Objective assessment of activity, energy expenditure, and functional limitations in older men: the Osteoporotic Fractures in Men study

Accelerometer-measured sedentary behavior and risk of functional disability in older Japanese adults: a 9-year prospective cohort study

BACKGROUND

The associations of sedentary time and patterns with functional disability among older adults remain unclear, and few studies have accounted for the co-dependency of sedentary behavior and physical activities when modeling sedentary behavior with risk of functional disability. We aimed to examine the associations between sedentary time and patterns and risk of incident functional disability, and assess whether replacing sedentary time with light physical activity (LPA) or moderate-to-vigorous intensity physical activity (MVPA) is associated with reduced risk of functional disability in community-dwelling older adults.

METHODS

A total of 1,687 Japanese adults aged ≥ 65 years without functional disability at baseline were prospectively followed-up for 9 years (2011-2020). Functional disability was ascertained using the national database of Japan's Long-term Care Insurance System. Sedentary time and patterns, LPA, and MVPA were measured using a tri-axial accelerometer secured to participants' waists.

RESULTS

During follow-up, 466 participants developed functional disability. Compared with the lowest quartile of total sedentary time, the multivariable-adjusted hazard ratios (95% confidence intervals) of functional disability for the second, third, and top quartiles were 1.21 (0.91‒1.62), 1.45 (1.10‒1.92), and 1.40 (1.05‒1.88) (p for trend = 0.01). After further adjusting for MVPA, total sedentary time was no longer significantly associated with the risk of functional disability (p for trend = 0.41). Replacing 10 min/day of sedentary time with the same amount of MVPA (but not LPA) was significantly associated with a 12% reduced risk of functional disability (hazard ratio [95% confidence interval]: 0.88 [0.84‒0.92]). No significant association was observed between sedentary bout length and functional disability.

CONCLUSION

Higher levels of total sedentary time were associated with an increased risk of incident functional disability. However, this association was not independent of MVPA. Replacing sedentary time with MVPA, but not LPA, was associated with reduced risk of functional disability in older adults.

Changes in Objectively Measured Physical Activity Are Associated With Perceived Physical and Mental Fatigability in Older Men

BACKGROUND

Lower physical activity (PA) is associated with greater perceived fatigability, a person-centered outcome. The association between change in PA and fatigability with advanced age has yet to be established.

METHODS

Community-dwelling older men (N = 1 113, age = 84.1 ± 3.9 years at Year 14) had free-living PA assessed using SenseWear Armband prospectively at Year 7 (2007-2009) and Year 14 (2014-2016) of Osteoporotic Fractures in Men Study, a longitudinal cohort established in 2000 (baseline). We categorized percent changes in PA into groups (large decline → large increase) for 4 metrics: step count, light intensity PA (LIPA, metabolic equivalents [METs] >1.5 to <3.0), moderate-to-vigorous PA (MVPA, METs ≥ 3.0), and sedentary behavior (SB, METs ≤ 1.5, excluding sleep). Perceived physical and mental fatigability were measured (Year 14) with the Pittsburgh Fatigability Scale (PFS, higher score = greater fatigability; range = 0-50). Associations between each metric of percent changes in PA and fatigability were examined using linear regression, adjusted for demographics, change in health conditions, and Year 7 step count or total PA (METs > 1.5).

RESULTS

Men declined 2 336 ± 2 546 (34%) steps/d, 24 ± 31 (25%) LIPA min/d, 33 ± 58 (19%) MVPA min/d, and increased 40 ± 107 (6%) SB min/d over 7.2 ± 0.7 years. Compared to large decline (% change less than -50%), those that maintained or increased step count had 3-8 points lower PFS Physical scores; those who maintained or increased LIPA and MVPA had 2-3 and 2-4 points lower PFS Physical scores, respectively (all p ≤ .01). Associations were similar, but smaller, for PFS Mental scores.

CONCLUSION

Older men who maintained or increased PA had lower fatigability, independent of initial PA. Our findings inform the types and doses of PA that should be targeted to reduce fatigability in older adults.

Historical development of accelerometry measures and methods for physical activity and sedentary behavior research worldwide: A scoping review of observational studies of adults

This scoping review identified observational studies of adults that utilized accelerometry to assess physical activity and sedentary behavior. Key elements on accelerometry data collection were abstracted to describe current practices and completeness of reporting. We searched three databases (PubMed, Web of Science, and SPORTDiscus) on June 1, 2021 for articles published up to that date. We included studies of non-institutionalized adults with an analytic sample size of at least 500. The search returned 5686 unique records. After reviewing 1027 full-text publications, we identified and abstracted accelerometry characteristics on 155 unique observational studies (154 cross-sectional/cohort studies and 1 case control study). The countries with the highest number of studies included the United States, the United Kingdom, and Japan. Fewer studies were identified from the continent of Africa. Five of these studies were distributed donor studies, where participants connected their devices to an application and voluntarily shared data with researchers. Data collection occurred between 1999 to 2019. Most studies used one accelerometer (94.2%), but 8 studies (5.2%) used 2 accelerometers and 1 study (0.6%) used 4 accelerometers. Accelerometers were more commonly worn on the hip (48.4%) as compared to the wrist (22.3%), thigh (5.4%), other locations (14.9%), or not reported (9.0%). Overall, 12.7% of the accelerometers collected raw accelerations and 44.6% were worn for 24 hours/day throughout the collection period. The review identified 155 observational studies of adults that collected accelerometry, utilizing a wide range of accelerometer data processing methods. Researchers inconsistently reported key aspects of the process from collection to analysis, which needs addressing to support accurate comparisons across studies.

