Effect of aerobic exercise on cancer-associated cognitive impairment: A proof-of-concept RCT.

BACKGROUND: Change in cognitive ability is a commonly reported adverse effect by breast cancer survivors. The underlying etiology of cognitive complaints is unclear and to date, there is limited evidence for effective intervention strategies. Exercise has been shown to improve cognitive function in older adults and animal models treated with chemotherapy. This proof-of-concept randomized controlled trial tested the effect of aerobic exercise versus usual lifestyle on cognitive function in postmenopausal breast cancer survivors. METHODS: Women, aged 40 to 65 years, postmenopausal, stages I to IIIA breast cancer, and who self-reported cognitive dysfunction following chemotherapy treatment, were recruited and randomized to a 24-week aerobic exercise intervention (EX; n = 10) or usual lifestyle control (CON; n = 9). Participants completed self-report measures of the impact of cognitive issues on quality of life (Functional Assessment of Cancer Therapy-Cognitive version 3), objective neuropsychological testing, and functional magnetic resonance imaging at baseline and 24 weeks. RESULTS: Compared to CON, EX had a reduced time to complete a processing speed test (trail making test-A) (-14.2 seconds, P < .01; effect size 0.35). Compared to CON, there was no improvement in self-reported cognitive function and effect sizes were small. Interestingly, lack of between-group differences in Stroop behavioral performance was accompanied by functional changes in several brain regions of interest in EX compared to CON at 24 weeks. CONCLUSION: These findings provide preliminary proof-of-concept results for the potential of aerobic exercise to improve cancer-related cognitive impairment and will serve to inform the development of future trials.

Attentional requirements of postural control in people with spinal cord injury: the effect of dual task.

STUDY DESIGN: Cross-sectional study. OBJECTIVES: To investigate the attentional requirements for maintaining standing balance in people with spinal cord injury (SCI) using a dual-task paradigm and to compare standing balance performance between SCI and able-bodied (AB) controls. SETTING: LaboratoryMethods:Nine adults with incomplete SCI, who were able to stand unassisted were recruited, along with eight AB controls. Subjects performed a dual task involving counting backwards by 3 s out loud while standing with eyes open or closed. The primary outcome measures were the differences between SCI and control groups for movement reinvestment and the change in performance between single task and dual task for: (i) maximum standing time (STime); (ii) error ratio and total number of words uttered; and (iii) center of pressure measures. Perceptual measures included perceived mental workload, fear and confidence. RESULTS: SCI subjects stood for shorter duration during dual task (stand and count) than single task (stand) compared with controls during eyes closed. Significant differences between groups were observed for movement reinvestment, center of pressure, perceived mental effort, fear and confidence. No significant effects were observed for math-task performance. CONCLUSIONS: Total STime during eyes closed is adversely affected by the addition of a math task for SCI subjects. Perceptual measures appear to correspond to increases in postural sway and conscious control of standing in subjects with SCI. Individuals who can stand for >60 s with eyes closed do not appear to be significantly affected by the addition of a concurrent secondary task of minimal mental workload.

Risk factors for hip impact during real-life falls captured on video in long-term care.

UNLABELLED: Hip fracture risk is increased by landing on the hip. We examined factors that contribute to hip impact during real-life falls in long-term care facilities. Our results indicate that hip impact is equally likely in falls initially directed forward as sideways and more common among individuals with dependent Activities of Daily Living (ADL) performance. INTRODUCTION: The risk for hip fracture in older adults increases 30-fold by impacting the hip during a fall. This study examined biomechanical and health status factors that contribute to hip impact through the analysis of real-life falls captured on video in long-term care (LTC) facilities. METHODS: Over a 7-year period, we captured 520 falls experienced by 160 residents who provided consent for releasing their health records. Each video was analyzed by a three-member team using a validated questionnaire to determine whether impact occurred to the hip or hand, the initial fall direction and landing configuration, attempts of stepping responses, and use of mobility aids. We also collected information related to resident physical and cognitive function, disease diagnoses, and use of medications from the Minimum Data Set. RESULTS: Hip impact occurred in 40 % of falls. Falling forward or sideways was significantly associated with higher odds of hip impact, compared to falling backward (OR 4.2, 95 % CI 2.4-7.1) and straight down (7.9, 4.1-15.6). In 32 % of sideways falls, individuals rotated to land backward. This substantially reduced the odds for hip impact (0.1, 0.03-0.4). Tendency for body rotation was decreased for individuals with dependent ADL performance (0.43, 0.2-1.0). CONCLUSIONS: Hip impact was equally likely in falls initially directed forward as sideways, due to the tendency for axial body rotation during descent. A rotation from sideways to backward decreased the odds of hip impact 10-fold. Our results may contribute to improvements in risk assessment and strategies to reduce risk for hip fracture in older adults.

