Self-reported Mobility Limitations Research Articles

Early-Life Exposure to War and Later-Life Physical Functional Health.

A growing body of research shows that early-life exposure to war has adverse effects on later-life health. Research has emphasized the importance of exposure timing implicating domain-specific developmental processes and associated critical/sensitive periods. This study looks at the impacts of early childhood war exposure and the repercussions for later-life physical and functional health, with a focus on time of exposure as a source of variability. We use residential histories from the Survey of Health Ageing, and Retirement in Europe linked to external data on the location and timing of hostilities to examine the impact of early-life exposure to World War II on later-life physical and functional health. Exposure to war increases the risk of objective (grip strength, chair rise, and peak expiratory flow) and self-reported (mobility limitations and activities of daily living) measures of functional health. Effects are especially pronounced for those born during the war and for those with more prolonged exposures. There is little evidence that the impact of war is mediated by war-related hardships, socioeconomic conditions, health behaviors, or adult chronic disease. Our results suggest early-life exposure to war has a lasting impact on physical functional health. Exposure appears to largely operate via direct effects, indicative of altered initial development of physical capacity in early life. Because exposure was so pervasive among some cohorts of older individuals, understanding the health of present older European populations requires wrestling with the residual consequences of wartime exposure at the start of their lives.

Association of chronic conditions and physical multimorbidity with new-onset incontinence in a nationwide prospective cohort study of older adults ≥ 50years in China.

The relationship between multimorbidity (i.e. ≥ 2 chronic conditions) and incontinence (i.e. urinary and/or faecal incontinence) is underexplored. This study investigated the association between multimorbidity and incident incontinence in Chinese adults aged ≥50years. Data from the 2011 and 2015 waves of the China Health and Retirement Longitudinal Study were used. The association between 12 chronic conditions, multimorbidity and new-onset incontinence was analysed using weighted logistic regression models. Mediation analysis was conducted to explore the potential mediators (self-reported health, subjective memory, depressive symptoms, disability, cognitive function, handgrip strength, mobility limitations, medications and frailty status) between multimorbidity and incontinence. Among 9,986 individuals aged ≥50years who were continent at baseline, 5.3% (n = 521) were newly incontinent 4years later (incident cases). The risk of incident incontinence increased with physical multimorbidity (OR 2.04, 95% CI 1.62-2.57). Compared to no chronic condition, having 1, 2, 3 and ≥ 4 chronic conditions were associated with incident incontinence with OR (95% CI): 1.41 (1.01-1.97), 1.74 (1.24-2.44), 2.82 (1.93-4.12) and 3.99 (2.29-6.95), respectively. The association between multimorbidity and incontinence was mediated by self-reported health (41.2%), medications (26.6%), mobility limitations (20.9%), depressive symptoms (12.8%), disability (11.6%), subjective memory (8.7%) and frailty status (8.3%). This longitudinal study found that physical multimorbidity and specific chronic conditions may increase the risk of new-onset incontinence among Chinese adults aged ≥50years. Self-reported health, medications and mobility limitations seemed to be important intermediate conditions between multimorbidity and incident incontinence.

Using item response theory to estimate interpretation threshold values for the Frailty Index in community dwelling older adults

BackgroundAlthough the frailty index (FI) is designed as a continuous measure of frailty, thresholds are often needed to guide its interpretation. This study aimed to introduce and demonstrate the utility of an item response theory (IRT) method in estimating FI interpretation thresholds in community-dwelling adults and to compare them with cutoffs estimated using the receiver operating characteristics (ROC) method. MethodsA sample of 1,149 community-dwelling adults (mean[SD], 68[7] years) participated in this cross-sectional study. Participants completed a multi-domain geriatric screen from which the 40-item FI and 3 clinical anchors were computed – namely, (i)self-reported mobility limitations (SRML), (ii)"fair" or "poor" self-rated health (SRH), and (iii) restricted life-space mobility (RLSM). Participants were classified as having SRML-1 if they responded "Yes" to either of the 2 questions regarding walking and stair climbing difficulty and SRML-2 if they reported having walking and stair climbing difficulty. Participants with a Life Space Assessment score <60 points were classified as having RLSM. Threshold values for all anchor questions were estimated using the IRT method and ROC analysis with Youden criterion. ResultsThe proportions of participants with SRML-1, SRML-2, Fair/Poor SRH, and RLSM were 21 %, 8 %, 22 %, and 9 %, respectively. The IRT-based thresholds for SRML-2 (0.26), fair/poor SRH (0.29), and RLSM (0.32) were significantly higher than those for SRML-1 (0.18). ROC-based FI cutoffs were significantly lower than IRT-based values for SRML-2, SRH, and RLSM (0.12 to 0.17), and they varied minimally and non-systematically across the anchors. ConclusionsThe IRT method identifies biologically plausible FI thresholds that could meaningfully complement and contextualize existing thresholds for defining frailty.

