Association between changes in habitual stepping activity and cognition in older adults

Advancing age is associated with declines in cognitive function. Although physical activity is thought to protect against this decline, it is unclear how a short-term uptake in daily steps or a decline in day-to-day step variability may contribute to cognition among older adults. We tested associations between changes in step counts, day-to-day step variability and executive cognitive functions among older adults taking part in a physical activity intervention. Thirty-seven older adults (33 females; 71.4 ± 6.3 years) completed a 10-week personalized physical activity intervention. Participants wore a Fitbit to measure daily step counts throughout the study. They also completed a computerized Stroop task before and after the intervention. Average step counts and step count variability via average-real-variability (ARV) were determined. Compared to pre-intervention, step counts increased (p < 0.001) and step variability decreased post-intervention (p = 0.04). Models describing the changes in step counts and ARV over the 10-weeks were cubic (both, p < 0.04). Reaction times during the simple (p = 0.002) and switching (p = 0.04) conditions were faster post-intervention. Change in step variability was positively associated with the change in reaction time for the switching condition (β = 0.029, p = 0.002). On average, a reduction in day-to-day step variability was associated with improvements in cognitive flexibility.

Frailty is associated with worse executive function and higher cerebral blood velocity in cognitively healthy older adults: a cross-sectional study

Frailty is characterized by an increased vulnerability to adverse health events. Executive function impairment is an early sign of progression towards cognitive impairments. Whether frailty is associated with executive function and the associated mechanisms are unclear. We test the hypothesis that higher frailty is associated with worse executive function (Trail Making Test) and if aerobic fitness, prefrontal cortex oxygenation (ΔO2Hb), or middle-cerebral artery velocity (MCAv) impact this association. Forty-one (38 females) cognitively health older adults (70.1 ± 6.3 years) completed a Trail task and 6-min walk test. Prefrontal cortex oxygenation was measured during the Trail task (via functional near-infrared spectroscopy) and MCAv in a sub-sample (n=26, via transcranial Doppler). A 35-item frailty index was used. Frailty was independently, non-linearly related to trail B performance (Frailty2: β=1927 [95% CI: 321-3533], p = 0.02), with the model explaining 22% of the variance of trail B time (p = 0.02). Aerobic fitness was an independent predictor of trail B (β=-0.05 [95% CI: -0.10-0.004], p = 0.04), but age and ΔO2Hb were not (both, p > 0.78). Frailty was positively associated with the difference between trails B and A (β=105 [95% CI: 24-186], p = 0.01). Frailty was also associated with a higher peak MCAv (ρ = 0.40, p = 0.04), but lower ΔO2Hb-peakMCAv ratio (ρ = -0.44, p = 0.02). Higher frailty levels are associated to worse Trail times after controlling for age, aerobic fitness, and prefrontal oxygenation. High frailty level may disproportionately predispose older adults to challenges performing executive function tasks that may manifest early as a compensatory higher MCAv despite worse executive function, and indicate a greater risk of progressing to cognitive impairment.

Binge drinking and smoking are associated with worse academic performance in Canadian undergraduate students

OBJECTIVE

Test the hypothesis that smoking, fast-food consumption, and binge drinking were negatively associated with academic performance in Canadian undergraduate students.

PARTICIPANTS

Undergraduate students across Canada [n = 411 (335♀) aged: 22 ± 4 years] completed a questionnaire regarding their lifestyle behaviors and academic grades.

METHODS

Relationships between lifestyle behaviors and academic performance were assessed via covariate-adjusted multiple regressions. Mediation models were used to test whether significant relationships between smoking/fast-food and grades were explained by binge drinking.

RESULTS

Smoking (β= -4.00, p < .001) and binge drinking (β= -1.98, p = .002) were independent predictors of grades (average: 84 ± 8%). Binge drinking partially mediated the relationships between smoking (indirect effect β= -1.19, 95%CI [-2.49, -0.08] and fast-food consumption (indirect effect: β= -.75, 95%CI [-1.20, -0.29]), with grades.

CONCLUSIONS

These findings highlight the negative influence of binge drinking, smoking, and fast-food consumption on academic success, with binge drinking as a partial mediator of these relationships.