Social isolation due to COVID-19: impact on loneliness, sedentary behavior, and falls in older adults

OBJECTIVES

The World Health Organization has recommended social isolation to prevent the transmission of COVID-19. Thus, feelings of loneliness, sedentary behavior, and predisposition to falls have been reported more often due to the adoption of social isolation, especially for older adults. The objective of this study was to compare older adults' loneliness, sedentary behavior, and occurrence of falls before and during social isolation due to the pandemic as well as to analyze the association of loneliness with sedentary lifestyle and falls in older adults.

METHOD

Retrospective analytical study conducted through an online survey with older adults from Brazilian states in social isolation, approved by the Research Ethics Committee (number 32168920.0.0000.0068).

RESULTS

There was a significant increase in loneliness and sedentary behavior during social isolation (p-value < 0.05 for both), but no increase was observed for falls (p-value = 0.615). There was no correlation between the outcomes, nor was there a correlation between the outcomes and the number of days in social isolation.

CONCLUSION

The results of this research show that adoption of social isolation due to the COVID-19 pandemic brought an increase in sedentary behavior and loneliness for older adults but had no effect on the number of falls.

Association between physical activity and physical and functional performance in non-institutionalized Mexican older adults: a cohort study

BACKGROUND

Aging is an independent risk factor for deterioration in functional capacity. Some studies have reported that physical activity (PA) improves functional capacity and physical performance among older adults (OA). Thus the objective of the present study was to assess the longitudinal association between PA and functional and physical performance in non-institutionalized OA.

METHODS

A longitudinal analysis using data from the Frailty, Dynapenia and Sarcopenia in Mexican adults (FRADYSMEX, by its Spanish acronym) cohort study was conducted. PA was assessed through the Community Healthy Activities Model Program for Seniors (CHAMPS) instrument. Functionality was measured with the Barthel index and the Lawton and Brody scale, while physical performance was measured with the Short Physical Performance Battery (SPPB). To evaluate the association between the level of PA and physical and functional performance as a continuous variable, a linear regression of mixed effects was performed. To assess PA and dependence in basic activities of the daily life (BADL), instrumental activities of the daily life (IADL), and low physical performance (PP), generalized estimation equation models [to compute odds ratios (OR) and 95% confidence intervals (95%CI)] were computed.

RESULTS

Older people who performed moderate to vigorous-intensity PA had a lower risk of dependence in IADL (OR = 0.17; 95%CI: 0.10, 0.80) and lower risk of low PP (OR = 0.18; 95%CI: 0.11, 0.58) compared to those in lower categories of PA.

CONCLUSIONS

Older adults living in the community who perform PA of moderate to vigorous intensity have a lower risk of dependence in BADL and IADL and have a lower risk of low PP.

The Association of Objectively Measured Physical Activity and Sedentary Behavior with (Instrumental) Activities of Daily Living in Community-Dwelling Older Adults: A Systematic Review

Up to 60% of older adults have a lifestyle characterized by low physical activity (PA) and high sedentary behavior (SB). This can amplify age-related declines in physical and cognitive functions and may therefore affect the ability to complete basic and instrumental activities of daily living (ADL and IADL, respectively), which are essential for independence. This systematic review aims to describe the association of objectively measured PA and SB with ADL and IADL in community-dwelling older adults. Six databases (PubMed, Embase, the Cochrane library, CINAHL, PsychINFO, SPORTDiscuss) were searched from inception to 21/06/2020 for articles meeting our eligibility criteria: 1) observational or experimental study, 2) participants’ mean/median age ≥60 years, 3) community-dwelling older adults, 4) PA and SB were measured with a(n) accelerometer/pedometer, 5) PA and SB were studied in relation to ADL and/or IADL. Risk of bias was assessed in duplicate using modified versions of the Newcastle–Ottawa scale. Effect direction heat maps provided an overview of associations and standardized regression coefficients (βs) were depicted in albatross plots. Thirty articles (6 longitudinal; 24 cross-sectional) were included representing 24,959 (range: 23 to 2749) community-dwelling older adults with mean/median age ranging from 60.0 to 92.3 years (54.6% female). Higher PA and lower SB were associated with better ability to complete ADL and IADL in all longitudinal studies and overall results of cross-sectional studies supported these associations, which underscores the importance of an active lifestyle. The median [interquartile range] of βs for associations of PA/SB with ADL and IADL were, respectively, 0.145 [0.072, 0.280] and 0.135 [0.093, 0.211]. Our strategy to address confounding may have suppressed the true relationship of PA and SB with ADL or IADL because of over-adjustment in some included studies. Future research should aim for standardization in PA and SB assessment to unravel dose–response relationships and inform guidelines.

Physical activity trajectories, mortality, hospitalization, and disability in the Toledo Study of Healthy Aging

BACKGROUND

Physical activity (PA) is a recognized contributor to healthy aging. However, the majority of studies exploring its associations with adverse outcomes in cohorts of older adults use single-time PA estimates, which do not consider its dynamic nature. The aim of the present study is to explore the presence of different PA trajectories in the Toledo Study of Healthy Aging and their association with adverse outcomes. Our hypothesis is that prospectively maintaining or increasing PA is associated with a reduced risk of adverse outcomes.

