Home-Based Gait Speed Assessment: Normative Data and Racial/Ethnic Correlates Among Older Adults

The Importance of Racially and Ethnically Inclusive Gait Speed Reference Values in Individuals 90 Years and Older: LifeAfter90

BACKGROUND AND PURPOSE

Clinicians use reference values to contextualize physical performance scores, but data are sparse in individuals 90 years and older and racial/ethnic diversity is limited in existing studies. Gait speed provides valuable information about an individual's health status. Slow gait speed is associated with falls, cognitive decline, and mortality. Here, we report gait speed reference values in a racially/ethnically diverse oldest-old cohort.

METHODS

LifeAfter90 is a multiethnic cohort study of individuals 90 years and older. Participants are long-term members of an integrated healthcare delivery system without a dementia diagnosis at enrollment. We assessed gait speed using the 4-m walk test and calculated means, standard deviations, and percentiles by age, sex, assistive device use, and device type. We used linear regression to compare means by sex, age, device use and type, living situation and arrangement, and race/ethnicity.

RESULTS AND DISCUSSION

The mean age of the 502 participants was 92.9 (range 90.1-102.8) years. Of these, 62.6% were women, 34.7% were college educated, 90.8% lived in a private residence, 20.9% self-reported as Asian, 22.5% as Black, 11.8% as Hispanic, 35.7% as White, and 9.2% as multiple, "other," or declined to state. The overall mean gait speed was 0.54 m/s (women = 0.51 m/s, men = 0.58 m/s). Mean gait speeds were 0.58 m/s, 0.53 m/s, and 0.48 m/s in the 90 to 91, 92 to 93, and 94+ age categories, respectively. In those without a device, mean gait speed was 0.63 m/s compared to 0.40 m/s in those with a device (cane = 0.44 m/s, walker = 0.37 m/s). Mean gait speed was significantly slower in women compared to men, age category 94+ compared to 90 to 91, participants with a device compared to those without, participants with a walker compared to a cane, and Black participants compared to Asian and White participants. However, differences by race/ethnicity were attenuated when chronic health conditions were considered.

CONCLUSIONS

Reference values developed from this multiethnic 90+ cohort will help clinicians interpret gait speed measures and tailor recommendations toward a 90+ population that is growing in number and in racial/ethnic diversity.

Risk factors associated with the Motoric Cognitive Risk syndrome: A meta-analysis of data from a cross-national study

BACKGROUND

Identifying risk factors associated with the Motoric Cognitive Risk (MCR) syndrome (a pre-dementia syndrome) can assist in developing risk reduction strategies and interventions to delay progression to dementia. Tailored interventions require comparisons of high- and middle-income countries to determine if the same or different risk factors should be targeted. We examined risk factors associated with MCR in seven Health and Retirement Studies with harmonized measures.

METHODS

Data from adults aged ≥65 years (n = 20,036, mean age 71.2(SD 6.2)-80.1(SD 4.1)) from the U.S. Health and Retirement Study, English Longitudinal Study of Aging, Survey of Health, Aging and Retirement in Europe, China Health and Retirement Longitudinal Study, Harmonized Diagnostic Assessment of Dementia for Longitudinal Aging Study in India, Mexican Health and Aging Study, and Brazilian Longitudinal Study of Aging was included. MCR was defined as the presence of cognitive complaints and slow gait (no mobility disability and dementia). Associations of demographic [education], medical [hypertension, diabetes, heart disease, obesity, stroke, Parkinson's, falls], psychological [depressive symptoms, psychiatric problems], sensorimotor [grip strength, hearing], and behavioral factors [smoking, sedentariness, sleep], with prevalent MCR were examined using age- and sex-adjusted logistic regression models. A meta-analysis was performed to compare risk factors for MCR in high- versus middle-income countries.

RESULTS

Except for depressive symptoms and weak grip strength, different risk factor clusters were associated with individual studies. Poor sleep, hearing, weak grip, and multiple falls emerged as novel associations with MCR. When grouped by income, some risk factors (i.e., education) were associated with MCR in high- and middle-income countries. Others (i.e., obesity) were specific to high-income countries.

CONCLUSIONS

This cross-sectional, cross-national study identified new, shared, and specific risk factors associated with MCR in high- and middle-income countries, providing insights to develop public health approaches and interventions to forestall the onset of dementia in those with MCR.

Walking speed questionnaire used to estimate gait speed in older adults: Comparisons with testing protocols and diagnostic accuracy

BACKGROUND

Walking speed is an important clinical tool in the physical therapy examination of older adults, but not always feasible to measure. Clinicians may be limited by space, a client's functional limitations, or use of telehealth. The Walking Speed Questionnaire (WSQ) can be used to estimate walking speed, but the effects of testing protocols on the accuracy and diagnostic capability of the WSQ have not yet been investigated.

