Risk Of Major Mobility Disability Research Articles

Effect of a physical activity intervention and frailty on frailty trajectory and major mobility disability.

Physical activity (PA) interventions may reduce the burden of frailty and can prevent mobility disability for older adults. We explored whether a 2-year PA intervention would improve frailty trajectory, lead to clinically meaningful frailty changes (CMC), or impact major mobility disability (MMD) across baseline frailty levels. We analyzed data for 1635 community-dwelling participants who were 70-89 years old (mean baseline age [SD]: 78.9 [5.2] years, 67.2% female) from the Lifestyle Interventions and Independence Study. Participants were randomized to either PA or health education (HE) intervention. A 44-item frailty index (FI) was constructed at baseline and 0.5, 1, 1.5, and 2 years after baseline. CMC was defined as change in FI of ≥0.03. MMD was the inability to complete a 400 m-walk within 15 min without assistance. Mixed-effects models were used to estimate frailty trajectory and CMC. Cox regression models were used to determine whether the effect of PA on the composite of MMD or death differed by baseline FI. Mean FI (SD) at baseline for both the PA and HE groups was 0.18 (0.10). Two years after baseline, mean FIs were 0.23 (0.12) for PA and 0.24 (0.12) for HE. The MMD rates were 30.1% (246/818) and 35.5% (290/817) for PA and HE, respectively. There was no time-by-intervention interaction for frailty trajectory or for CMC. Regarding the composite MMD and death, there was no FI-by-intervention interaction. Simple association analyses revealed that when baseline FI was centered at 0.15 or higher, the PA intervention was associated with lower risk of MMD or death compared to HE (HR [CI] range for FI ≥ 0.15: 0.65-0.81 [0.43-0.67, 0.90-0.98]). Participants in both groups showed similar frailty trajectories and CMC. Those who were frailer benefitted more from the PA intervention regarding MMD and death and may be a focus of recruitments for future PA program.

Elevated IL-6 and CRP Levels Are Associated With Incident Self-Reported Major Mobility Disability: A Pooled Analysis of Older Adults With Slow Gait Speed.

Elevated interleukine-6 (IL-6) and C-reactive protein (CRP) are associated with aging-related reductions in physical function, but little is known about their independent and combined relationships with major mobility disability (MMD), defined as the self-reported inability to walk a quarter mile. We estimated the absolute and relative effect of elevated baseline IL-6, CRP, and their combination on self-reported MMD risk among older adults (≥68 years; 59% female) with slow gait speed (<1.0 m/s). Participants were MMD-free at baseline. IL-6 and CRP were assessed using a central laboratory. The study combined a cohort of community-dwelling high-functioning older adults (Health ABC) with 2 trials of low-functioning adults at risk of MMD (LIFE-P, LIFE). Analyses utilized Poisson regression for absolute MMD incidence and proportional hazards models for relative risk. We found higher MMD risk per unit increase in log IL-6 (hazard ratio [HR] = 1.26; 95% confidence interval [95% CI] 1.13-1.41). IL-6 meeting predetermined threshold considered to be high (>2.5 pg/mL) was similarly associated with higher risk of MMD (HR = 1.31; 95% CI 1.12-1.54). Elevated CRP (CRP >3.0 mg/L) was also associated with increased MMD risk (HR = 1.38; 95% CI 1.10-1.74). The CRP effect was more pronounced among participants with elevated IL-6 (HR = 1.62; 95% CI 1.12-2.33) compared to lower IL-6 levels (HR = 1.19; 95% CI 0.85-1.66). High baseline IL-6 and CRP were associated with an increased risk of MMD among older adults with slow gait speed. A combined biomarker model suggests CRP was associated with MMD when IL-6 was elevated.

Ratings of Perceived Exertion During Walking: Predicting Major Mobility Disability and Effect of Structured Physical Activity in Mobility-Limited Older Adults.