METHODS

We used data from 1679 participants enrolled in the Toledo Study of Healthy Aging. Trajectories based on the Physical Activity Scale for the Elderly were identified using group-based trajectory modelling. Cox and logistic regression were used to investigate associations between PA trajectories and mortality and hospitalization, and incident and worsening disability, respectively. Mortality was ascertained by linkage to the Spanish National Death Index; disability was evaluated through the Katz Index; and hospitalization was defined as the first admission to Toledo Hospital. Models were adjusted by age, sex, smoking, Charlson Index, education, cognitive impairment, polypharmacy, and Katz Index at Wave 2.

RESULTS

We found four PA-decreasing and one PA-increasing trajectories: high PA-consistent (n = 566), moderate PA-mildly decreasing (n = 392), low PA-increasing (n = 237), moderate PA-consistent (n = 191), and low PA-decreasing (n = 293). Belonging to the high PA-consistent trajectory group was associated with reduced risks of mortality as compared with the low PA-decreasing group [hazard ratio (HR) 1.68; 95% confidence interval (CI) = 1.21-2.31] and hospitalization compared with the low PA-increasing and low PA-decreasing trajectory groups (HR 1.24; 95% CI = 1.004-1.54 and HR 1.25; 95% CI = 1.01-1.55, respectively) and with lower rates of incident [odds ratio (OR) 3.14; 95% CI = 1.59-6.19] and worsening disability (OR 2.16; 95% CI = 1.35-3.45) in relation to the low PA-decreasing trajectory group and at follow-up. Increasing PA during late life (low PA-increasing group) was associated with lower incident disability rates (OR 0.38; 95% CI = 0.19-0.82) compared with decreasing PA (low PA-decreasing group), despite similar baseline PA.

CONCLUSIONS

Our results suggest that sustaining higher PA levels during aging might lead to healthy aging, characterized by a reduction in adverse outcomes. Our study supports the need for enhancing PA participation among older populations, with the goal of reducing personal and economic burden in a worldwide aging population.

The Association Between Objectively Measured Physical Activity and Subsequent Health Care Utilization in Older Men

BACKGROUND

To examine the associations between objective physical activity measures and subsequent health care utilization.

METHODS

We studied 1,283 men (mean age 79.1 years, SD 5.3) participating in the Osteoporotic Fractures in Men Study. Participants wore a SenseWear® Pro Armband monitor for 1 week. Data was summarized as daily (i) step counts, (ii) total energy expenditure, (iii) active energy expenditure, and (iv) activity time (sedentary, ≥ light, ≥ moderate). The outcome measures of 1-year hospitalizations/duration of stay from Medicare data were analyzed with a two-part hurdle model. Covariates included age, clinical center, body mass index, marital status, depressive symptoms, medical conditions, cognitive function, and prior hospitalization.

RESULTS

Each 1 SD = 3,092 step increase in daily step count was associated with a 34% (95% confidence interval [CI]: 19%-46%) lower odds of hospitalization in base model (age and center) and 21% (95% CI: 4%-35%) lower odds of hospitalization in fully adjusted models. Similar but smaller associations held for other physical activity measures, but these associations were not significant in fully adjusted models. Among those hospitalized, higher step count was associated with shorter total duration of acute/postacute care stays in the base model only. There was a fourfold significant difference (from model-based estimates) in predicted care days comparing those with 2,000 versus 10,000 daily steps in the base model, but only a twofold difference (not significant) in the full model.

CONCLUSION

Daily step count is an easily determined measure of physical activity that may be useful in assessment of future health care burden in older men.

Multimodal Intervention to Improve Functional Status in Hypertensive Older Adults: A Pilot Randomized Controlled Trial

This pilot randomized controlled trial (RCT) was designed to provide the preliminary data necessary to conduct a full-scale trial to compare the efficacy of differing first-line antihypertensive medications in improving functional status in older adults, when combined with exercise. The primary objectives were to assess study feasibility, safety, and protocol integrity. Dependent outcomes included gait speed, exercise capacity, body composition, and systemic cardiometabolic biomarkers. Thirty-one physically inactive older adults (70.6 ± 6.1 years) with hypertension and functional limitations were randomly assigned to (1) Perindopril (8 mg/day n = 10), (2) Losartan (100 mg/day; n = 13), or (3) Hydrochlorothiazide (HCTZ: 25 mg/day; n = 8). Participants were also assigned to a 24-week multimodal exercise intervention, separated into an aerobic and concurrent (aerobic + resistance) phase to evaluate potential mode effects. Retention was 84% (26/31), and compliance was >90% and >79% with medication and exercise, respectively. A total of 29 adverse events (Perindopril = 5; Losartan = 12; HCTZ = 11) and one unrelated serious adverse event were observed throughout the trial. Overall, this pilot RCT provided critical data and identified several challenges to ultimately designing and implementing a fully powered trial.

The Association Between Trajectories of Physical Activity and All-Cause and Cause-Specific Mortality

Background

The benefits of physical activity (PA) for health have primarily been evaluated during midlife. Whether patterns of change in late-life PA associate with overall and cause-specific mortality remains unclear.