Cognitive status is a determinant of health resource utilization among individuals with a history of falls: a 12-month prospective cohort study.

SUMMARY: Falls are a costly public health problem worldwide. The literature is devoid of prospective data that identifies factors among fallers that significantly drive health care resource utilization. We found that cognitive function--specifically, executive functions--and cognitive status are significant determinants of health resource utilization among older fallers. INTRODUCTION: Although falls are costly, there are no prospective data examining factors among fallers that drive health care resource utilization. We identified key determinants of health resource utilization (HRU) at 6 and 12 months among older adults with a history of falls. Specifically, with the increasing recognition that cognitive impairment is associated with increased falls risk, we investigated cognition as a potential driver of health resource utilization. METHODS: This 12-month prospective cohort study at the Vancouver Falls Prevention Clinic (n = 319) included participants with a history of at least one fall in the previous 12 months. Based on their cognitive status, participants were divided into two groups: (1) no mild cognitive impairment (MCI) and (2) MCI. We constructed two linear regression models with HRU at 6 and 12 months as the dependent variables for each model, respectively. Predictors relating to mobility, global cognition, executive functions, and cognitive status (MCI versus no MCI) were examined. Age, sex, comorbidities, depression status, and activities of daily living were included regardless of statistical significance. RESULTS: Global cognition, comorbidities, working memory, and cognitive status (MCI versus no MCI ascertained using the Montreal Cognitive Assessment (MoCA)) were significant determinants of total HRU at 6 months. The number of medical comorbidities and global cognition were significant determinants of total HRU at 12 months. CONCLUSION: MCI status was a determinant of HRU at 6 months among older adults with a history of falls. As such, efforts to minimize health care resource use related to falls, it is important to tailor future interventions to be effective for people with MCI who fall. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT01022866.

Does frequency of resistance training affect tibial cortical bone density in older women? A randomized controlled trial.

SUMMARY: This randomized controlled trial evaluated the effect of resistance training frequency (0, 1, and 2 times/week) on cortical volumetric bone mineral density (vBMD) at the tibia in older women. There was no mean difference in change in tibial cortical vBMD in older women who engaged in resistance training (RT) one or two times/week compared with the control group over 12 months after adjusting for baseline values. INTRODUCTION: National guidelines recommend RT two to three times/week to optimize bone health. Our objective was to determine the effect of a 12-month intervention of three different RT frequencies on tibial volumetric cortical density (CovBMD) in healthy older women. METHODS: We randomized participants to the following groups: (1) 2×/week balance and tone group (i.e., no resistance beyond body weight, BT), (2) 1×/week RT (RT1), and (3) 2×/week RT (RT2). Treatment allocation was concealed, and measurement team and the bone data analyst were blinded to group allocation. We used peripheral quantitative computed tomography to acquire one 2.3-mm scan at the 50 % tibia, and the primary outcome was CovBMD. Data were collected at baseline, 6 and 12 months, and we used linear mixed modeling to assess the effect at 12 months. RESULTS: We assessed 147 participants; 100 women provided data at all three points. Baseline unadjusted mean (SD) tibial CovBMD (in milligrams per cubic centimeter) at the 50 % site was 1,077.4 (43.0) (BT), 1,087.8 (42.0) (RT1), and 1,058.7 (60.4) (RT2). At 12 months, there were no statistically significant differences (-0.45 to -0.17 %) between BT and RT groups for mean difference in change in tibial CovBMD for exercise interventions (BT, RT1, RT2) after adjusting for baseline tibial CovBMD. CONCLUSION: We note no mean difference in change in tibial CovBMD in older women who engaged in RT one or two times/week compared with the control group over 12 months. It is unknown if RT of 3× or 4×/week would be enough to promote a statistically significant difference in change of bone density.

