Reshaping the path of vascular cognitive impairment with resistance training: a study protocol for a randomized controlled trial

Background

Subcortical ischemic vascular cognitive impairment (SIVCI) is the most common form of vascular cognitive impairment. Importantly, SIVCI is considered the most treatable form of cognitive impairment in older adults, due to its modifiable risk factors such as hypertension, diabetes mellitus, and hypercholesterolemia. Exercise training is a promising intervention to delay the progression of SIVCI, as it actively targets these cardiometabolic risk factors. Despite the demonstrated benefits of resistance training on cognitive function and emerging evidence suggesting resistance training may reduce the progression of white matter hyperintensities (WMHs), research on SIVCI has predominantly focused on the use of aerobic exercise. Thus, the primary aim of this proof-of-concept randomized controlled trial is to investigate the efficacy of a 12-month, twice-weekly progressive resistance training program on cognitive function and WMH progression in adults with SIVCI. We will also assess the efficiency of the intervention.

Methods

Eighty-eight community-dwelling adults, aged > 55 years, with SIVCI from metropolitan Vancouver will be recruited to participate in this study. SIVCI will be determined by the presence of cognitive impairment (Montreal Cognitive Assessment < 26) and cerebral small vessel disease using computed tomography or magnetic resonance imaging. Participants will be randomly allocated to a twice-weekly exercise program of (1) progressive resistance training or (2) balance and tone training (i.e., active control). The primary outcomes are cognitive function measured by the Alzheimer’s Disease Assessment Scale-Cognitive-Plus (ADAS-Cog-13 with additional cognitive tests) and WMH progression.

Discussion

The burden of SIVCI is immense, and to our knowledge, this will be the first study to quantify the effect of progressive resistance training on cognitive function and WMH progression among adults with SIVCI. Slowing the rate of cognitive decline and WMH progression could preserve functional independence and quality of life. This could lead to reduced health care costs and avoidance of early institutional care.

Trial registration

ClinicalTrials.gov NCT02669394. Registered on February 1, 2016

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-021-05156-1.

Cognitive Function and Functional Mobility Predict Exercise Adherence in Older Adults Who Fall

INTRODUCTION

Strength and balance exercises prevent falls. Yet, exercise adherence is often low. To maximize the benefit of exercise on falls prevention, we aimed to identify baseline cognitive and mobility factors that predict adherence to the Otago Exercise Program (OEP) - a home-based exercise program proven to prevent falls.

METHODS

We conducted a secondary longitudinal analysis of data from a randomized clinical trial (RCT) (OEP compared with usual care) among 172 participants who were assigned to the OEP intervention of the RCT. Adherence to the OEP was calculated as a percent score (i.e., [frequency of strength and balance retraining session per week/3 strength and balance retraining sessions per week] × 100). Executive function (i.e., mental flexibility) was measured using the Trail Making Tests (Part A and B: TMT B - TMT A) and the Digit Symbol Substitution Test (DSST). Short-term memory and encoding was measured using the Verbal Digits Forward test. Executive function (i.e., inhibition and working memory) was measured using the Stroop Color-Word Test and the Verbal Digits Forward minus Verbal Digits Backward test. Mobility was assessed using the Short Performance Physical Battery and the Timed Up and Go test. We used general estimation equations analysis to determine the predictors of adherence to the OEP.

RESULTS

Better set shifting (β = -0.06, z = -2.43, [SE = 0.02] p = 0.018] predicted greater OEP adherence. Greater attention and short-term memory (β = -6.99, z = -2.37 [SE = 2.95]) predicted poorer OEP adherence. Response inhibition, processing speed, working memory, and mobility assessed by the SPPB were not associated with adherence. Poorer baseline Timed Up and Go (β = 1.48 z = 1.94, [SE = 0.76]; p < 0.001), predicted better OEP adherence.

CONCLUSION

Specific cognitive processes (i.e., executive function of set shifting, attention, and short-term memory) and functional mobility predicted exercise adherence. Further research needs to explore the pathways that explain why better attention and short-term memory predicted lower adherence and why poorer functional mobility led to better OEP adherence.

Shining the Light on the MotionWatch8 Light Sensor for Sleep and Aging Research: What Can We Measure and What Are We Missing?

Background

Poor sleep is common among older adults at risk for dementia and may be due to circadian dysregulation. Light is the most important external stimulus to the circadian clock and bright light therapy (BLT) has been used for >20 years to help realign circadian rhythms. However, the ability of field methods (e.g., actigraphy) to accurately determine the type and intensity of light is unknown.