Methods

We examined the association between PA trajectories and subsequent mortality among 3,767 men aged ≥65 years. Men self-reported PA using the Physical Activity Scale for the Elderly (PASE) at up to four time points from 2000 through 2009 (Year 7); mortality was assessed over an average of 7.1 years after the Year 7 contact. Group-based trajectory modeling identified patterns of PA change. Cox proportional hazards models described associations between patterns of change in PA, Year 7 PA, and subsequent mortality risk.

Results

Three discrete PA patterns were identified, all with declining PA. Compared to low-activity declining men, moderate (hazard ratio [HR] = 0.78; 95% confidence interval [CI]: 0.70, 0.88) and high-activity (HR = 0.69, 95% CI: 0.57, 0.83) declining groups were associated with lower risk of all-cause mortality. Among models with a single time point, the last time point (Year 7 PA score) was a strong predictor of mortality with HR = 0.85 (95% CI: 0.78, 0.93) per SD increase in PASE score. PA patterns were not a risk factor for mortality after adjustment for the Year 7 PA score.

Conclusions

Recent PA levels are a stronger indicator of subsequent mortality risk than PA patterns reported over the prior 7 years or prior PA level, suggesting that current PA rather than history of PA is the most relevant parameter in clinical settings.

Analysis of Physical Activity Among Free-Living Nonagenarians From a Sardinian Longevous Population

Physical activity was identified as a major determinant of longevity. Using wearable accelerometers, we evaluated energy expenditure (EE), including resting- (REE) and total-energy expenditure (TEE), physical activity level (PAL), percentage of PAL ≥ 3 metabolic equivalent tasks (METs), number of steps, resting index (RI%) and sleep patterns in 44 free-living nonagenarians (27 men) residing in a Sardinian village famous for its longevous population. The average REE and TEE recorded were 1275 ± 163 kcal/day and 2284 ± 543 in the men and 952 ± 108 kcal/day and 1810 ± 302 in the women, respectively. The average PAL was 1.8, and the percentage of physical activity >3 METs was greater than 40%. A significant negative correlation (p < 0.05) between disability and PAL was found among the women. This study provides evidence that nonagenarians from the longevous population of Sardinia show excellent physical functionality indexes. Their longevity might result, at least in part, from their ability to stay physically fit during aging.

Sedentary time in older adults: a critical review of measurement, associations with health, and interventions

Sedentary time (ST) is an important risk factor for a variety of health outcomes in older adults. Consensus is needed on future research directions so that collaborative and timely efforts can be made globally to address this modifiable risk factor. In this review, we examined current literature to identify gaps and inform future research priorities on ST and healthy ageing. We reviewed three primary topics:(1) the validity/reliability of self-report measurement tools, (2) the consequences of prolonged ST on geriatric-relevant health outcomes (physical function, cognitive function, mental health, incontinence and quality of life) and(3) the effectiveness of interventions to reduce ST in older adults.

METHODS

A trained librarian created a search strategy that was peer reviewed for completeness.

RESULTS

Self-report assessment of the context and type of ST is important but the tools tend to underestimate total ST. There appears to be an association between ST and geriatric-relevant health outcomes, although there is insufficient longitudinal evidence to determine a dose-response relationship or a threshold for clinically relevant risk. The type of ST may also affect health; some cognitively engaging sedentary behaviours appear to benefit health, while time spent in more passive activities may be detrimental. Short-term feasibility studies of individual-level ST interventions have been conducted; however, few studies have appropriately assessed the impact of these interventions on geriatric-relevant health outcomes, nor have they addressed organisation or environment level changes. Research is specifically needed to inform evidence-based interventions that help maintain functional autonomy among older adults.This consensus statement has been endorsed by the following societies: Academy of Geriatric Physical Therapy, Exercise & Sports Science Australia, Canadian Centre for Activity and Aging, Society of Behavioral Medicine, and the National Centre for Sport and Exercise Medicine.

Biomarkers associated with sedentary behaviour in older adults: A systematic review

OBJECTIVE

Pathomechanisms of sedentary behaviour (SB) are unclear. We conducted a systematic review to investigate the associations between SB and various biomarkers in older adults.

METHODS

Electronic databases were searched (MEDLINE, EMBASE, CINAHL, AMED) up to July 2015 to identify studies with objective or subjective measures of SB, sample size ≥50, mean age ≥60years and accelerometer wear time ≥3days. Methodological quality was appraised with the CASP tool. The protocol was pre-specified (PROSPERO CRD42015023731).

RESULTS

12701 abstracts were retrieved, 275 full text articles further explored, from which 249 were excluded. In the final sample (26 articles) a total of 63 biomarkers were detected. Most investigated markers were: body mass index (BMI, n=15), waist circumference (WC, n=15), blood pressure (n=11), triglycerides (n=12) and high density lipoprotein (HDL, n=15). Some inflammation markers were identified such as interleukin-6, C-reactive protein or tumor necrosis factor alpha. There was a lack of renal, muscle or bone biomarkers. Randomized controlled trials found a positive correlation for SB with BMI, neck circumference, fat mass, HbA1C, cholesterol and insulin levels, cohort studies additionally for WC, leptin, C-peptide, ApoA1 and Low density lipoprotein and a negative correlation for HDL.