Estimating cutpoints of gait speed and sit-to-stand test values for self-reported mobility limitations in a cohort of community-dwelling older adults from Singapore: comparing receiver operating characteristic (ROC) analysis with adjusted predictive modelling

ObjectivesClinical interpretability of the gait speed and 5-times sit-to-stand (5-STS) tests is commonly established by comparing older adults with and without self-reported mobility limitations (SRML) on gait speed and 5-STS performance, and estimating clinical cutpoints for SRML using the receiver operating characteristics (ROC) method. Accumulating evidence, however, suggests that the adjusted predictive modeling (APM) method may be more appropriate to estimate these interpretational cutpoints. Thus, we aimed to compare, in community-dwelling older adults, gait speed and 5-STS cutpoints estimated using the ROC and APM methods. DesignCross-sectional study. Setting and ParticipantsThis study analyzed data from 955 community-dwelling independently walking older adults (73%women) aged ≥60 years (mean, 68; range, 60–88). MethodsParticipants completed the 10-metre gait speed and 5-STS tests. Participants were classified as having SRML if they responded "Yes" to either of the 2 questions regarding walking and stair climbing difficulty. Cutpoints for SRML and its component questions were estimated using ROC analysis with Youden criterion and the APM method. ResultsThe proportions of participants with self-reported walking difficulty, self-reported stair climbing difficulty, and SRML were 10%, 19%, and 22%, respectively. Gait speed and 5-STS time were moderately correlated with each other (r=-0.56) and with the self-reported measures (absolute r-values, 0.39–0.44). ROC-based gait speed cutpoints were 0.14 to 0.16 m/s greater than APM-based cutpoints (P < 0.05) whilst ROC-based 5-STS time cutpoints were 0.8 to 3.3 s lower than APM-based cutpoints (P < 0.05 for walking difficulty). Compared with ROC-based cutpoints, APM-based cutptoints were more precise and they varied monotonically with self-reported walking difficulty, self-reported stair climbing difficulty, and SRML. Conclusions and implicationsIn a sample of 955 older adults, our findings of precise and biologically plausible gait speed and 5-STS cutpoints for SRML estimated using the APM method indicate that this promising method could potentially complement or even replace traditional ROC methods.

Associations of height, weight, and body mass index with handgrip strength: A Bayesian comparison in older adults

Handgrip strength is commonly normalized or stratified by body size to define subgroup-specific cut-points and reference limits values. However, it remains unclear which anthropometric variable is most strongly associated with handgrip strength. We aimed to, in older adults with no self-reported mobility limitations, determine whether height, weight, and body mass index (BMI) were meaningfully associated with handgrip strength. This cross-sectional study included community-dwelling ambulant participants, and we identified 775 older adults who reported no difficulty walking 100m, climbing stairs, and rising from the chair. Handgrip strength was measured with a digital dynamometer. Bayesian linear regression was used to estimate the probabilities that the positive associations of height, weight, and BMI with handgrip strength exceeded 0kg (the null value) and 2.5kg (the clinically meaningful threshold value). Mean handgrip strength was 22.1kg (SD, 4) for women and 32.9kg (SD, 6) for men. Body height, weight, and BMI had >99.9% probabilities of a positive association with handgrip strength; however, the associations of per interquartile increase in body weight and BMI with handgrip strength had low probabilities (<5%) of exceeding the clinically meaningful threshold of 2.5kg. In contrast, body height had the highest probability (99.6%) of a clinically meaningful association with handgrip strength: adjusting for age and gender, handgrip strength was 3.2kg (95% CrI, 2.7 to 3.8) greater in older adults 1.61m tall than in older adults 1.51m tall. In a large sample of mobile-intact older adults, handgrip strength differed meaningfully by body height. Although requiring validation, our findings suggest that future efforts should be directed at normalizing handgrip strength by body height to better define subgroup-specific handgrip weakness. A web-based application (https://sghpt.shinyapps.io/ippts/) was created to allow interactive exploration of predicted values and reference limits of age-, gender-, and height-subgroups.