Objective

We examined the ability of the MotionWatch8 (MW8) light sensor to determine: 1) light versus dark, 2) electrical light versus daylight, and 3) device-based BLT versus light which was not BLT.

Methods

We tested the MW8 under 17 daily light scenarios. Light exposure data was collected for 5 minutes during each scenario. Concurrently, we measured light exposure using the LT40 Light Meter, a sensitive measure of light intensity. We then developed individual cut-points using receiver operator characteristics analyses to determine optimal MW8 cut-points for 1) light versus dark; 2) electrical light versus daylight; and 3) light from a BLT box versus light which was not BLT. Bland-Altman plots tested the precision of the MW8 compared to the LT40.

Results

The MW8 accurately discriminated light versus dark (>32 lux), and electrical light versus daylight (<323 lux). However, the MW8 had poor accuracy for 1) discriminating BLT from light which was not BLT; and 2) low precision compared to the LT40.

Conclusion

The MW8 appears to be able to discern light versus dark and electrical light versus daylight; however, there remains a need for accurate field methods capable of measuring light exposure.

Sensorimotor, Cognitive, and Affective Functions Contribute to the Prediction of Falls in Old Age and Neurologic Disorders: An Observational Study

OBJECTIVE

To determine whether impairments across cognitive and affective domains provide additional information to sensorimotor deficits for fall prediction among various populations.

DESIGN

We pooled data from 5 studies for this observational analysis of prospective falls.

SETTING

Community or low-level care facility.

PARTICIPANTS

Older people (N=1090; 74.0±9.4y; 579 female); 500 neurologically intact (NI) older people and 3 groups with neurologic disorders (cognitive impairment, n=174; multiple sclerosis (MS), n=111; Parkinson disease, n=305).

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

Sensorimotor function was assessed with the Physiological Profile Assessment, cognitive function with tests of executive function, affect with questionnaires of depression, and concern about falling with falls efficacy questionnaires. These variables were associated with fall incidence rates, obtained prospectively over 6-12 months.

RESULTS

Poorer sensorimotor function was associated with falls (incidence rate ratio [95% CI], 1.46 [1.28-1.66]). Impaired executive function was the strongest predictor of falls overall (2.91 [2.27-3.73]), followed by depressive symptoms (2.07 [1.56-2.75]) and concern about falling (2.02 [1.61-2.55]). Associations were similar among groups, except for a weaker relationship with executive impairment in NI persons and a stronger relationship with concern about falling in persons with MS. Multivariable analyses showed that executive impairment, poorer sensorimotor performance, depressive symptoms, and concern about falling were independently associated with falls.

CONCLUSIONS

Deficits in cognition (executive function) and affect (depressive symptoms) and concern about falling are as important as sensorimotor function for fall prediction. These domains should be included in fall risk assessments for older people and clinical groups.

Risk factors for recurrent falls in older adults: A systematic review with meta-analysis

Older adults who fall recurrently (i.e., 2 or more falls/year) are at risk of functional decline and mortality. Understanding which risk factors for recurrent falls are most important will inform secondary fall prevention strategies that can reduce recurrent falls risk. Thus, we conducted a systematic review with meta-analysis to determine the relative risk of recurrent falls for different types of falls risk factors. MEDLINE, EMBASE, PsycINFO, and CINAHL databases were searched on April 25, 2019 (Prospero Registration: CRD42019118888). We included peer-reviewed prospective studies which examined risk factors that contributed to recurrent falls in adults aged ≥ 60 years. Using the falls risk classification system of Lord and colleagues, we classified each risk factor into one of the following domains: 1) balance and mobility; 2) environmental; 3) psychological; 4) medical; 5) medication; 6) sensory and neuromuscular; or 7) sociodemographic. We calculated the summary relative risk (RR) for each domain and evaluated the risk of bias and quality of reporting. Twenty-two studies were included in this systematic review and meta-analysis. Four domains predicted recurrent falls: balance and mobility (RR:1.32;95 % CI:[1.10, 1.59]), medication (RR:1.53;95 % CI:[1.11, 2.10]), psychological (RR:1.35;95 % CI:[1.03, 1.78]), and sensory and neuromuscular (RR:1.51;95 % CI:[1.18, 1.92]). Each of these four domains can be viewed as a marker of frailty. The risk of bias was low, and the study quality was high (minimum:19/22). Older adults with markers of frailty are up to 53 % more likely to experience recurrent falls. Strategies that identify and resolve frailty markers should be a frontline approach to preventing recurrent falls.

A pragmatic randomized controlled trial testing the effects of the international scientific SCI exercise guidelines on SCI chronic pain: protocol for the EPIC-SCI trial

STUDY DESIGN

Protocol for a pragmatic randomized controlled trial (the Exercise guideline Promotion and Implementation in Chronic SCI [EPIC-SCI] Trial).

