Physical Performance Across the Adult Life Span: Correlates With Age and Physical Activity

Running biomechanical and isokinetic strength differences in masters runners with and without Achilles tendinopathy

Masters runners are an increasing proportion of the running community. The most significant musculoskeletal changes in runners occur after the age of 50 in addition to changes in injury rates and types, the most common being Achilles tendinopathy (AT). Previous evidence has suggested similarities between risk factors for AT and age-related changes that are focused at the hip and the ankle during the propulsive stage of running. The purpose of this study was to investigate biomechanical and peak torque association to AT in masters runners. Thirty-two masters runners over age 50 with AT (60.31 ± 8.37, n = 16) and without (59.94 ± 4.95 n = 16) were included. 3D motion capture and force plates were used to assess running biomechanics. A motor-driven dynamometer was used to assess isokinetic peak torque production. No significant differences in running biomechanics were found between masters runners with and without AT. Hip peak isokinetic torque production was found to be significantly less in masters runners with AT, but no significant differences in ankle plantarflexion peak isokinetic torque production were found. Masters runners with AT may be able to adapt their running biomechanics and muscular torque production during submaximal running efforts.

Cross-sectional interactive associations of physical activity and sedentary behaviour with physical capacity across adulthood

BACKGROUND

The way physical activity (PA) and sedentary behaviour (SB) independently and interactively modify the age-related decline in physical capacity remains poorly understood. This cross-sectional study investigated the independent and interactive associations of PA and SB with physical function and performance throughout the adult life course.

METHODS

Data from 499 community-dwelling adults (63% female) aged 20-92 years, involved in the INSPIRE Human Translational Cohort, were used in this cross-sectional study. Daily time spent on moderate-to-vigorous PA (MVPA, min/day) and SB (h/day) was measured with activPAL triaxial accelerometers. Physical function and performance were assessed through the measurement of the 4-m usual gait speed (m/s), handgrip strength (kg), lower-limb strength (isokinetic knee extension torque, N·m), estimated lower-limb power (five-time chair-rise test performance, s) and cardiorespiratory fitness (V̇O2max, mL/kg/min). Confounder-adjusted multiple linear and curvilinear regressions were performed to investigate how MVPA, SB and their interactions were associated with the physical outcomes (all square root-transformed except gait speed) throughout the adulthood spectrum.

RESULTS

Interaction analyses revealed that the combination of higher levels of MVPA with lower levels of SB favourably reshaped the negative relationship between handgrip strength and age (age2 × SB × MVPA: B = -7E-08, SE = 3E-08, P < 0.05). In addition, higher levels of MVPA were independently associated with an improved age-related profile in gait speed (age2 × MVPA: B = 3E-06, SE = 1E-06, P < 0.05), chair-rise performance (age × MVPA: B = -9E-05, SE = 4E-05, P < 0.05) and V̇O2max (MVPA at 21 years: B = 3E-02, SE = 7E-03, P < 0.05; age × MVPA: B = -5E-04, SE = 2E-04, P < 0.05). Conversely, the detrimental association of age with lower-limb muscle strength (age × SB: B = -1E-04, SE = 6E-05, P < 0.05) and chair-rise performance (age × SB: B = 1E-05, SE = 7E-06, P < 0.05) was exacerbated with increasing duration of SB, independently of MVPA. Supplementary analyses further revealed that some of these associations were age and sex specific.

CONCLUSIONS

This cross-sectional study demonstrated that reduced sedentary time and increased activity duration were independently and synergistically associated with an attenuated age-related loss in physical capacity. These findings need to be confirmed with longitudinal data but encourage both adopting an active lifestyle and reducing sedentary time as preventive measures against physical aging.

Associations Between Gait Speed and Fat Mass in Older Adults

Purpose

Although both gait speed and fat mass are crucial for healthy aging, evidence suggests that the associations between these components remain unclear. Therefore, the main purpose of the study was to examine the associations between gait speed and fat mass.

Patients and Methods

In this cross-sectional study, we recruited 643 older men and women aged >60 years. Fat mass was assessed using bioelectrical impedance analysis, while gait speed was determined by calculating the time an individual has taken to walk across a 4.6-m distance. Receiver operating characteristic (ROC) curves and odds ratios (OR) were performed to determine cut-off points and mutual associations.

Results

In older men, the optimal threshold of gait speed to detect high level of fat mass was 1.40 m/s with the area under the curve (AUC) being 0.82 (95% CI 0.76-0.89, p < 0.001). In older women, the optimal cut-off point was 1.37 m/s (AUC = 0.85, 95% CI 0.81-0.90, p < 0.001). Older men and women who walked below the newly developed threshold were approximately 12 times more likely to have high level of fat.

Conclusion

In summary, newly developed cut-off points of gait speed have adequate discriminatory ability to detect older men and women with high level of fat mass. Although gait speed may be considered as a satisfactory screening tool for fat mass, its utility in clinical practice needs to be further investigated.

Correlates of life course physical activity in participants of the Baltimore longitudinal study of aging

Physical activity is consistently associated with better health and longer life spans. However, the extent to which length and intensity of exercise across the life course impact health outcomes relative to current activity is undefined. Participants of the Baltimore Longitudinal Study of Aging were asked to categorize their level of physical activity in each decade of life from adolescence to the current decade. In linear mixed effects models, self-reported past levels of physical activity were significantly associated with activity assessed at study visits in the corresponding decade of life either by questionnaire or accelerometry. A pattern of life course physical activity (LCPA) derived by ranking participants on reported activity intensity across multiple decades was consistent with the trajectories of activity estimated from standard physical activity questionnaires assessed at prior study visits. In multivariable linear regression models LCPA was associated with clinical characteristics, measures of body composition and indicators of physical performance independent of current physical activity. After adjustment for minutes of high intensity exercise, LCPA remained significantly associated with peak VO2, fasting glucose, thigh muscle area and density, abdominal subcutaneous fat, usual gait speed, lower extremity performance, and multimorbidity (all p < 0.01) at the index visit. The observed associations suggest that an estimate of physical activity across decades provides complementary information to information on current activity and reemphasizes the importance of consistently engaging in physical activity over the life course.

Association of Sit-to-Stand Capacity and Free-Living Performance Using Thigh-Worn Accelerometers among 60- to 90-Yr-Old Adults

PURPOSE

Five times sit-to-stand (STS) test is commonly used as a clinical assessment of lower-extremity functional ability, but its association with free-living performance has not been studied. Therefore, we investigated the association between laboratory-based STS capacity and free-living STS performance using accelerometry. The results were stratified according to age and functional ability groups.

METHODS

This cross-sectional study included 497 participants (63% women) 60-90 yr old from three independent studies. A thigh-worn triaxial accelerometer was used to estimate angular velocity in maximal laboratory-based STS capacity and in free-living STS transitions over 3-7 d of continuous monitoring. Functional ability was assessed with short physical performance battery.

RESULTS

Laboratory-based STS capacity was moderately associated with the free-living mean and maximal STS performance ( r = 0.52-0.65, P < 0.01). Angular velocity was lower in older compared with younger and in low- versus high-functioning groups, in both capacity and free-living STS variables (all P < 0.05). Overall, angular velocity was higher in capacity compared with free-living STS performance. The STS reserve (test capacity - free-living maximal performance) was larger in younger and in high-functioning groups compared with older and low-functioning groups (all P < 0.05).

CONCLUSIONS

Laboratory-based STS capacity and free-living performance were found to be associated. However, capacity and performance are not interchangeable but rather provide complementary information. Older and low-functioning individuals seemed to perform free-living STS movements at a higher percentage of their maximal capacity compared with younger and high-functioning individuals. Therefore, we postulate that low capacity may limit free-living performance.

Changes in women's physical function in mid-life by reproductive age and hormones: a longitudinal study

BACKGROUND

Whether women's physical function in mid-life is related to their reproductive age is not known. The objectives of this study were to examine and compare changes in physical function in women by reproductive age, measured as time since final menstrual period (FMP), and chronological age, and to explore associations with repeatedly assessed levels of reproductive hormones.