Effects of Exercise Alone or Combined With Cognitive Training and Vitamin D Supplementation to Improve Cognition in Adults With Mild Cognitive Impairment: A Randomized Clinical Trial

Importance

Exercise, cognitive training, and vitamin D may enhance cognition in older adults with mild cognitive impairment (MCI).

Objective

To determine whether aerobic-resistance exercises would improve cognition relative to an active control and if a multidomain intervention including exercises, computerized cognitive training, and vitamin D supplementation would show greater improvements than exercise alone.

Design, Setting, and Participants

This randomized clinical trial (the SYNERGIC Study) was a multisite, double-masked, fractional factorial trial that evaluated the effects of aerobic-resistance exercise, computerized cognitive training, and vitamin D on cognition. Eligible participants were between ages 65 and 84 years with MCI enrolled from September 19, 2016, to April 7, 2020. Data were analyzed from February 2021 to December 2022.

Interventions

Participants were randomized to 5 study arms and treated for 20 weeks: arm 1 (multidomain intervention with exercise, cognitive training, and vitamin D), arm 2 (exercise, cognitive training, and placebo vitamin D), arm 3 (exercise, sham cognitive training, and vitamin D), arm 4 (exercise, sham cognitive training, and placebo vitamin D), and arm 5 (control group with balance-toning exercise, sham cognitive training, and placebo vitamin D). The vitamin D regimen was a 10 000 IU dose 3 times weekly.

Main Outcomes and Measures

Primary outcomes were changes in ADAS-Cog-13 and Plus variant at 6 months.

Results

Among 175 randomized participants (mean [SD] age, 73.1 [6.6] years; 86 [49.1%] women), 144 (82%) completed the intervention and 133 (76%) completed the follow-up (month 12). At 6 months, all active arms (ie, arms 1 through 4) with aerobic-resistance exercise regardless of the addition of cognitive training or vitamin D, improved ADAS-Cog-13 when compared with control (mean difference, -1.79 points; 95% CI, -3.27 to -0.31 points; P = .02; d = 0.64). Compared with exercise alone (arms 3 and 4), exercise and cognitive training (arms 1 and 2) improved the ADAS-Cog-13 (mean difference, -1.45 points; 95% CI, -2.70 to -0.21 points; P = .02; d = 0.39). No significant improvement was found with vitamin D. Finally, the multidomain intervention (arm 1) improved the ADAS-Cog-13 score significantly compared with control (mean difference, -2.64 points; 95% CI, -4.42 to -0.80 points; P = .005; d = 0.71). Changes in ADAS-Cog-Plus were not significant.

Conclusions and Relevance

In this clinical trial, older adults with MCI receiving aerobic-resistance exercises with sequential computerized cognitive training significantly improved cognition, although some results were inconsistent. Vitamin D supplementation had no effect. Our findings suggest that this multidomain intervention may improve cognition and potentially delay dementia onset in MCI.

Trial Registration

ClinicalTrials.gov Identifier: NCT02808676.

Combining exercise with cognitive training and vitamin D3 to improve functional brain connectivity (FBC) in older adults with mild cognitive impairment (MCI). Results from the SYNERGIC trial

Changes in functional brain connectivity (FBC) may indicate how lifestyle modifications can prevent the progression to dementia; FBC identifies areas that are spatially separate but temporally synchronized in their activation and is altered in those with mild cognitive impairment (MCI), a prodromal state between healthy cognitive aging and dementia. Participants with MCI were randomly assigned to one of five study arms. Three times per week for 20-weeks, participants performed 30-min of (control) cognitive training, followed by 60-min of (control) physical exercise. Additionally, a vitamin D₃ (10,000 IU/pill) or a placebo capsule was ingested three times per week for 20-weeks. Using the CONN toolbox, we measured FBC change (Post-Pre) across four statistical models that collapsed for and/or included some or all study arms. We conducted Pearson correlations between FBC change and changes in physical and cognitive functioning. Our sample included 120 participants (mean age: 73.89 ± 6.50). Compared to the pure control, physical exercise (model one; p-False Discovery Rate (FDR) < 0.01 & < 0.05) with cognitive training (model two; p-FDR =  < 0.001), and all three interventions combined (model four; p-FDR =  < 0.01) demonstrated an increase in FBC between regions of the Default-Mode Network (i.e., hippocampus and angular gyrus). After controlling for false discovery rate, there were no significant correlations between change in connectivity and change in cognitive or physical function. Physical exercise alone appears to be as efficacious as combined interventional strategies in altering FBC, but implications for behavioral outcomes remain unclear.