Resistance Exercise Program in Cognitively Normal Older Adults: CERT-Based Exercise Protocol of the AGUEDA Randomized Controlled Trial.

OBJECTIVES: To provide a comprehensive CERT (Consensus on Exercise Reporting Template)-based description of the resistance exercise program implemented in the AGUEDA (Active Gains in brain Using Exercise During Aging) study, a randomized controlled trial investigating the effects of a 24-week supervised resistance exercise program on executive function and related brain structure and function in cognitively normal older adults. DESIGN AND PARTICIPANTS: 90 cognitively normal older adults aged 65 to 80 were randomized (1:1) to a: 1) resistance exercise group; or a 2) wait-list control group. Participants in the exercise group (n = 46) performed 180 min/week of resistance exercise (3 supervised sessions per week, 60 min/session) for 24 weeks. INTERVENTION: The exercise program consisted of a combination of upper and lower limb exercises using elastic bands and the participant's own body weight as the main resistance. The load and intensity were based on the resistance of the elastic bands (7 resistances), number of repetitions (individualized), motor complexity of exercises (3 levels), sets and rest (3 sets/60 sec rest), execution time (40-60 sec) and velocity (as fast as possible). SETTINGS: The maximum prescribed-target intensity was 70-80% of the participants' maximum rate of perceived exertion (7-8 RPE). Heart rate, sleep quality and feeling scale were recorded during all exercise sessions. Those in the wait-list control group (n = 44) were asked to maintain their usual lifestyle. The feasibility of AGUEDA project was evaluated by retention, adherence, adverse events and cost estimation on the exercise program. RESULTS AND CONCLUSIONS: This study details the exercise program of the AGUEDA trial, including well-described multi-language manuals and videos, which can be used by public health professionals, or general public who wish to implement a feasible and low-cost resistance exercise program. The AGUEDA exercise program seems to be feasible by the high retention (95.6%) and attendance rate (85.7%), very low serious adverse event (1%) and low economic cost (144.23 € /participant/24 weeks). We predict that a 24-week resistance exercise program will have positive effects on brain health in cognitively normal older adults.

SF-6D and EQ-5D result in widely divergent incremental cost-effectiveness ratios in a clinical trial of older women: implications for health policy decisions.

SUMMARY: Using two instruments (SF-6D and EQ-5D) to estimate quality adjusted life years (QALYs), we conducted an economic evaluation of a 12-month randomized controlled trial with a 12-month follow-up study in older women to evaluate the value for money of two doses of resistance training compared with balance and tone classes. We found that the incremental QALYs estimated from the SF-6D were two- to threefold greater than those estimated from the EQ-5D. INTRODUCTION: Decision makers must continually choose between existing and new interventions. Hence, economic evaluations are increasingly prevalent. The impact of quality-adjusted life year (QALY) estimates using different instruments on the incremental cost-effectiveness ratios (ICERs) is not well understood in older adults. Thus, we compared ICERs, in older women, estimated by the EuroQol-5D (EQ-5D) and the Short Form-6D (SF-6D) to discuss implications on decision making. METHODS: Using both the EQ-5D and the SF-6D, we compared the incremental cost per QALY gained in a randomized controlled trial of resistance training in 155 community-dwelling women aged 65 to 75 years. The 12-month randomized controlled trial included a subsequent 12-month follow-up. Our focus, the follow-up study, included 123 of the 155 participants from the Brain Power study; 98 took part in the economic evaluation (twice-weekly balance and tone exercises, n = 28; once-weekly resistance training, n = 35; twice-weekly resistance training, n = 35). Our primary outcome measure was the incremental cost per QALY gained of once- or twice-weekly resistance training compared with balance and tone exercises. RESULTS: At cessation of the follow-up study, the incremental QALY was -0.051 (EQ-5D) and -0.144 (SF-6D) for the once-weekly resistance training group and -0.081 (EQ-5D) and -0.127 (SF-6D) for the twice-weekly resistance training group compared with balance and tone classes. CONCLUSION: The incremental QALYs estimated from the SF-6D were two- to threefold greater than those estimated from the EQ-5D. Given the large magnitude of difference, the choice of preference-based utility instrument may substantially impact health care decisions.

Examining the relationship between specific cognitive processes and falls risk in older adults: a systematic review.

