The mediating role of lower body muscle strength and IGF-1 level in the relationship between age and cognition. A MIDUS substudy.

OBJECTIVE: Aging is a natural process associated with a decline in cognition. However, the mediating effect of physical function and circulating myokines on this relationship has yet to be fully clarified. This study investigated how muscle strength and circulating insulin-like growth factor-1 (IGF-1) levels mediate the relationship between age and cognitive functions. SUBJECTS AND METHODS: A total of 1255 participants aged 25-74 years included in the Midlife in the United States II study were retrospectively analyzed. In this cross-sectional analysis, we applied a serial mediation model to explore the mediating effects of muscle strength and circulating IGF-1 levels on the relationship between age and cognitive functions. We included potential confounding factors related to sociodemographics, lifestyle, and health status as covariates in the model. RESULTS: The results showed that aging had both direct and indirect effects on cognition. As predicted, muscle strength and IGF-1 levels mediated the relationship between age and specific cognitive functions. In addition, mediation analyses indicated that the association between aging and cognitive flexibility, immediate and delayed memory, and inductive reasoning were partially mediated by muscle strength and IGF-1 levels in a serial manner. CONCLUSIONS: Our study demonstrated the serial multiple mediation roles of muscle strength and IGF-1 levels on the relationship between age and specific cognitive functions. Further longitudinal research should be performed to confirm the serial mediation results.

Mastering the Relationship between the Body and the Brain? The Case of a Female Master Athlete.

BACKGROUND: Physical inactivity significantly increases risk of cardiovascular diseases, which are highly prevalent in aging. Conversely, higher levels of physical activity in aging have been associated with benefits for physical and cognitive health and is hypothesized to prevent and reduce development of cardiovascular risk factors. However, those older adults with the highest activity levels (i.e., Master Athletes [MA]) are relatively understudied, and even fewer studies involve female MA. OBJECTIVE: The aim of this study was to compare the physiological, physical, and cognitive profiles of an 83-year-old track-and-field MA runner to a sample of inactive age-matched females. RESULTS: Results revealed the MA had a high peak oxygen uptake and had superior performance on visuospatial memory tasks compared to her inactive counterparts. Cerebral blood flow was slightly elevated in the MA, but lower cerebrovascular reactivity was revealed compared to the other female included in the magnetic resonance imaging portion. CONCLUSION: Our results suggest that high levels of physical activity have benefits on multiple aspects of an aging female's life and that more studies should include MA, as well as a spectrum of cardiorespiratory fitness to further understand the role of physical activity in female aging.

Performances on the Montreal Cognitive Assessment Along the Cardiovascular Disease Continuum.

Cardiovascular diseases involve a continuum starting with risk factors, which can progress to coronary heart disease and eventually, to heart failure. Cognitive impairment (CI) is observed as early as cardiovascular risk factors, and in up to 50% of patients with heart failure. Because CI in cardiovascular disease is linked to poorer clinical outcomes, early detection is essential. The Montreal Cognitive Assessment (MoCA) is a screening tool widely used in clinical setting. To date, little is known about MoCA scores along the cardiovascular disease continuum. OBJECTIVE: This study compared performances of different cardiovascular disease profiles on the MoCA and its subscores. METHOD: Eighty participants (>50 years) from two studies conducted at the Montreal Heart Institute were separated into four groups: low cardiovascular risk factors (<2), high cardiovascular risk factors (>2), coronary heart disease, and stable heart failure. ANCOVAs were performed on the total score and on subscores, with sex, age, and education as covariates. RESULTS: Group differences were observed on the MoCA total score (heart failure < low cardiovascular risk), verbal fluency (heart failure < low cardiovascular risk), memory (coronary heart disease < low cardiovascular risk), and orientation (coronary heart disease < low and high cardiovascular risk) subscores. CONCLUSION: Results suggest that the MoCA, particularly verbal fluency and memory subscores, can detect cognitive changes in later stages of the cardiovascular disease continuum, such as heart failure. Detecting cognitive changes earlier on the cardiovascular disease continuum may require more in depth neuropsychological assessments.

Investigation of the Effects of Home-Based Exercise and Cognitive Training on Cognitive and Physical Functions in Cardiac Patients: The COVEPICARDIO Study Protocol of a Randomized Clinical Trial.