OBJECTIVES

The purposes of this study were to compare estimated with recorded walking speed and examine effects of start condition and instructions in healthy older adults.

METHODS

One hundred community dwelling adults 60 years or older were tested. After completing the WSQ, participants performed two trials of six walking conditions that included standing and walking starts under instructions to "walk at a usual pace," "as if crossing a street," and "fast."

RESULTS

Participants averaged 72.4 (9.6) years of age. The WSQ average walking speed was 1.22 (0.16) m/s and was slower than each condition, p-value = 0.001, except for those performed with instructions to walk at usual pace with both standing, 1.23 (0.29) m/s and walking starts, 1.26 (0.30) m/s. Compared to the usual pace walking start condition, the WSQ sensitivity and specificity were 31% and 94% respectively with an 82% accuracy. A modified cutoff of the WSQ to 1.17 m/s improves sensitivity.

CONCLUSIONS

If walking testing cannot be performed, the WSQ is a reasonable alternative providing an accurate estimate of a client's walking speed when walking at a usual pace.

Measurement properties of the usual and fast gait speed tests in community-dwelling older adults: a COSMIN-based systematic review

OBJECTIVE

The gait speed test is one of the most widely used mobility assessments for older adults. We conducted a systematic review to evaluate and compare the measurement properties of the usual and fast gait speed tests in community-dwelling older adults.

METHODS

Three databases were searched: MEDLINE, EMBASE and CINAHL. Peer-reviewed articles evaluating the gait speed test's measurement properties or interpretability in community-dwelling older adults were included. The Consensus-based Standards for the selection of health Measurement Instruments guidelines were followed for data synthesis and quality assessment.

RESULTS

Ninety-five articles met our inclusion criteria, with 79 evaluating a measurement property and 16 reporting on interpretability. There was sufficient reliability for both tests, with intraclass correlation coefficients (ICC) generally ranging from 0.72 to 0.98, but overall quality of evidence was low. For convergent/discriminant validity, an overall sufficient rating with moderate quality of evidence was found for both tests. Concurrent validity of the usual gait speed test was sufficient (ICCs = 0.79-0.93 with longer distances) with moderate quality of evidence; however, there were insufficient results for the fast gait speed test (e.g. low agreement with longer distances) supported by high-quality studies. Responsiveness was only evaluated in three articles, with low quality of evidence.

CONCLUSION

Findings from this review demonstrated evidence in support of the reliability and validity of the usual and fast gait speed tests in community-dwelling older adults. However, future validation studies should employ rigorous methodology and evaluate the tests' responsiveness.

Spatiotemporal gait characteristics across the adult lifespan: Reference values from a healthy population - Analysis of the COmPLETE cohort study

BACKGROUND

Gait changes with aging have been investigated, but few studies have examined a wide range of gait parameters across the adult lifespan. This study aimed to investigate gait differences across age groups stratified by sex.

METHODS

This cross-sectional study included 629 healthy, normal-weight (i.e., BMI < 30 kg/m2) participants from Switzerland of the COmPLETE cohort study, aged 20 to over 90 years. Gait metrics were assessed using an inertial measurement unit (IMU)-based gait analysis system, including speed, cycle duration variability, asymmetry, stride length, cycle duration, cadence, double support, stance (time foot is on the ground during a gait cycle), swing (time foot is in the air during a gait cycle), loading (early part of the stance phase), foot-flat (mid-stance phase when foot is flat), and pushing (late stance phase leading to toe-off) phases. Percentile curves were calculated using generalized additive models for location, scale, and shape.

RESULTS

Gait data from 545 participants (273 men and 272 women) were analyzed. Participants were equally distributed across the seven age decades, with an average of 40 men and 40 women representing every decade. Both men and women showed a reduction in gait speed and stride length, and an increase in cycle duration variability and asymmetry with aging. Gait speed and stride length declined across the age groups, with a significant difference found in participants aged 80 to 91 compared to younger age groups.

SIGNIFICANCE

Age-related changes in gait parameters were seen in both men and women. These may be attributed to the typical decline in muscle strength, balance, coordination, and neuromuscular function. The results of this study contribute to the understanding of gait changes throughout the lifespan and can be used for comparison with other populations and as reference values for individual patients.

Racial differences in phenotypic frailty assessment among general thoracic surgery patients

Objectives

The American Association for Thoracic Surgery recommends using frailty assessments to identify patients at higher risk of perioperative morbidity and mortality. We evaluated what patient factors are associated with frailty in a thoracic surgery patient population.

Methods

New patients aged more than 50 years who were evaluated in a thoracic surgery clinic underwent routine frailty screening with a modified Fried's Frailty Phenotype. Differences in demographics and comorbid conditions among frailty status groups were assessed with chi-square and Student t tests. Logistic regressions performed with binomial distribution assessed the association of demographic and clinical characteristics with nonfrail, frail, prefrail, and any frailty (prefrail/frail) status.