This systematic review aims to establish which cognitive domains are associated with falls or falls risk. Recent evidence suggests that impaired cognition increases seniors' risk of falling. The purpose of this review was to identify the cognitive domains that are significantly associated with falls or falls risk in older adults. We conducted a systematic review of peer-reviewed journal articles published from 1948 to present, focusing on studies investigating different domains of cognitive function and their association with falls or falls risk in adults aged 60 years or older. In accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, we completed a comprehensive search of MEDLINE, PubMed, and EMBASE databases to identify studies examining the association between cognitive function and falls or falls risk. With an expert in the field, we developed a quality assessment questionnaire to rate the quality of the studies included in this systematic review. Twenty-five studies were included in the review. We categorized studies based on two related but distinct cognitive domains: (1) executive functions or (2) dual-task ability. Twelve studies reported a significant association between executive functions and falls risk. Thirteen studies reported that dual-task performance is a predictor of falls or falls risk in older adults. Three studies did not report an association between cognition and falls risk. Consistent evidence demonstrated that executive functions and dual-task performance were highly associated with falls or falls risk. The results from this review will aid healthcare professionals and researchers in developing innovative screening and treatment strategies for mitigating falls risk by targeting specific cognitive domains.

Economic evaluation of dose-response resistance training in older women: a cost-effectiveness and cost-utility analysis.

SUMMARY: We estimated the incremental cost-effectiveness of a once-weekly or twice-weekly resistance training intervention compared with balance and tone classes in terms of falls prevented and quality-adjusted life years (QALYs) gained. Both resistance training interventions were more likely to save health care resource money and offer better health outcomes for falls prevention than balance and tone classes. INTRODUCTION: This study aims to estimate the incremental cost-effectiveness and cost-utility of a once-weekly or twice-weekly resistance training intervention compared with twice-weekly balance and tone classes in terms of falls prevented and QALYs gained. METHODS: Economic evaluation was conducted concurrently with a three-arm randomized controlled trial including 155 community-dwelling women aged 65 to 75 years, Mini Mental State Examination ≥24, and visual acuity 20/40 or better. Participants received the once-weekly resistance training (n = 54), the twice-weekly resistance training (n = 51) or the twice-weekly balance and tone (the comparator) classes (n = 50) for 1 year. Measurements included the number of falls for each participant, healthcare resource utilization, and associated costs over 9 months; health status was assessed using the EQ-5D and SF-6D to calculate QALYs. RESULTS: Based on the point estimates from our base case analysis, we found that both once- and twice-weekly resistance training groups were less costly (p < 0.05) and more effective than twice-weekly balance and tone classes. The incremental QALYs assessed using the SF-6D were 0.003 for both the once- and twice-weekly resistance training groups, compared with the twice-weekly balance and tone classes. The incremental QALYs assessed using the EQ-5D were 0.084 for the once-weekly and 0.179 for the twice-weekly resistance training groups, respectively, compared with the twice-weekly balance and tone classes. CONCLUSIONS: An individually tailored resistance training intervention delivered once or twice weekly provided better value for money for falls prevention than balance and tone classes.

COVID-19 infection in patients with intestinal failure: UK experience.

BACKGROUND: The direct effect of the coronavirus disease 2019 (COVID-19) pandemic on patients with intestinal failure (IF) has not been described. METHODS: We conducted a nationwide study of UK IF centers to evaluate the infection rates, presentations, and outcomes in patients with types 2 and 3 IF. RESULTS: A total of 45 patients with IF contracted COVID-19 between March and August 2020; this included 26 of 2191 (1.2%) home parenteral nutrition (HPN)-dependent adults and 19 of 298 (6.4%) adults hospitalized with type 2 IF. The proportion of patients receiving nursing care for HPN administration was higher in those with community-acquired COVID-19 (66.7%) than the proportion in the entire HPN cohort (26.1%; P < .01). Two HPN-dependent and 1 hospitalized patient with type 2 IF died as a direct consequence of the virus (6.7% of 45 patients with types 2 or 3 infected). CONCLUSION: This is the first study to describe the outcomes of COVID-19 in a large cohort of patients requiring long-term PN. Methods to reduce hospital and community nosocomial spread would likely be beneficial.

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.

International comparison of cost of falls in older adults living in the community: a systematic review.