This study evaluated the association between ratings of perceived exertion (RPE) of walking and major mobility disability (MMD), as well as their transitions in response to a physical activity (PA) compared to a health education (HE) program. Older adults (n = 1633) who were at risk for mobility impairment were randomized to structured PA or HE programs. During a 400 m walk, participants rated exertion as "light" or "hard." An MMD event was defined as the inability to walk 400 m. MMD events and RPE values were assessed every 6 months for an average of 2.6 years. Participants rating their exertion as "hard" had a nearly threefold higher risk of MMD compared with those rating their exertion as "light" (HR: 2.61, 95% CI: 2.19-3.11). The association was held after adjusting for disease conditions, depression, cognitive function, and walking speed (HR: 2.24, 95% CI: 1.87-2.69). The PA group was 25% more likely to transition from "light" to "hard" RPE than the HE group (HR: 1.25, 95% CI: 1.05-1.49). Additionally, the PA group was 27% (HR: 0.73, 95% CI: 0.55 - 0.97) less likely to transition from a "hard" RPE to inability to walk 400 m and was more likely to recover their ability to walk 400 m by transitioning to a "hard" RPE (HR: 2.10, 95% CI: 1.39-3.17) than the HE group. Older adults rating "hard" effort during a standardized walk test were at increased risk of subsequent MMD. A structured PA program enabled walking recovery, but was more likely to increase transition from "light" to "hard" effort, which may reflect the greater capacity to perform the test.

The Impact of ApoE e4 Allele in the Effects of Physical Activity Interventions on Major Mobility Disability Incidence

The apolipoprotein E (ApoE) e4 polymorphism is traditionally linked to increased rates of cognitive impairments and Alzheimer’s Disease. Recently, however, studies have connected ApoE e4 to self-reported mobility disability in those without cognitive impairment. We aimed to estimate the extent to which ApoE status is associated with incident major mobility disability (MMD) and whether it modifies the known beneficial effects of physical activity on incident MMD. Data were from 1,372 participants 70+ years old at risk for mobility impairments, enrolled in The LIFE Study. Participants were randomized to a structured physical activity (PA) or a health education program. The primary outcome was MMD, defined as the inability to walk 400 meters and measured every 6 months for an average follow-up period of 2.6 years. We used proportional hazards regression to examine the main effect of ApoE allele status and interaction with intervention group on MMD incidence. Cumulative MMD incident rates were similar in ApoE-e2 (31.46%), ApoE e3 (33.41%), and ApoE-e4 (33.33%) carriers. Compared to the common ApoE-e3, MMD risk was similar in ApoE-e2 (hazard ratio [HR], 0.945 [95%CI, 0.70-1.27], P=0.71) and ApoE-e4 carriers ([HR], 1.187 [95%CI, 0.95-1.48], P=0.41). Additionally, ApoE carrier status did not modify the positive effect that a PA intervention had on MMD risk (interaction p-value > 0.20). These results suggest that ApoE carrier status is not associated with incident mobility disability. ApoE carrier status does not impact the effect a structured PA program has on reducing the risk of MMD in older adults.

Association between a Deficit Accumulation Frailty Index and Mobility Outcomes in Older Adults: Secondary Analysis of the Lifestyle Interventions and Independence for Elders (LIFE) Study.

Frailty is a geriatric syndrome represented by susceptibility to precipitating health events and reduced functional reserve. Frailty can be difficult to measure in clinical practice and research. One approach to approximate frailty is based on a deficit accumulation approach, which assesses a larger number of less specific measures such as the presence of comorbidities, physical or cognitive assessments, and lab tests, and summarizes these as a frailty index. The objective of this study was to develop such an index using the Lifestyle Interventions and Independence for Elders (LIFE) Study and evaluate the validity of the frailty measure derived based on baseline information via its association with the primary outcomes of the trial, namely major mobility disability (MMD) and persistent MMD (pMMD). Further, this study aimed to evaluate the effectiveness of the physical activity intervention among participants based on their baseline frailty score. Subjects in the LIFE Study were evaluated at baseline for demographics, clinical history, and a battery of physical and cognitive functioning assessments. In total, 75 possible deficits were scored either as present (yes/no) or based on each score’s quintiles for score-based assessments. The frailty index was measured as the total sum of deficits divided by the total number of possible deficits on a continuous scale between 0 and 100 (i.e., percent of deficits present). The frailty index was further divided into quintiles for comparison. A proportional hazards model was estimated for the MMD outcome controlling for other baseline information. A data driven approach was also used to determine relevant cut-offs in the frailty index where the trial intervention appeared to be modified. Among 1635 trial participants, the mean frailty index was 30.4 ± 6.6 and normally distributed. Over 2.5 years of average follow-up, 14.6%, 16.5%, 18.6%, 22.6%, and 27.6% of participants experienced MMD in quintiles 1–5, respectively. Each 1-unit increase in the frailty index increased the hazard of MMD by 4% (2–5%), and there was a nearly 2-fold increase in MMD between the highest and lowest frailty quintiles. Using log-rank criteria, a cut-point at the median was identified. Further, iterations tested for a frailty cut-off and indicated a subgroup beyond the 85th percentile wherein the physical activity intervention appeared to be no longer be effective. This internally derived deficit accumulation frailty index was uniquely able to identify individuals at higher risk of MMD and pMMD and showed that along the spectrum of frailty, the physical activity intervention remained effective for the majority of participants.

