Aging is characterized by rising susceptibility to development of multiple chronic diseases and, therefore, represents the major risk factor for multimorbidity. From a gerontological perspective, the ...progressive accumulation of multiple diseases, which significantly accelerates at older ages, is a milestone for progressive loss of resilience and age-related multisystem homeostatic dysregulation. Because it is most likely that the same mechanisms that drive aging also drive multiple age-related chronic diseases, addressing those mechanisms may reduce the development of multimorbidity. According to this vision, studying multimorbidity may help to understand the biology of aging and, at the same time, understanding the underpinnings of aging may help to develop strategies to prevent or delay the burden of multimorbidity. As a consequence, we believe that it is time to build connections and dialogue between the clinical experience of general practitioners and geriatricians and the scientists who study aging, so as to stimulate innovative research projects to improve the management and the treatment of older patients with multiple morbidities.
OBJECTIVES: To assess whether the Timed Up and Go (TUG) is superior to gait speed in predicting multiple geriatric outcomes.
DESIGN: Prospective cohort study.
SETTING: Medicare health maintenance ...organization and Veterans Affairs primary care clinics.
PARTICIPANTS: Adults aged 65 and older (N=457).
MEASUREMENTS: Baseline gait speed and TUG were used to predict health decline according to EuroQol and Medical Outcomes Study 36‐item Short Form Survey (SF‐36) global health; functional decline according to National Health Interview Survey (NHIS) activities of daily living (ADLs) score and SF‐36 physical function index; hospitalization; and any falls and multiple falls over 1 year.
RESULTS: Mean age was 74, and 44% of participants were female. Odds ratios for all outcomes were equivalent for gait speed and TUG. Using area under the receiver operating characteristic curve of 0.7 or greater for acceptable predictive ability, gait speed and TUG each alone predicted decline in global health, new ADL difficulty, and falls, with no difference in predictive ability between performance measures. Neither performance measure predicted hospitalization, EuroQol decline, or physical function decline. As a continuous variable, TUG did not add predictive ability to gait speed for any outcome.
CONCLUSION: Gait speed predicts most geriatric outcomes, including falls, as does TUG. The time taken to complete TUG may not add to information provided by gait speed, although its qualitative elements may have other utility.
OBJECTIVES: To estimate the magnitude of small meaningful and substantial individual change in physical performance measures and evaluate their responsiveness.
DESIGN: Secondary data analyses using ...distribution‐ and anchor‐based methods to determine meaningful change.
SETTING: Secondary analysis of data from an observational study and clinical trials of community‐dwelling older people and subacute stroke survivors.
PARTICIPANTS: Older adults with mobility disabilities in a strength training trial (n=100), subacute stroke survivors in an intervention trial (n=100), and a prospective cohort of community‐dwelling older people (n=492).
MEASUREMENTS: Gait speed, Short Physical Performance Battery (SPPB), 6‐minute‐walk distance (6MWD), and self‐reported mobility.
RESULTS: Most small meaningful change estimates ranged from 0.04 to 0.06 m/s for gait speed, 0.27 to 0.55 points for SPPB, and 19 to 22 m for 6MWD. Most substantial change estimates ranged from 0.08 to 0.14 m/s for gait speed, 0.99 to 1.34 points for SPPB, and 47 to 49 m for 6MWD. Based on responsiveness indices, per‐group sample sizes for clinical trials ranged from 13 to 42 for substantial change and 71 to 161 for small meaningful change.
CONCLUSION: Best initial estimates of small meaningful change are near 0.05 m/s for gait speed, 0.5 points for SPPB, and 20 m for 6MWD and of substantial change are near 0.10 m/s for gait speed, 1.0 point for SPPB, and 50 m for 6MWD. For clinical use, substantial change in these measures and small change in gait speed and 6MWD, but not SPPB, are detectable. For research use, these measures yield feasible sample sizes for detecting meaningful change.
•Gait variability in aging is associated with altered brain structure and function.•Sensorimotor integration and coordination areas are most often altered.•In cognitive impairment and dementia, ...general and regional findings are limited.•Longitudinal studies of multiple brain areas are warranted to understand mechanisms.
While gait variability may reflect subtle changes due to aging or cognitive impairment (CI), associated brain characteristics remain unclear. We summarize structural and functional neuroimaging findings associated with gait variability in older adults with and without CI and dementia.