CONCLUSION

Most studied biomarkers associated with SB were of cardiovascular or metabolic origin. There is a suggestion of a negative impact of SB on biomarkers but still a paucity of high quality investigations exist. Longitudinal studies with objectively measured SB are needed to further elucidate the pathophysiological pathways and possible associations of unexplored biomarkers.

Effectiveness of a multicomponent exercise program in the attenuation of frailty in long-term nursing home residents: study protocol for a randomized clinical controlled trial

BACKGROUND

There is increasing evidence suggesting that cognition and physical frailty interact within a cycle of decline associated with aging which has been called cognitive frailty. Exercise programs have demonstrated to be an effective tool to prevent functional and cognitive decline during aging, but little is known about their potential to restore or maintain functionality in individuals that require long-term nursing care. Besides, WHO has recently highlighted the importance of introducing systematic musculoskeletal health programs for older people living in residential care, as they represent a particularly vulnerable group for the development of noncommunicable diseases.

METHODS

This is a multicentre randomized controlled trial. 114 participants will be randomly allocated to a usual care group or to an intervention group. Inclusion criteria are as follows: ≥ 70 years, ≥ 50 on the Barthel Index, ≥ 20 on MEC-35 who are capable to stand up and walk independently for 10 m. Subjects in the intervention group will add to the activities scheduled for the control group the participation in a 6 months long multicomponent exercise program designed to improve strength, balance and walking retraining. Study assessments will be conducted at baseline and at 3 and 6 months. The primary outcome is change in function assessed by Short Physical Performance Battery and secondary outcomes include other measurements to assess all together the condition of frailty, which includes functionality, sedentary behaviors, cognitive and emotional status and biological markers. The present study has been approved by the Committee on Ethics in Research of the University of the Basque Country (Humans Committee Code M10/2016/105; Biological Samples Committee Code M30/2016/106).

DISCUSSION

Results from this research will show if ageing related functional and cognitive deterioration can be effectively prevented by physical exercise in institutionalized elders. It is expected that the results of this research will guide clinical practice in nursing home settings, so that clinicians and policymakers can provide more evidence-based practice for the management of institutionalized elder people.

TRIAL REGISTRATION

The protocol has been registered under the Australian and New Zealand Clinical Trials Registry (ANZCTR) with the identifier: ACTRN12616001044415 .

Survey of the Relationship Between Activity Energy Expenditure Metabolic Equivalents and Barrier Factors of Physical Activity in the Elderly in Kashan

BACKGROUND

Physical activity in the elderly is influenced by aspects of aging that cause personal, mental, environmental, and social changes. Increases in factors that are barriers to activity cause physical energy expenditure to decrease.

OBJECTIVES

The aim of the present study was to survey the relationship between energy expenditure in metabolic equivalent units (MET) and factors that are barriers to physical activity in elderly people in Kashan, Iran.

METHODS

This is a descriptive analysis done in 2014. The study population was 400 people above 60 years old in medical facilities in Kashan. Multistage sampling was used in 10 clinics in 5 areas of Kashan. The sample size was varied according to gender and elderly population. Contributors were given questionnaires concerning energy expenditure levels in physical activity and factors that are barriers to being active.

RESULTS

The average age among the study population was 67.6 ± 6.8 years median, and the interquartile range (IQR) of barriers to physical activity among Kashan's elderly was (8.75) ± 33. Average energy expenditure was 326.21 ± 364.84 based on metabolic equivalent units (MET). In fact, 340 persons (85%) were practically without any active energy expenditure. The most common barrier was the lack of an appropriate place for doing physical activity; 298 (74%) of the participants cited this barrier. The results show the Spearman rank-order correlation is significant (P = 0.038, r = 0.104) between barriers to physical activity and activity energy expenditure in Kashan's elderly.

CONCLUSIONS

Decreasing barriers to physical activity among the elderly causes physical activities to increase; therefore, energy expenditure is increased. Decreasing social and environmental problems for the elderly is effective in increasing physical activity and energy expenditure.

Actigraphy features for predicting mobility disability in older adults

Actigraphy has attracted much attention for assessing physical activity in the past decade. Many algorithms have been developed to automate the analysis process, but none has targeted a general model to discover related features for detecting or predicting mobility function, or more specifically, mobility impairment and major mobility disability (MMD). Men (N  =  357) and women (N  =  778) aged 70-89 years wore a tri-axial accelerometer (Actigraph GT3X) on the right hip during free-living conditions for 8.4  ±  3.0 d. One-second epoch data were summarized into 67 features. Several machine learning techniques were used to select features from the free-living condition to predict mobility impairment, defined as 400 m walking speed  <0.80 m s^-1. Selected features were also included in a model to predict the first occurrence of MMD-defined as the loss in the ability to walk 400 m. Each method yielded a similar estimate of 400 m walking speed with a root mean square error of ~0.07 m s^-1 and an R-squared values ranging from 0.37-0.41. Sensitivity and specificity of identifying slow walkers was approximately 70% and 80% for all methods, respectively. The top five features, which were related to movement pace and amount (activity counts and steps), length in activity engagement (bout length), accumulation patterns of activity, and movement variability significantly improved the prediction of MMD beyond that found with common covariates (age, diseases, anthropometry, etc). This study identified a subset of actigraphy features collected in free-living conditions that are moderately accurate in identifying persons with clinically-assessed mobility impaired and significantly improve the prediction of MMD. These findings suggest that the combination of features as opposed to a specific feature is important to consider when choosing features and/or combinations of features for prediction of mobility phenotypes in older adults.