Impact of Anticholinergic Medication Burden on Mobility and Falls in the Lifestyle Interventions for Elders (LIFE) Study

Anticholinergic cognitive burden (ACB) may be associated with detrimental effects on mobility and physical independence in older adults. We evaluated the incidence of major mobility disability (MMD), persistent major mobility disability (PMMD), and injurious falls among participants within the Lifestyle Interventions for Elders (LIFE) trial according to varied anticholinergic burden levels. Participants aged 70–89 years were randomized to a physical activity (PA) or successful aging (SA) intervention and evaluated by ACB medication use as a summed score of a previously developed ACB scale. Confounders included demographic characteristics, physical function, cognitive function, and fall history. Average participant follow-up was 2.6 years and included outcome assessment for MMD, PMMD, and injurious falls every six months. Adjusted proportional hazards models evaluated the independent effects of ACB scores as well as interaction effects with the intervention. Of the 1635 participants, 986 (60%) used ≥1 anticholinergic medication. Compared to those with no burden, participants with an ACB score of 1 demonstrated increased MMD (HR = 1.42 [1.13–1.78]), PMMD (HR = 1.53 [1.12–2.09]), and injurious falls (HR = 1.60 [1.10–2.32]). Results similar in magnitude were observed for all other ACB levels versus the no burden group. Stepwise dose–response comparisons between ACB groupings did not demonstrate significant differences in outcomes. Stratification by PA or SA interventions demonstrated few differences from the combined overall trial results. Compared to those not taking anticholinergic medications, participants taking anticholinergic medications generally demonstrated increased risk of MMD, PMMD, and injurious falls. Total anticholinergic burden was not associated with a stepwise dose–response relationship in mobility disability and may lack sensitivity to capture varied responses.

Relationships Between Profiles of Physical Activity and Major Mobility Disability in the LIFE Study.

To examine the relationship between time spent in light physical activity (LPA) and in moderate to vigorous physical activity (MVPA) and the pattern of accumulation on the risk for major mobility disability (MMD) in a large multicenter study of physical activity (PA) and aging, the Lifestyle Interventions and Independence for Elders (LIFE) study. Data were collected from individuals randomized to a PA intervention as part of the LIFE study, an eight-center single-blind randomized clinical trial conducted between February 2010 and December 2013. Lifestyle Interventions and Independence for Elders Study PARTICIPANTS: Older adult participants (78.4 years; N = 507) at risk for MMD. All older adults included in these analyses were randomized to a structured PA intervention that included two center-based plus three to four home-based exercise sessions per week with a primary goal of walking for 150 minutes weekly. Participants attended the intervention for 2.5 years on average. MMD was defined as the inability to complete a 400-m walk within 15 minutes and without assistance. Physical function was assessed via the Short Physical Performance Battery (SPPB). Actigraph accelerometers were used to quantify amount and variability in LPA and MVPA. In an adjusted Cox proportional hazards regression, we identified a significant interaction (P = .017) between SPPB score and LPA amount and variability such that more LPA was associated with a reduced risk for MMD among those with higher initial function, as was lower variability (eg, via distributing LPA across the day). The SPPB × MVPA interaction was significant (P = .04), such that more MVPA was associated with lower MMD risk among those with lower function. Finally, greater MVPA variability was associated with lower risk for MMD. A prescription of PA for older adults should account for key factors such as physical function and emphasize both amount and pattern of accumulation of PA from across the intensity continuum. J Am Geriatr Soc 68:1476-1483, 2020.

Impact of Baseline Fatigue on a Physical Activity Intervention to Prevent Mobility Disability.