Impact of Exercise Training Interventions on Flow-Mediated Dilation in Adults: An Umbrella Review

BACKGROUND

Dysfunction of the endothelium is a key precursor of cardiovascular disease. Endothelial function, as assessed via the flow-mediated dilation test, is attenuated with chronic disease (e.g., type 2 diabetes mellitus, hypertension). Exercise training may mitigate this dysfunction and promote better vascular health.

OBJECTIVE

The main objective of this umbrella review was to determine the impact of exercise training on flow-mediated dilation in healthy adults and those with chronic disease.

METHODS

Studies were included if they conducted a systematic review and/or meta-analysis on flow-mediated dilation responses to exercise interventions in adults. Sources were searched in January 2022 and included Scopus, EMBASE, MEDLINE, CINAHL, and Academic Search Premier. National Institutes of Health quality assessment tools were used. The results were presented narratively.

RESULTS

Twenty-seven systematic reviews, including 19 meta-analyses, (total: 5464 unique participants, 2181 reported unique female individuals) met the inclusion criteria. The average overall quality of included reviews was 8.8/11. The quality of studies within each included review varied from low to moderate using a variety of quality assessment scales. Reviews were conducted in healthy adults (n = 9, meta-analyses = 6), as well as those with type 2 diabetes (n = 5, meta-analyses = 4), cardiovascular conditions [i.e., conditions that impact the cardiovascular system, but excluding samples of only type 2 diabetes] (n = 11, meta-analyses = 7), and other chronic conditions (n = 2, meta-analyses = 2). Overall, the included reviews provided evidence that the type of training to optimally improve FMD may vary based on disease condition. Specifically, the evidence suggests that healthy adults benefitted most from higher intensity aerobic training and/or more frequent low-to-moderate resistance training. In addition, adults with type 2 diabetes benefitted most from low-intensity resistance or aerobic exercise training, whereas those with cardiovascular conditions should consider engaging in high-intensity aerobic training to improve endothelial function.

CONCLUSIONS

This information may help guide the design of specific exercise programs or recommendations for adults with chronic conditions.

The importance of collaboration between medical and exercise professionals in addressing patient physical inactivity

Physical activity has declined further during the coronavirus disease 2019 (COVID-19) pandemic. Physicians are at the front lines of proactively educating and promoting physical activity to patients; however, physicians do not feel confident and face numerous barriers in prescribing exercise to patients. Exercise referral schemes, comprising collaborations with qualified exercise professionals, represent a fruitful option for supporting physicians hoping to promote physical activity to more patients. Herein, we provide practical suggestions for establishing and creating a successful referral scheme. Ultimately, exercise referral schemes offer an alternative to help physician burnout and mitigate patient physical inactivity during and beyond the COVID-19 pandemic.

Exercise training augments brain function and reduces pain perception in adults with chronic pain: A systematic review of intervention studies

Introduction

Chronic pain (CP) is a leading cause of disability worldwide. Pain may be measured using subjective questionnaires, but understanding the underlying physiology, such as brain function, could improve prognosis. Further, there has been a shift towards cost-effective lifestyle modification for the management of CP.

Methods

We conducted a systematic review (Registration: #CRD42022331870) using articles retrieved from four databases (Pubmed, EMBASE, AMED, and CINAHL) to assess the effect of exercise on brain function and pain perception/quality of life in adults with CP.

Results

Our search yielded 1879 articles; after exclusion, ten were included in the final review. Study participants were diagnosed with either osteoarthritis or fibromyalgia. However, two studies included "fibromyalgia and low back pain" or "fibromyalgia, back, and complex regional pain." Exercise interventions that were 12 weeks or longer (n = 8/10) altered brain function and improved pain and/or quality of life outcomes. The cortico-limbic pathway, default-mode network, and dorsolateral prefrontal cortex were key regions that experienced alterations post-intervention. All studies that reported an improvement in brain function also demonstrated an improvement in pain perception and/or quality of life.

Discussion

Our review suggests that alterations in brain function, notably the cortico-limbic, default-mode and dorsolateral prefrontal cortex, may be responsible for the downstream improvements in the subjective experience of CP. Through appropriate programming (i.e., length of intervention), exercise may represent a viable option to manage CP via its positive influence on brain health.