SUMMARY: Our objective was to determine international estimates of the economic burden of falls in older people living in the community. Our systematic review emphasized the need for a consensus on methodology for cost of falls studies to enable more accurate comparisons and subgroup-specific estimates among different countries. INTRODUCTION: The purpose of this study was to determine international estimates of the economic burden of falls in older people living in the community. METHODS: This is a systematic review of peer-reviewed journal articles reporting estimates for the cost of falls in people aged > or =60 years living in the community. We searched for papers published between 1945 and December 2008 in MEDLINE, PUBMED, EMBASE, CINAHL, Cochrane Collaboration, and NHS EED databases that identified cost of falls in older adults. We extracted the cost of falls in the reported currency and converted them to US dollars at 2008 prices, cost items measured, perspective, time horizon, and sensitivity analysis. We assessed the quality of the studies using a selection of questions from Drummond's checklist. RESULTS: Seventeen studies met our inclusion criteria. Studies varied with respect to viewpoint of the analysis, definition of falls, identification of important and relevant cost items, and time horizon. Only two studies reported a sensitivity analysis and only four studies identified the viewpoint of their economic analysis. In the USA, non-fatal and fatal falls cost US $23.3 billion (2008 prices) annually and US $1.6 billion in the UK. CONCLUSIONS: The economic cost of falls is likely greater than policy makers appreciate. The mean cost of falls was dependent on the denominator used and ranged from US $3,476 per faller to US $10,749 per injurious fall and US $26,483 per fall requiring hospitalization. A consensus on methodology for cost of falls studies would enable more accurate comparisons and subgroup-specific estimates among different countries.

Independent and inverse association of healthcare utilisation with physical activity in older adults with multiple chronic conditions.

OBJECTIVE: In this study, whether physical activity is independently associated with direct healthcare costs in community-dwelling older adults with multiple chronic conditions was examined. DESIGN: Cross-sectional analysis. SETTING: Research laboratory. PARTICIPANTS: 299 community-dwelling men and women volunteers aged 65 years and older with chronic conditions. INTERVENTION: None. MAIN OUTCOME MEASURES: Primary dependent variable was direct healthcare costs incurred in the previous 3 months. Participants completed the Health Resource Utilisation (HRU) questionnaire. To estimate HRU, direct costs in the previous 3 months were calculated using the three-party payer perspective of the British Columbia Ministry of Health, deemed representative of the Canadian healthcare system costs. For medications, the Retail Pharmacy Dispensed prescription cost tables were used. Primary independent variables were (1) self-report current level of physical activity as assessed by the Physical Activity Scale for Individuals with Physical Disabilities (PASIPD) and (2) general balance and mobility as assessed by the National Institute on Aging Balance Scale. RESULTS: The mean number of chronic conditions per participant was six. Current level of physical activity was independently and inversely associated with HRU. Age, sex, number of chronic conditions, global cognitive function, body mass index, and general balance and mobility together accounted for 24.3% of the total variance. Adding the PASIPD score resulted in an R2 change of 3.3% and significantly improved the model. The total variance accounted by the final model was 27.6%. CONCLUSIONS: Physical activity promotion may reduce healthcare costs in older adults with chronic conditions.

Does a home-based strength and balance programme in people aged > or =80 years provide the best value for money to prevent falls? A systematic review of economic evaluations of falls prevention interventions.

OBJECTIVES: To investigate the value for money of strategies to prevent falls in older adults living in the community. DESIGN: Systematic review of peer reviewed journal articles reporting an economic evaluation of a falls prevention intervention as part of a randomised controlled trial or a controlled trial, or using an analytical model. MEDLINE, PUBMED, EMBASE and NHS EED databases were searched to identify cost-effectiveness, cost-utility and cost-benefit studies from 1945 through July 2008. MAIN OUTCOME MEASURES: The primary outcome measure was incremental cost-effectiveness, cost-utility and cost-benefit ratios in the reported currency and in pounds sterling at 2008 prices. The quality of the studies was assessed using two instruments: (1) an economic evaluation checklist developed by Drummond and colleagues and (2) the Quality of Health Economic Studies instrument. RESULTS: Nine studies meeting our inclusion criteria included eight cost-effectiveness analyses, one cost-utility and one cost-benefit analysis. Three effective falls prevention strategies were cost saving in a subgroup of PARTICIPANTS: (1) an individually customised multifactorial programme in those with four or more of the eight targeted fall risk factors, (2) the home-based Otago Exercise Programme in people > or =80 years and (3) a home safety programme in the subgroup with a previous fall. These three findings were from six studies that scored > or =75% on the Quality of Health Economic Studies instrument. CONCLUSIONS: Best value for money came from effective single factor interventions such as the Otago Exercise Programme which was cost saving in adults 80 years and older. This programme has broad applicability thus warranting warrants health policy decision-makers' close scrutiny.