Sensorimotor Peripheral Nerve Function and Physical Activity in Older Men

We determined whether sensorimotor peripheral nerve (PN) function was associated with physical activity (PA) in older men. The Osteoporotic Fractures in Men Study Pittsburgh, PA, site (n = 328, age 78.8 ± 4.7 years) conducted PN testing, including: peroneal motor and sural sensory nerve conduction (latencies, amplitudes: CMAP and SNAP for motor and sensory amplitude, respectively), 1.4g/10g monofilament (dorsum of the great toe), and neuropathy symptoms. ANOVA and multivariate linear regression modeled PN associations with PA (Physical Activity Scale for the Elderly [PASE] and SenseWear Armband). After multivariable adjustment, better motor latency was associated with higher PASE scores (160.5 ± 4.8 vs. 135.6 ± 6.7, p < .01). Those without versus with neuropathy symptoms had higher PASE scores (157.6 ± 5.3 vs. 132.9 ± 7.1, p < .01). Better versus worse SNAP was associated with slightly more daily vigorous activity (9.5 ± 0.8 vs. 7.3 ± 0.7, p = .05). Other PN measures were not associated with PA. Certain PN measures were associated with lower PA, suggesting a potential pathway for disability.

Reliability of Physical Activity Measures During Free-Living Activities in People After Total Knee Arthroplasty

BACKGROUND

Few instruments that measure physical activity (PA) can accurately quantify PA performed at light and moderate intensities, which is particularly relevant in older adults. The evidence of their reliability in free-living conditions is limited.

OBJECTIVE

The study objectives were: (1) to determine the test-retest reliability of the Actigraph (ACT), SenseWear Armband (SWA), and Community Healthy Activities Model Program for Seniors (CHAMPS) questionnaire in assessing free-living PA at light and moderate intensities in people after total knee arthroplasty; (2) to compare the reliability of the 3 instruments relative to each other; and (3) to determine the reliability of commonly used monitoring time frames (24 hours, waking hours, and 10 hours from awakening).

DESIGN

A one-group, repeated-measures design was used.

METHODS

Participants wore the activity monitors for 2 weeks, and the CHAMPS questionnaire was completed at the end of each week. Test-retest reliability was determined by using the intraclass correlation coefficient (ICC [2,k]) to compare PA measures from one week with those from the other week.

RESULTS

Data from 28 participants who reported similar PA during the 2 weeks were included in the analysis. The mean age of these participants was 69 years (SD=8), and 75% of them were women. Reliability ranged from moderate to excellent for the ACT (ICC=.75-.86) and was excellent for the SWA (ICC=.93-.95) and the CHAMPS questionnaire (ICC=.86-.92). The 95% confidence intervals (95% CI) of the ICCs from the SWA were the only ones within the excellent reliability range (.85-.98). The CHAMPS questionnaire showed systematic bias, with less PA being reported in week 2. The reliability of PA measures in the waking-hour time frame was comparable to that in the 24-hour time frame and reflected most PA performed during this period.

LIMITATIONS

Reliability may be lower for time intervals longer than 1 week.

CONCLUSIONS

All PA measures showed good reliability. The reliability of the ACT was lower than those of the SWA and the CHAMPS questionnaire. The SWA provided more precise reliability estimates. Wearing PA monitors during waking hours provided sufficiently reliable measures and can reduce the burden on people wearing them.

A review of the assessment and prevalence of sedentarism in older adults, its physiology/health impact and non-exercise mobility counter-measures

This literature review focuses on aspects of sedentary behaviour (SB) in elderly. Since it has been identified as a distinct health risk, independent of physical activity, SB is a significant issue. This is particularly true for an ageing population as evidence shows that older adults (aged ≥65 years) are the most sedentary age group (on average 8.5–9.6 h daily sitting time). Accurate SB assessment is important for understanding this habitual behaviour and its impact. However, SB measurement is challenging, regardless of the method used. Although negative associations of SB in elderly have been reported for several health outcomes, evidence is inconclusive, apart from the evidence on the adverse SB effect on the all-cause mortality rate. Generally, strategies have been proposed to counteract SB, of which breaking prolonged sedentary bouts with at least light-intensity physical activity seems to be the most promising. Overall, further research in elderly is required to increase the evidence and to either support or refute the current findings. Moreover, further research will help to develop informed SB guidelines for an optimal strategy to counteract SB and its health effects in older adults.

Neighborhood environmental attributes and adults' sedentary behaviors: Review and research agenda

OBJECTIVE

Physical activity recommendations are beginning to address sedentary behaviors - time spent sitting. Environmental and policy initiatives for physical activity might assist in addressing sedentary behaviors, but sedentary-specific innovations may be required. This review synthesizes current evidence on associations of neighborhood environmental attributes with adults' sedentary behaviors.

METHODS

A search was conducted using three electronic databases (PubMed, Web of Science, and Transport Research Information Services). Relevant articles were assessed for their eligibility for inclusion (English-language articles with a quantitative examination of associations of neighborhood environmental attributes with adults' sedentary behaviors).