The Influence of Motivators and Barriers to Exercise on Attaining Physical Activity and Sedentary Time Guidelines among Canadian Undergraduate Students

Canadian 24 h movement guidelines recommend engaging in >150 min/week of moderate-vigorous-intensity physical activity and ≤8 h/day of sedentary time. Half of Canadian post-secondary students do not meet physical activity or sedentary time guidelines. This pan-Canadian study aimed to (1) identify commonly cited motivators/barriers to exercise, and (2) determine which motivators/barriers were most influential for attaining physical and sedentary activity guidelines. A total of 341 respondents (279 females, 23 ± 4 years old, 53% met activity guidelines, 49% met sedentary guidelines) completed an online survey regarding undergraduate student lifestyle behaviours. Improved physical health (74% of respondents), mental health (67%), physical appearance (60%), and athletic performance (28%) were the most common motivators to exercise. The most common barriers were school obligations (68%), time commitments (58%), job obligations (32%), and lack of available fitness classes (26%). Students citing improved athletic performance (odds ratio (OR) = 1.94, p = 0.02) were more likely to adhere to activity guidelines, while those who selected physical health (OR = 0.56, p = 0.03) and physical appearance (OR = 0.46, p = 0.001) as motivators were less likely to meet activity guidelines. Students who cited school obligations as a barrier were less likely (OR = 0.59, p = 0.03) to meet sedentary guidelines. The motivators and barriers identified provide a foundation for university-led initiatives aimed at promoting physical activity and reducing sedentary time among undergraduate students. Strategies that positively re-frame students' physical health and appearance-based motivations for exercise may be particularly useful in helping more students achieve national activity recommendations.

What is the impact of aerobic fitness and movement interventions on low-flow-mediated vasoconstriction? A systematic review of observational and intervention studies

The cardiovascular benefits of physical exercise are well established. The vasoreactivity that occurs during reductions in local arterial blood flow, termed low-flow-mediated constriction (L-FMC), is a measure of endothelial-dependent vasoconstrictor function. It is unclear whether aerobic fitness and movement (or lack thereof) influences L-FMC. We systematically reviewed studies examining the impact of physical behaviours on L-FMC. To be included, cross-sectional and interventional studies had to examine the impact of a physical behaviour on L-FMC in adults. There were no language or date of publication restrictions. Sources were searched in May, 2021 and included Scopus, Embase, MEDLINE, CINAHL, and Academic Search Premier. National Institutes of Health quality assessment tools were used. Fourteen studies (15 arms; 313 participants; 398 total observations from four arteries) met the inclusion criteria. The study quality varied from four out of 14 (controlled intervention scoring) to nine out of 12 (longitudinal intervention with no control group scoring) with the total points dependent upon the study design. Conflicting results were reported for acute prolonged sitting studies (attenuated L-FMC: n = 1; no change: n = 1) and resistance exercise (increased L-FMC: n = 2; no change: n = 2). Most observational studies examining aerobic fitness (3/4 studies) and aerobic exercise interventions (4/5 studies) observed a favourable effect on L-FMC. Overall, the included studies support that higher aerobic fitness and engaging in aerobic exercise training may augment L-FMC responses. Our systematic review highlights the heterogeneity between studies and identifies current gaps and future directions to better our understanding of (in)activity, exercise, and posture on endothelial vasoconstrictor function. PROSPERO Registration No.: CRD42021248241.

A scoping review of exercise referral schemes involving qualified exercise professionals in primary health care

Qualified exercise professionals (QEPs) have the training, knowledge, and scope of practice to effectively provide physical activity counselling, prescribe exercise, and deliver exercise programming to patients with or without chronic diseases. Healthcare providers identify an interest in referring patients to QEPs; however, the impact of exercise referral schemes (ERS) involving QEPs on patients' physical health is unclear. A scoping review regarding the available evidence of ERS involving healthcare provider referrals to QEPs was performed. A literature search was conducted in 6 databases (initially: n = 6011 articles), yielding n = 23 articles examining QEP delivered physical activity counselling (n = 7), QEP supervised exercise training (n = 4), or some combination (n = 12). Although studies were heterogeneous in methods, procedures, and populations, ERSs increased patients' subjective physical activity levels. Few studies incorporated objective physical activity measures (n = 5/23), and almost half measured aerobic fitness (n = 11/23). ERS involving a QEP that includes activity counselling and/or exercise programming/training report favourable impacts on patients' subjectively measured physical activity and objectively measured aerobic fitness. Based on the existing literature on the topic, this scoping review provides recommendations for designing and evaluating ERS with QEPs that include: objective measures, long-term follow-up, QEP qualifications, and the cost-effectiveness of ERS. Novelty: ERS involving QEPs report increased patients' perceived physical activity level and may improve patients' cardiorespiratory fitness. Promoting the collaboration of QEPs with other healthcare providers can enhance patients' physical fitness and health. This scoping review provides recommendations for the design and evaluation of ERS involving QEPs.