Changes in Mild Neurocognitive Disorder Status in Mobility Limited Older Primary Care Patients: Implications for Rehabilitative Care.

The aim of the study is to identify potential rehabilitative treatment targets associated with participants' annual cognitive status. A cohort study patients with self-reported mobility limitation who completed neuropsychological, physical performance testing, and questionnaires at baseline to 2-year follow-up were categorized into three groups (persistently cognitively normal, nonpersistent mild neurocognitive disorder, and persistently mild neurocognitive disorder) based on their annual cognitive status using baseline, years 1 and 2 performance on Hopkins Verbal Learning, Trail Making, and Digit Symbol Substitution Tests. Repeated measures multinomial regression analysis was used to examine the differences between groups and associated characteristics. Study included 349 participants (mean age, 76 ± 7) with 57% of participants were persistently cognitively normal, 16% persistently mild neurocognitive disorder, and 27% nonpersistent mild neurocognitive disorder over 2 yrs of follow-up. Faster gait speed (relative risk reduction, 0.64-0.89) was associated with risk reduction and increase in depressive symptoms (relative risk reduction, 1.09-1.12) was associated with greater risk of being classified into the nonpersistent or persistently mild neurocognitive disorder compared with persistently cognitively normal. Variability across cognitive status over time was observed. Gait speed and depressive symptoms were modifiable risk factors associated with nonpersistent and persistent mild neurocognitive disorder status. This study reinforces the potential benefit of multifaceted rehabilitation for preventing and treating older adults with mobility and/or cognitive problems.

ASSOCIATIONS BETWEEN NEIGHBORHOOD DISADVANTAGE AND MOBILITY LIMITATIONS AMONG AFRICAN AMERICANS

Abstract Research has shown that socioeconomic factors influence physical mobility; however, less is known about the influence of neighborhood disadvantage on mobility among African American older adults. Data from the Baltimore Study of Black Aging (N=602) were used to examine associations between neighborhood disadvantage, as measured by the Area Deprivation Index (ADI), and self-reported mobility limitations. Two-step logistic regression showed that participants residing in more disadvantaged neighborhoods, based on national ADI, had higher odds of mobility limitations, but those in less disadvantaged neighborhoods, based on state ADI, had higher odds of mobility limitations (national: OR = 1.02 (95% CI: 1.00–1.03); state: OR = 0.78 (95% CI: 0.65–0.92)). Stratified models showed the association was significant only within women (national: OR = 1.02 (95% CI: 1.00–1.04); state: OR = 0.77 (0.63-0.95)). These findings suggest that neighborhood disadvantage is an essential consideration when examining mobility limitations among African Americans.