Geophysical imaging of ophiolite structure in the United Arab Emirates.

The Oman-United Arab Emirates ophiolite has been used extensively to document the geological processes that form oceanic crust. The geometry of the ophiolite, its extension into the Gulf of Oman, and the nature of the crust that underlies it are, however, unknown. Here, we show the ophiolite forms a high velocity, high density, >15 km thick east-dipping body that during emplacement flexed down a previously rifted continental margin thereby contributing to subsidence of flanking sedimentary basins. The western limit of the ophiolite is defined onshore by the Semail thrust while the eastern limit extends several km offshore, where it is defined seismically by a ~40-45°, east-dipping, normal fault. The fault is interpreted as the southwestern margin of an incipient suture zone that separates the Arabian plate from in situ Gulf of Oman oceanic crust and mantle presently subducting northwards beneath the Eurasian plate along the Makran trench.

Cortical and trabecular bone in the femoral neck both contribute to proximal femur failure load prediction.

UNLABELLED: We examined the contributions of femoral neck cortical and trabecular bone to proximal femur failure load. We found that trabecular bone mineral density explained a significant proportion of variance in failure load after accounting for total bone size and cortical bone mineral content or cortical area. INTRODUCTION: The relative contribution of femoral neck trabecular and cortical bone to proximal femur failure load is unclear. OBJECTIVES: Our primary objective was to determine whether trabecular bone mineral density (TbBMD) contributes to proximal femur failure load after accounting for total bone size and cortical bone content. Our secondary objective was to describe regional differences in the relationship among cortical bone, trabecular bone, and failure load within a cross-section of the femoral neck. MATERIALS AND METHODS: We imaged 36 human cadaveric proximal femora using quantitative computed tomography (QCT). We report total bone area (ToA), cortical area (CoA), cortical bone mineral content (CoBMC), and TbBMD measured in the femoral neck cross-section and eight 45 degrees regions. The femora were loaded to failure. RESULTS AND OBSERVATIONS: Trabecular bone mineral density explained a significant proportion of variance in failure load after accounting for ToA and then either CoBMC or CoA respectively. CoBMC contributed significantly to failure load in all regions of the femoral neck except the posterior region. TbBMD contributed significantly to failure load in all regions of the femoral neck except the inferoanterior, superoposterior, and the posterior regions. CONCLUSION: Both cortical and trabecular bone make significant contributions to failure load in ex vivo measures of bone strength.

Exercise and cognition in older adults: is there a role for resistance training programmes?

In recent years, there has been a strong interest in physical activity as a primary behavioural prevention strategy against cognitive decline. A number of large prospective cohort studies have highlighted the protective role of regular physical activity in lowering the risk of cognitive impairment and dementia. Most prospective intervention studies of exercise and cognition to date have focused on aerobic-based exercise training. These studies highlight that aerobic-based exercise training enhances both brain structure and function. However, it has been suggested that other types of exercise training, such as resistance training, may also benefit cognition. The purpose of this brief review is to examine the evidence regarding resistance training and cognitive benefits. Three recent randomised exercise trials involving resistance training among seniors provide evidence that resistance training may have cognitive benefits. Resistance training may prevent cognitive decline among seniors via mechanisms involving insulin-like growth factor I and homocysteine. A side benefit of resistance training, albeit a very important one, is its established role in reducing morbidity among seniors. Resistance training specifically moderates the development of sarcopenia. The multifactorial deleterious sequelae of sarcopenia include increased falls and fracture risk as well as physical disability. Thus, clinicians should consider encouraging their clients to undertake both aerobic-based exercise training and resistance training not only for "physical health" but also because of the almost certain benefits for "brain health".

The effect of group-based exercise on cognitive performance and mood in seniors residing in intermediate care and self-care retirement facilities: a randomised controlled trial.