Results

The study population included 317 patients screened over 19 months. Of patients screened, 198 (62.5%) were frail or prefrail. Frail patients undergoing thoracic surgery were older, were more likely single or never married, had lower median income, and had lower percent predicted diffusion capacity of the lungs for carbon monoxide and forced expiratory volume during 1 second (all P < .05). More non-Hispanic Black patients were frail and prefrail compared with non-Hispanic White patients (P = .003) and were more likely to score at least 1 point on Fried's Frailty Phenotype (adjusted odds ratio, 3.77; P = .02) when controlling for age, sex, number of comorbidities, median income, diffusion capacity of the lungs for carbon monoxide, and forced expiratory volume during 1 second. Non-Hispanic Black patients were more likely than non-Hispanic White patients to score points for slow gait and low activity (both P < .05).

Conclusions

Non-Hispanic Black patients undergoing thoracic surgery are more likely to score as frail or prefrail than non-Hispanic White patients. This disparity stems from differences in activity and gait speed. Frailty tools should be examined for factors contributing to this disparity, including bias.

Correlates of Gait Speed Among Older Adults From 6 Countries: Findings From the COSMIC Collaboration

BACKGROUND

Few studies have compared gait speed and its correlates among different ethnogeographic regions. The goals of this study were to describe usual and rapid gait speed, and identify their correlates across Australian, Asian, and African countries.

METHODS

We used data from 6 population-based cohorts of adults aged 65+ from 6 countries and 3 continents (N = 6 472), with samples ranging from 231 to 1 913. All cohorts are members of the Cohort Studies of Memory in an International Consortium collaboration. We investigated whether clinical (body mass index [BMI], hypertension, stroke, apolipoprotein status), psychological (cognition, mood, general health), and behavioral factors (smoking, drinking, physical activity) correlated with usual (N = 4 cohorts) and rapid gait speed (N = 3 cohorts) similarly across cohorts. Regression models were controlled for age, sex, and education, and were sex-stratified.

RESULTS

Age- and sex-standardized usual gait speed means ranged from 0.61 to 1.06 m/s and rapid gait speed means ranged from 1.16 to 1.64 m/s. Lower BMI and better cognitive function consistently correlated with faster gait speed in all cohorts. Less consistently, not having hypertension and greater physical activity engagement were associated with faster gait speed. Associations with mood, smoking, and drinking were largely nonsignificant. These patterns were not attenuated by demographics. There was limited evidence that the associations differed by sex, except physical activity, where the greater intensity was associated with usual gait among men but not women.

CONCLUSIONS

This study is among the first to describe the usual and rapid gait speeds across older adults in Africa, Asia, and Australia.

A Scoping Review of the Predictive Qualities of Walking Speed in Older Adults

BACKGROUND AND PURPOSE

Walking speed (WS) is an easily assessable and interpretable functional outcome measure with great utility for the physical therapist providing care to older adults. Since WS was proposed as the sixth vital sign, research into its interpretation and use has flourished. The purpose of this scoping review is to identify the current prognostic value of WS for the older adult.

METHODS

A scoping review was conducted using PubMed, CINAHL, and SPORTDiscus to find relevant articles highlighting the predictive capabilities of WS for older adults. Titles and abstracts were reviewed to identify relevant articles. Articles were excluded based on the following criteria: sample included both younger and older adults without separate analyses, sample was focused on a particular disease, if the study was published before 2017, or if the study did not report relevant cut points for interpretation of WS. The search returned 1064 results. Following removal of articles not meeting inclusion criteria and critical appraisal, relevant cut points were extracted from 47 original research publications.

RESULTS AND DISCUSSION

A preliminary review of the included articles showed that WS is a valuable prognostic tool across many health domains, including mental health, mortality, disability, pain, bone and joint health, falls, cognition, physical activity, metabolic health, risk for cardiovascular disease, socialization, and metabolic health. The fastest WS of 1.32 meters per second (m/s) served as a cutoff for decreased risk for incident development of type 2 diabetes, while the slowest WS of less than 0.2 m/s was associated with increased duration of hospitalization. Multiple studies reported on the prognostic value of WS slower than 1.0 m/s.

CONCLUSION

Although the reported range of predictive WS values was broad, multiple studies found WS of approximately 1.0 m/s to be a useful marker for delineating risk or decline across a variety of health domains. Clinicians may find it useful to use a WS slower than 1.0 m/s as a "yellow flag" to guide evaluation and intervention for their older adult clients.