Our aim was to examine the impacts of baseline fatigue on the effectiveness of a physical activity (PA) intervention to prevent major mobility disability (MMD) and persistent major mobility disability (PMMD) in participants from the Lifestyle Interventions and Independence for Elders (LIFE) study. Prospective cohort of individuals aged 65 years or older undergoing structured PA intervention or health education (HE) for a mean of 2.6 years. LIFE was a multicenter eight-site randomized trial that compared the efficacy of a structured PA intervention with an HE program in reducing the incidence of MMD. Study participants (N = 1591) at baseline were 78.9 ± 5.2 years of age, with low PA and at risk for mobility impairment. Self-reported fatigue was assessed using the modified trait version of the Exercise-Induced Feelings Inventory, a six-question scale rating energy levels in the past week. Responses ranged from 0 (none of the time) to 5 (all of the time). Total score was calculated by averaging across questions; baseline fatigue was based on the median split: 2 or higher = more fatigue (N = 856) and lower than 2 = less fatigue (N = 735). Participants performed a usual-paced 400-m walk every 6 months. We defined incident MMD as the inability to walk 400-m at follow-up visits; PMMD was defined as two consecutive walk failures. Cox proportional hazard models quantified the risk of MMD and PMMD in PA vs HE stratified by baseline fatigue adjusted for covariates. Among those with higher baseline fatigue, PA participants had a 29% and 40% lower risk of MMD and PMMD, respectively, over the trial compared with HE (hazard ratio [HR] for MMD = .71; 95% confidence interval [CI] = .57-.90; P = .004) and PMMD (HR = .60; 95% CI = .44-.82; P = .001). For those with lower baseline fatigue, no group differences in MMD (P = .36) or PMMD (P = .82) were found. Results of baseline fatigue by intervention interaction was MMD (P = .18) and PMMD (P = .05). A long-term moderate intensity PA intervention was particularly effective at preserving mobility in older adults with higher levels of baseline fatigue. J Am Geriatr Soc 68:619-624, 2020.

RATINGS OF PERCEIVED EXERTION: PREDICTING MOBILITY DISABILITY AND RESPONSE TO PHYSICAL ACTIVITY IN OLDER ADULTS

Ratings of perceived exertion (RPE) during exercise are linked to several physiological indices and are often elevated in older adults. This study evaluated the association between RPE of walking and incident major mobility disability (MMD) as well as response to a physical activity (PA) program. Older adults (n=1633) at-risk for mobility impairment were randomized to a structured PA or health education (HE) program. During a 400m walk, participants rated exertion as “none”, “light”, “somewhat hard” or “hard”. An MMD event was defined as the inability to complete the 400m walk. Transitions between RPE states and an MMD event—when RPE was not collected— were assessed over the follow-up (every 6 months for an average of 2.6 years). Participants rating their exertion as “hard” at baseline 400m walk had nearly 3-fold higher risk of MMD compared with those rating as “light” (HR: 2.61, 95%CI: 2.19-3.11). During follow-up, the PA group was 25% more likely to transition from “light” to “hard” RPE (1.25, 1.05-1.49), but was 27% (0.73, 0.55 – 0.97) less likely to transition from a “hard” RPE to MMD than the HE group. Additionally, the PA group was more likely to transition from an MMD event to a “hard” RPE (2.09, 1.38-3.17) than the HE group (i.e. recovery). Older adults rating “hard” effort during a standardized walk test were at increased risk of MMD. A structured PA program increased transition from light to hard effort, which may reflect greater capacity to perform the test and increased recovery from an MMD event.

Association of Fish Oil and Physical Activity on Mobility Disability in Older Adults.