OBJECTIVE: To determine the effect of a general group-based exercise programme on cognitive performance and mood among seniors without dementia living in retirement villages. DESIGN: Randomised controlled trial. SETTING: Four intermediate care and four self-care retirement village sites in Sydney, Australia. PARTICIPANTS: 154 seniors (19 men, 135 women; age range 62 to 95 years), who were residents of intermediate care and self-care retirement facilities. INTERVENTION: Participants were randomised to one of three experimental groups: (1) a general group-based exercise (GE) programme composed of resistance training and balance training exercises; (2) a flexibility exercise and relaxation technique (FR) programme; or (3) no-exercise control (NEC). The intervention groups (GE and FR) participated in 1-hour exercise classes twice a week for a total period of 6 months. MAIN OUTCOME MEASURES: Using standard neuropsychological tests, we assessed cognitive performance at baseline and at 6-month re-test in three domains: (1) fluid intelligence; (2) visual, verbal and working memory; and (3) executive functioning. We also assessed mood using the Geriatric Depression Scale (GDS) and the Positive and Negative Affect Schedule (PANAS). RESULTS: The GE programme significantly improved cognitive performance of fluid intelligence compared with FR or NEC. There were also significant improvements in the positive PANAS scale within both the GE and FR groups and an indication that the two exercise programmes reduced depression in those with initially high GDS scores. CONCLUSIONS: Our GE programme significantly improved cognitive performance of fluid intelligence in seniors residing in retirement villages compared with our FR programme and the NEC group. Furthermore, both group-based exercise programmes were beneficial for certain aspects of mood within the 6-month intervention period.

The Role of S100B in Aerobic Training Efficacy in Older Adults with Mild Vascular Cognitive Impairment: Secondary Analysis of a Randomized Controlled Trial.

Aerobic training improves cognitive and brain outcomes across different populations and neurocognitive disorders of aging, including mild subcortical ischemic vascular cognitive impairment (SIVCI). However, little is known of the underlying mechanisms through which aerobic training exerts its beneficial effects on the brain. Recently, S100 calcium-binding protein B (S100B) has been proposed as a possible mediator of aerobic training. Thus we conducted a secondary analysis of data collected from the proof-of-concept single-blind randomized controlled trial (NCT01027858) in older adults with mild SIVCI to determine whether the beneficial effects of 6-months, thrice weekly, moderate-intensity aerobic training on cognitive performance is related to changes in S100B levels. At trial completion, aerobic training decreased circulating levels of S100B compared with usual care plus education. Furthermore, reduced S100B levels were associated with improved global cognitive function in those who received the aerobic exercise intervention. Together these findings suggest that S100B is a promising target mediating the beneficial effects of moderate-intensity aerobic training on brain health in older adults with mild SIVCI.

Muscle power is related to tibial bone strength in older women.

UNLABELLED: We enrolled 65 to 75 year-old community-dwelling women and measured muscle power, strength, physical activity using accelerometry and tibial bone strength using peripheral quantitative computed tomography (pQCT). Muscle power contributed 6.6% of the variance in the bone strength-strain index and 8.9% in the section modulus after accounting for age, height, weight, and physical activity; moderate to vigorous physical activity was related to muscle power in the lower extremity. INTRODUCTION: Muscle power is associated with DXA measurements of bone mass, but it is not known whether muscle power is associated with bone strength. There are no reports of investigations that have tested the effect of muscle power on bone compartments using advanced imaging. METHODS: We enrolled 74 community-dwelling women aged 65-75 years. We measured muscle power and strength of leg extension using Keiser air-pressure resistance equipment. All participants wore a waist-mounted Actigraph accelerometer to record physical activity. We used peripheral quantitative computed tomography (pQCT) to measure tibial mid-shaft (50% of the site) bone strength (strength-strain index, section modulus). We used Pearson correlations and multi-level linear regression to investigate the associations between muscle and bone. RESULTS: Muscle power contributed 6.6% (p = 0.007) of the variance in the bone strength-strain index and 8.9% (p = 0.001) the variance in the section modulus in older women after accounting for age, height, weight, and physical activity. Moderate to vigorous physical activity was significantly related to muscle power in the lower extremity (r = 0.260; p = 0.041). CONCLUSION: Muscle power significantly contributed to the variance in estimated bone strength. Whether power training will prove to be a more effective stimulus for bone strength than conventional strength training will require further studies.