The Benefit of Virtual Outpatient Rehabilitative Care: a Pilot Study

<h3>Research Objectives</h3> To examine the feasibility of the Live Long Walk Strong (LLWS) rehabilitation program delivered via telehealth. Secondary objectives are to examine the preliminary efficacy of LLWS on mobility and exercise self-efficacy. <h3>Design</h3> Nonrandomized, noncontrolled pilot with 16-week follow-up. <h3>Setting</h3> Ambulatory Care at the VA Boston Healthcare System. <h3>Participants</h3> Community-dwelling Veterans, aged 50 years and older. <h3>Interventions</h3> An evidence-based outpatient rehabilitation program was adapted as a telehealth program during year one of the COVID-19 pandemic. It included 10 sessions with a physical therapist over 8 weeks via VA Video Connect. LLWS uniquely addresses impairments linked to mobility decline and behavior change strategies targeting exercise adoption. <h3>Main Outcome Measures</h3> The primary outcome was feasibility measured by recruitment and retention, number and type of technology problems, and completion of program components. Secondary outcomes included the Activity Measure for Post-Acute Care (AM-PAC) outpatient mobility measure and the Self-Efficacy for Exercise (SEE) scale. <h3>Results</h3> After contacting 178 primary care patients with self-reported mobility limitations, 21 enrolled in the study (12%). Seven never initiated the study due to intercurrent medical issues (n=5) and delayed disclosure of participation in another exercise study (n=2). Participants averaged 2 technology interruptions. Over 99% of the technology issues were resolved by the PT and fell into 2 broad categories of connectivity and ease of use. Attendance rate was 98% across all intervention visits. We examined the change in self-reported mobility and self-efficacy from baseline through follow-up using linear mixed models with a fixed effect of time. The AM-PAC scores improved from baseline by average of 4.1 points (p = 0.019) at 2 weeks follow-up and remained (4.2 points, p=0.014) at 16 weeks follow-up. This improvement in mobility surpassed clinically meaningful levels. The change in self-efficacy (0.9 points) was not statistically significant. <h3>Conclusions</h3> The telehealth LLWS program appears feasible and capable to produce both short and long term improvements in physical functioning. Its benefits need to be tested in studies scaled to better evaluate efficacy and effectiveness. <h3>Author(s) Disclosures</h3> VA RR&D Merit Award #5I01RX003095-03

Reference Ranges for Gait Speed and Sit-to-Stand Performance in a Cohort of Mobility-Intact Community-Dwelling Older Adults From Singapore.

Slow gait speed and sit-to-stand performance are associated with adverse clinical outcomes in older adults. Identifying older adults with functional performance "below norms" is the first step toward prevention. We aimed to (1) examine the associations of age, body height, and gender with gait speed and sit-to-stand performance and (2) develop subgroup-specific reference ranges in older adults with no self-reported mobility limitations. Cross-sectional study. This study analyzed data from 775 community-dwelling older adults who reported no difficulty walking 100m, climbing stairs, and rising from the chair. Gait speed and sit-to-stand performance were measured by the 10-m gait speed test and 5-times sit-to-stand test, respectively. Bayesian linear regression was used to derive 95% reference ranges for gait speed and sit-to-stand performance, defined by different levels of age, body height, and gender. Overall, 95% reference range was 0.89-1.79m/s for habitual gait speed and 7.4-27.9 stands/30s for sit-to-stand pace. Age had the highest posterior probability (>99%) of a meaningful association with both functional outcomes. Additionally, height was strongly associated with gait speed: a 10-cm increase in height was associated with 0.07m/s (95% credible interval, 0.05-0.10) faster gait speed. For sit-to-stand test, the lower 95% reference range limits tended to be similar across gender and gender-specific height subgroups, owing to the associations of faster sit-to-stand pace with shorter height and male gender. Because extensive tables of reference ranges are impractical, a web-based application (https://sghpt.shinyapps.io/ippts/) is created to provide subgroup-specific reference ranges. In a large sample of mobile-intact older adults, reference ranges for gait speed and sit-to-stand performance differed meaningfully by age. Furthermore, gait speed was stature dependent. Although requiring validation, our findings may be used to define subgroup-specific "below-range" values and to complement existing universal clinical cut points for gait speed and sit-to-stand performance.