PRIMARY OBJECTIVES

To test if home-/community-based exercise, prescribed according to the international SCI exercise guidelines, significantly reduces chronic bodily pain in adults with SCI.

SECONDARY OBJECTIVES

To investigate: (1) the effects of exercise on musculoskeletal and neuropathic chronic pain; (2) if reduced inflammation and increased descending inhibitory control are viable pathways by which exercise reduces pain; (3) the effects of chronic pain reductions on subjective well-being; and (4) efficiency of a home-/community-based exercise intervention.

SETTING

Exercise in home-/community-based settings; assessments in university-based laboratories in British Columbia, Canada.

METHOD

Eighty-four adults with chronic SCI, reporting chronic musculoskeletal or neuropathic pain, and not meeting the current SCI exercise guidelines, will be recruited and randomized to a 6-month Exercise or Wait-List Control condition. Exercise will occur in home/community settings and will be supported through behavioral counseling. All measures will be taken at baseline, 3-months and 6-months. Analyses will consist of linear mixed effect models, multiple regression analyses and a cost-utility analysis. The economic evaluation will examine the incremental costs and health benefits generated by the intervention compared with usual care.

ETHICS AND DISSEMINATION

The University of British Columbia Clinical Research Ethics Board approved the protocol (#H19-01650). Using an integrated knowledge translation approach, stakeholders will be engaged throughout the trial and will co-create and disseminate evidence-based recommendations and messages regarding the use of exercise to manage SCI chronic pain.

Action Seniors! Cost-Effectiveness Analysis of a Secondary Falls Prevention Strategy Among Community-Dwelling Older Fallers

BACKGROUND

The Otago Exercise Program (OEP) has demonstrated cost-effectiveness for the primary prevention of falls in a general community setting. The cost-effectiveness of exercise as a secondary falls prevention (ie, preventing falls among those who have already fallen) strategy remains unknown. The primary objective was to estimate the cost-effectiveness (incremental cost-effectiveness/utility ratio) of the OEP from a healthcare system perspective.

DESIGN

A concurrent 12-month prospective economic evaluation conducted alongside the Action Seniors! randomized critical trial (OEP compared with usual care).

SETTING

Vancouver Falls Prevention Clinic (Vancouver, BC, Canada; http://www.fallsclinic.ca).

PARTICIPANTS

A total of 344 community-dwelling older adults, aged 70 years and older, who attended a geriatrician-led Falls Prevention Clinic in Vancouver, after sustaining a fall in the previous 12 months.

MEASUREMENTS

Main outcome measures included: incidence rate ratio for falls, healthcare costs, incremental cost per fall prevented, and incremental cost per quality-adjusted life year (QALY) gained.

RESULTS

The OEP costs $393 CAD per participant to implement. The incremental cost per fall prevented resulted in a savings of $2 CAD. The incremental cost per QALY gained (where QALYs were estimated using the Euro-Qol 5D three-level version [EQ-5D-3L]) indicated the OEP was less effective than usual care. The incremental cost per QALY gained (where QALYs were estimated using the Short Form 6D [SF-6D]) indicated the OEP was more effective and less costly than usual care. The incremental QALYs estimated using the EQ-5D-3L and the SF-6D were not clinically significant and close to zero, indicating no change in quality of life.

CONCLUSION

Compared with usual care, healthcare system costs are saved and falls are prevented when older fallers who attend a geriatrician-led falls clinic are allocated to, and provided, the physiotherapist-guided exercise-based falls prevention program (the OEP).

Risk factors for recurrent falls in older adults: a study protocol for a systematic review with meta-analysis

INTRODUCTION

Older adults who fall recurrently (i.e., >1 fall/year) are at risk for functional decline and mortality. Key risk factors for recurrent falls in community-dwelling older adults are not well established due to methodological limitations, such as recall bias. A better understanding of the risk factors for recurrent falls will aid in refining clinical practice guidelines for secondary fall prevention strategies. The primary objective of this systematic review with meta-analysis is to examine the risk factors for recurrent falls in prospective studies among community-dwelling older adults.