METHODS

We used data from 2319 UK women with up to three repeated measurements of physical function (median length of follow up: 2 years), focusing on changes occurring in women experiencing a natural menopausal transition. The main outcome was a composite physical function score that incorporated assessments of strength (grip strength), balance (one-leg stand) and cardiorespiratory fitness (timed chair rises). Associations with time since FMP, age, and time-updated measures of anti-Müllerian hormone, follicle-stimulating hormone and luteinizing hormone were assessed by multilevel models and generalised estimating equations models adjusted for the underlying effects of chronological age and confounding by education, age at first birth and smoking.

RESULTS

The results showed that, adjusted for these confounders, time since FMP (- 0.21 SD per 10 years, 95% CI - 0.37, - 0.06) and chronological age (- 0.31 SD per 10 years, 95% CI - 0.46, - 0.15) were inversely associated with the physical function composite score. Grip strength seemed to be the main contributor to the decline in the composite score by time since FMP. There was no strong evidence of associations between any of the three reproductive hormones and the composite score.

CONCLUSIONS

Physical function in women in mid-life declined with both chronological and reproductive age. The decline with reproductive age was independent of chronological age but did not seem to be driven by changes in reproductive hormones.

Physical inactivity among internally displaced persons in Nigeria

Background

Physical inactivity may complicate physical and mental health problems among internally displaced persons (IDPs). This study aimed to assess the prevalence of physical inactivity and its sociodemographic correlates among IDPs in Northeastern Nigeria.

Methods

A total of 363 participants recruited from four IDP camps were categorized into physically inactive and active using International Physical Activity Questionnaire. Multiple logistic regression was used to explore the association between physical inactivity and sociodemographic correlates.

Results

The prevalence of physical inactivity was 36.2%. Those who were males (Odd Ratio (OR) = 4.52, 95% Confidence Interval (CI) = 2.33 to 8.78) and Kanuri (OR = 2.53, 95% CI = 1.44 to 4.45) were more likely to be physically inactive. Younger participants were less likely to be physically inactive than those who were aged >49 years old.

Conclusion

There is a high prevalence of physical inactivity among IDPs in Nigeria, and we found important sociodemographic factors associated with physical inactivity.

Impact of Comorbidities on the Cause of Death by Necrotizing Soft Tissue Infections

Background: The aim of this study was to identify the cause of death in patients with necrotizing soft tissue infections (NSTIs) stratified by patient's pre-existing comorbidities (American Society of Anesthesiologists [ASA] classification 3/4 vs. ASA 1/2). Differences in clinical presentation, mortality rate, and factors associated with mortality between those two comorbidity groups were investigated. Patients and Methods: A retrospective multicenter study of patients with NSTIs between 2010 and 2020 was conducted. The primary outcome was the cause of death within the first 30 days. Furthermore, factors associated with mortality were identified. All analysis were stratified by severity of comorbidities (ASA 1/2 or ASA 3/4). Results: Of the 187 patients, 39 patients (21%) died within 30 days. American Society of Anesthesiologists 1/2 patients (overall mortality rate, 11%) died more often as direct result of the infection compared with ASA 3/4 patients (overall mortality rate, 33%) (ASA 1/2 group: 92% vs. ASA 3/4 group: 48%; p = 0.013). American Society of Anesthesiologists 3/4 patients died more often due to withdrawal of life-sustaining therapies based on assumed poor outcome after severe critical illness (ASA 1/2 group: 52% vs. ASA 3/4 group: 8%; p = 0.013). Conclusions: Mortality rates of patients with NSTIs varied from 11% in previously healthy patients to 33% in patients with multiple or severe comorbidities. The predominant cause of mortality was overwhelming infection and associated sepsis in healthy patients whereas in patients with multiple or severe pre-existing medical disease, death most often occurred after treatment limitations based on patient's wishes and prognosis.

A 7-Year Study of the Durability of Improvements in Pain, Physical Function, and Work Productivity After Roux-en-Y Gastric Bypass and Sleeve Gastrectomy

IMPORTANCE

Bariatric surgical procedures are associated with clinically important improvements (CIIs) in pain and physical function. However, there are declines in initial improvement by the third postoperative year, and the long-term durability of improvements are not well-described.

OBJECTIVE

To evaluate the durability of improvements in pain and physical function through 7 years after Roux-en-Y gastric bypass (RYGB) or sleeve gastrectomy (SG).

DESIGN, SETTING, AND PARTICIPANTS

This study is part of the Longitudinal Assessment of Bariatric Surgery-2 (LABS-2), a cohort study at 10 US hospitals. Adults with severe obesity (ie, body mass index of 35 or greater) undergoing bariatric surgery were assessed preoperatively (2006-2009) and followed up annually for as long as 7 years or until 2015. Of 1829 participants who underwent RYGB or SG in LABS-2, 338 were excluded from this study because they had a follow-up period of less than 5 years. Analysis of participants who underwent RYGB or SG and completed research assessments preoperatively and postoperatively for 5 to 7 years was conducted from March to April 2022.

MAIN OUTCOMES AND MEASURES

Preoperative-to-postoperative CIIs in pain and physical function scores from the 36-Item Short Form Health Survey and the Western Ontario McMaster Osteoarthritis Index, and 400-meter walk time, using previously established thresholds; and remission of mobility deficit, ie, inability to walk 400 meters in 7 minutes or less.

RESULTS

A total of 1491 individuals were included, with 1194 (80%) women; 59 (4%) Hispanic, 164 (11%) non-Hispanic Black, and 1205 (82%) non-Hispanic White individuals; a preoperative median (IQR) age of 47 (38-55) years; and a preoperative median (IQR) body mass index of 47 (42-52). Between 3 and 7 years after surgery, the percentage of participants with preoperative-to-postoperative CIIs in bodily pain decreased from 50% (95% CI, 48%-53%) to 43% (95% CI, 40%-46%), in physical function from 75% (95% CI, 73%-77%) to 64% (95% CI, 61%-68%), and in 400-meter walk time from 61% (95% CI, 56%-65%) to 50% (95% CI, 45%-55%). Among participants with a preoperative mobility deficit, remission decreased from 50% (95% CI, 42%-57%) to 41% (95% CI, 32%-49%), and among participants with severe knee or hip pain or disability, the percentage with CIIs in knee and hip pain and function decreased (eg, hip pain: from 77% [95% CI, 72%-82%] to 65% [95% CI, 58%-72%]; knee function: from 77% [95% CI, 73%-82%] to 72% [95% CI, 67%-77%]).

CONCLUSIONS AND RELEVANCE

In this cohort study, despite decreases in preoperative-to-postoperative improvements across follow-up, CIIs in perceived bodily and joint-specific pain and in self-reported and objectively measured physical function ranged from 41% to 72%, depending on the measure and subgroup, 7 years after surgery, suggesting that RYGB and SG are commonly associated with long-term CIIs in pain and physical function.

Improvements of Physical Activity Performance and Motivation in Adult Men through Augmented Reality Approach: A Randomized Controlled Trial

The COVID-19 pandemic had a global impact, increasing the prevalence of physical inactivity, which is mostly due to the lockdown and social distancing measures adopted during the pandemic. Hence, this study aimed to compare the efficacy of augmented reality-based training on physical activity performance and motivation in healthy adults to mirror visual feedback training and conventional physical therapy. This study used the randomized control trial pretest-posttest research design. Forty-eight healthy men aged 18–35 years who were engaged in recreational physical activities were enrolled and randomly divided into four groups: augmented reality-based training reality (ART), mirror visual feedback training (MVFT), therapist-based training (TBT), and control group. The total training program was held for four weeks. The isokinetic dynamometer, sit-and-reach test, Y balance test, and the intrinsic motivation inventory-22 were used to measure the outcomes before and after the intervention. Paired sample t-test was used to compare the changes before and after the intervention within groups, while the one-way ANOVA was used for the comparison between the groups. Results of the study showed that, after four weeks of intervention, balance, muscle strength, and muscle endurance in all groups significantly improved except for the control group. The ART group showed the highest increase in muscle strength, muscle endurance, and balance compared to the other groups. The motivation level increased in all three feedback groups and was observed in the following order: ART group > MVFT group > TBT group > control group. This study highlighted the most effective method that may be applied for home training during and after this period of the pandemic. The findings revealed that training while receiving real-time feedback via AR devices improves both physical performance and motivation. Augmented reality-based training can be used as an effective training option for improving physical activity and motivation and can be suggested for home training programs.