Animal foods and mobility limitations in community-dwelling young-old adults: longitudinal analysis of the EpiDoC cohort

BackgroundNutrition and particularly protein play a role in optimally stimulating muscle protein synthesis and maintaining function. Animal foods are excellent sources of high-quality protein. Therefore, we aimed to determine the association between the consumption of animal foods and mobility limitations in young-old adults.MethodsThe analytic sample was composed of 2860 community-dwelling adults aged 50 and over from a nationally representative longitudinal cohort of Portuguese adults who were followed up to 2.7 years. An animal food intake score was derived from the frequency of consumption of meat, fish, and dairy products. Mobility limitations were defined as the difficulty standing up from a chair, walking, and climbing stairs. To determine the association between animal food intake and mobility limitations mixed effects logistic models were fitted.ResultsAssociations between quartiles of animal food intake and mobility limitations (for example, for walking outdoors Quartile 4 v Q1: OR: 0.29; 95%CI: 0.15, 0.56) in unadjusted models were present, but there was no difference in the rate of change of mobility limitations over time in unadjusted models. These associations were no longer present when models were adjusted for sociodemographic, lifestyle and health variables. For example, participants in Q4 of animal food intake were not more or less likely to have difficulty climbing stairs than those in Q1 (OR: 0.95; 95%CI: 0.65, 1.38) nor have a different rate of change over time (OR: 0.86; 95%CI: 0.54, 1.37).ConclusionsNo convincing evidence was found to support an effect of animal foods intake measured at baseline on self-reported mobility limitations over a short period of time.

The cost effectiveness of personalized dietary advice to increase protein intake in older adults with lower habitual protein intake: a randomized controlled trial

PurposeTo examine the cost effectiveness of dietary advice to increase protein intake on 6-month change in physical functioning among older adults.MethodsIn this multicenter randomized controlled trial, 276 community-dwelling older adults with a habitual protein intake < 1.0 g/kg adjusted body weight (aBW)/d were randomly assigned to either Intervention 1; advice to increase protein intake to ≥ 1.2 g/kg aBW/d (PROT, n = 96), Intervention 2; similar advice and in addition advice to consume protein (en)rich(ed) foods within half an hour after usual physical activity (PROT + TIMING, n = 89), or continue the habitual diet with no advice (CON, n = 91). Primary outcome was 6-month change in 400-m walk time. Secondary outcomes were 6-month change in physical performance, leg extension strength, grip strength, body composition, self-reported mobility limitations and quality of life. We evaluated cost effectiveness from a societal perspective.ResultsCompared to CON, a positive effect on walk time was observed for PROT; – 12.4 s (95%CI, – 21.8 to – 2.9), and for PROT + TIMING; – 4.9 s (95%CI, – 14.5 to 4.7). Leg extension strength significantly increased in PROT (+ 32.6 N (95%CI, 10.6–54.5)) and PROT + TIMING (+ 24.3 N (95%CI, 0.2–48.5)) compared to CON. No significant intervention effects were observed for the other secondary outcomes. From a societal perspective, PROT was cost effective compared to CON.ConclusionDietary advice to increase protein intake to ≥ 1.2 g/kg aBW/d improved 400-m walk time and leg strength among older adults with a lower habitual protein intake. From a societal perspective, PROT was considered cost-effective compared to CON. These findings support the need for re-evaluating the protein RDA of 0.8 g/kg BW/d for older adults.Trial registrationThe trial has been registered at ClinicalTrials.gov (NCT03712306). Date of registration: October 2018. Registry name: The (Cost) Effectiveness of Increasing Protein Intake on Physical Functioning in Older Adults. Trial Identifier: NCT03712306.

What Cut-Point in Gait Speed Best Discriminates Community-Dwelling Older Adults With Mobility Complaints From Those Without? A Pooled Analysis From the Sarcopenia Definitions and Outcomes Consortium.