RESULTS

Within 17 studies meeting inclusion criteria, associations of environmental attributes with sedentary behaviors were examined in 89 instances. Significant associations were found in 28% (n=25) of them; however, non-significant associations were found in 56% (n=50) of these instances. The most consistent association was for lower levels of sedentary behavior among residents of urban compared to regional areas.

CONCLUSIONS

There is a modest but mixed initial evidence in associations of neighborhood environmental attributes with adults' sedentary behaviors. A research agenda required for this emerging field should include the development of more relevant conceptual models, measuring domain-specific sedentary behavior objectively, examining environments in close vicinity of and a larger area around home, and the use of prospective designs.

Novel strategies for sedentary behavior research

PURPOSE

This article reports on the "Novel Strategies for Sedentary Behavior Research" session of the Sedentary Behavior: Identifying Research Priorities workshop.

METHODS

The purpose of this session of the workshop were to propose strategies for accomplishing a research agenda in dealing with sedentary behavior and to consider research priorities for people at high risk for excess sedentary behavior.

RESULTS AND CONCLUSIONS

The four major recommendations from this workshop were as follows: 1) To add repeated objective measures of physical activity and sedentary behavior to existing cohort studies and standardize approaches to measurement and analysis. Epidemiologic studies will be the most efficient design for addressing some research questions. 2) To increase research efficiency, consider the advantages of a network of connected research studies and health systems. Advantages include access to existing data in electronic health records. 3) To carefully select a variety of high-risk study populations and preplan collaboration among studies in intervention research. This strategy can efficiently address the breadth of issues in sedentary behavior research. 4) To include comparative effectiveness designs and pure environmental interventions in intervention research. This strategy facilitates and enhances translation of interventions into practice.

Sedentary behavior is associated with disability status and walking performance, but not cognitive function, in multiple sclerosis

Eighty-two persons with multiple sclerosis wore an accelerometer as a measure of sedentary time (min/day) and completed measures of disability status (self-reported Expanded Disability Status Scale), walking performance (timed 25-foot walk and 6-min walk), and cognitive function (symbol digit modalities test). Accelerometry-measured sedentary time was significantly correlated with disability status scores (r = 0.31, p < 0.01), 6-min walk distance (r = –0.40, p < 0.01), and timed 25-foot walk performance (r = 0.35, p < 0.01), but not cognitive function performance (r = –0.12, p = 0.29).

Accelerometer-monitored sedentary behavior and observed physical function loss

OBJECTIVES

We examined whether objectively measured sedentary behavior is related to subsequent functional loss among community-dwelling adults with or at high risk for knee osteoarthritis.

METHODS

We analyzed longitudinal data (2008-2012) from 1659 Osteoarthritis Initiative participants aged 49 to 83 years in 4 cities. Baseline sedentary time was assessed by accelerometer monitoring. Functional loss (gait speed and chair stand testing) was regressed on baseline sedentary time and covariates (baseline function; socioeconomics [age, gender, race/ethnicity, income, education], health factors [obesity, depression, comorbidities, knee symptoms, knee osteoarthritis severity, prior knee injury, other lower extremity pain, smoking], and moderate-to-vigorous activity).

RESULTS

This cohort spent almost two thirds of their waking hours (average=9.8 h) in sedentary behaviors. Sedentary time was significantly positively associated with subsequent functional loss in both gait speed (-1.66 ft/min decrease per 10% increment sedentary percentage waking hours) and chair stand rate (-0.75 repetitions/min decrease), controlling for covariates.

CONCLUSIONS

Being less sedentary was related to less future decline in function, independent of time spent in moderate-to-vigorous activity. Both limiting sedentary activities and promoting physical activity in adults with knee osteoarthritis may be important in maintaining function.

Breaking-up sedentary time is associated with physical function in older adults

BACKGROUND

Physical function is a key determinant that corresponds to the physiological capacity of older adults to perform normal everyday activities, safely and independently, without undue fatigue. We examined the associations of sedentary behavior (SB), breaks in sedentary time (BST), and moderate-to-vigorous physical activity (MVPA) with physical function in older adults.

METHODS

Physical activity and SB were assessed with accelerometers (ActiGraph, GT1M) and physical function with the Senior Fitness Test battery, among 87 males and 128 females aged between 65 and 94 years. A composite Z-score was created based on the individual scores for each Senior Fitness Test battery item. Associations of SB, BST, and MVPA with physical function were examined, adjusting for demographic attributes, physical independence, and medical status.

RESULTS

A significant positive association was found between BST and the composite physical function Z-score, after adjusting for total SB, MVPA, and potential confounders. MVPA was also positively associated with physical function, after adjusting for SB, BST, and potential confounders. Those with low BST in conjunction with performing less than 30min/d of MVPA had lower physical function.

CONCLUSIONS

Breaking-up sedentary time is associated with better physical function in older adults; and, it may have an important place in future guidelines on preserving older adults' physical function to support activities of daily living.

Statins and physical activity in older men: the osteoporotic fractures in men study

IMPORTANCE

Muscle pain, fatigue, and weakness are common adverse effects of statin medications and may decrease physical activity in older men.

OBJECTIVE

To determine whether statin use is associated with physical activity, longitudinally and cross-sectionally.