Associations of multicomponent exercise and aspects of physical performance with frailty trajectory in older adults

BACKGROUND

Previous research has shown that frailty leads to falls, institutionalization, hospitalization, and the loss of functional capacity. While numerous intervention methods aim to reverse frailty, the most effective in older adults is multicomponent exercise. Physical performance has been highlighted as a key factor in mobility, independence, and the burden of chronic disease. Several studies have demonstrated an association between physical performance and frailty; however, the relation between the two over the long term has not yet been fully investigated. Therefore, the current study aims to examine how aspects of physical performance are associated with frailty in the long run for older adults in Taiwan.

METHODS

This nine-month longitudinal study employed the generalized estimating equation (GEE) modeling to identify measures associated with frailty trajectory. A sample of 159 community-dwelling older adults was recruited through purposive sampling in 12 community care centers in Taiwan. A quasi-experimental approach was adopted in which participants were assigned to the control group or to receive a multicomponent exercise intervention and examined sociodemographic, physical performance, and other factors at the baseline, post intervention (3 months), and follow up (6 months) levels. The multicomponent exercise program was designed based on the principles of the American College of Sports Medicine and comprised aerobic exercise, muscle-strengthening activities, balance training, and stretching exercises once per week for 2 h per session for 12 weeks.

RESULTS

After intervention, we found that the multicomponent exercise group exhibited better performance in the 2-minute step test than the control group (p < 0.05). Regarding long-term effects on frailty trajectories, the study finds that age progression, being female, and longer completion time in the timed up and go test increase the probability of frailty (p < 0.05). Conversely, more steps in the 2-minute step test and undertaking the multicomponent exercise program reduced the long-term probability of frailty (p < 0.05).

CONCLUSIONS

This study is the first to explore the relation between indicators of physical performance and frailty trajectory among older adults in Taiwan. Furthermore, we provided support for the efficacy of the multicomponent exercise program in improving frailty status.

Six-minute walk distance in healthy subjects: reference standards from a general population sample

Introduction

The 6-min walking distance (6MWD) test is a useful tool to obtain a measure of functional exercise capacity. However, reference equations have been mainly based on selected populations or small samples. The purpose of this study was to determine the reference equations to predict the 6MWD in a large Italian population sample of healthy adults of a wide age range.

Methods

In the frame of the multi case–control population-based study Gene Environment Interaction in Respiratory Diseases (GEIRD), we studied 530 healthy subjects: 287 females ranging 21–76 and 243 males ranging 21–78 years of age. We measured 6MWD, demographic and anthropometric data and collected the reported physical activity. A multiple linear regression model for the 6MWD included age, age², height, weight and physical activity for both sex equations. The two-way interaction age-height and age-weight and the quadratic terms of weight and height were also tested for inclusion separately in each model.

Results

The mean ± SD for 6MWD was 581.4 ± 66.5 m (range 383–800 m) for females and 608.7 ± 80.1 m (range 410–875 m) for males. The reference equations were 6MWD = 8.10*age + 1.61*height_cm−0.99*weight_kg + 22.58*active−0.10*age² + 222.55 for females (R squared = 0.238) and 6MWD = 26.80*age + 8.46*height_cm−0.45*weight_kg−2.54*active−0.06*age²−0.13*age*height_cm−890.18 for males (R squared = 0.159), where “active” is 1 when the subject is physically active, 0 otherwise.

Conclusion

This study is the first to describe the 6MWD in a large population sample of young, middle aged and elderly healthy Caucasian subjects, and to determine reference equations. These findings will help to improve the evaluation of Italian and European patients with diseases influencing their functional capacity.

Changes in Physical Activity Patterns Due to the Covid-19 Pandemic: A Systematic Review and Meta-Analysis

With the outbreak of the Corona Virus Disease 19 (Covid-19) in late 2019, governments increasingly imposed containment strategies, including social distancing as well as restricted population movement, potentially having negative impacts on mental and physical health. A growing number of studies have examined the impact of the pandemic on different facets of physical activity (PA); an overview combining these (mixed) results, however, is missing. Thus, the objective of this systematic review and meta-analysis was to investigate whether and to which extent PA changed from before to during the Covid-19 pandemic, taking age, gender, and measurement method into account. The literature search was conducted using PubMed, Web of Science, and Scopus. Results of the main characteristics were descriptively synthesized and analyzed in a meta-analysis quantifying effects of the pandemic on PA divided by age groups, with additional subgroup analyses of the characteristics age, gender, and measurement method being narratively synthesized. Overall, 57 studies with a total sample size of 119,094 participants (N between 10 and 60,560 subjects) from 14 countries worldwide with participants aged between four and 93 years were included. Thirty-two studies revealed a significant decline in PA, whereas only five studies found a significant increase in PA during the Covid-19 pandemic. Fourteen studies revealed mixed results. PA decreased in all age groups, independent of gender. Most self-reported and all device-based measurement methods showed a reduction in PA. However, effects were not found to be significant in all age groups. Nevertheless, the declining trend should be noted and governments should strive to enable PA within periods of pandemic restrictions, or promote alternatives such as digital training to avoid negative health consequences within the population.

Physical Activity, Fitness, and Cognitive Performance of Estonian First-Grade Schoolchildren According Their MVPA Level in Kindergarten: A Longitudinal Study

Little is known about the longitudinal trajectories and associations regarding physical activity (PA), physical fitness (PF), and cognitive skills in childhood. Accelerometer-based PA, sedentary behavior (SB), PF, and cognitive skills were measured in Estonian children (n = 147) in kindergarten (6.6 years) and again at school (7.6 years). Children were subgrouped into lower and upper quartiles by their moderate-to-vigorous PA (MVPA) at 6.6 years. Children in the upper quartile had lower SB, higher PA, and greater muscular strength. Attending school, MVPA in the lower quartile improved. In both subgroups, most strength values and cognitive skills improved, while balance deteriorated in first grade. In the upper quartile, a greater MPA at 6.6 years predicted lower perceptual skills at 7.6 years. A greater SB at 6.6 years predicted higher verbal skills, light and moderate PA and MVPA, and lower verbal skills at 7.6 years after taking into account confounding factors such as the child's sex, age, awake wear time (AWT), maternal education, and/or child's sports participation. A vigorous PA at 6.6 years predicted perceptual (in upper quartile) or verbal (in lower quartile) skills at 7.6 years after controlling for similar confounders. No correlation for PF at 6.6 years and cognitive skills at 7.6 years existed; after adjusting for the above-mentioned confounders relative to upper/lower-limb strength, the 4 × 10 m shuttle run results predicted higher perceptual or verbal skills; static balance and cardiorespiratory fitness predicted lower verbal skills. Cardiorespiratory fitness predicted higher perceptual skills after controlling for sex, age, and AWT. Overall, PA and strength were constantly better and SB lower in the upper quartile, yet the lower quartile demonstrated improved MVPA in first grade, and both subgroups increased most components of their strength and cognitive skills in first grade. Higher levels of VPA at kindergarten predicted either better perceptual or verbal skills in first grade after controlling for confounders; the opposite associations were found for other PA levels and cognitive skills in the higher quartile. PF components at kindergarten predicted either superior or inferior cognitive skills in first grade after adjusting for confounders.

The association between nutritional status and functional limitations among centenarians: a cross-sectional study

Background

Although there have been studies on the association between nutritional status and functional limitations, there were few studies on Asian centenarians in community. Therefore, this study aims to identify associations between nutritional status and functional limitations among centenarians in China.

Methods

This cross-sectional study was conducted with the data from the China Hainan Centenarian Cohort Study. These data ultimately included basic characteristics, hematologic indicators, and chronic disease status for 1,002 centenarians. The nutritional status was evaluated using the Mini Nutritional Assessment Short-Form scale. The functional limitations were assessed using the activities of daily living (ADL) scale, namely Barthel Index and Lawton Scale. The association between nutritional status and ADL was assessed using multivariate logistic regression models.