Cut-points to define slow walking speed have largely been derived from expert opinion. Study participants (13 589 men and 5043 women aged ≥65years) had walking speed (m/s) measured over 4-6 m (mean ± SD: 1.20 ± 0.27 m/s in men and 0.94 ± 0.24 m/s in women.) Mobility limitation was defined as any self-reported difficulty with walking approximately 1/4 mile (prevalence: 12.6% men, 26.4% women). Sex-stratified classification and regression tree (CART) models with 10-fold cross-validation identified walking speed cut-points that optimally discriminated those who reported mobility limitation from those who did not. Among 5043 women, CART analysis identified 2 cut-points, classifying 4144 (82.2%) with walking speed ≥0.75 m/s, which we labeled as "fast"; 478 (9.5%) as "intermediate" (walking speed ≥0.62 m/s but <0.75 m/s); and 421 (8.3%) as "slow" (walking speed <0.62 m/s). Among 13 589 men, CART analysis identified 3 cut-points, classifying 10 001 (73.6%) with walking speed ≥1.00 m/s ("very fast"); 2901 (21.3%) as "fast" (walking speed ≥0.74 m/s but <1.00 m/s); 497 (3.7%) as "intermediate" (walking speed ≥0.57 m/s but <0.74 m/s); and 190 (1.4%) as "slow" (walking speed <0.57 m/s). Prevalence of self-reported mobility limitation was lowest in the "fast" or "very fast" (11% for men and 19% for women) and highest in the "slow" (60.5% in men and 71.0% in women). Rounding the 2 slower cut-points to 0.60 m/s and 0.75 m/s reclassified very few participants. Cut-points in walking speed of approximately 0.60 m/s and 0.75 m/s discriminate those with self-reported mobility limitation from those without.

Body Weight, BMI, Percent Fat and Associations with Mortality and Incident Mobility Limitation in Older Men.

How different measures of adiposity are similarly or differentially related to mobility limitation and mortality is not clear. In total, 5849 community-dwelling men aged ≥65 years (mean age: 72 years) were followed mortality over 10 years and self-reported mobility limitations (any difficulty walking 2–3 blocks or with climbing 10 steps) at six contacts over 14 years. Baseline measures of adiposity included weight, BMI and percent fat by DXA. Appendicular lean mass (ALM, by DXA) was analyzed as ALM/ht2. Proportional hazards models estimated the risk of mortality, and repeated measures generalized estimating equations estimated the likelihood of mobility limitation. Over 10 years, 27.9% of men died; over 14 years, 48.0% of men reported at least one mobility limitation. We observed U-shaped relationships between weight, BMI, percent fat and ALM/ht2 with mortality. There was a clear log-linear relationship between weight, BMI and percent fat with incident mobility limitation, with higher values associated with a greater likelihood of mobility limitation. In contrast, there was a U-shaped relationship between ALM/ht2 and incident mobility limitation. These observational data suggest that no single measure of adiposity or body composition reflects both the lowest risk of mortality and the lowest likelihood for developing mobility limitation in older men.

Clinically Important Differences for Mobility Measures Derived from the Testosterone Trials.

Accurate estimates of clinically important difference (CID) are required for interpreting the clinical importance of treatments to improve physical function, but CID estimates vary in different disease populations. We determined the CID for two common measures of walking ability in mobility-limited older men. Longitudinal, multisite placebo-controlled trial. Men enrolled in the Testosterone Trials who had self-reported mobility limitation and gait speed less than 1.2 m/second (n = 429). Testosterone- and placebo-allocated participants were combined for this study. Mean changes from baseline, adjusting for time-in-intervention and site, were 29.6, 13.2, 12.5, -2.4, and -32.6 m for 6MWD, and 15.4, 7.2, 2.1, -3.4, and -7.2 for PF10 in men who reported their mobility was "very/much better," "little better," "no change," "little worse," or "much worse," respectively. CID estimates using regression, ROC, and eCDF varied from 5.0-29.6 m for 6MWD, and 5.0-15.2 points for PF10. CID estimates vary by the population studied and by the method and precision of measurement. Increases of 16 to 30 m for 6MWD and 5 to 15 points for PF10 over 12 months appear to be clinically meaningful in mobility-limited, older hypogonadal men. These CID estimates may be useful in the design of efficacy trials of therapies to improve physical function.

Physical activity coaching for adults with mobility limitations: protocol for the ComeBACK pragmatic hybrid effectiveness-implementation type 1 randomised controlled trial

IntroductionMobility limitation is common and often results from neurological and musculoskeletal health conditions, ageing and/or physical inactivity. In consultation with consumers, clinicians and policymakers, we have developed two affordable and...