METHODS AND ANALYSIS

A comprehensive search for articles indexed in MEDLINE, EMBASE, PsycINFO and CINAHL databases as well as grey literature was conducted on April 25, 2019. We will use MeSH and keyword search terms around the following topics: falls, recurrence, fall-risk, ageing and prospective studies. Prospective studies with monthly falls monitoring for 12 months, investigating risk factors for recurrent falls in older adults will be included. One author will complete the search. Two authors will remove duplicates and screen the titles and abstracts for their potential inclusion against the eligibility criteria. Two authors will screen the full texts and extract the data using a piloted extraction sheet. Included studies will be evaluated for the risk of bias with the Joanna Briggs Institute Prevalence Critical Appraisal tools. The quality of reporting will be determined with the Strengthening the Reporting of OBservational studies in Epidemiology. The data extraction will include study characteristics as well as sociodemographic, balance and mobility, sensory and neuromuscular, psychological, medical, medication and environmental factors. The results will be presented via figures, summary tables, meta-analysis (when possible) and narrative summaries.

ETHICS AND DISSEMINATION

No ethics approval will be required. Findings will be disseminated through publication and media.

PROSPERO REGISTRATION NUMBER

CRD42019118888; Pre-results.

Health-related quality of life in home care recipients after a falls prevention intervention: a 6-month follow-up

BACKGROUND

Falls in older adults are an increasingly important public health concern due to the expanding older population and contribute considerably to the global burden of disease. Home care recipients have a high incidence of falls and a low level of health-related quality of life (HRQOL). In this understudied group of older adults, exercise interventions could prevent falls, promote HRQOL and enable healthy ageing in the longer term.

METHODS

The study is a single-blinded parallel-group randomized controlled trial, lasting 3 months with a follow-up at 6 months, conducted in primary care. The objective was to explore the effects of a falls prevention exercise programme post-intervention at a 6-month follow-up in home care recipients 67+ years with a history of falls. The Otago Exercise Programme lasting 3 months was performed. The primary outcome was HRQOL measured by the Short Form 36 Health Survey (SF-36). Linear mixed regression models and structural equation models were employed.

RESULTS

At 6-month follow-up, the intervention group scored significantly higher on SF-36's physical component summary compared with the controls; 3.0 points, 95% confidence interval (CI) = 0.4, 5.6. This effect was mediated by an increased probability of maintaining exercise in the post-intervention period; odds ratio = 2.3 (CI = 1.1, 5.1). Exercising was associated with a 7.1-point increase in physical component summary (CI = 3.2, 10.9).

CONCLUSION

A falls prevention exercise programme can improve physical HRQOL in home care recipients post-intervention. The exercise programme also led to longer-term changes in exercise behaviour mediating this effect.

Patient-Reported Outcome Measures (PROMs) to Support Adherence to Falls Prevention Clinic Recommendations: A Qualitative Study

PURPOSE

We examined how patient-reported outcome measures (PROMs) support patients' adherence to fall prevention recommendations in a novel primary care setting - the Falls Prevention Clinic.

PATIENTS AND METHODS

Using a patient-oriented qualitative study design, we recruited patient partners to our study team to assist in developing focus group prompts. A trained facilitator conducted five semi-structured interviews with a total of 21 Falls Prevention Clinic participants. A trained facilitator prompted participants about: their views on the EuroQol 5 domain - 5 level (EQ-5D-5L) PROM, their preferences for PROM administration and feedback, the presentation of PROM questionnaire data, the use of comparative data and the EQ-5D-5L in improving adherence to recommendations, and other information they would need to improve adherence. Participants' responses were coded according to three stages of qualitative analysis: open, axial and selective coding using an iterative and comparative approach.

RESULTS

"Opportunity" and "Development" emerged as higher-level themes for the participants' perspectives on how the EQ-5D-5L may be helpful for their appointments. "Frequency" described how often the participants believed the EQ-5D-5L should be administered and feedback provided. "Challenges", "Benefits", "Patients' Understanding", "Relevance of Data", and "Usefulness of Data" provided insight on how PROMs data presentation was viewed by patients. "Performance", "Resources", "Knowledge", "Role in Behaviour Change" highlighted the participants' ideas for the role of the EQ-5D-5L and additional information in supporting their adherence to falls prevention recommendations. Participants emphasized that patients would value further support information to facilitate their adherence.

CONCLUSION

This patient-oriented qualitative study, among individuals at high risk of future falls, sheds light on the importance of timely, understandable feedback, integrated with other clinical feedback in supporting adherence.