Results

In this study, the prevalence of malnutrition was 20.8 % among centenarians, basic ADL (BADL) limitation was 28.6 %, and instrumental ADL (IADL) limitation was 64.7 %. As the nutritional status deteriorated, the risk of ADL limitations increased in total population (BADL limitation: OR = 17.060, 95 % CI: 8.093-35.964; IADL limitation: OR = 11.221, 95 % CI: 5.853-21.511; p for trend < 0.001). Similar results were found in both men and women after stratifying sex but were more prominent in women.

Conclusions

Malnutrition is associated with functional limitations among centenarians in China and more pronounced among women.

Profiling age-related muscle weakness and wasting: neuromuscular junction transmission as a driver of age-related physical decline

Pathological age-related loss of skeletal muscle strength and mass contribute to impaired physical function in older adults. Factors that promote the development of these conditions remain incompletely understood, impeding development of effective and specific diagnostic and therapeutic approaches. Inconclusive evidence across species suggests disruption of action potential signal transmission at the neuromuscular junction (NMJ), the crucial connection between the nervous and muscular systems, as a possible contributor to age-related muscle dysfunction. Here we investigated age-related loss of NMJ function using clinically relevant, electrophysiological measures (single-fiber electromyography (SFEMG) and repetitive nerve stimulation (RNS)) in aged (26 months) versus young (6 months) F344 rats. Measures of muscle function (e.g., grip strength, peak plantarflexion contractility torque) and mass were assessed for correlations with physiological measures (e.g., indices of NMJ transmission). Other outcomes also included plantarflexion muscle contractility tetanic torque fade during 1-s trains of stimulation as well as gastrocnemius motor unit size and number. Profiling NMJ function in aged rats identified significant declines in NMJ transmission stability and reliability. Further, NMJ deficits were tightly correlated with hindlimb grip strength, gastrocnemius muscle weight, loss of peak contractility torque, degree of tetanic fade, and motor unit loss. Thus, these findings provide direct evidence for NMJ dysfunction as a potential mechanism of age-related muscle dysfunction pathogenesis and severity. These findings also suggest that NMJ transmission modulation may serve as a target for therapeutic development for age-related loss of physical function.

Distinct Trajectories of Individual Physical Performance Measures Across 9 Years in 60- to 70-Year-Old Adults

Background

Physical performance is an important factor for successful aging. This study aimed to identify distinct trajectories of multiple physical performance measures over 9 years in individuals aged 60–70 years and to evaluate their characteristics and the overlap between measures.

Methods

Four physical performance measures were assessed in 440 participants of the Longitudinal Aging Study Amsterdam: tandem stand, gait speed, chair stand, and handgrip strength. Gender-specific latent class models were conducted to obtain distinct trajectories and their degree of overlap.

Results

Mean age at baseline was 67.9 (SD 1.7) years for males and 68.0 (SD 1.7) years for females. The optimal number of trajectories differed across measures. For tandem stand, no distinct trajectories were found (all 179 males, 198 females). For gait speed, three trajectories were identified, dependent on baseline speed: high-stable (47 males, 27 females), intermediate-stable (132 males, 130 females), and low-declining performance (6 males, 48 females). Two trajectories were identified for the chair stand: a stable (168 males, 150 females) and declining trajectory (10 males, 38 females). For handgrip strength, three declining trajectories were identified differing in baseline performance: high (55 males, 75 females), intermediate (111 males, 118 females), and low (17 males, 10 females). Overall, 11.9% of males and 5.7% of females were classified in similar trajectories across measures.

Conclusions

Trajectories of physical performance were heterogeneous, but showed similar patterns for males and females. Little overlap between measures was shown, suggesting different mechanisms for decline. This study emphasizes the use of multiple domains to assess physical performance.

Reference Values of Gait Speed and Gait Spatiotemporal Parameters for a South East Asian Population: The Yishun Study

Background

Age-related slowing of gait has been reported to start as early as the fifth decade and accelerate beyond the seventh decade of life. A single cut-off for slow gait may not be appropriate for men and women of different ages. We aimed to report reference values for gait speed and spatiotemporal gait parameters of adult age groups in a South East Asian population.

Methods

A total of 507 community-dwelling adults, aged 21-90 years were recruited into the study through random sampling, filling quotas of 20-40 participants in each sex and age group (10-year age groups between 21 and 60 years; 5-year age groups beyond age 60 years). Demographic data, height, weight and information on comorbidities were recorded. Habitual gait speed and spatiotemporal parameters were measured, and the average of three trials was recorded using the GAITRite system.

Results

Gait speed peaked in their 40s for both men and women, but the trajectories differed slightly across age groups. Although similar for men in their 50s and 60s, gait speed was significantly slower among those aged 71 years and older. For women beyond 50 years old, gait slowed with age. After adjusting for height, women were found to walk significantly faster and with a longer step length than men. Women also walked with a significantly narrower stride width and less external rotation of the feet. The lowest quintile for gait speed in our study cohort was 0.9m/s, below the recommended cut-off of 1.0m/s.

Conclusion

We established the reference values as well as the quintiles for gait speed and spatiotemporal gait parameters across adult age groups in a multi-ethnic Asian population. This contributes to a valuable database for gait assessment and evaluation of preventive or rehabilitative programs.

Nutritional Intervention to Prevent the Functional Decline in Community-Dwelling Older Adults: A Systematic Review

Aging is a global public health concern. From the age of 50, muscle mass, muscle strength and physical performance tend to decline. Sarcopenia and frailty are frequent in community-dwelling older adults and are associated with negative outcomes such as physical disability and mortality. Therefore, the identification of therapeutic strategies to prevent and fight sarcopenia and frailty is of great interest. This systematic review aims to summarize the impact of nutritional interventions alone or combined with other treatment(s) in older community-dwelling adults on (1) the three indicators of sarcopenia, i.e., muscle mass, muscle strength and physical performance; and (2) the hospitalization and readmission rates. The literature search was performed on Medline and included studies published between January 2010 and June 2020. We included randomized controlled trials of nutritional intervention alone or combined with other treatment(s) in community-living subjects aged 65 or older. In total, 28 articles were retained in the final analysis. This systematic review highlights the importance of a multimodal approach, including at least a combined nutritional and exercise intervention, to improve muscle mass, muscle strength and physical performance, in community-dwelling older adults but especially in frail and sarcopenic subjects. Regarding hospitalization and readmission rate, data were limited and inconclusive. Future studies should continue to investigate the effects of such interventions in this population.

Accelerometer-Based Machine Learning Categorization of Body Position in Adult Populations

This manuscript describes tests and results of a study to evaluate classification algorithms derived from accelerometer data collected on healthy adults and older adults to better classify posture movements. Specifically, tests were conducted to 1) compare performance of 1 sensor vs. 2 sensors; 2) examine custom trained algorithms to classify for a given task 3) determine overall classifier accuracy for healthy adults under 55 and older adults (55 or older). Despite the current variety of commercially available platforms, sensors, and analysis software, many do not provide the data granularity needed to characterize all stages of movement. Additionally, some clinicians have expressed concerns regarding validity of analysis on specialized populations, such as hospitalized older adults. Accurate classification of movement data is important in a clinical setting as more hospital systems are using sensors to help with clinical decision making. We developed custom software and classification algorithms to identify laying, reclining, sitting, standing, and walking. Our algorithm accuracy is 93.2% for healthy adults under 55 and 95% for healthy older adults over 55 for the tasks in our setting. The high accuracy of this approach will aid future investigation into classifying movement in hospitalized older adults. Results from these tests also indicate that researchers and clinicians need to be aware of sensor body position in relation to where the algorithm used was trained. Additionally, results suggest more research is needed to determine if algorithms trained on one population can accurately be used to classify data from another population.

Impact of a Knowledge Translation Intervention on Physical Activity and Mobility in Older Adults (the Move4Age Study): Randomized Controlled Trial

Background

The McMaster Optimal Aging Portal (the Portal) was launched in 2014 as a knowledge translation (KT) tool to increase access to evidence-based health information.