The effect of physical exercise on functional brain network connectivity in older adults with and without cognitive impairment. A systematic review

INTRODUCTION

Neurodegeneration is a biproduct of aging that results in concomitant cognitive decline. Physical exercise is an emerging intervention to improve brain health. The underlying neural mechanisms linking exercise to neurodegeneration, however, are unclear. Functional brain network connectivity (FBNC) refers to neural regions that are anatomically separate but temporally synched in functional signalling. FBNC can be measured using functional Magnetic Resonance Imaging (fMRI) and is affected by neurodegeneration.

METHODS

We conducted a systematic review using PubMed and EMBASE to assess the effect of physical exercise on FBNC in older adults with and without cognitive impairment.

RESULTS

Our search yielded 1474 articles; after exclusion, 13 were included in the final review, 8 of which focused on cognitively healthy older adults. 10 studies demonstrated an increase in FBNC post-exercise intervention, while 11 studies showed improvements in secondary outcomes (cognitive and/or physical performance). One study showed significant correlations between FBNC and cognitive performance measures that significantly improved post-intervention.

DISCUSSION

We found evidence that physical exercise increases FBNC. When assessing the association between FBNC with physical and cognitive functioning, careful consideration must be given to variability in exercise parameters, neural regions of interest and networks examined, and heterogeneity in methodological approaches.

The role of physical exercise in modulating peripheral inflammatory and neurotrophic biomarkers in older adults: A systematic review and meta-analysis

BACKGROUND

Physiological cascades of neurotrophic factors and inflammatory cytokines may mediate the exercise-induced amelioration of cognition in older adults. However, there is limited understanding on how different exercise modalities improving cognition alter biomarkers. Our aim was to evaluate the effects of different exercise modalities on blood biomarker concentrations in cognitive clinical trials of older adults.

METHODS

A systematic review (SR) and meta-analysis (MA) were performed using the databases PubMed, EMBASE, and SCOPUS. After exclusions, 17 trials with 18 distinct exercise interventions were included.

RESULTS

Aerobic training increased (n = 2) or did not significantly change BDNF (n = 5), and resistance training increased (n = 2) or did not significantly change (n = 2) IGF-1. Multimodal training significantly increased (n = 1) or did not change (n = 3) BDNF. Interventions that recruited sex-specific cohorts showed an advantage in males for blood marker concentrations and cognitive performance outcomes (n = 3) compared to females (n = 3). Only one of three interventions decreased concentrations of CRP. Eight studies examining BDNF changes were suited for MA and showed that higher BDNF concentrations were reached post intervention, although not reaching statistical significance (p = .26, I² = 44 %).

DISCUSSION

Our results suggest that exercise has potential to ameliorate cognitive decline in older adults with divergent, modality-specific, neurotrophic mechanisms.

Dual decline in gait speed and cognition is associated with future dementia: evidence for a phenotype

BACKGROUND

concurrent declines in gait speed and cognition have been associated with future dementia. However, the clinical profile of 'dual decliners', those with concomitant decline in both gait speed and cognition, has not been yet described. We aimed to describe the phenotype and the risk for incident dementia of those who present with dual decline in comparison with non-dual decliners.

METHODS

prospective cohort of community-dwelling older adults free of dementia at baseline. We evaluated participants' gait speed, cognition, medical status, functionality, incidence of adverse events and dementia, biannually over 7 years. Gait speed was assessed with a 6-m electronic walkway and global cognition using the MoCA test. We compared characteristics between dual decliners and non-dual decliners using t-test, chi-square and hierarchical regression models. We estimated incident dementia using Cox models.