Prevalence and Trends of Slow Gait Speed in the United States

Gait speed is a simple, effective indicator of age-related disease and disability. We sought to examine the prevalence and trends of slow gait speed in older Americans. Our unweighted analytic sample included 12,427 adults aged ≥ 65 years from the 2006-2016 waves of the Health and Retirement Study. Gait speed was measured in participant residences. Persons with gait speed < 0.8 or <0.6 m/s were slow. Sample weights were used to generate nationally representative estimates. The overall estimated prevalence of slow gait speed with the <0.8 m/s cut-point was 48.6% (95% confidence interval (CI): 47.4-49.8) in the 2006-2008 waves yet was 45.7% (CI: 44.3-47.1) in the 2014-2016 waves, but this downward trend was not statistically significant (p = 0.06). The estimated prevalence of slowness with the <0.6 m/s cut-point was 21.3% (CI: 20.4-22.3) for the 2006-2008 waves, 18.5% (CI: 17.5-19.4) for the 2010-2012 waves, and 19.2% (CI: 18.2-20.2) for the 2014-2016 waves, but there were again no significant trends (p = 0.61). Our findings showed that the estimated prevalence of slow gait speed in older Americans is pronounced, and different cut-points largely inform how slowness is categorized. Continued surveillance of slowness over time will help guide screening for disablement and identify sub-populations at greatest risk for targeted interventions.

Home-based gait speed and the association with sociodemographic and anthropometric variables: A national study (ELSI-Brazil)

OBJECTIVES

To investigate home-based gait speed performance for men and women stratified by age group and its associations with sociodemographic and anthropometric variables.

METHODS

Data from the 2^nd wave of the Brazilian Longitudinal Study of Aging (ELSI-Brazil, 2019-2021) were used. Gait speed was tested twice at home over 3.0 meters at usual pace. Associations of sociodemographic and anthropometric variables with gait speed were evaluated using gamma regression.

RESULTS

Median gait speed value reduced with increasing age in both sexes [men: 0.70 m/s (50-59 years) to 0.53 m/s (≥80 years); women: 0.68 m/s (50-59 years) to 0.48 m/s (≥80 years)] and was significantly lower in women than men in the age groups of 60-69 and 70-79 years. Age group and education among men and age group, education, and waist circumference among women were significantly associated with gait speed.

CONCLUSIONS

Our findings may be helpful as reference values to identify mobility limitation among older Brazilians.

Measuring physical performance in later life: reliability of protocol variations for common performance-based mobility tests

BACKGROUND AND AIMS

Performance-based tests of mobility or physical function such as the Timed Up and Go (TUG), gait speed, chair-rise, and single-leg stance (SLS) are often administered using different protocols in aging populations, however, the reliability of their assessment protocols is not often considered. The purpose of this study was to examine the reliabilities of frequently used assessment protocols for the TUG, gait speed, chair-rise, and SLS in different age groups.

METHODS

We administered the following assessment protocols in an age-stratified (50-64, 65-74, 75+ years) sample of participants (N = 147) from the Canadian Longitudinal Study on Aging (CLSA): TUG fast pace and TUG normal pace: TUG-cognitive counting backwards by ones and counting back by threes, gait speed with 3-m and 4-m course, chair-rise with arms crossed and allowing the use of arms, and SLS using preferred leg or both legs-on two occasions within 1 week. We assessed the relative (intra-class correlation) and absolute reliability (standard error of measurement, SEM and minimal detectable change, MDC) for each protocol variation and provided recommendations based on relative reliability.

RESULTS

For participants aged 50-64 years, our results suggest better reliability for TUG fast-pace compared with normal-pace (ICC and 95% CI 0.70; 0.41-0.85 versus 0.38; 0.12-0.59). The reliability values for 3-m gait speed were potentially higher than for 4-m gait speed (ICC 0.75; 0.67-0.82 versus 0.64; 0.54-0.73) and values for chair-rise suggested better reliability allowing participants to use their arms than with arms crossed (ICC 0.79; 0.66-0.86 versus 0.64; 0.45-0.77) for participants overall. For participants aged 75+ years, ICCs for SLS with the preferred leg showed better reliability than for both legs (ICC = 0.62-0.79 versus 0.30-0.39).

CONCLUSIONS AND DISCUSSION

These reliability data and the recommendations can help guide the selection of the most appropriate performance-based test protocols for measuring mobility in middle-aged and older community-dwelling adults.

Normative values for grip strength, gait speed, timed up and go, single leg balance, and chair rise derived from the Canadian longitudinal study on ageing

BACKGROUND

decreased muscle strength and physical function often precede disability, nursing home admission, home care use and mortality in older adults. Normative values for commonly used physical performance-based tests are not widely available for older adults but are required for clinicians and researchers to easily identify individuals with low performance.

OBJECTIVE

to develop normative values for grip strength, gait speed, timed up and go, single-leg balance and five-repetition chair rise tests in a large population-based sample of Canadians aged 45-85 years.

METHODS

baseline data (2011-2015) from the Canadian Longitudinal Study on Ageing was used to estimate age- and sex-specific normative values for each of the physical tests. Participants were without disability or mobility limitation (no assistance with activities of daily living or use of mobility devices).