ABILITY OF THE PHYSIOLOGICAL PROFILE ASSESSMENT TO CLASSIFY FALLER TYPE: A PROSPECTIVE COHORT STUDY

Accurately identifying older adults who will experience subsequent falls is important for the provision of secondary fall prevention. The purpose of this study was to determine the accuracy of the Physiological Profile Assessment (PPA) – a valid and reliable fall-risk assessment [1] – in predicting subsequent falls over a 12-month period in older adults who sought for medical attention after an index fall. Seven hundred thirty-seven community-dwelling adults, aged 70 years and older, who were seen at the Vancouver General Hospital Fall Prevention Clinic, completed the PPA at their initial visit. Falls over the subsequent 12 months were tracked prospectively via monthly falls calendars. All individuals received geriatric care at baseline. Binary logistic regressions were performed to determine the accuracy of classifying two prospective faller types: 1) no additional falls; 2) one or more additional fall(s). Baseline PPA, age, and sex were entered as independent variables. During the 12 month observation period, 345 participants had no additional falls (Age:81.3±6.6yrs;Female=251) and 392 fell one or more times (Age:82.3±6.5yrs;Female=230). The classification accuracy was 51.3% for those who had no additional falls and 64.8% for those with one or more additional fall(s) (Overall:58.5%;χ2=29.0;PPA:β=-0.21;Age:β=-0.01;Sex:β=-60). The PPA was not able to accurately differentiate between those who did and did not subsequently fall. Fall-risk assessment sensitivity and specificity should be improved in older adults seeking medical attention following an index fall to inform secondary fall prevention. [1] Lord SR, et al., 2003. Phys Ther.

MULTIMODAL PERSONALIZED CHRONOTHERAPY IMPROVES SLEEP IN ADULTS WITH MILD COGNITIVE IMPAIRMENT: A RANDOMIZED TRIAL

Poor sleep is common among older adults with Mild Cognitive Impairment (MCI) and may contribute to their increased risk for dementia. Chronotherapy is a set of intervention strategies which can improve sleep quality by strengthening the entrainment of the biological clock to the solar light-dark cycle, and includes strategies such as: 1) bright light therapy (BLT); 2) physical activity (PA); and 3) good sleep hygiene. Thus, in this 24-week randomized controlled trial (RCT; NCT02926157), we aimed to examine the efficacy of a multimodal, personalized chronotherapy intervention to improve sleep quality among older adults with MCI. Ninety-six older adults (65+ years) with MCI were randomized to either: 1) a multimodal personalized chronotherapy group (INT); or 2) a waitlist-plus-education control group (CON). Participants allocated to the INT received four once-weekly, general sleep hygiene education classes, followed by 20 weeks of 1) individually-timed BLT; and 2) bi-weekly, individually-tailored PA counselling in conjunction with receiving a consumer-available PA tracker (Fitbit® FlexTM). We found a significant group x time interaction for objectively measured sleep fragmentation (5.01; p< 0.01) and also for Pittsburgh Sleep Quality Index (PSQI) score (p= 0.03), such that the INT: 1) maintained sleep fragmentation while CON worsened at 12 weeks (p< 0.01); and 2) had improved PSQI score compared to CON at both 12 weeks (p< 0.01) and 24 weeks (p= 0.04). Our results provide novel evidence that a multimodal personalized chronotherapy approach may promote both objective and subjective aspects of sleep quality in older adults with MCI.

EFFECT OF A HOME-BASED EXERCISE PROGRAM ON SUBSEQUENT FALLS IN SENIORS AFTER A FALL: A RANDOMIZED CLINICAL TRIAL

We assessed the efficacy of the home-based Otago Exercise Program (OEP) as a secondary falls prevention strategy in seniors referred to a falls prevention clinic after an index fall. We conducted a 12-month randomized controlled trial of 344 adults, aged 70 years and older, with = or &gt; 1 fall resulting in medical attention in the prior 12 months. Participants were randomized to OEP or standard of care (CON). The OEP is a home-based strength and balance training program delivered by a physical therapist. All participants received AGS Guideline Care for falls prevention from a geriatrician. Differences in falls rate was tested with a negative binomial regression model. The rate of falls was lower in the OEP group vs the CON group (incident rate ratio [IRR] = 0.64, 95% CI 0.46 to 0.90). The estimated incidence rate of falls per person-year was 1.4 (95% CI 0.1 to 2.0) in the OEP group and 2.1 (95% CI 0.1 to 3.2) in the CON group, with an absolute incidence rate difference of 0.74 (95% CI 0.04 to 1.78) falls per person-year. DSST performance also increased in the OEP group by a mean change of 1.1 points (95% CI 0.02 to 2.1) vs the CON group. Improved DSST was associated with fewer falls (IRR = 0.80, 95% CI 0.68 to 0.95). These findings support the use of the OEP for secondary falls prevention.

