal Health Research Institute (V16-03309) Human Research Ethics. Dissemination will be via publications, conference presentations, newsletter articles, social media, talks to clinicians and consumers and meetings with health departments/managers.It is expected that communication of results will allow for the development of more effective evidence-based exercise prescription guidelines in this population while investigating the benefits of HIIT and POWER on subclinical markers of disease. TRIAL REGISTRATION NUMBER: ACTRN12617001440314 Australian New Zealand Clinical Trials Registry.

Cardiometabolic risk, biological sex, and age do not share an interactive relationship with cognitive function: a cross-sectional analysis of the Canadian Longitudinal Study on Aging.

It is unclear whether cardiometabolic risk shares an interactive relationship with age-associated differences in cognition, and whether this relationship varies by biological sex. We conducted a cross-sectional analysis using baseline data from the Canadian Longitudinal Study on Aging (CLSA; 2010-2015) to examine whether 1) cardiometabolic risk has an interactive relationship with age-associated cognition; and 2) interactive effects are sex-dependent. We measured memory, executive function, and verbal fluency in the Comprehensive cohort (N = 25 830; 45-86 years). Each cognitive domain was modeled using restricted cubic splines for age and each cardiometabolic risk factor (HbA1c, HSCRP, TG, and LDL and HDL cholesterol). Sex was included as a predictor in all models. Wald χ2 statistics were used to determine the relative importance of age, cardiometabolic risk, sex, and their interactive effects on cognition. Age was the most important variable in each model (proportion χ2 = 34%-48%). Biological sex was the second most important variable for memory (proportion χ2 = 26%) but was unimportant for executive function and verbal fluency (proportion χ2 = 3%-5%). Cardiometabolic risk factors were unimportant predictors in each model (proportion χ2 = 1%-3%). Two- and 3-way interactions between cardiometabolic risk, age, and sex were also unimportant (proportion χ2 = 0%-2%). Thus, cardiometabolic risk factors did not meaningfully account for age-associated differences in cognition, and these associations (or lack thereof) did not vary by sex. Novelty: Males have poorer age-associated cognitive performance than females. Females and males differ in cardiometabolic risk across middle and older adulthood. Cardiometabolic risk has a small association with age-associated cognition, and there are no sex differences in this relationship.

Sweat the Fall Stuff: Physical Activity Moderates the Association of White Matter Hyperintensities With Falls Risk in Older Adults.

Background: Falls in older adults are a major public health problem. White matter hyperintensities (WMHs) are highly prevalent in older adults and are a risk factor for falls. In the absence of a cure for WMHs, identifying potential strategies to counteract the risk of WMHs on falls are of great importance. Physical activity (PA) is a promising countermeasure to reduce both WMHs and falls risk. However, no study has yet investigated whether PA attenuates the association of WMHs with falls risk. We hypothesized that PA moderates the association between WMHs and falls risk. Methods: Seventy-six community-dwelling older adults aged 70-80 years old were included in this cross-sectional study. We indexed PA using the Physical Activity Score for the Elderly (PASE) Questionnaire. Falls risk was assessed using the Physiological Profile Assessment (PPA), and WMH volume (mm3) was determined by an experienced radiologist on T2-weighted and PD-weighted MRI scans. We first examined the independent associations of WMH volume and PASE score with PPA. Subsequently, we examined whether PASE moderated the relationship between WMH volume and PPA. We plotted simple slopes to interpret the interaction effects. Age, sex, and Montreal Cognitive Assessment (MoCA) score were included as covariates in all models. Results: Participants had a mean age of 74 years (SD = 3 years) and 54 (74%) were female. Forty-nine participants (66%) had a Fazekas score of 1, 19 (26%) had a score of 2, and 6 (8%) a score of 3. Both PASE (ß = -0.26 ± 0.11; p = 0.022) and WMH volume (ß = 0.23 ± 0.11; p = 0.043) were each independently associated with PPA score. The interaction model indicated that PASE score moderated the association between WMH volume and PPA (ß = -0.27 ± 0.12; p = 0.030), whereby higher PASE score attenuated the association between WMHs and falls risk. Conclusion: PA is an important moderator of falls risk. Importantly, older adults with WMH can reduce their risk of falls by increasing their PA.