Objective

The purpose of this study was to understand if and how dissemination of mobility information through the Portal impacts physical activity (PA) in older adults.

Methods

In this randomized controlled trial, participants (n=510) were assigned to a 12-week mobility-focused KT intervention or self-serve control group. The intervention included weekly email alerts and a study-specific social media hashtag linking to mobility-focused Portal materials. The control group was able to access the Portal on their own but did not receive targeted KT strategies. Participants completed questionnaires (including the Rapid Assessment of Physical Activity to quantify PA) at baseline, end of the study, and 3-month follow-up.

Results

Participants were predominantly female (430/510, 84.3%), mean age 64.7 years, with no baseline differences between groups. Over half (277/510, 54.3%) of the participants were classified as “active” at baseline. There was no significant between-group difference in the PA category. Overall, both groups increased their PA with improvements maintained at 3-month follow-up (P<.001). In planned subgroup analyses, the KT intervention had a significant effect for those with poor or fair baseline self-rated health (P=.03).

Conclusions

No differences were found between those who received the targeted intervention and a control group with self-serve access to the Portal, except in subgroups with low self-rated health. Both groups did report increases in PA that were sustained beyond participation in a research study. Findings suggest that different KT strategies may be needed for different types of users, with more intense interventions being most impactful for certain groups (ie, those with lower self-rated health).

Trial Registration

ClinicalTrials.gov NCT02947230; https://clinicaltrials.gov/ct2/show/NCT02947230

Age-Related Adverse Inflammatory and Metabolic Changes Begin Early in Adulthood

Aging is characterized by deleterious immune and metabolic changes, but the onset of these changes is unknown. We measured immune and metabolic biomarkers in adults beginning at age 30. To our knowledge, this is the first study to evaluate these biomarkers in adults aged 30 to over 80. Biomarkers were quantified in 961 adults. Tumor necrosis factor alpha (TNF-α), tumor necrosis factor receptor I (TNFR-I), tumor necrosis factor receptor II (TNFR-II), interleukin (IL)-2, IL-6, VCAM-I, D-Dimer, G-CSF, regulated on activation, normal T cell expressed and secreted (RANTES), matrix metalloproteinase-3 (MMP-3), adiponectin, and paraoxonase activity were measured by ELISA. Acylcarnitines and amino acids (AAs) were measured by mass spectrometry and reduced to a single factor using principal components analysis (PCA). Glycine was analyzed separately. The relationship between age and biomarkers was analyzed by linear regression with sex, race, and body mass index (BMI) as covariates. Age was positively correlated with TNF-α, TNFR-I, TNFR-II, IL-6, IL-2, VCAM-1, D-Dimer, MMP-3, adiponectin, acylcarnitines, and AAs. Age was negative correlated with G-CSF, RANTES, and paraoxonase activity. BMI was significant for all biomarkers except IL-2, VCAM-1, RANTES, paraoxonase activity, and the AA factor. Excluding MMP-3, greater BMI was associated with potentially adverse changes in biomarker concentrations. Age-related changes in immune and metabolic biomarkers, known to be associated with poor outcomes in older adults, begin as early as the thirties.

Sex differences in physical performance by age, educational level, ethnic groups and birth cohort: The Longitudinal Aging Study Amsterdam

BACKGROUND

Older women perform consistently poorer on physical performance tests compared to men. Risk groups for this "female disadvantage" in physical performance and it's development over successive birth cohorts are unknown. This is important information for preventive strategies aimed to enhance healthy aging in all older women. This study aims to longitudinal investigate whether there are risk groups for a more apparent female disadvantage and study its trend over successive birth cohorts.

METHODS

Data of the Longitudinal Aging Study Amsterdam (LASA) were used. All participants were aged 55-65 years at baseline. Longitudinal data of two birth cohorts with baseline measurements in 1992/1993 (n = 966, 24 year follow-up) and 2002/2003 (n = 1002, 12 year follow-up) were included. Follow-up measurements were repeated every three/four years. Cross-sectional data of two additional cohorts were included to compare ethnic groups: a Dutch cohort (2012/2013, n = 1023) and a Migration cohort (2013/2014, n = 478) consisting of migrants with a Turkish/Moroccan ethnicity.

RESULTS

Mixed model analysis showed that women aged 55 years and older had a lower age- and height-adjusted gait speed (-0.03 m/s; -0.063-0.001), chair stand speed (-0.05 stand/s; -0.071--0.033), handgrip strength (-14,8 kg; -15.69--13.84) and balance (OR = 0.71; 0.547-0.916) compared to men. The sex difference in handgrip strength diminished with increasing age, but remained stable for gait speed, chair stand speed and balance. In general, results were consistent across different, educational levels and Turkish/Moroccan ethnic groups and birth cohorts.

CONCLUSIONS

There is a consistent "female disadvantage" in physical performance among older adults, which remains stable with increasing age (except for handgrip strength) and is consistent across different educational levels, ethnic groups and successive birth cohorts. So, no specific risk groups for the female disadvantage in physical performance were identified. Preventive strategies aimed to enhance healthy aging in older women are needed and should target all older women.

The age-performance relationship in the general population and strategies to delay age related decline in performance

The age-performance relationship describes changes in the organism's structural and functional capabilities over the course of the lifespan. The typical, empirical pattern is an asymmetrical inverted-U shape association with peak capacity occurring early in life. This process is well described in the literature, with an increasing interest in features that characterize this pattern, such as the rate of growth, age of peak performance, and rate of decline with aging. This is usually examined in cohorts of individuals followed over time with repeat assessments of physical or cognitive abilities. This framework ought to be integrated into public health programs, embedding the beneficial (such as physical or cognitive training) or adverse effects (such as chronic diseases or injuries) that respectively sustain or limit capabilities. The maintenance of physical or cognitive performances at older ages would result in both optimal health and promote resistance to disabling conditions and chronic diseases, such as obesity and type 2 diabetes. The causes of accelerated degeneration of health optima are mainly: sedentary and unhealthy lifestyles -including poor nutrition-, exposure to environmental pollutants, and heterogeneity in aging. Better knowledge of optima, compatible with or required for good health, should also allow for establishing ideal conditions for longevity.

Lisinopril Preserves Physical Resilience and Extends Life Span in a Genotype-Specific Manner in Drosophila melanogaster

Physical resiliency declines with age and comorbid conditions. In humans, angiotensin-converting enzyme (ACE) has been associated with attenuation of the decline in physical performance with age. ACE-inhibitor compounds, commonly prescribed for hypertension, often have beneficial effects on physical performance however the generality of these effects are unclear. Here, we tested the effects of the ACE-inhibitor Lisinopril on life span, and age-specific speed, endurance, and strength using three genotypes of the Drosophila melanogaster Genetic Reference Panel. We show that age-related decline in physical performance and survivorship varies with genetic background. Lisinopril treatment increased mean life span in all Drosophila Genetic Reference Panel lines, but its effects on life span, speed, endurance, and strength depended on genotype. We show that genotypes with increased physical performance on Lisinopril treatment experienced reduced age-related protein aggregation in muscle. Knockdown of skeletal muscle-specific Ance, the Drosophila ortholog of ACE, abolished the effects of Lisinopril on life span, implying a role for skeletal muscle Ance in survivorship. Using transcriptome profiling, we identified genes involved in stress response that showed expression changes associated with genotype and age-dependent responsiveness to Lisinopril. Our results demonstrate that Ance is involved in physical decline and demonstrate genetic variation in phenotypic responses to an ACE inhibitor.

Prevalence of Activity Limitations and Association with Multimorbidity Among US Adults 50 to 64 Years Old

BACKGROUND

Functional limitations may be more common in middle-aged adults than previously recognized. However, there are few published data on the prevalence of activity limitations, and their association with multimorbidity, among adults 50 to 64 years old.

OBJECTIVE

To describe the prevalence of activity limitations and the association with multimorbidity in middle-aged adults.

DESIGN

Cross-sectional analysis of US population-based National Health and Nutrition Examination Survey (NHANES) 2011-2016.

PARTICIPANTS

The total number of community-dwelling NHANES participants aged 50-64 years old is 4217.