QUADRICEPS STRENGTH IS ASSOCIATED WITH COGNITION IN OLDER ADULTS WITH CHRONIC STROKE

Individuals who have suffered a stroke are at risk for developing cognitive impairment and dementia. Thus, it is important to identify modifiable risk factor for cognitive decline in this population. Among older adults without a history of stroke, greater muscle strength is associated with better cognitive function. Whether this relationship also exist in older adults with a history of stroke is not known. Thus, we aimed to examine whether cognition, as measured by both the Montreal Cognitive Assessment (MoCA) and the 13-item Alzheimer’s Disease Assessment Scale-Cognitive (ADAS-Cog 13), is associated with lower extremity muscle strength in adults with chronic stroke (&gt; 1 year post stroke). Ninety-one community-dwelling adults, aged 55 years and older, with chronic stroke were included in this analysis. Isometric strength of the quadriceps was measured bilaterally in kilograms. Two linear regression models were constructed to determine the independent association of quadriceps strength (mean kilograms of both legs) with: 1) MoCA; and 2) ADAS-Cog 13, after controlling for age, sex, and mood. Mean quadriceps strength was independently associated with both MoCA and ADAS-Cog scores, after accounting for age, sex, and mood. Specifically, quadriceps strength explained an additional 5.6% of the variable in MoCA scores; total variance explained by the model was 12.0%. For ADAS-Cog 13, quadriceps strength explained an additional 5.4% of the variance; total variance explained by the model was 16.5%. Our current cross-sectional results suggest that the maintenance of muscle strength may be important for cognitive health in older adults who have suffered a stroke.

Evaluating a falls prevention intervention in older home care recipients: a comparison of SF-6D and EQ-5D

PURPOSE

Health-related quality of life (HRQOL) is an important outcome in economic evaluations of health care interventions for older adults. The aim of this study was to compare two commonly used preference-based utility measures, SF-6D and EQ-5D, to provide knowledge on their applicability when evaluating falls prevention interventions in primary health care.

METHODS

The study is a secondary analysis of longitudinal data from a randomised controlled trial, which included 155 older home care recipients participating in a falls prevention intervention in Norway. HRQOL was measured by SF-6D and EQ-5D. Physical function was measured by Berg Balance Scale, 4-m walk test, 30-s sit-to-stand and Falls Efficacy Scale International. Assessments were performed at baseline, 3 months and 6 months. The agreement between SF-6D and EQ-5D was examined using Bland-Altman plots and Spearman correlations. Elasticities from regression analysis were employed to compare the instruments' responsiveness.

RESULTS

SF-6D and EQ-5D were strongly correlated (0.71), but there were differences in the instruments' agreement and domains of HRQOL covered. Participants with a higher mean HRQOL and/or better physical function scored generally higher on EQ-5D. Participants with a lower mean HRQOL and/or poorer physical function achieved a relatively higher score on SF-6D. EQ-5D was more responsive to changes in physical function compared to SF-6D.

CONCLUSIONS

SF-6D and EQ-5D have both similarities and differences regarding sensitivity, domains covered and responsiveness to changes when evaluating a falls prevention intervention. Selecting the appropriate instrument depends on the characteristics of the participants and the intervention being evaluated.

The Independent Associations of Physical Activity and Sleep with Cognitive Function in Older Adults

BACKGROUND

Current evidence suggests physical activity (PA) and sleep are important for cognitive health; however, few studies examining the role of PA and sleep for cognitive health have measured these behaviors objectively.

OBJECTIVE

We cross-sectionally examined whether 1) higher PA is associated with better cognitive performance independently of sleep quality; 2) higher sleep quality is associated with better cognitive performance independently of PA; and 3) whether higher PA is associated with better sleep quality.

METHODS

We measured PA, subjective sleep quality using the Pittsburgh Sleep Quality Index (PSQI), and objective sleep quality (i.e., fragmentation, efficiency, duration, and latency) using the MotionWatch8© in community-dwelling adults (N = 137; aged 55+). Cognitive function was indexed using the Alzheimer's Disease Assessment Scale-Plus. Correlation analyses were performed to determine relationships between PA, sleep quality, and cognitive function. We then used latent variable modelling to examine the relationships of PA with cognitive function independently of sleep quality, sleep quality with cognitive function independently of PA, and PA with sleep quality.

RESULTS

We found greater PA was associated with better cognitive performance independently of 1) PSQI (β= -0.03; p < 0.01); 2) sleep fragmentation (β= -0.02; p < 0.01); 3) sleep duration (β= -0.02; p < 0.01); and 4) sleep latency (β= -0.02; p < 0.01). In addition, better sleep efficiency was associated with better cognitive performance independently of PA (β= -0.01; p = 0.04). We did not find any associations between PA and sleep quality.