RESULTS

of the 25,470 participants eligible for the analyses 48.6% (n = 12,369) were female with a mean age of 58.6 ± 9.5 years. Sex-specific 5th, 10th, 20th, 50th, 80th, 90th and 95th percentile values for each physical performance-based test were estimated. Cross-validation (n = 100 repetitions) with a 30% holdout sample was used to evaluate model fit.

CONCLUSIONS

the normative values developed in this paper can be used in clinical and research settings to identify individuals with low performance relative to their peers of the same age and sex. Interventions targeting these at-risk individuals including physical activity can prevent or delay mobility disability and the resulting cascade of increasing care requirements, health care costs and mortality.

DeepHAR: a deep feed-forward neural network algorithm for smart insole-based human activity recognition

Health monitoring, rehabilitation, and fitness are just a few domains where human activity recognition can be applied. In this study, a deep learning approach has been proposed to recognise ambulation and fitness activities from data collected by five participants using smart insoles. Smart insoles, consisting of pressure and inertial sensors, allowed for seamless data collection while minimising user discomfort, laying the baseline for the development of a monitoring and/or rehabilitation system for everyday life. The key objective has been to enhance the deep learning model performance through several techniques, including data segmentation with overlapping technique (2 s with 50% overlap), signal down-sampling by averaging contiguous samples, and a cost-sensitive re-weighting strategy for the loss function for handling the imbalanced dataset. The proposed solution achieved an Accuracy and F1-Score of 98.56% and 98.57%, respectively. The Sitting activities obtained the highest degree of recognition, closely followed by the Spinning Bike class, but fitness activities were recognised at a higher rate than ambulation activities. A comparative analysis was carried out both to determine the impact that pre-processing had on the proposed core architecture and to compare the proposed solution with existing state-of-the-art solutions. The results, in addition to demonstrating how deep learning solutions outperformed those of shallow machine learning, showed that in our solution the use of data pre-processing increased performance by about 2%, optimising the handling of the imbalanced dataset and allowing a relatively simple network to outperform more complex networks, reducing the computational impact required for such applications.

Determinants of age-related decline in walking speed in older women

Background

Walking speed is reduced with aging. However, it is not certain whether the reduced walking speed is associated with physical and coordination fitness. This study explores the physical and coordination determinants of the walking speed decline in older women.

Methods

One-hundred-eighty-seven active older women (72.2 ± 6.8 years) were asked to perform a 10-m walk test (self-selected and maximal walking speed) and a battery of the Senior fitness test: lower body strength, lower body flexibility, agility/dynamic balance, and aerobic endurance. Two parameters characterized the walking performance: closeness to the modeled speed minimizing the energetic cost per unit distance (locomotor rehabilitation index, LRI), and the ratio of step length to step cadence (walk ratio, WR). For dependent variables (self-selected and maximal walking speeds), a recursive partitioning algorithm (classification and regression tree) was adopted, highlighting interactions across all the independent variables.

Results

Participants were aged from 60 to 88 years, and their self-selected and maximal speeds declined by 22% and 26% (p < 0.05), respectively. Similarly, all physical fitness variables worsened with aging (muscle strength: 33%; flexibility: 0 to -8 cm; balance: 22%; aerobic endurance: 12%; all p < 0.050). The predictors of maximal walking speed were only WR and balance. No meaningful predictions could be made using LRI and WR as dependent variables.

Discussion

The results suggest that at self-selected speed, the decrease in speed itself is sufficient to compensate for the age-related decline in the motor functions tested; by contrast, lowering the WR is required at maximal speed, presumably to prevent imbalance. Therefore, any excessive lowering of LRI and WR indicates loss of homeostasis of walking mechanics and invites diagnostic investigation.

Assessing Sarcopenia, Frailty, and Malnutrition in Community-Dwelling Dependant Older Adults-An Exploratory Home-Based Study of an Underserved Group in Research

BACKGROUND

Adults of advanced age, with functional dependency, socioeconomic disadvantage, or a need for home care, are expected to be at high risk of sarcopenia, frailty and malnutrition, yet are likely to be underrepresented in research. We aimed to explore the assessment of sarcopenia, frailty, and malnutrition in-home, and to describe the practicality of performing these assessments.

METHODS

Home-based health assessments and post-study feedback surveys were conducted among community-dwelling older adults ≥65 years in receipt of state-funded home care (n = 31). Assessments included probable sarcopenia [hand-grip strength (HGS), chair rise-test, and SARC-F case-finding tool], the Mini Nutritional Assessment (MNA), and the Clinical Frailty Scale (CFS).