Effectiveness and cost-effectiveness of personalised dietary advice aiming at increasing protein intake on physical functioning in community-dwelling older adults with lower habitual protein intake: rationale and design of the PROMISS randomised controlled trial.

IntroductionShort-term metabolic and observational studies suggest that protein intake above the recommended dietary allowance of 0.83 g/kg body weight (BW)/day may support preservation of lean body mass and physical function in old age, but evidence from randomised controlled trials is inconclusive.Methods and analysisThe PRevention Of Malnutrition In Senior Subjects in the EU (PROMISS) trial examines the effect of personalised dietary advice aiming at increasing protein intake with or without advice regarding timing of protein intake to close proximity of usual physical activity, on change in physical functioning after 6 months among community-dwelling older adults (≥65 years) with a habitual protein intake of <1.0 g/kg adjusted (a)BW/day. Participants (n=264) will be recruited in Finland and the Netherlands, and will be randomised into three groups; two intervention groups and one control group. Intervention group 1 (n=88) receives personalised dietary advice and protein-enriched food products in order to increase their protein intake to at least 1.2 g/kg aBW/day. Intervention group 2 (n=88) receives the same advice as described for intervention group 1, and in addition advice to consume 7.5–10 g protein through protein-(en)rich(ed) foods within half an hour after performing usual physical activity. The control group (n=88) receives no intervention. All participants will be invited to attend lectures not related to health. The primary outcome is a 6-month change in physical functioning measured by change in walk time using a 400 m walk test. Secondary outcomes are: 6-month change in the Short Physical Performance Battery score, muscle strength, body composition, self-reported mobility limitations, quality of life, incidence of frailty, incidence of sarcopenia risk and incidence of malnutrition. We also investigate cost-effectiveness by change in healthcare costs.DiscussionThe PROMISS trial will provide evidence whether increasing protein intake, and additionally optimising the timing of protein intake, has a positive effect on the course of physical functioning after 6 months among community-dwelling older adults with a habitual protein intake of <1.0 g/kg aBW/day.Ethics and disseminationThe study has been approved by the Ethics Committee of the Helsinki University Central Hospital, Finland (ID of the approval: HUS/1530/2018) and The Medical Ethical Committee of the Amsterdam UMC, location VUmc, Amsterdam, the Netherlands (ID of the approval: 2018.399). All participants provided written informed consent prior to being enrolled onto the study. Results will be submitted for publication in peer-reviewed journals and will be made available to stakeholders (ie, older adults, healthcare professionals and industry).Trial registration numberClinicalTrials.gov Registry (NCT03712306).

Working conditions mediate the association between social class and physical function in older age in Sweden: a prospective cohort study

BackgroundGlobal demographics are changing as societies all over the world are aging. This puts focus on maintaining functional ability and independence into older age. Individuals from lower social classes are at greater risk of developing limitations in physical function later in life. In this study, we investigated the mediating role of working conditions in the association between occupation-based social class and physical function measured as self-reported mobility limitations and objectively measured physical impairment in older age.MethodsTwo Swedish surveys, linked at the individual level, were used (n = 676–814 depending on the outcome). Follow-up time was 20–24 years. Multiple logistic regression analyses were performed with adjustments for age, sex, level of education, mobility, and health problems at baseline. This was followed by analyses of the size of the mediating effect of working conditions.ResultsWorking conditions seem to mediate 35–74% of the association between social class and physical impairment in older age. The pattern of mediation was primarily driven by passive jobs, i.e., low psychological demands and low control, among blue-collar workers. Working conditions did not mediate the association between social class and self-reported mobility limitations in older age.ConclusionsThe results of this study indicate that working conditions are important in combating the social gradient in healthy aging, contributing to the evidence regarding the magnitude of impact exerted by both the physical and psychosocial work environment separately and in conjunction.