CONCLUSIONS

PA is associated with better cognitive performance independently of sleep quality, and sleep efficiency is associated with better cognitive performance independently of PA. However, PA is not associated with sleep quality and thus PA and sleep quality may be related to cognitive performance through independent mechanisms.

Effect of a Home-Based Exercise Program on Subsequent Falls Among Community-Dwelling High-Risk Older Adults After a Fall: A Randomized Clinical Trial

IMPORTANCE

Whether exercise reduces subsequent falls in high-risk older adults who have already experienced a fall is unknown.

OBJECTIVE

To assess the effect of a home-based exercise program as a fall prevention strategy in older adults who were referred to a fall prevention clinic after an index fall.

DESIGN, SETTING, AND PARTICIPANTS

A 12-month, single-blind, randomized clinical trial conducted from April 22, 2009, to June 5, 2018, among adults aged at least 70 years who had a fall within the past 12 months and were recruited from a fall prevention clinic.

INTERVENTIONS

Participants were randomized to receive usual care plus a home-based strength and balance retraining exercise program delivered by a physical therapist (intervention group; n = 173) or usual care, consisting of fall prevention care provided by a geriatrician (usual care group; n = 172). Both were provided for 12 months.

MAIN OUTCOMES AND MEASURES

The primary outcome was self-reported number of falls over 12 months. Adverse event data were collected in the exercise group only and consisted of falls, injuries, or muscle soreness related to the exercise intervention.

RESULTS

Among 345 randomized patients (mean age, 81.6 [SD, 6.1] years; 67% women), 296 (86%) completed the trial. During a mean follow-up of 338 (SD, 81) days, a total of 236 falls occurred among 172 participants in the exercise group vs 366 falls among 172 participants in the usual care group. Estimated incidence rates of falls per person-year were 1.4 (95% CI, 0.1-2.0) vs 2.1 (95% CI, 0.1-3.2), respectively. The absolute difference in fall incidence was 0.74 (95% CI, 0.04-1.78; P = .006) falls per person-year and the incident rate ratio was 0.64 (95% CI, 0.46-0.90; P = .009). No adverse events related to the intervention were reported.

CONCLUSIONS AND RELEVANCE

Among older adults receiving care at a fall prevention clinic after a fall, a home-based strength and balance retraining exercise program significantly reduced the rate of subsequent falls compared with usual care provided by a geriatrician. These findings support the use of this home-based exercise program for secondary fall prevention but require replication in other clinical settings.

TRIAL REGISTRATION

ClinicalTrials.gov Identifiers: NCT01029171; NCT00323596.

Antinociceptive activity of thiazole-containing cyclized DAMGO and Leu-(Met) enkephalin analogs

Numerous studies demonstrate the promise of opioid peptides as analgesics, but poor oral bioavailability has limited their therapeutic development. This study sought to increase the oral bioavailability of opioid peptides by cyclization, using Hantzsch-based macrocyclization strategies to produce two new series of cyclized DAMGO and Leu/Met-enkephalin analogs. Opioid receptor affinity and selectivity for compounds in each series were assessed in vitro with radioligand competition binding assays. Compounds demonstrated modest affinity but high selectivity for the mu, delta, and kappa opioid receptors (MOR, DOR and KOR), while selectivity for mu opioid receptors varied by structure. Antinociceptive activity of each compound was initially screened in vivo following intracerebroventricular (i.c.v.) administration and testing in the mouse 55 °C warm-water tail-withdrawal test. The four most active compounds were then evaluated for dose- and time-dependent antinociception, and opioid receptor selectivity in vivo. Cyclic compounds 1924-10, 1936-1, 1936-7, and 1936-9 produced robust and long- lasting antinociception with ED₅₀ values ranging from 0.32-0.75 nmol following i.c.v. administration mediated primarily by mu- and delta-opioid receptor agonism. Compounds 1924-10, 1936-1 and 1936-9 further displayed significant time-dependent antinociception after oral (10 mg kg^-1, p.o.) administration. A higher oral dose (30 mg kg^-1. p.o.) of all four cyclic peptides also reduced centrally-mediated respiration, suggesting successful penitration into the CNS. Overall, these data suggest cyclized opioid peptides synthesized by a Hantzsch-based macrocyclization strategy can retain opioid agonist activity to produce potent antinociception in vivo while conveying improved bioavailability following oral administration.

Population attributable fraction of leading non-communicable cardiovascular diseases due to leisure-time physical inactivity: a systematic review

Objective

The aim of this systematic review was to investigate the methods used for estimating the population attributable fraction (PAF) to leisure-time physical inactivity (PI) of coronary artery diseases, hypertension and stroke in order to provide the best available estimate for PAF.