Introduction: During the COVID-19 pandemic, confinement measures are likely to produce collateral damage to health (stress, confusion, anxiety), especially in frail individuals and those living with cardiovascular disease (CVD). In cardiac patients in particular, these measures dramatically increase the level of physical inactivity and sedentary lifestyle, which can decrease cardiorespiratory capacity and increase the risk of acute events, rehospitalization, and depressive syndromes. Maintaining a minimum level of physical activity and cognitive stimulation during the COVID-19 crisis is essential for cardiac patients. This study is designed to document the effects of 6 months of home-based physical exercise alone or combined with cognitive training on cognitive and physical functions in patients with CVD over 50 years old. Methods and Analysis: 122 patients (>50 years old) with stable CVD and no contraindication to perform physical exercise training will be recruited and randomly assigned to one of the 2 following arms: (1) Home-based physical exercise alone, (2) Home-based physical exercise combined with cognitive training. The intervention lasts 6 months, with remote assessments performed prior to, mid and post-training. A follow-up 6 months after the end of the intervention (12 month) is also proposed. The primary outcome is cognition, including general functioning (Montreal Cognitive Assessment (MoCA) score), as well as performances on measures of executive functions, processing speed, and episodic memory. The secondary outcome is physical performance, including balance, gait and mobility, leg muscle strength and estimated cardiorespiratory fitness. Tertiary outcomes include mood, anxiety, and health-related quality of life as assessed by self-reported online questionnaires. Discussion: With the COVID-19 crisis, there is a critical need for remote exercise and cognitive training, and to further investigate this topic, in particular for cardiac patients. The present context can be viewed as an opportunity to perform a major shift from center-based programs to home-based physical exercise. This is especially important to reach out to older adults living in remote areas, where access to such interventions is limited. ClinicalTrials.gov: [https://clinicaltrials.gov/ct2/show/NCT04661189], NCT04661189.

COVEPIC (Cognitive and spOrt Virtual EPIC training) investigating the effects of home-based physical exercise and cognitive training on cognitive and physical functions in community-dwelling older adults: study protocol of a randomized single-blinded clinical trial.

BACKGROUND: In the context of the COVID-19 pandemic, lockdown and social distancing measures are applied to prevent the spread of the virus. It is well known that confinement and social isolation can have a negative impact on physical and mental health, including cognition. Physical activity and cognitive training can help enhance older adults' cognitive and physical health and prevent the negative collateral impacts of social isolation and physical inactivity. The COVEPIC study aims to document the effects of 6 months of home-based physical exercise alone versus home-based physical exercise combined with cognitive training on cognitive and physical functions in adults 50 years and older. METHODS: One hundred twenty-two healthy older adults (> 50 years old) will be recruited from the community and randomized to one of the two arms for 6 months: (1) home-based physical exercises monitoring alone and (2) combined physical exercises monitoring with home-based cognitive training. The primary outcome is cognition, including general functioning (Montreal Cognitive Assessment (MoCA) score), as well as executive functions, processing speed, and episodic memory (composite Z-scores based on validated neuropsychological tests and computerized tasks). The secondary outcome is physical functions, including balance (one-leg stance test), gait and mobility performance (Timed Up and Go, 4-meter walk test), leg muscle strength (5-time sit-to-stand), and estimated cardiorespiratory fitness (Matthews' questionnaire). Exploratory outcomes include mood, anxiety, and health-related quality of life as assessed by self-reported questionnaires (i.e., Geriatric depression scale-30 items, Perceived stress scale, State-trait anxiety inventory-36 items, Perseverative thinking questionnaire, Connor-Davidson Resilience Scale 10, and 12-item Short Form Survey). DISCUSSION: This trial will document the remote monitoring of home-based physical exercise alone and home-based physical combined with cognitive training to enhance cognitive and physical health of older adults during the COVID-19 pandemic period. Remote interventions represent a promising strategy to help maintain or enhance health and cognition in seniors, and potentially an opportunity to reach older adults in remote areas, where access to such interventions is limited. TRIAL REGISTRATION: Clinical trial Identifier NCT04635462 . COVEPIC was retrospectively registered on November 19, 2020.

Statin use moderates the beneficial effects of aerobic exercise on older adults' performances on the Stroop test: A subanalysis.

Aerobic training can lead to improved cognition in older adults and this effect can be explained by enhanced cardiorespiratory fitness. However, statins could limit the physical benefits of aerobic training by altering the mechanisms through which exercise improves cognition. Whether statins could have an effect on the cognitive benefits associated with aerobic training remains to be elucidated. The objective of this study was to determine whether the cognitive benefits of aerobic training were comparable in statin users and non-users. A total of 144 sedentary participants (>60 y.o.; 106 non-users, 38 statin users) were included. Participants were either part of an aerobic training group (n = 75) or a control group (n = 69). Cognition was assessed using the Stroop test. Analyses were performed on z-score changes from pre to post-intervention of Stroop reaction time (RT) and number of errors, using Two-factor ANCOVAs, while controlling for potential confounding factors (age, education, BMI, Charlson Comorbidity Index, sex, protocol and handgrip strength). The moderating effect of statins on the cognitive changes associated with aerobic training was determined through moderation analyses. An interaction effect on the Stroop switching condition was detected between intervention and statin intake (F [1, 140] = 5.659, P < 0.01). The intervention effect on switching RT was moderated by statin intake, where intervention improved switching RT only in non-users (Effect = 0.1678; P < 0.01). Statins could limit the cognitive benefits of aerobic training on switching capacities in some patients. Future randomized studies including a larger number of participants and looking at different types of statins should be conducted to confirm these results.