We identified 17 eligible studies; all were cross-sectional; few examined multiple brain areas. In older adults, temporal gait variability was associated with structural differences in medial areas important for lower limb coordination and balance. Both temporal and spatial gait variability were associated with structural and functional differences in hippocampus and primary sensorimotor cortex and structural differences in anterior cingulate cortex, basal ganglia, association tracts, and posterior thalamic radiation. In CI or dementia, some associations were found in primary motor cortex, hippocampus, prefrontal cortex and basal ganglia.
In older adults, gait variability may be associated with areas important for sensorimotor integration and coordination. To comprehend the neural basis of gait variability with aging and CI, longitudinal studies of multiple brain areas are needed.
Low muscle mass and weakness are common and potentially disabling in older adults, but in order to become recognized as a clinical condition, criteria for diagnosis should be based on clinically ...relevant thresholds and independently validated. The Foundation for the National Institutes of Health Biomarkers Consortium Sarcopenia Project used an evidence-based approach to develop these criteria. Initial findings were presented at a conference in May 2012, which generated recommendations that guided additional analyses to determine final recommended criteria. Details of the Project and its findings are presented in four accompanying manuscripts.
The Foundation for the National Institutes of Health Sarcopenia Project used data from nine sources of community-dwelling older persons: Age, Gene/Environment Susceptibility-Reykjavik Study, Boston Puerto Rican Health Study, a series of six clinical trials, Framingham Heart Study, Health, Aging, and Body Composition, Invecchiare in Chianti, Osteoporotic Fractures in Men Study, Rancho Bernardo Study, and Study of Osteoporotic Fractures. Feedback from conference attendees was obtained via surveys and breakout groups.
The pooled sample included 26,625 participants (57% women, mean age in men 75.2 ±6.1 SD and in women 78.6 ±5.9 years). Conference attendees emphasized the importance of evaluating the influence of body mass on cutpoints. Based on the analyses presented in this series, the final recommended cutpoints for weakness are grip strength <26kg for men and <16kg for women, and for low lean mass, appendicular lean mass adjusted for body mass index <0.789 for men and <0.512 for women.
These evidence-based cutpoints, based on a large and diverse population, may help identify participants for clinical trials and should be evaluated among populations with high rates of functional limitations.
to examine the clinical evidence reporting the prevalence of sarcopenia and the effect of nutrition and exercise interventions from studies using the consensus definition of sarcopenia proposed by ...the European Working Group on Sarcopenia in Older People (EWGSOP).
PubMed and Dialog databases were searched (January 2000-October 2013) using pre-defined search terms. Prevalence studies and intervention studies investigating muscle mass plus strength or function outcome measures using the EWGSOP definition of sarcopenia, in well-defined populations of adults aged ≥50 years were selected.
prevalence of sarcopenia was, with regional and age-related variations, 1-29% in community-dwelling populations, 14-33% in long-term care populations and 10% in the only acute hospital-care population examined. Moderate quality evidence suggests that exercise interventions improve muscle strength and physical performance. The results of nutrition interventions are equivocal due to the low number of studies and heterogeneous study design. Essential amino acid (EAA) supplements, including ∼2.5 g of leucine, and β-hydroxy β-methylbutyric acid (HMB) supplements, show some effects in improving muscle mass and function parameters. Protein supplements have not shown consistent benefits on muscle mass and function.
prevalence of sarcopenia is substantial in most geriatric settings. Well-designed, standardised studies evaluating exercise or nutrition interventions are needed before treatment guidelines can be developed. Physicians should screen for sarcopenia in both community and geriatric settings, with diagnosis based on muscle mass and function. Supervised resistance exercise is recommended for individuals with sarcopenia. EAA (with leucine) and HMB may improve muscle outcomes.
ABSTRACT
Background
Mobility, such as walking 1/4 mile, is a valuable but underutilized health indicator among older adults. For mobility to be successfully integrated into clinical practice and ...health policy, an easily assessed marker that predicts subsequent health outcomes is required.
Objective
To determine the association between mobility, defined as self-reported ability to walk 1/4 mile, and mortality, functional decline, and health care utilization and costs during the subsequent year.
Design
Analysis of longitudinal data from the 2003–2004 Medicare Current Beneficiary Survey, a nationally representative sample of Medicare beneficiaries.
Participants
Participants comprised 5895 community-dwelling adults aged 65 years or older enrolled in Medicare.
Main Measures
Mobility (self-reported ability to walk 1/4 mile), mortality, incident difficulty with activities of daily living (ADLs), total annual health care costs, and hospitalization rates.