Design

Systematic review.

Data sources

Four electronic databases (MEDLINE/PubMed, EMBASE, SPORTDiscus, and Cumulative Index to Nursing and Allied Health Literature) were searched from inception to August 2018.

Eligibility criteria for selecting studies

This review included prospective cohort studies, with men and women aged ≥18 years old, investigating the PAF attributable to leisure-time PI related to coronary artery diseases, hypertension and stroke.

Results

The PAF estimates of the three studies included were 13% (3%–22%) for ‘stage-1 hypertension’ subtype incidence due to ‘non-regular exercise’; 25% (10.4%–35.8%) for ‘stage-2 hypertension’ subtype incidence due to ‘activity of daily living’ and ‘vigorous-intensity sports’; and 8.5% (1.7%–16.7%) for ‘total: fatal and non-fatal’ cardiovascular events of ‘incidence and mortality’ endpoints due to non-accumulation of 550 kcal/week (subsets not specified).

Conclusions

The PAF estimate exhibited a protective dose–response relationship between hypertension and an increased amount of energy expenditure of leisure-time PI. In order to enhance accuracy of PAF estimates, the following steps are recommended: (1) to clearly define and state the working definition of leisure-time PI and dose using a reliable and valid objective measurement tool; (2) use a clear definition of outcome subtypes and endpoints using reliable and valid objective measures; and (3) estimate PAF using modelling techniques based on prospective data and ensuring to report 95% CI.

Impact of exercise training on physical and cognitive function among older adults: a systematic review and meta-analysis

Exercise plays a key role in healthy aging by promoting both physical and cognitive function. Physical function and cognitive function appear to be interrelated and may share common mechanisms. Thus, exercise-induced improvements in physical function and cognitive function may co-occur and be associated with each other. However, no systematic review has specifically assessed and compared the effects of exercise on both physical function and cognitive function in older adults, and the association between changes in both outcomes after exercise training. Thus, we conducted a systematic review and meta-analysis (N = 48 studies) among older adults (60+ years). These data suggest exercise training has a significant benefit for both physical function (g = 0.39; p < 0.001) and cognitive function (g = 0.24; p < 0.001). At the study level, there was a positive correlation between the size of the exercise-induced effect on physical function and on cognitive function (b = 0.41; p = 0.002). Our results indicate exercise improves both physical and cognitive function, reiterating the notion that exercise is a panacea for aging well.

Geriatrician-led evidence-based Falls Prevention Clinic: a prospective 12-month feasibility and acceptability cohort study among older adults

OBJECTIVE

We assessed the feasibility and acceptability of delivering a geriatrician-led evidence-based Falls Prevention Clinic to older adults with a history of falls.

DESIGN

12-month prospective cohort study.

SETTING

Vancouver Falls Prevention Clinic, Vancouver, British Columbia, Canada (www.fallsclinic.ca).

PARTICIPANTS

188 community-dwelling older adults aged ≥70 years who received a baseline assessment at the Vancouver Falls Prevention Clinic due to having had at least one fall resulting in medical attention in the previous 12 months. Fifty-six per cent of participants were also participating in a randomised controlled trial.

MEASUREMENTS

Feasibility was ascertained by measuring demand (clinic attendance). Acceptability was measured by compliance with recommendations, completion of monthly fall calendars and patient experience.

RESULTS

The attendance was 65% of those eligible and invited. This indicates feasibility for demand. 155 received at least one of the following clinical management recommendations from four domains (compliance reported in %): (1) medication changes (78%); (2) exercise prescription (58%); (3) referrals to other healthcare professionals (78%); and/or (4) lifestyle modifications (35%) excluding exercise. Overall compliance to all recommendations was 69%. Patient experience was related to factors impacting patient perceived physical benefit and attributes influencing patient satisfaction.

CONCLUSION

This study demonstrated the feasibility and acceptability of a multifactorial intervention approach based on best available evidence-based medicine.

Scaffold Ranking and Positional Scanning Identify Novel Neurite Outgrowth Promoters with Nanomolar Potency

Central nervous system (CNS) neurons typically fail to regrow their axons after injury. Injuries or neuropathies that damage CNS axons and disrupt neuronal circuitry often result in permanent functional deficits. Axon regeneration is therefore an intensely pursued therapeutic strategy for numerous CNS disorders. Phenotypic screens utilizing primary neurons have proven successful at identifying agents that promote axon regeneration in vivo. Here, we report the screening of mixture-based combinatorial small molecule libraries in a phenotypic assay utilizing primary CNS neurons and the discovery of neurite outgrowth promoters with low nanomolar potency.