High-intensity interval training vs. hydrochlorothiazide on blood pressure, cardiovascular health and cognition: Protocol of a non-inferiority trial.

BACKGROUND: While the number of people with hypertension (HBP) continues to increase, the therapeutic target for optimal blood pressure (BP) has been revised to a lower level. Studies have suggested that High-Intensity Interval Training (HIIT) could be as efficient as BP-lowering drugs, but no study has compared their efficacy in a randomized trial. The aim of this protocol is to determine if HIIT is as efficient as Hydrochlorothiazide (HCTZ) in lowering 24 h ambulatory BP in prehypertensive older adults. Moreover, the secondary aim is to determine if HIIT is associated with greater cardiovascular and cognitive benefits than HCTZ. METHODS: This study is an interventional, single-center, non-inferiority trial, with two randomized parallel groups of prehypertensive participants aged 60 years or more. One group will be prescribed daily doses of 12.5 mg of HCTZ for 12 weeks, and the other group will follow thrice-weekly HIIT for 12 weeks. Each group will be composed of 30 participants. The primary outcome is 24 h ambulatory BP. Secondary outcomes are scores on neuropsychological assessments, balance and gait performances, maximal oxygen uptake, peripheral endothelial function, and arterial stiffness. Non-inferiority tests will be performed on the primary outcome, and secondary outcomes will be compared using independent t-tests. CONCLUSION: This study will determine if HIIT is at least as efficient as HCTZ in lowering BP in prehypertensive older adults. This study will also determine if HIIT provides greater benefits in terms of cardiovascular and cognitive status (NCT04103411).

Normative Data for a Tablet-Based Dual-Task Assessment in Healthy Older Adults.

OBJECTIVE: The objective of this study is to provide normative data for a tablet-based dual-task assessment in older adults without cognitive deficits. METHOD: In total, 264 participants aged between 60 and 90 years, French and English-speaking, were asked to perform two discrimination tasks, alone and concurrently. The participants had to answer as fast as possible to one or two images appearing in the center of the tablet by pressing to the corresponding buttons. Normative data are provided for reaction time (RT), coefficient of variation, and accuracy. Analyses of variance were performed by trial types (single-pure, single-mixed, dual-mixed), and linear regressions assessed the relationship between performance and sociodemographic characteristics. RESULTS: The participants were highly educated and a large proportion of them were women (73.9%). The accuracy on the task was very high across all blocks. RT data revealed both a task-set cost and a dual-task cost between the blocks. Age was associated with slower RT and with higher coefficient of variability. Men were significantly slower on dual-mixed trials, but their coefficient of variability was lower on single-pure trials. Education was not associated with performance. CONCLUSIONS: This study provides normative data for a tablet-based dual-task assessment in older adults without cognitive impairment, which was lacking. All participants completed the task with good accuracy in less than 15 minutes and thus, the task is transferable to clinical and research settings.

Association between Statin Use and Balance in Older Adults.

Background: Several medications have been associated with an increased risk of balance deficits and greater likelihood to sustain a fall, representing a large health and economic issue. Statins are regularly prescribed to prevent strokes and heart attacks, but their impact on balance is unknown. The aim of this paper was to determine whether statin use is associated with poorer balance performances in older adults. Methods: All participants, one group taking statins (n = 34), and the other group not taking statins (n = 31), completed a balance assessment with their eyes closed and their eyes opened on a MatScan Pressure Sensing Mat. Center of Pressure (CoP) velocity, peak-to-peak distance, and standard deviation were collected in both anteroposterior (AP) and mediolateral (ML) directions. Multiple linear regression analyses were performed for each balance outcome, testing the statin use status as a predictor and controlling for appropriate factors including participants characteristics, lipid profile, and cardiovascular disease. Results: After controlling for confounding factors, statin use significantly predicted both CoP ML-Amplitude (ß = 0.638, p = 0.004) and ML-Velocity (ß = 0.653, p = 0.002) in the eyes-opened condition. Conclusions: The present study detected a negative association between statin use and balance control in the ML direction, suggesting that caution should be taken when prescribing statins in older adults, as this could decrease ML stability and ultimately increase fall and fracture risks.

Switching Ability Mediates the Age-Related Difference in Timed Up and Go Performance.

Age-related mobility and cognitive declines are closely linked, but their relationship is complex and needs to be further investigated. The study aimed to test if cognition (processing speed, inhibition and switching performances) mediates the age-related difference in mobility. Mediation analyses were used to test whether processing speed, inhibition and switching performances on the Stroop test independently mediate the relationship between age and performances at the Timed Up and Go (TUG). Results revealed that only switching performances mediated the age-related difference in TUG (65.1% of the total effect) supporting the notion that executive control plays a critical role in older adults' mobility.