RESULTS

among 144 participants (mean age 74.23 ± 6.72 years, 54% women), 17% progressed to dementia. Dual decliners had a 3-fold risk (HR: 3.12, 95%CI: 1.23-7.93, P = 0.017) of progression to dementia compared with non-dual decliners. Dual decliners were significantly older with a higher prevalence of hypertension and dyslipidemia (P = 0.002). Hierarchical regression models show that age and sex alone explained 3% of the variation in the dual decliners group. Adding hypertension and dyslipidemia increased the explained variation by 8 and 10%, respectively. The risk of becoming a dual decliner was 4-fold higher if hypertension was present.

CONCLUSION

older adults with a concurrent decline in gait speed and cognition represent a group at the highest risk of progression to dementia. Older adults with dual decline have a distinct phenotype with a higher prevalence of hypertension, a treatable condition.

Practical Implications for Strength and Conditioning of Older Pre-Frail Females

Approaches to and benefits from resistance training for non-compromised older adults are well known. Less is understood about resistance training with pre-frail older adults, and even less information is available on the practical approaches to delivery. Herein, we describe an approach in pre-frail females who undertook a multi-component exercise intervention, inclusive of high-intensity, free-weight, functional resistance training. Capitalizing on the principle of overload is possible and safe for pre-frail females through constant reassurance of ability and adjustments in technique. Making exercise functionally relevant, for example, a squat is the ability to get on and off a toilet, resonates meaning. Older pre-frail females are affected by outside (clinical) influences. The exercise participant, and extraneous persons need to be educated on exercise approaches, to increase awareness, debunk myths, and enhance support for participation. Identification of individuality in a group session offers ability to navigate barriers for successful implementation.

Multi-Component Exercise with High-Intensity, Free-Weight, Functional Resistance Training in Pre-Frail Females: A Quasi-Experimental, Pilot Study

BACKGROUND

No study has performed an exercise intervention that included high-intensity, free-weight, functional resistance training, and assessed frailty status as an inclusion criteria and outcome measure via original, standardized tools, in pre-frail females.

OBJECTIVES

Determine if the intervention strategy is not only feasible and safe, but can also improve frailty status, functional task performance, and muscle strength.

DESIGN

Pilot, quasi-experimental.

SETTING

Community.

PARTICIPANTS

20 older-adults with pre-frailty characteristics.

INTERVENTION

12-weeks (3 days/week, 45-60 minutes/session) of multi-component exercise, inclusive of aerobic, resistance, balance and flexibility exercises. The crux of the program was balance and resistance exercises, the latter utilized high-intensity, free-weight, functional resistance training. The control group maintained their usual care.

MEASUREMENTS

1) Feasibility and safety (dropout, adherence, and adverse event); 2) Frailty (Frailty Phenotype, Clinical Frailty Scale, and gait speed); 3) Functional task performance (grip strength and sit-to-stand time); and 4) Isometric and isotonic strength of the knee extensors and elbow flexors.

RESULTS

No participants dropped out of the intervention or experienced an adverse event, and adherence averaged 88.3%. The exercise group became less frail, whereas the control group became more frail. There was a significant within-group improvement in exercise participants gait speed (p ≤ 0.01, +0.24 m/sec), grip strength (p ≤ 0.01, +3.9 kg), and sit-to-stand time (p ≤ 0.01, -5.0 sec). There was a significant within-group improvement in exercise participants knee extension isometric torque (p ≤ 0.05, +7.4 Nm) and isotonic velocity (p = ≤ 0.01, +37.5 ˚/sec). Elbow flexion isotonic velocity significantly declined within the control group (p ≤ 0.01, -20.2 ˚/sec) and demonstrated a significant between-group difference (p ≤ 0.05, 40.73 ˚/sec) post-intervention.

CONCLUSIONS

The intervention strategy appears to be feasible and safe, and may also improve frailty status, functional task performance, and muscle strength. These results help calculate effect size for a future randomized controlled trial.

The Effect of High Dose Vitamin D3 on Physical Performance in Frail Older Adults. A Feasibility Study

BACKGROUND

Vitamin D deficiency is ubiquitous in frailty but the effectiveness of vitamin D supplementation to improve outcomes in frail individuals is unclear. It has been postulated that higher than the current recommended doses (800 IU/day) may be needed to achieve a neuromuscular effect in frail individuals.