This study aimed to examine whether long-term fish oil (FO) supplementation is associated with a lower risk of mobility disability and enhances benefits of physical activity (PA). A total of 1635 sedentary adults age 70 to 89 yr from the Lifestyle Interventions and Independence for Elders single-blinded randomized, multicenter clinical trial, which compared a structured PA program to a health education program. Primary outcome was incident major mobility disability (MMD), defined by loss of ability to walk 400 m, measured every 6 months for an average of 2.6 yr. Secondary outcomes included persistent mobility disability, Short Physical Performance Battery, 400-m walk speed, and grip strength. A third of participants reported using FO at baseline (456 (28%); mean age, 78.5 yr; 70.5% women). MMD was experienced by 131 participants (28.7%) in the FO group and 405 (34.4%) participants in the nonuser group. After adjusting for confounders, FO supplementation was associated with a lower risk (HR, 0.78; 95% confidence interval (CI), 0.64-0.96) of incident MMD. However, there was no interaction (P = 0.19) between FO supplementation and PA intervention for MMD. For the secondary outcome of persistent mobility disability, the intervention association differed by supplementation (P = 0.002) with PA intervention associations of (HR, 1.36; 95% CI, 0.83-2.23) for users and (HR, 0.61; 95% CI, 0.46-0.81) for nonusers. Changes in physical performance outcomes were not modified by baseline FO supplementation or combination with PA. FO supplementation was associated with a lower risk of MMD in low to moderate functioning older adults. However, supplementation did not enhance the benefit of PA on risk of mobility disability. These results are hypothesis generating and need to be confirmed in randomized trials.

Cognitive Function as a Predictor of Major Mobility Disability in Older Adults: Results From the LIFE Study.

Background and ObjectivesMany cross-sectional studies have confirmed a link between gait speed and cognitive function. However, it is unknown whether cognitive function plays a role in the onset of major mobility disability (MMD) and if the effects are independent of physical function. This study examined cognitive and physical function as predictors of MMD across an average of 2.6 years of follow-up in community-dwelling older adults with compromised mobility.Research Design and MethodData were collected from 1,635 participants in the Lifestyle Interventions and Independence for Elders (LIFE) study ages 70–89 years free of MMD at baseline. MMD was assessed every 6 months and defined as the inability to walk 400 m in ≤15 min without assistance or sitting. Cognitive function was assessed at baseline, 18 months, and 24 months using a cognitive battery categorized into four domains: global cognitive function, processing speed, verbal memory, and executive function.ResultsAcross the study duration of 2.6 years, 536 participants (32.8%) developed MMD. Cox Proportional Hazard models indicated a protective relationship for higher baseline processing speed (Hazard Ratio [HR] per standard deviation: 0.86, p = .006), executive function (HR: 0.86, p = .002), and global cognition (HR: 0.85, p = .001) on incidence of MMD adjusted for demographics, intervention, and comorbidities. Results were not significant after adjustment for gait speed. In adjusted longitudinal models, a positive change in processing speed was significantly associated with reduced risk of MMD (HR: 0.52, p < .001) while other domains were not.Discussion and ImplicationsIn the LIFE study, processing speed at baseline and follow-up was a significant predictor of subsequent MMD although the observed association may be explained by physical function as reflected in gait speed. More studies are needed to understand how cognitive function, alone and in combination with physical function, influences risk of MMD.

A Case for Promoting Movement Medicine: Preventing Disability in the LIFE Randomized Controlled Trial.

The movement profile of older adults with compromised function is unknown, as is the relationship between these profiles and the development of major mobility disability (MMD)-a critical clinical outcome. We first describe the dimensions of movement in older adults with compromised function and then examine whether these dimensions predict the onset of MMD. Older adults at risk for MMD (N = 1,022, mean age = 78.7 years) were randomized to receive a structured physical activity intervention or health education control. We assessed MMD in 6-month intervals (average follow-up of 2.2 years until incident MMD), with activity assessed at baseline, 6-, 12- and 24-month follow-up via accelerometry. A principal components analysis of 11 accelerometer-derived metrics yielded three components representing lifestyle movement (LM), extended bouts of moderate-to-vigorous physical activity (MVPA), and stationary body posture. LM accounted for the greatest proportion of variance in movement (53%). Within health education, both baseline LM (HR = 0.74; 95% CI 0.62 to 0.88) and moderate-to-vigorous physical activity (HR = 0.69; 95% CI 0.54 to 0.87) were associated with MMD, whereas only LM was associated with MMD within physical activity (HR = 0.74; 95% CI 0.61 to 0.89). There were similar nonlinear relationships present for LM in both physical activity and health education (p < .04), whereby risk for MMD was lower among individuals with higher levels of LM. Both LM and moderate-to-vigorous physical activity should be central in treatment regimens for older adults at risk for MMD. clinicaltrials.gov Identifier NCT01072500.