Key Results
Among older adults, 28% reported difficulty and 17% inability to walk 1/4 mile at baseline. Compared to those without difficulty and adjusting for demographics, socioeconomic status, chronic conditions, and health behaviors, mortality was greater in those with difficulty AOR (95% CI): 1.57 (1.10-2.24) and inability AOR (CI): 2.73 (1.79-4.15). New functional disability also occurred more frequently as self-reported ability to walk 1/4 mile declined (subsequent incident disability among those with no difficulty, difficulty, or inability to walk 1/4 mile at baseline was 11%, 29%, and 47% for instrumental ADLs, and 4%, 14%, and 23% for basic ADLs). Total annual health care costs were $2773 higher (95% CI $1443-4102) in persons with difficulty and $3919 higher (CI $1948-5890) in those who were unable. For each 100 persons, older adults reporting difficulty walking 1/4 mile at baseline experienced an additional 14 hospitalizations (95% CI 8-20), and those who were unable experienced an additional 22 hospitalizations (CI 14-30) during the follow-up period, compared to persons without walking difficulty.
Conclusions
Mobility disability, a simple self-report measure, is a powerful predictor of future health, function, and utilization independent of usual health and demographic indicators. Mobility disability may be used to target high-risk patients for care management and preventive interventions.
OBJECTIVES: To estimate the relationship between 1‐year improvement in measures of health and physical function and 8‐year survival.
DESIGN: Prospective cohort study.
SETTING: Medicare health ...maintenance organization and Veterans Affairs primary care programs.
PARTICIPANTS: Persons aged 65 and older (N=439).
MEASUREMENTS: Six measures of health and function assessed at baseline and quarterly over 1 year. Participants were classified as improved at 1 year, transiently improved, or never improved for each measure using a priori definitions of meaningful change: gait speed (usual walking pace over 4 m), 0.1 m/s; Short Physical Performance Battery, 1 point; Medical Outcomes Study 36‐item Short Form Health Survey physical function, 10 points; EuroQol, 0.1 point; National Health Interview activity of daily living scale, 2 points; and global health change, two levels or reaching the ceiling. Mortality was ascertained from the National Death Index. Covariates included demographics, comorbidity, cognitive function, and hospitalization.
RESULTS: Of the six measures, only improved gait speed was associated with survival. Mortality after 8 years was 31.6%, 41.2%, and 49.3% for those with improved, transiently improved, and never improved gait speed, respectively. The survival benefit for improvement at 1 year persisted after adjustment for covariates (hazard ratio=0.42, 95% confidence interval=0.29–0.61, P<.001) and was consistent across subgroups based on age, sex, ethnicity, initial gait speed, healthcare system, and hospitalization.
CONCLUSION: Improvement in usual gait speed predicts a substantial reduction in mortality. Because gait speed is easily measured, clinically interpretable, and potentially modifiable, it may be a useful “vital sign” for older adults. Further research is needed to determine whether interventions to improve gait speed affect survival.
Weakness is common and contributes to disability, but no consensus exists regarding a strength cutpoint to identify persons at high risk. This analysis, conducted as part of the Foundation for the ...National Institutes of Health Sarcopenia Project, sought to identify cutpoints that distinguish weakness associated with mobility impairment, defined as gait speed less than 0.8 m/s.
In pooled cross-sectional data (9,897 men and 10,950 women), Classification and Regression Tree analysis was used to derive cutpoints for grip strength associated with mobility impairment.
In men, a grip strength of 26-32 kg was classified as "intermediate" and less than 26 kg as "weak"; 11% of men were intermediate and 5% were weak. Compared with men with normal strength, odds ratios for mobility impairment were 3.63 (95% CI: 3.01-4.38) and 7.62 (95% CI 6.13-9.49), respectively. In women, a grip strength of 16-20 kg was classified as "intermediate" and less than 16 kg as "weak"; 25% of women were intermediate and 18% were weak. Compared with women with normal strength, odds ratios for mobility impairment were 2.44 (95% CI 2.20-2.71) and 4.42 (95% CI 3.94-4.97), respectively. Weakness based on these cutpoints was associated with mobility impairment across subgroups based on age, body mass index, height, and disease status. Notably, in women, grip strength divided by body mass index provided better fit relative to grip strength alone, but fit was not sufficiently improved to merit different measures by gender and use of a more complex measure.
Cutpoints for weakness derived from this large, diverse sample of older adults may be useful to identify populations who may benefit from interventions to improve muscle strength and function.
PDF