OBJECTIVES

1) determine if 4000 IU per day of vitamin D3 is safe for frail older adults; and 2) establish the efficacy of this dose to improve physical performance outcomes in this population.

DESIGN

Open-label, feasibility study.

SETTING

Community retirement centre.

PARTICIPANTS

40 older adults with frail or pre-frail characteristics.

INTERVENTION

4000 IU of vitamin D3 and 1200 mcg of calcium carbonate daily for four months.

MEASUREMENTS

Physical performance (grip strength, gait speed and short physical performance battery score), cognitive health and vitamin D and iPTH serum levels before and after the intervention.

RESULTS

Frail individuals improved short physical performance battery score (1.19, p = 0.005), fast gait speed (4.65, p = 0.066) and vitamin D levels (7.81, p = 0.011). Only frail females made a significant improvement in grip strength (1.92, p = 0.003). Stratifying the sample by baseline vitamin D levels revealed that participants with vitamin D insufficiency (≤ 75 nmol/L) significantly improved short physical performance battery score (1.06, p = 0.04), fast gait speed (6.28, p = 0.004) and vitamin D levels (25.73, p = <0.0001). Pre-frail individuals, as well as those with sufficient vitamin D levels (> 75 nmol/L) made no significant improvement in any outcome.

CONCLUSIONS

Vitamin D supplementation using 4000 IU/daily is safe and has a modest beneficial effect on physical performance for frail individuals and those with insufficient vitamin D levels. Participants with vitamin D insufficiency (≤ 75 nmol/L) showed greater benefits. Our feasibility study provides results to help calculate effect size for a future RCT.

Exercise prescription to reverse frailty

Frailty is a clinical geriatric syndrome caused by physiological deficits across multiple systems. These deficits make it challenging to sustain homeostasis required for the demands of everyday life. Exercise is likely the best therapy to reverse frailty status. Literature to date suggests that pre-frail older adults, those with 1–2 deficits on the Cardiovascular Health Study-Frailty Phenotype (CHS-frailty phenotype), should exercise 2–3 times a week, for 45–60 min. Aerobic, resistance, flexibility, and balance training components should be incorporated but resistance and balance activities should be emphasized. On the other hand, frail (CHS-frailty phenotype ≥ 3 physical deficits) older adults should exercise 3 times per week, for 30–45 min for each session with an emphasis on aerobic training. During aerobic, balance, and flexibility training, both frail and pre-frail older adults should work at an intensity equivalent to a rating of perceived exertion of 3–4 (“somewhat hard”) on the Borg CR10 scale. Resistance-training intensity should be based on a percentage of 1-repetition estimated maximum (1RM). Program onset should occur at 55% of 1RM (endurance) and progress to higher intensities of 80% of 1RM (strength) to maximize functional gains. Exercise is the medicine to reverse or mitigate frailty, preserve quality of life, and restore independent functioning in older adults at risk of frailty.

Developmental and intellectual differences in self-report and strategy use

The veridicality and reactivity of children's self-report of covert and overt memory strategies were investigated in a task allowing a direct comparison of self-report and the strategy observed. External memory strategies (e.g., moving objects) were investigated with 7-, 9-, 11-, and 17-year-old typical children and 11- and 17-year-old children with mild mental retardation. Participants placed objects in specified spatial locations after hearing sequences of tape-recorded sentences. After each trial, half of the children immediately reported the strategy used. There were strong positive correlations between the frequency of reported strategy use and observed strategy use. Self-reports were accurate but not always complete. There was no effect of the self-reporting procedure on measures of verbal strategies, external memory strategies, and accuracy of recall. Children were less likely to report strategies not related to recall; these results are compatible with a "goal-sketch" mechanism.

Instructional and contextual effects on eternal memory strategy use in young children

Young children's ability to devise external representations in problem-solving tasks has not been fully examined. The present two experiments investigated children's creation and use of external representations (i.e., external representation strategies) in different conditions. In each experiment, 4- and 6-year-old children listened to a series of sentences (e.g., "The doll is on the table") and were required to remember where to place the objects named in the sentences. In Experiment 1, direct training increased the use of external representations. When the salience of task dimensions increased in Experiment 2, children's external representation strategies also increased. Four-year-old children showed a utilization deficiency in external representation strategy use in the prompt conditions, but not in the training condition. Thus, young children require additional situational support before they demonstrate cognitive competencies.