MAIN MEASURES

Chronic conditions included hypertension, high cholesterol, diabetes mellitus, obesity, chronic kidney disease, cancer, stroke, coronary heart disease, heart failure, chronic obstructive pulmonary disease/asthma, arthritis, and depression. Activity limitations were defined as any difficulty within each of four International Classification of Functioning (ICF) domains: functional limitations (kneeling, carrying, standing, sitting, reaching, grasping, pulling), mobility (walking ¼ mile, climbing 10 steps), basic activities of daily living (BADLs; walking, transferring, eating, dressing), and instrumental activities of daily living (IADLs; finances, chores, cooking). We calculated prevalence ratios for activity limitations using generalized estimating equations.

KEY RESULTS

The prevalence of functional limitations, mobility limitations, BADL difficulty, and IADL difficulty was 34%, 11%, 15%, and 17%, respectively. Seventy-two percent of participants had two or more chronic conditions; 23% had two, 18% had three, 15% had four, and 16% had five or more. Multivariable adjusted prevalence ratios (95% CI) for functional limitations among those with 2, 3, 4, and 5 or more chronic conditions, compared with 0-1 conditions, were 1.94 (1.43-2.63), 2.50 (1.93-3.23), 3.26 (2.48-4.27), and 4.54 (3.48-5.93), respectively (p trend < 0.001). Larger prevalence ratios at a higher number of chronic conditions were present for mobility limitations, BADL difficulty, and IADL difficulty.

CONCLUSIONS

Problems with function are not limited to older adults and multimorbidity may be helpful for identifying middle-aged adults with a high prevalence of activity limitations.

Biomarkers of leaky gut are related to inflammation and reduced physical function in older adults with cardiometabolic disease and mobility limitations

Intestinal barrier dysfunction is hypothesized to be a contributing determinant of two prominent characteristics of aging: inflammation and decline in physical function. A relationship between microbial translocation (MT), or their biomarkers (lipopolysaccharide binding protein-1 [LBP-1], soluble cluster of differentiation [sCD]-14), and physical function has been reported in healthy older adults, rats, and invertebrates. However, it is not known whether the existence of comorbidities, or clinical interventions intended to reduce comorbidities through weight loss or exercise, alters this connection. We measured inflammation, MT, and physical function in 288 overweight/obese older patients with cardiometabolic disease and self-reported mobility limitations who were enrolled in a weight loss and lifestyle intervention study. At baseline, inflammatory cytokines and LBP-1 were positively correlated after adjustment for age, gender, and body mass index. A higher LBP-1 was significantly associated with poorer physical functional after covariate adjustment. Further, even when IL-6 levels were included in the models, 400-m walk time (p = 0.003), short physical performance battery (p = 0.07), and IL-8 (p < 0.001) remained positively associated with LBP-1. Lifestyle interventions improved body mass and some functional measures; however, MT and inflammation were unchanged. MT is reliably related to inflammation, and to poorer physical function in older adults with comorbid conditions. Intestinal barrier function did not appear to improve as a result of intervention assignment, suggesting alternative strategies are needed to target this pro-inflammatory pathway in aging.

The Sedentary Time and Physical Activity Levels on Physical Fitness in the Elderly: A Comparative Cross Sectional Study

Background: Ageing is a life-long process characterized by a progressive loss of physical fitness compromising strength, flexibility, and agility. The purpose of this study was to use accelerometry to examine the relationship between sedentary time, light physical activity (LPA), and moderate to vigorous physical activity (MVPA) with the elderly’s physical fitness. Additionally, we aimed to examine the association between the aforementioned variables on older adults who fulfilled global recommendations on physical activity for health and on those who did not fulfil these recommendations. Methods: Eighty-three elderly (mean ± SD: 72.14 ± 5.61 years old) of both genders volunteered to participate in this cross-sectional study, being divided into an active group (n = 53; 71.02 ± 5.27 years old) and an inactive group (n = 30; 74.13 ± 5.72 years old) according to the established guidelines. Sedentary and physical activity times were assessed using an ActiGraph^® GT1M accelerometer, whereas physical fitness was evaluated with the Senior Fitness Test. Results: MVPA time was correlated with lower body mass index (BMI) ((r_s = −0.218; p = 0.048; −0.3 < r ≤ −0.1 (small)) and shorter time to complete the agility test ((r_s = −0.367; p = 0.001; −0.5 < r ≤ −0.3 (low)). Moreover, MVPA time was positively correlated with aerobic endurance ((r_s = 0.397; p = 0.000; 0.5 < r ≤ 0.3 (low)) and strength ((r_s = 0.243; p = 0.027; 0.3 < r ≤ 0.1 (small)). In the inactive group, MVPA time was positively correlated with upper limb flexibility ((rs = 0.400; p = 0.028; 0.5 < r ≤ 0.3 (low)); moreover, sedentary time was negatively correlated with upper limb flexibility ((r = −0.443; p = 0.014; −0.5 < r ≤ −0.3 (low)), and LPA time was negatively correlated with BMI ((r = −0.423; p = 0.020; −0.5 < r ≤ −0.3 (low)). In the active group, MVPA time was correlated with lower BMI ((rs = −0.320; p = 0.020; −0.5 < r ≤ −0.3 (low)), and shorter time to complete agility test ((rs = −0.296; p = 0.031; −0.3 < r ≤ −0.1 (small)). Conclusions: Our results reinforce the importance of promoting MVPA practice among the elderly, thereby allowing physical fitness maintenance or improvement.

Age-related differences of inter-joint coordination in elderly during squat jumping

Background

Explosive movement requires that the individual exerts force and power with appropriate magnitude and timing. These coordination aspects have received less attention despite being a basic prerequisite for daily mobility and physical autonomy, especially in older people. Therefore, the purpose of this study is to characterize the effect of age on inter-joint coordination during explosive movement.

Methods

Twenty-one elderly and twenty young participants performed three maximal vertical jumps, while kinematics were recorded throughout each squat jump. Inter-joint coordination and coordination variability were calculated for selected sagittal hip-knee, knee-ankle, and hip-ankle joint couplings using the continuous relative phase method.

Results

The young participants produced significantly greater jump height performance (0.36 ± 0.07 m vs. 0.12 ± 0.04 m, p < 0.001). The mean absolute continuous relative phase for ankle-knee and knee-hip joint couplings were significantly greater for the elderly in comparison to the young group (p < 0.01 for the both). No significant differences between senior and young participants in the mean absolute continuous relative phase for ankle-hip joint couplings (p = 0.25) was observed. However, there was significantly more variability in inter-joint coordination in the elderly marked by greater continuous relative phase variabilities in ankle-knee, ankle-hip and knee-hip joint couplings (p < 0.001) than those observed in young adults.

Conclusion

In this study, seniors demonstrated proximodistal inter-joint coordination but with different delays in the pattern of inter-joint coordination during squat jumps compared to young adults. In addition, a higher continuous relative phase variability in the elderly may be needed to improve stability or compensate for strength deficits in jump achievement.

A Mobility-Focused Knowledge Translation Randomized Controlled Trial to Improve Physical Activity: Process Evaluation of the Move4Age Study

Background

Maintaining physical activity and physical function is important for healthy aging. We recently completed a randomized controlled trial of a targeted knowledge translation (KT) intervention delivered through the McMaster Optimal Aging Portal with the goal to increase physical activity and physical mobility in middle-aged and older adults, with results reported elsewhere.

Objective

The purpose of this process evaluation study is to explore which KT strategies were used by both intervention and control group participants, as well as the intervention groups’ engagement, satisfaction, and perceived usefulness of the targeted KT intervention.

Methods

Data on engagement with the intervention materials were gathered quantitatively through Google Analytics and Hootsuite throughout the intervention. Qualitative data were collected through a combination of open-ended surveys and qualitative interviews with a subset of participants at the end of the study to further understand engagement, satisfaction, and usefulness of the KT strategies.

Results

Throughout the intervention period, engagement with content delivered through weekly emails was highest, and participants rated email content most favorably in both surveys and interviews. Participants were generally satisfied with the intervention, noting the ease of participating and the distillation of information in an easy-to-access format being beneficial features. Participants who did not find the intervention useful were those with already high levels of baseline physical activity or physical function and those who were looking for more specific or individualized content.