Physical Activity and Performance Impact Long-term Quality of Life in Older Adults at Risk for Major Mobility Disability

Older adults are a rapidly growing segment of the U.S. Mobility problems that lead to further disability can be addressed through physical activity interventions. Quality of life outcome results are reported from a large trial of physical activity for sedentary older adults at risk for mobility disability. Data were from the Lifestyle Interventions and Independence for Elders study. This multisite RCT compared physical activity to health education among 1,635 randomly assigned sedentary older adults at risk for mobility disability in 2010-2011. Measures included demographics; comorbidity; a timed 400-meter walk; the Short Physical Performance Battery; and the Quality of Well-Being Scale (0-1.0 scale). Baseline and long-term follow-up (2.6 years) health-related quality of life data were collected as a secondary outcome. Multivariate linear regression modeling was used to examine covariates of health-related quality of life over time in 2017. The sample had an overall mean Quality of Well-Being score of 0.613. Both groups declined in quality of life over time, but assignment to the physical activity intervention resulted in a slower decline in health-related quality of life scores (p=0.03). Intervention attendance was associated with higher health-related quality of life for both groups. Baseline characteristics including younger age, fewer comorbid conditions, non-white ethnicity, and faster 400-meter walk times were also associated with higher health-related quality of life over time. Declining mobility measured by physical performance is associated with lower quality of life in sedentary older adults. Physical activity interventions can slow the decline in quality of life, and targeting specific subgroups may enhance the effects of such interventions.

Exercise's effect on mobility disability in older adults with and without obesity: The LIFE study randomized clinical trial.

ObjectiveSome data suggests that obesity blunts the benefits of exercise on mobility in older adults. We tested the homogeneity of the effect of a physical activity intervention on major mobility disability across baseline obesity classifications in the Lifestyle Interventions and Independence for Elders (LIFE) Study. LIFE randomized 1,635 sedentary men and women 70–89 years to a moderate intensity physical activity (PA) or health education (HE) program.MethodsMajor mobility disability (MMD), defined as the inability to walk 400m, was determined over an average follow up of 2.6 years. Participants were divided into 4 subgroups: 1) non-obese (BMI < 30 kg/m2; n=437); 2) non-obese with high waist circumference (WC >102 cm [men], >88 cm [women]; n=434); 3) class 1 obesity (30 kg/m2 ≤ BMI < 35 kg/m2; n=430); and 4) class 2+ obesity (BMI ≥ 35 kg/m2; n=312). Cox proportional hazard modeling was used to test an obesity by intervention interaction.ResultsThe PA intervention had the largest benefit in participants with class 2+ obesity (HR 0.69, 95% CI 0.48, 0.98). However, there was no statistically significant difference in benefit across obesity categories.ConclusionA structured PA program reduced the risk of MMD even in older adults with extreme obesity.

Role of Fatigue on the Effectiveness of a Physical Activity Intervention Aimed at Preventing Mobility Disability

While physical activity (PA) is known to preserve mobility and functional capacity in older adults, greater self-reported fatigue is associated with slower gait speed and poorer mobility. The potential impact of initial fatigue levels in mitigating the effects of a physical activity intervention on major mobility disability (MMD) outcomes has yet to be explored. PURPOSE: To examine the impact of a PA intervention on the risk of MMD by baseline (BL) fatigue status in older adults at risk for mobility disability. METHODS: The Lifestyle Interventions and Independence for Elders (LIFE) Study was a randomized clinical trial of a structured, moderate-intensity PA program (mean duration=2.6 years) consisting primarily of walking compared to a successful aging health education (SA) program in 1635 older adults, mean age 78.9±5.2 years. Self-reported fatigue was assessed using the Trait version of the Exercise-Induced Feelings Inventory (EFI-T), a 6-item scale with each item scored 0 (none of the time) to 5 (all of the time). A total score was calculated by averaging the items and the median split was used to define BL fatigue status: higher fatigue ≥2 (N=876) and lower fatigue <2 (N=755). A usual-paced 400m walk was conducted every 6 months; MMD was defined as the loss of ability to walk the 400m within 15 min. Cox proportional hazard models were used for the analysis of MMD in the PA vs. SA groups according to baseline fatigue status. RESULTS: Time to walk 400m at BL was slower for those with higher fatigue (521.0±113.3 sec) compared to lower fatigue (494.6±112.8 sec), p<0.0001. Participants with higher BL fatigue who were randomized to the PA program had a 26% lower risk of MMD compared to those who self-reported higher BL fatigue in SA (hazard ratio [HR] 0.74 [95% CI, 0.59-0.92], p=0.006). For those with lower BL fatigue, there was no difference between intervention programs on MMD (HR 0.88 [95% CI, 0.66-1.17], p=0.39); p-value for BL fatigue by intervention interaction: 0.24. Results did not change after adjustment for BL 400m walk time. CONCLUSION: A long-term moderate intensity PA intervention may be particularly effective in preserving mobility in older adults at risk for MMD who self-reported higher levels of initial fatigue. Supported by U01AG22376 from the NIH.