RESULTS

The study group was of mean age 83.2 ± 8.2 years, 74% were female and 23% lived in socioeconomically disadvantaged areas. Almost all met the criteria for probable sarcopenia (94%, n = 29/31), were frail or vulnerable by the CFS (97%, n = 30/31), and over a quarter were at risk of malnutrition (26%, n = 8). Participants had low physical activity (71.0%, n = 22/31), with a mean daytime average of 11.4 ± 1.6 h spent sitting. It was possible to assess probable sarcopenia (by HGS and SARC-F, but not the chair rise test), malnutrition (MNA), and frailty (CFS). Home-based research was a complex environment, and unearthed significant unmet need, prompting referrals to health services (36%, n = 11), in addition to technology assistance. The majority of participants (93%) reported a willingness to partake in future research.

CONCLUSIONS

Most community-dwelling older people in receipt of home support, assessed in this exploratory study, were at risk of probable sarcopenia, frailty, and low physical activity, with over a quarter were at risk of malnutrition. Our initial findings provide practical data for large scale studies and may inform the development of intervention studies aiming to support ageing in place.

A Matched Cohort Analysis for Examining the Association Between Slow Gait Speed and Shortened Longevity in Older Americans

This investigation examined the association between slow gait speed, as defined with newly established cut-points, and all-cause mortality in older Americans with a matched cohort analysis. The analytic sample included 10,259 Americans aged ≥65 years from the 2006-2014 waves of the Health and Retirement Study. Walking speed was measured in participant residences. Slow gait speed cut-points of <0.60 and <0.75 m/s were used separately for classifying participants as having slow walking speed. Nearest-neighbor propensity score matching was used to match the slow to the not-slow cohorts separately using both cut-points using relevant covariates. Persons with gait speed <0.60 m/s had a 1.42 higher hazard for mortality (95% CI: 1.28-1.57). Older Americans with gait speed <0.75 m/s had a 1.36 higher hazard for mortality (95% CI: 1.23-1.50). Slow gait speed may represent failing health and addressing how slow gait speed could be improved may help with referrals to appropriate interventions.

Changes in objectively-measured physical capability over 4-year, risk of diabetes, and glycemic control in older adults: The China Health and Retirement Longitudinal study

AIMS

High physical capability reduces risk of diabetes, but the association of its changes with risk of diabetes and glycemic control is unclear in older adults. This study aimed to quantify their association.

METHODS

A total of 1,667 participants without diabetes and aged ≥ 60 years from the China Health and Retirement Longitudinal Study were included and followed over 4 years. Physical capability was objectively measured at baseline and 4-year later. Logistic regression models were used to assess the association of changes in physical capability with risk of diabetes.

RESULTS

During follow-up, 160 participants developed diabetes. None of the changes in physical capability expressed in continuous scales or in tertiles was associated with risk of diabetes in unadjusted or adjusted models (all P > 0.05), and no favorable joint effects were observed. Changes in physical capability were not associated with changes in fasting plasma glucose or hemoglobin A1c. Yet increases in walking speed or grip strength were related to reduced metabolic score for insulin resistance (both P ≤ 0.03).

CONCLUSIONS

Increases in objectively-measured physical capability were not associated with reduced risk of diabetes but may ameliorate insulin resistance in older adults. Studies with longer follow-up periods are required to confirm these findings.

Four-year changes in central fatness, risk of diabetes, and metabolic control in older adults: a cohort study with mediation analysis

BACKGROUND/AIMS

Older adults are vulnerable to central obesity, while the association of changes in central fatness with risk of diabetes and metabolic control has not been investigated among this particular population. This study was aimed to address these issues.

METHODS

A total of 1,815 adults aged ≥ 60 years without diabetes at baseline were followed for 4 years. Incident diabetes was ascertained based on plasma glucose, hemoglobin A1c, medical history, and/or the use of anti-diabetic drugs. Central fatness was assessed by waist circumference (WC), waist-height ratio (WHtR), and body roundness index (BRI). Logistic regression analyses were used to assess the association of changes in central fatness with risk of diabetes, along with dose-response and mediation analyses.

RESULTS

During the 4-year follow-up, 177 participants developed diabetes. The risk of diabetes was increased by 42%, 41%, and 40% per 1 standard deviation increases in WC, WHtR, and BRI, respectively, in multivariable-adjusted models (all p < 0.01). Moreover, these relationships were all linearly-shaped (all pnonlinearity ≥ 0.11). Increases in WC, WHtR, and BRI correlated with increases in hemoglobin A1c, triglycerides-and-glucose index, triglycerides, white blood cell, and C-reactive protein (all p ≤ 0.04). Yet only changes in hemoglobin A1c and triglycerides-and-glucose index were identified as the possible mediators for risk of diabetes, with their mediating effect being about 35% and 21%, respectively.

CONCLUSION

Increases in central fatness were related to elevated risk of diabetes, and this association might be partly explained by the worsening of glycemic control and insulin resistance in older adults.