Conclusions

This process evaluation provides insight into our randomized controlled trial findings and provides information that can be used to improve future online KT interventions.

Trial Registration

ClinicalTrials.gov NCT02947230; https://clinicaltrials.gov/ct2/show/nct02947230 (Archived by WebCite at http://www.webcitation.org/78t4tR8tM)

The Role of Muscle Perfusion in the Age-Associated Decline of Mitochondrial Function in Healthy Individuals

Maximum oxidative capacity of skeletal muscle measured by in vivo phosphorus magnetic resonance spectroscopy (³¹P-MRS) declines with age, and negatively affects whole-body aerobic capacity. However, it remains unclear whether the loss of oxidative capacity is caused by reduced volume and function of mitochondria or limited substrate availability secondary to impaired muscle perfusion. Therefore, we sought to elucidate the role of muscle perfusion on the age-related decline of muscle oxidative capacity and ultimately whole-body aerobic capacity. Muscle oxidative capacity was assessed by ³¹P-MRS post-exercise phosphocreatine recovery time (τ_PCr), with higher τ_PCr reflecting lower oxidative capacity, in 75 healthy participants (48 men, 22–89 years) of the Genetic and Epigenetic Signatures of Translational Aging Laboratory Testing study. Muscle perfusion was characterized as an index of blood volume at rest using a customized diffusion-weighted MRI technique and analysis method developed in our laboratory. Aerobic capacity (peak-VO₂) was also measured during a graded treadmill exercise test in the same visit. Muscle oxidative capacity, peak-VO₂, and resting muscle perfusion were significantly lower at older ages independent of sex, race, and body mass index (BMI). τ_PCr was significantly associated with resting muscle perfusion independent of age, sex, race, and BMI (p-value = 0.004, β = −0.34). τ_PCr was also a significant independent predictor of peak-VO₂ and, in a mediation analysis, significantly attenuated the association between muscle perfusion and peak-VO₂ (34% reduction for β in perfusion). These findings suggest that the age-associated decline in muscle oxidative capacity is partly due to impaired muscle perfusion and not mitochondrial dysfunction alone. Furthermore, our findings show that part of the decline in whole-body aerobic capacity observed with aging is also due to reduced microvascular blood volume at rest, representing a basal capacity of the microvascular system, which is mediated by muscle oxidative capacity. This finding suggests potential benefit of interventions that target an overall increase in muscle perfusion for the restoration of energetic capacity and mitochondrial function with aging.

Effect of aging on muscle and tendon properties in highly functioning elderly people

This study analyzes long-term changes in muscle strength, muscle architecture, and patellar tendon mechanical properties in a specific sample of physically active elderly people. Twenty-two participants were re-examined from a former 12-week-long skiing intervention study: 11 from the intervention group (IG: 7 ♀, 4 ♂; 67 ± 3 years) and 11 from the control group (CG: 6 ♀, 5 ♂; 66 ± 4 years). Muscle architecture, strength endurance, maximum torque, and tendon properties were analyzed three times within 6 months, and again 6 years later in a follow-up test. No changes in either group could be observed between June 2009 and April 2015 in any parameter. This can be interpreted positively because no age-related decreases were found. Although our participants were physically active from the very beginning (>150 min/wk), it must be noted that the intensity of the physical activity was too low to provoke physiological improvements in leg strength or muscle/tendon morphology.

Low Levels of Physical Activity Among Older Persons Living with HIV/AIDS Are Associated with Poor Physical Function

Antiretroviral therapy (ART) has prolonged lives of persons living with HIV/AIDS (PLWHA), resulting in greater incidence of aging-related diseases and disability. Physical activity (PA) is recommended for healthy aging, but little is known about PA in older PLWHA. The purpose of this study was to objectively assess PA levels in older PLWHA and the associations with physical function. Twenty-one PLWHA, ≥50 years old, on ART with undetectable HIV-1 viral loads, wore an accelerometer to assess PA, including number of steps, activity intensity, and energy expenditure over 7 days. A physical function performance battery assessing aerobic capacity, strength, and gait speed was also completed. Average age was 66, and 67% were male. An average of 3,442 (interquartile range: 4,613) steps were walked daily, with 254.9 kcals expended. Participants spent most waking hours (75%) sedentary, with minimal hours (24%) in light-intensity activity. Only 5 min per day (35 min per week), on average, were spent in moderate-to-vigorous physical activity (MVPA). Maximal gait speed and 6-min walk test significantly correlated (p < .05) with all PA outcomes. Usual gait speed significantly correlated with all PA outcomes, except for daily kcals and light-intensity activity. Greater PA was associated with better physical performance, while high sedentary time was associated with poorer performance. To our knowledge, this is the first study to objectively measure PA in older PLWHA. Our findings indicate that older PLWHA accumulate substantial sedentary time. Most (86%) do not achieve recommended MVPA levels. This activity profile was associated with poor physical function. Providers should promote PA among PLWHA.

Beam Walking to Assess Dynamic Balance in Health and Disease: A Protocol for the "BEAM" Multicenter Observational Study

BACKGROUND

Dynamic balance keeps the vertical projection of the center of mass within the base of support while walking. Dynamic balance tests are used to predict the risks of falls and eventual falls. The psychometric properties of most dynamic balance tests are unsatisfactory and do not comprise an actual loss of balance while walking.

OBJECTIVES

Using beam walking distance as a measure of dynamic balance, the BEAM consortium will determine the psychometric properties, lifespan and patient reference values, the relationship with selected "dynamic balance tests," and the accuracy of beam walking distance to predict falls.

METHODS

This cross-sectional observational study will examine healthy adults in 7 decades (n = 432) at 4 centers. Center 5 will examine patients (n = 100) diagnosed with Parkinson's disease, multiple sclerosis, stroke, and balance disorders. In test 1, all participants will be measured for demographics, medical history, muscle strength, gait, static balance, dynamic balance using beam walking under single (beam walking only) and dual task conditions (beam walking while concurrently performing an arithmetic task), and several cognitive functions. Patients and healthy participants age 50 years or older will be additionally measured for fear of falling, history of falls, miniBESTest, functional reach on a force platform, timed up and go, and reactive balance. All participants age 50 years or older will be recalled to report fear of falling and fall history 6 and 12 months after test 1. In test 2, seven to ten days after test 1, healthy young adults and age 50 years or older (n = 40) will be retested for reliability of beam walking performance.

CONCLUSION

We expect to find that beam walking performance vis-à-vis the traditionally used balance outcomes predicts more accurately fall risks and falls.

CLINICAL TRIAL REGISTRATION NUMBER

NCT03532984.

The Impact of Multiple Dimensions of Socioeconomic Status on Physical Functioning Across the Life Course

Objective: We used the Physical Performance Across the LifeSpan Study to investigate the relationships of multiple indicators of socioeconomic status (SES), both in early life and late life, with physical function. Method: We examined associations between multiple early and late life SES indicators with physical function measured by aerobic endurance, gait speed, and lower body strength. Results: Higher participant education and household income were associated with increased physical function. In our age-stratified analysis, we observed widening SES disparities with increasing age among those in the two younger strata with lower SES associated with worse physical function. Finally, we observed an association between socioeconomic trend and gait speed, aerobic endurance, and lower body strength. There was also an association between lower aerobic endurance and being in a downward socioeconomic trend. Discussion: These findings highlight the significance of considering multiple dimensions of the social environment as important correlates of physical functioning across the life course.