DESIGN, SETTING, AND PARTICIPANTS

Men participating in the Osteoporotic Fractures in Men Study (N = 5994), a multicenter prospective cohort study of community-living men 65 years and older, enrolled between March 2000 and April 2002. Follow-up was conducted through 2009.

EXPOSURES

Statin use as determined by an inventory of medications (taken within the last 30 days). In cross-sectional analyses (n = 4137), statin use categories were users and nonusers. In longitudinal analyses (n = 3039), categories were prevalent users (baseline use and throughout the study), new users (initiated use during the study), and nonusers (never used).

MAIN OUTCOMES AND MEASURES

Self-reported physical activity at baseline and 2 follow-up visits using the Physical Activity Scale for the Elderly (PASE). At the third visit, an accelerometer measured metabolic equivalents (METs [kilocalories per kilogram per hour]) and minutes of moderate activity (METs ≥3.0), vigorous activity (METs ≥6.0), and sedentary behavior (METs ≤1.5).

RESULTS

At baseline, 989 men (24%) were users and 3148 (76%) were nonusers. The adjusted difference in baseline PASE between users and nonusers was -5.8 points (95% CI, -10.9 to -0.7 points). A total of 3039 men met the inclusion criteria for longitudinal analysis: 727 (24%) prevalent users, 845 (28%) new users, and 1467 (48%) nonusers. PASE score declined by a mean (95% CI) of 2.5 (2.0 to 3.0) points per year for nonusers and 2.8 (2.1 to 3.5) points per year for prevalent users, a nonstatistical difference (0.3 [-0.5 to 1.0] points). For new users, annual PASE score declined at a faster rate than nonusers (difference of 0.9 [95% CI, 0.1 to 1.7] points). A total of 3071 men had adequate accelerometry data, 1542 (50%) were statin users. Statin users expended less METs (0.03 [95% CI, 0.02-0.04] METs less) and engaged in less moderate physical activity (5.4 [95% CI, 1.9-8.8] fewer minutes per day), less vigorous activity (0.6 [95% CI, 0.1-1.1] fewer minutes per day), and more sedentary behavior (7.6 [95% CI, 2.6-12.4] greater minutes per day).

CONCLUSIONS AND RELEVANCE

Statin use was associated with modestly lower physical activity among community-living men, even after accounting for medical history and other potentially confounding factors. The clinical significance of these findings deserves further investigation.

Low validity of the Sensewear Pro3 activity monitor compared to indirect calorimetry during simulated free living in patients with osteoarthritis of the hip

Background

To validate physical activity estimates by the Sensewear Pro3 activity monitor compared with indirect calorimetry during simulated free living in patients diagnosed with osteoarthritis of the hip pre or post total hip arthroplasty.

Methods

Twenty patients diagnosed with hip osteoarthritis (10 pre- and 10 post total hip arthroplasty; 40% female; age: 63.3 ± 9.0; BMI: 23.7 ± 3.7). All patients completed a 2 hour protocol of simulated free living with 8 different typical physical activity types. Energy consumption (kcal/min) was estimated by the Sense Wear pro3 Armband activity monitor and validated against indirect calorimetry (criterion method) by means of a portable unit (Cosmed K4b²). Bias and variance was analyzed using functional ANOVA.

Results

Mean bias during all activities was 1.5 Kcal/min 95%CI [1.3; 1.8] corresponding to 72% (overestimation). Normal gait speed showed an overestimation of 2.8 Kcal/min, 95%CI [2.3; 3.3] (93%) while an underestimation of -1.1 Kcal/min, 95%CI [-1.8; -0.3] (-25%) was recorded during stair climb. Activities dominated by upper body movements showed large overestimation with 4.37 Kcal/min, 95%CI [3.8; 5.1] (170%) being recorded during gardening. Both bias and variance appeared to be dependent on activity type.

Conclusion

The activity monitor generally overestimated the energy consumption during common activities of low to medium intensity in the patient group. The size and direction of the bias was highly dependent on the activity type which indicates the activity monitor is of limited value in patients with hip osteoarthritis and that the results do not express the real energy expenditure.

Nutrition and protein energy homeostasis in elderly

Protein-energy homeostasis is a major determinant of healthy aging. Inadequate nutritional intakes and physical activity, together with endocrine disturbances are associated with of sarcopenia and frailty. Guidelines from scientific societies mainly address the quantitative aspects of protein and energy nutrition in elderly. Besides these quantitative aspects of protein load, perspective strategies to promote muscle protein synthesis and prevent sarcopenia include pulse feeding, the use of fast proteins and the addition of leucine or citrulline to dietary protein. An integrated management of sarcopenia, taking into account the determinants of muscle wasting, i.e. nutrition, physical activity, anabolic factors such as androgens, vitamin D and n-3 polyunsaturated fatty acids status, needs to be tested in the prevention and treatment of sarcopenia. The importance of physical activity, specifically resistance training, is emphasized, not only in order to facilitate muscle protein anabolism but also to increase appetite and food intake in elderly people at risk of malnutrition. According to present data, healthy nutrition in elderly should respect the guidelines for protein and energy requirement, privilege a Mediterranean way of alimentation, and be associated with a regular physical activity. Further issues relate to the identification of the genetics determinants of protein energy wasting in elderly.