The MAT-sf: identifying risk for major mobility disability.

The assessment of mobility is essential to both aging research and clinical geriatric practice. A newly developed self-report measure of mobility, the mobility assessment tool-short form (MAT-sf), uses video animations as an innovative method to improve measurement accuracy/precision. The primary aim of the current study was to evaluate whether MAT-sf scores can be used to identify risk for major mobility disability (MMD). This article is based on data collected from the Lifestyle Interventions and Independence for Elders study and involved 1,574 older adults between the ages of 70-89. The MAT-sf was administered at baseline; MMD, operationalized as failure to complete the 400-m walk ≤ 15 minutes, was evaluated at 6-month intervals across a period of 42 months. The outcome of interest was the first occurrence of MMD or incident MMD. After controlling for age, sex, clinic site, and treatment arm, baseline MAT-sf scores were found to be effective in identifying risk for MMD (p < .0001). Partitioning the MAT-sf into four groups revealed that persons with scores <40, 40-49, 50-59, and 60+ had failure rates across 42 months of follow-up of 66%, 52%, 35%, and 22%, respectively. The MAT-sf is a quick and efficient way of identifying older adults at risk for MMD. It could be used to clinically identify older adults that are in need of intervention for MMD and provides a simple means for monitoring the status of patients' mobility, an important dimension of functional health.

Effect of structured physical activity on prevention of major mobility disability in older adults: the LIFE study randomized clinical trial.

In older adults reduced mobility is common and is an independent risk factor for morbidity, hospitalization, disability, and mortality. Limited evidence suggests that physical activity may help prevent mobility disability; however, there are no definitive clinical trials examining whether physical activity prevents or delays mobility disability. To test the hypothesis that a long-term structured physical activity program is more effective than a health education program (also referred to as a successful aging program) in reducing the risk of major mobility disability. The Lifestyle Interventions and Independence for Elders (LIFE) study was a multicenter, randomized trial that enrolled participants between February 2010 and December 2011, who participated for an average of 2.6 years. Follow-up ended in December 2013. Outcome assessors were blinded to the intervention assignment. Participants were recruited from urban, suburban, and rural communities at 8 centers throughout the United States. We randomized a volunteer sample of 1635 sedentary men and women aged 70 to 89 years who had physical limitations, defined as a score on the Short Physical Performance Battery of 9 or below, but were able to walk 400 m. Participants were randomized to a structured, moderate-intensity physical activity program (n = 818) conducted in a center (twice/wk) and at home (3-4 times/wk) that included aerobic, resistance, and flexibility training activities or to a health education program (n = 817) consisting of workshops on topics relevant to older adults and upper extremity stretching exercises. The primary outcome was major mobility disability objectively defined by loss of ability to walk 400 m. Incident major mobility disability occurred in 30.1% (246 participants) of the physical activity group and 35.5% (290 participants) of the health education group (hazard ratio [HR], 0.82 [95% CI, 0.69-0.98], P = .03).Persistent mobility disability was experienced by 120 participants (14.7%) in the physical activity group and 162 participants (19.8%) in the health education group (HR, 0.72 [95% CI, 0.57-0.91]; P = .006). Serious adverse events were reported by 404 participants (49.4%) in the physical activity group and 373 participants (45.7%) in the health education group (risk ratio, 1.08 [95% CI, 0.98-1.20]). A structured, moderate-intensity physical activity program compared with a health education program reduced major mobility disability over 2.6 years among older adults at risk for disability. These findings suggest mobility benefit from such a program in vulnerable older adults. clinicaltrials.gov Identifier: NCT01072500.

Evidence Regarding the Benefits of Physical Exercise

Evidence Regarding the Benefits of Physical Exercise