Impact of habitual physical activity and type of exercise on physical performance across ages in community-living people

The maintenance of muscle function into late life protects against various negative health outcomes. The present study was undertaken to evaluate the impact of habitual physical activity and exercise types on physical performance across ages in community-living adults. The Longevity check-up 7+ (Lookup 7+) project is an ongoing cross-sectional survey conducted in unconventional settings (e.g., exhibitions, malls, and health promotion campaigns across Italy) that began on June 1st 2015. The project was designed to raise awareness in the general population on major lifestyle behaviors and risk factors for chronic diseases. Candidate participants are eligible for enrolment if they are at least 18 years of age and provide written informed consent. Physical performance is evaluated through the 5-repetition chair stand test. Analyses were conducted in 6,242 community-living adults enrolled between June 1st 2015 and June 30th 2017, after excluding 81 participants for missing values of the variables of interest. The mean age of the 6,242 participants was 54.4 years (standard deviation 15.2, range 18-98 years), and 3552 (57%) were women. The time to complete the chair stand test was similar from 18 to 40-44 years, and declined progressively across subsequent age groups. Overall, the performance on the chair stand test was better in physically active participants, who completed the test with a mean of 0.5 s less than sedentary enrollees (p < .001). After adjusting for potential confounders, a different distribution of physical performance across exercise intensities was observed, with better performance being recorded in participants engaged in more vigorous activities. Our findings suggest that regular physical activity modifies the age-related pattern of decline in physical performance, with greater benefits observed for more intensive activities. Efforts are needed from health authorities and healthcare providers to promote the large-scale adoption of an active lifestyle throughout the life course.

Assessing Dynamic Balance Performance During Exergaming Based on Speed and Curvature of Body Movements

Improving balance performance among the elderly is of utmost importance because of the increasing number of injuries and fatalities caused by fall incidences. Digital games controlled by body movements (exergames) have been proposed as a way to improve balance among older people. However, the assessment of balance performance in real-time during exergaming remains a challenging task. This assessment could be used to provide instantaneous feedback and automatically adjust the exergame difficulty. Such features could potentially increase the motivation of the player, thus augmenting the effectiveness of exergames. As clear differences in balance performance have been identified between older and younger people, distinguishing between older and younger adults can help identifying measures of balance performance. We used generalized linear models to investigate whether the assessment of balance performance based on movement speed can be improved by incorporating curvature of the movement trajectory into the analysis. Indeed, our results indicated that curvature improves the performance of the models. Five-fold cross validation indicated that our method is promising for the assessment of balance performance in real-time by showing more than 90% classification accuracy. Finally, this method could be valuable not only for exergaming, but also for real-time assessment of body movements in sports, rehabilitation, and medicine.

Executive Network Activation is Linked to Walking Speed in Older Adults: Functional MRI and TCD Ultrasound Evidence From the MOBILIZE Boston Study

BACKGROUND

Changes in cerebral blood flow velocity (CBF) in response to a cognitive task (task-related ΔCBF) have been shown by Transcranial Doppler ultrasonography (TCD) to be reduced in slow walkers. However, it is unknown whether reduced task-related ΔCBF is associated with reduced neural activity in specific brain regions, as measured by blood-oxygen-level dependent (BOLD) functional magnetic resonance imaging (fMRI).

METHODS

We assessed the regional changes in neural activity associated with reduced middle cerebral artery (MCA) task-related ΔCBF to an executive task and slow walking speed in 67 community-dwelling older adults from the MOBILIZE Boston Study. Participants underwent walking assessments and TCD ultrasonography measures of MCA ΔCBF during the n-back task of executive function. A subset of participants (n = 27) completed the same task during fMRI. Individual BOLD activation maps for the n-back task were correlated with TCD measures and network-level averages were associated with TCD and preferred walking speed.

RESULTS

Participants with diminished task-related ΔCBF walked more slowly (β = .39, p = .001). fMRI revealed significant associations between task-related ΔCBF and regional BOLD activation in several brain regions/networks supplied by the MCA. Of these regions and networks, those within the executive network were most strongly associated with walking speed (β = .36, p = .01).

CONCLUSIONS

Task-related ΔCBF during an executive function task is related to activation in several neural networks and impairment in the ability to recruit the executive network in particular is associated with slow walking speed in older adults.

Usual Alcohol Consumption and Risks for Nonfatal Fall Injuries in the United States: Results From the 2004-2013 National Health Interview Survey

BACKGROUND

Acute alcohol consumption is known to be a risk factor for fall injuries.

OBJECTIVE

The study sought to determine whether usual alcohol consumption increases the risk for nonfatal fall injuries.

METHOD

Data from 289,187 sample adults in the 2004-2013 U.S. National Health Interview Surveys were analyzed. Of these, 3,368 (∼1%) reported a total of 3,579 fall-injury episodes requiring medical consultation in the past 3 months. Latent class analysis based on four contextual indicators identified four ecological subtypes of fall injury within two age groups (18-49 and 50+). Five drinking patterns (i.e., lifetime abstainer, former drinker, low-risk drinker, increased-risk drinker, and highest-risk drinker) were categorized according to the National Institute on Alcohol Abuse and Alcoholism (NIAAA) low-risk drinking guidelines. Controlling for potential confounders, negative binomial regression estimated the adjusted rates of any type and subtypes of fall injury, by gender, for each drinking pattern relative to lifetime abstainer.

RESULTS

Compared with lifetime abstainers, the adjusted rate of any fall injury for adults ages 18-49 was significantly higher among highest-risk drinkers (men: incidence rate ratio [IRR] = 2.59, 95% confidence interval [CI] [1.60, 4.20]; women: IRR = 1.90, 95% CI [1.24, 2.91]) and increased-risk drinkers (men: IRR = 1.94, 95% CI [1.25, 3.00]; women: IRR = 1.51, 95% CI [1.11, 2.07]). Furthermore, highest-risk drinkers had higher adjusted rates of either leisure- or sports-related fall injuries than lifetime abstainers.

CONCLUSIONS

Alcohol consumption exceeding NIAAA's low-risk drinking guidelines is associated with elevated rates of nonfatal fall injuries. Findings underscore the importance of adhering to these recommendations.

Instrumented Assessment of Physical Activity Is Associated With Muscle Function but Not With Muscle Mass in a General Population

OBJECTIVES

Self-reported physical activity has shown to affect muscle-related parameters. As self-report is likely biased, this study aimed to assess the association between instrumented assessment of physical activity (I-PA) and muscle-related parameters in a general population.

METHOD

Included were 156 young-to-middle-aged and 80 older community-dwelling adults. Seven days of trunk accelerometry (DynaPort MoveMonitor, McRoberts B.V.) quantified daily physical activity (i.e., active/inactive duration, number and mean duration of active/inactive periods, and number of steps per day). Muscle-related parameters included muscle mass, handgrip strength, and gait speed.

RESULTS

I-PA was associated with handgrip strength in young-to-middle-aged adults and with gait speed in older adults. I-PA was not associated with muscle mass in either age group.

DISCUSSION

The association between I-PA and muscle-related parameters was age dependent. The lack of an association between I-PA and muscle mass indicates the relevance of muscle function rather than muscle mass.

van de Gronde J, J. C. Lamoth C, van Diest M, M. Maurits N, B. T. M. Roerdink J. Visual Data Exploration for Balance Quantification in Real-Time During Exergaming

Unintentional injuries are among the ten leading causes of death in older adults; falls cause 60% of these deaths. Despite their effectiveness to improve balance and reduce the risk of falls, balance training programs have several drawbacks in practice, such as lack of engaging elements, boring exercises, and the effort and cost of travelling, ultimately resulting in low adherence. Exergames, that is, digital games controlled by body movements, have been proposed as an alternative to improve balance. One of the main challenges for exergames is to automatically quantify balance during game-play in order to adapt the game difficulty according to the skills of the player. Here we perform a multidimensional exploratory data analysis, using visualization techniques, to find useful measures for quantifying balance in real-time. First, we visualize exergaming data, derived from 400 force plate recordings of 40 participants from 20 to 79 years and 10 trials per participant, as heat maps and violin plots to get quick insight into the nature of the data. Second, we extract known and new features from the data, such as instantaneous speed, measures of dispersion, turbulence measures derived from speed, and curvature values. Finally, we analyze and visualize these features using several visualizations such as a heat map, overlapping violin plots, a parallel coordinate plot, a projection of the two first principal components, and a scatter plot matrix. Our visualizations and findings suggest that heat maps and violin plots can provide quick insight and directions for further data exploration. The most promising measures to quantify balance in real-time are speed, curvature and a turbulence measure, because these measures show age-related changes in balance performance. The next step is to apply the present techniques to data of whole body movements as recorded by devices such as Kinect.