External and verbal strategies in children with and without mild mental retardation

External memory strategies (e.g., moving objects) were investigated in 11- and 17-year-old children with mild mental retardation and 7-, 9-, 11- and 17-year-old children without mental retardation (N = 95). In an external memory task, after hearing from 1 to 7 sentences, subjects placed objects in specified spatial locations. In the verbal memory task, subjects recalled sentences orally. Target-oriented strategies increased with the number of sentences and were positively related to accuracy. There was no difference between children with mental retardation and their age peers in object-oriented strategies. For all groups, external strategies were used more frequently than verbal strategies. These results show that children with mental retardation have more strategy competencies than reported in studies of covert verbally based strategies.

Intellectual and developmental differences in external memory strategies

External memory strategies (e.g., moving objects) were investigated in 11-year-old children with mild mental retardation and 7- and 11-year-olds without mental retardation. Participants attempted to place objects at specified spatial locations after hearing sequences of tape-recorded instructions. During baseline, children with mental retardation and 7-year-olds used external strategies more frequently than did 11-year-olds. All three groups used external strategies after prompting that represented the correct spatial locations, and all used the same tactics. In contrast to expected deficiencies in the use of strategies, results show areas of overlap in strategy capabilities among the groups.

A comparison of cycloplegic refraction to the near retinoscopy technique for refractive error determination

The near retinoscopy technique of refractive error determination was compared to the standard method of cycloplegic refraction using 10 "infants" (3-12 months of age) and 10 "children" (32-109 months of age). There was a significant difference between the techniques for both sphere and cylinder power. Although there was no interaction of refractive technique and age group, the difference between near retinoscopy and cycloplegic refractive error tended to be larger for infants than for children. No significant difference was found when the average refractive values were compared for monocular or binocular conditions and no significant effect was found for either gender or laterality (right versus left eye). Based on these findings, it is suggested that caution be used in substituting the near retinoscopy technique for cycloplegic refraction even utilizing a "correction" factor for the dioptric difference between techniques.

Comparison and message-formulation skills in the referential communication of severely mentally retarded children

The importance of comparison and message-formulation skills in referential communication was studied with severely mentally retarded children. A store game task was used that required the child to communicate a choice of one or two objects on a shelf. Comparison training taught the children to select the appropriate object when paired with a similar but inappropriate object. Message training taught the children to communicate by pointing and/or gesturing. Results indicated that combined comparison and message training produced higher communication accuracy than did comparison training alone. Comparison training, however, increased subjects' accuracy of communicating as compared to an untrained control group. A parallel pattern of results was found for communication frequency. The training groups either maintained or improved their communicative performance in a near-generalization task, suggesting that they learned communicative behavior and not merely task-specific behavior.

Developmental progressions and regressions in the selective remembering strategies of EMR individuals

Developmental changes in the use of strategies to eliminate interference from irrelevant information in memory were investigated. The participants in the first experiment were 11-, 15-, and 18-year-old EMR students, and those in the second experiment were 30-year-old retarded and nonretarded adults. In both experiments a directed forgetting paradigm was used in which the person was presented two sets of pictures but only recalled one set on a trial. On some trials there was a cue to forget the first set and to remember only the second set. The cue to forget was not used by the youngest group of students. The 15- and 18-year-olds used the cue, but interference from the to-be-forgotten items remained. The 30-year-old retarded group regressed to the performance pattern of the youngest group, whereas the nonretarded adults used appropriate selective remembering strategies. The implications of developmental changes in the memory performance of retarded persons were discussed.

The effect of communicative demands on request-making in the moderately and severely mentally retarded

Two experiments were reported investigating the conditions that elicit request-making in the moderately and the severely mentally retarded. In both experiments single-subject designs were used with a store game task designed to closely approximate a naturalistic communication situation. In the first experiment moderately retarded adults were able to consistently communicate which of two objects they wished to obtain from a store counter. In the second, severely retarded adolescents initially made some errors but communicated effectively on 100% of the trials by the end of the experiment. These results contrast markedly with the results from the less naturalistic task used previously. In both experiments the amount of verbalization was greater when the task was arranged to create a demand for communication. Applications of these findings to everyday communicative situations involving the mentally retarded are discussed.