Inflammatory biomarkers and motoric cognitive risk syndrome: Multicohort survey

•

Raised IL-6 and CRP levels are associated with increased odds of MCR.

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IL-6 and CRP are involved in overlapping inflammatory, vascular, and neurological pathology.

•

Establishing these pathways can guide interventions to prevent progression of MCR to dementia.

Background

Inflammation may play a role in Motoric Cognitive Risk (MCR) syndrome, a pre-dementia syndrome comprised of slow gait and cognitive complaints. Our objective was to examine associations of inflammatory biomarkers with MCR.

Methods

We examined association of interleukin-6 (IL-6) and C-reactive protein (CRP) with prevalent MCR using logistic regression in 3,101 older adults (52% female) from five cohorts (National Center for Geriatrics & Gerontology Study of Geriatric Syndromes [NCGG-SGS], Central Control of Mobility in Aging [CCMA], Tasmanian Study of Cognition and Gait [TASCOG], LonGenity, and Einstein Aging Study [EAS]). Associations were reported as odds ratios adjusted for sex, age, education, depressive symptoms, body mass index, and vascular diseases (aOR) with 95% confidence intervals (CI). Meta-analysis and analyses stratified by vascular disease were also done.

Results

Although associations between higher (worse) CRP and IL-6 tertiles and MCR were only seen in three out of the five cohorts (EAS, TASCOG, and LonGenity), when a pooled meta-analysis was performed, a robust association was demonstrated. In meta-analysis, highest tertiles of IL-6 (aOR 1.57, 95%CI 1.01- 2.44) and CRP (aOR 1.65, 95%CI 1.09–2.48) was associated with MCR versus lowest tertiles in the pooled sample. Higher CRP was associated with MCR among those with vascular disease in TASCOG and LonGenity cohorts, and among those without vascular disease in EAS.

Conclusions

IL-6 and CRP levels are associated with MCR in older adults, and this association varies by presence of vascular disease.

Gait speed reference values in community-dwelling older adults - Cross-sectional analysis from the Rotterdam Study

BACKGROUND

Gait speed is a simple, inexpensive and clinically useful marker of physical function in older adults. We aimed to establish gait speed reference values for community-dwelling older adults. To this end, we further explored the association of age, sex and height with gait speed.

METHODS

This study included community-dwelling participants aged 50 years and over enrolled in the Rotterdam Study. Participants completed the gait protocol between 2009 and 2016. The mean gait speed was calculated for age and height groups, stratified by sex. Reference values for gait speed were calculated using a quantile regression model adjusted for sex, the non-linear effects of age and height, as well as the interaction between age and sex plus the interaction between age and height.

RESULTS

The study population included 4656 Dutch participants with a mean (standard deviation) age of 67.7 (9.5) years, comprising 2569 (55.2%) women. The mean height of the participants was 1.69 (0.10) meters and the mean gait speed was 1.20 (0.20) m/s. Gait speed was lower with older age and greater with taller stature, but the effect of height disappeared above the age of 80 years. Sex did not affect gait speed after accounting for age and height. Age-, sex-, and height-specific reference values for gait speed are available for use at https://emcbiostatistics.shinyapps.io/GaitSpeedReferenceValues/.

CONCLUSIONS

We found that height explains the commonly noted difference in usual gait speed between sexes and that neither height nor sex impacts gait speed in the very oldest adults. We developed reference values for usual gait speed in Western European community-dwelling older adults.

Walking Speed and Mortality: An Updated Systematic Review

OBJECTIVE

The aim of our systematic review was to update the current evidence on the association between slow walking speed (WS) and mortality, expanding the current knowledge available in the literature.

METHODS

A systematic review of the published data on the association of WS and mortality was carried out by searching on PubMed and ISI Web of Knowledge databases.

RESULTS

From a title and abstract analysis, 61 articles were included that met the prespecified criteria. After a full-text analysis, 6 articles were excluded and the remaining articles accounted for 120,838 patients and > 25,148 deaths were registered. The duration of follow-ups ranged between 2 and 21 years. In general, studies have shown a consistent association between WS and mortality from all causes.

CONCLUSIONS

WS showed continuous and consistent evidence to be a good predictor of mortality. As such, our study supports the use of this tool in clinical practice as a way to improve health care.

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

BACKGROUND

Cut-points to define slow walking speed have largely been derived from expert opinion.

METHODS

Study participants (13,589 men and 5,043 women aged ≥65years) had walking speed (m/s) measured over 4-6 meters (mean ± SD: 1.20 ± 0.27 m/s in men and 0.94 ± 0.24 m/s in women.) Mobility limitation was defined as self-reported any difficulty with walking ~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.

RESULTS

Among 5,043 women, CART analysis identified two cut-points, classifying 4,144 (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 three cut-points, classifying 10,001 (73.6%) with walking speed ≥1.00 m/s ("very fast"); 2,901 (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 two slower cut-points to 0.60 m/s and 0.75 m/s reclassified very few participants.