Development of a Predictive Algorithm to Identify Adults With Mobility Limitations Using VA Health Care Administrative Data

An estimated 31.5 million Americans have a mobility limitation. Health care administrative data could be a valuable resource for research on this population but methods for cohort identification are lacking. We developed and tested an algorithm to reliably identify adults with mobility limitation in U.S. Department of Veterans Affairs health care data. We linked diagnosis, encounter, durable medical equipment, and demographic data for 964 veterans to their self-reported mobility limitation from the Medicare Current Beneficiary Survey. We evaluated performance of logistic regression models in classifying mobility limitation. The binary approach (yes/no limitation) had good sensitivity (70%) and specificity (79%), whereas the multilevel approach did not perform well. The algorithms for predicting a binary mobility limitation outcome performed well at discriminating between veterans who did and did not have mobility limitation. Future work should focus on multilevel approaches to predicting mobility limitation and samples with greater proportions of women and younger adults.

Body Weight, BMI, Percent Fat, Lean Mass and Their Long-Term Associations with Mortality and Incident Mobility Limitation

Abstract Objectives Adiposity is often approximated by body mass index (BMI), weight, and % fat from dual energy x-ray absorptiometry (DXA). We aimed to describe how different measures of adiposity and body composition are similarly or differentially related to mobility limitation and mortality. Methods Older community-dwelling men aged ≥65 yrs were followed for 10 years for mortality (N = 5849) and at six study contacts over 14 year for self-reported mobility limitations (any difficulty walking 2–3 blocks or with climbing 10 steps, N = 5841). Baseline measures of adiposity included weight, BMI, % fat by DXA. Appendicular lean mass (ALM, by DXA) was analyzed as ALM/ht2. Proportional hazards models estimated the risk of mortality and repeated measures generalized estimating equations estimated the likelihood of mobility limitation. Adiposity and ALM/ht2 measures were analyzed as quintiles and with splines. Results Over 10 years, 27.9% of men died; over 14 years, 48.0% of men reported at least one mobility limitation. We observed U-shaped relationships between weight, BMI, % fat and ALM/ht2 with mortality. There was a log-linear relationship between weight, BMI and % fat with incident mobility limitation, with higher values associated with greater likelihood of mobility limitation: for those with the lowest values of each of these metrics (quintile 1), the likelihood of mobility limitation was 1.6 to 3.5 times greater than those with the highest values for these metrics (quintile 5, P &amp;lt; .001 for all). In contrast, there was a U-shaped relationship between ALM/ht2 and incident mobility limitation. Conclusions These observational data suggest that there is not a single weight, BMI or % fat value that can represent both the lowest risk of mortality and also the lowest likelihood for developing mobility limitation over time in older men. Funding Sources National Institute on Aging and Abbott Nutrition.

Sarcopenia Definition: The Position Statements of the Sarcopenia Definition and Outcomes Consortium.

To develop an evidence-based definition of sarcopenia that can facilitate identification of older adults at risk for clinically relevant outcomes (eg, self-reported mobility limitation, falls, fractures, and mortality), the Sarcopenia Definition and Outcomes Consortium (SDOC) crafted a set of position statements informed by a literature review and SDOC's analyses of eight epidemiologic studies, six randomized clinical trials, four cohort studies of special populations, and two nationally representative population-based studies. Thirteen position statements related to the putative components of a sarcopenia definition, informed by the SDOC analyses and literature synthesis, were reviewed by an independent international expert panel (panel) iteratively and voted on by the panel during the Sarcopenia Position Statement Conference. Four position statements related to grip strength, three to lean mass derived from dual-energy x-ray absorptiometry (DXA), and four to gait speed; two were summary statements. The SDOC analyses identified grip strength, either absolute or scaled to measures of body size, as an important discriminator of slowness. Both low grip strength and low usual gait speed independently predicted falls, self-reported mobility limitation, hip fractures, and mortality in community-dwelling older adults. Lean mass measured by DXA was not associated with incident adverse health-related outcomes in community-dwelling older adults with or without adjustment for body size. The panel agreed that both weakness defined by low grip strength and slowness defined by low usual gait speed should be included in the definition of sarcopenia. These position statements offer a rational basis for an evidence-based definition of sarcopenia. The analyses that informed these position statements are summarized in this article and discussed in accompanying articles in this issue of the journal. J Am Geriatr Soc 68:1410-1418, 2020.