CONCLUSIONS

Cut-points in walking speed of ~0.60 m/s and 0.75 m/s discriminate those with self-reported mobility limitation from those without.

Subjective Motoric Complaints and New Onset Slow Gait

BACKGROUND

While reports of mobility problems are common with aging, their relationship to new onset of slow gait is unknown. Our objective was to examine the validity of subjective motoric complaints for predicting the incidence of slow gait.

METHODS

Ambulatory community-residing participants (mean age 76.6, 55% women) with gait speeds in the normal range enrolled in an aging cohort. Five subjective motoric complaints were assessed. Incident slow gait (walking speed 1 SD below age and sex means) was the primary outcome.

RESULTS

Of the 548 participants at baseline, 90 had prevalent slow gait and 253 participants (73.7%) reported one or more subjective motoric complaints. Subjective motoric complaints were more common in women than men (1.78 vs 1.23). Over a median follow-up of 3.34 years, 68 participants developed new onset slow gait. All 5 questions predicted incident slow gait (adjusted hazard ratios varying from 2.26 to 4.44). More subjective motoric complaints were associated with increased risk of developing incident slow gait (hazard ratio per complaint 1.81). Predictive validity of subjective motoric complaints for incident slow gait was unchanged when using alternate outcome definitions, accounting for diagnostic misclassification, recall bias, or adjusting for multiple confounders.

CONCLUSIONS

Subjective motoric complaints are a harbinger of mobility disability, and can help improve clinical risk assessments and identify high-risk individuals for interventions to prevent onset of slow gait.

Racial differences in gait mechanics

The effect of race has rarely been investigated in biomechanics studies despite racial health disparities in the incidence of musculoskeletal injuries and disease, hindering both treatment and assessment of rehabilitation. The purpose of this study was to test the hypothesis that racial differences in gait mechanics exist between African Americans (AA) and white Americans (WA). Ninety-two participants (18-30 years old) were recruited with equal numbers in each racial group and sex. Self-selected walking speed was measured for each participant. 3D motion capture and force plate data were recorded during 7 walking trials at regular and fast set speeds. Step length, step width, peak vertical ground reaction force, peak hip extension, peak knee flexion, and peak ankle plantarflexion were computed for all trials at both set speeds. Multivariate and post-hoc univariate ANOVA models were fit to determine main and interaction effects of sex and race (SPSS V26, α = 0.05). Self-selected walking speed was slower in AA (p = 0.004, ƞ_p² = 0.088). No significant interactions between race and sex were identified. Males took longer steps (regular: p < 0.001, ƞ_p² = 0.288, fast: p < 0.001, ƞ_p² = 0.193) and had larger peak knee flexion (regular: p = 0.007, ƞ_p² = 0.081, fast: p < 0.001, ƞ_p² = 0.188) and ankle plantarflexion angles (regular: p = 0.050, ƞ_p² = 0.044, fast: p = 0.049, ƞ_p² = 0.044). Peak ankle plantarflexion angle (regular: p = 0.012, ƞ_p² = 0.071, fast: p < 0.001, ƞ_p² = 0.137) and peak hip extension angle during fast walking (p = 0.007, ƞ_p² = 0.083) were smaller in AA. Equivalency in gait measures between racial groups should not be assumed. Racially diverse study samples should be prioritized in the development of future research and individualized treatment protocols.

Gait Variability Using Waist- and Ankle-Worn Inertial Measurement Units in Healthy Older Adults

Gait variability observed in step duration is predictive of impending adverse health outcomes among apparently healthy older adults and could potentially be evaluated using wearable sensors (inertial measurement units, IMU). The purpose of the present study was to establish the reliability and concurrent validity of gait variability and complexity evaluated with a waist and an ankle-worn IMU. Seventeen women (age 74.8 (SD 44) years) and 10 men (73.7 (4.1) years) attended two laboratory measurement sessions a week apart. Their stride duration variability was concurrently evaluated based on a continuous 3 min walk using a force plate and a waist- and an ankle-worn IMU. Their gait complexity (multiscale sample entropy) was evaluated from the waist-worn IMU. The force plate indicated excellent stride duration variability reliability (intra-class correlation coefficient, ICC = 0.90), whereas fair to good reliability (ICC = 0.47 to 0.66) was observed from the IMUs. The IMUs exhibited poor to excellent concurrent validity in stride duration variability compared to the force plate (ICC = 0.22 to 0.93). A good to excellent reliability was observed for gait complexity in most coarseness scales (ICC = 0.60 to 0.82). A reasonable congruence with the force plate-measured stride duration variability was observed on many coarseness scales (correlation coefficient = 0.38 to 0.83). In conclusion, waist-worn IMU entropy estimates may provide a feasible indicator of gait variability among community-dwelling ambulatory older adults.