Gait variability is associated with frailty in community-dwelling older adults

Spatial and temporal gait characteristics in pre-frail community-dwelling older adults

AIM

A number of studies have explored possible relationships, behavior, and meanings of spatial and temporal gait variables in frail and pre-frail older adults, particularly the gait speed variable. However, it is necessary to know the relationship of other spatial and temporal gait variables of pre-frail older adults. Thus, the objective of the present study was to evaluate and compare gait standards between pre-frail and non-frail older people.

METHODS

A total of 69 older adults aged 60 year and older, divided into two groups, non-frail (n = 42) and pre-frail (n = 27), were evaluated. Gait parameters were analyzed using the GAITRite® Platinum 26' Portable Walkway System.

RESULTS

Pre-frail older people had smaller step lengths (P = 0.041), larger base of support (P = 0.040), lower speed (P = 0.019), lower single support percentage (P = 0.033) and higher double support percentage (P = 0.036), compared with non-frail older people. A history of falls was correlated to lower gait speed and step length in pre-frail older adults.

CONCLUSIONS

Identifying pre-frail older people could have significant clinical consequences, as frailty is a dynamic process, and such individuals can therefore progress into a state of frailty or revert to a non-frail state. Therefore, the identification of gait variables in pre-frail older people can be an important tool to recognize gait deficits and to initiate the appropriate treatment. Geriatr Gerontol Int 2016; 16: 1102-1108.

Frailty assessment based on trunk kinematic parameters during walking

Background

Physical frailty has become the center of attention of basic, clinical and demographic research due to its incidence level and gravity of adverse outcomes with age. Frailty syndrome is estimated to affect 20 % of the population older than 75 years. Thus, one of the greatest current challenges in this field is to identify parameters that can discriminate between vulnerable and robust subjects. Gait analysis has been widely used to predict frailty. The aim of the present study was to investigate whether a collection of parameters extracted from the trunk acceleration signals could provide additional accurate information about frailty syndrome.

Methods

A total of 718 subjects from an elderly population (319 males, 399 females; age: 75.4 ± 6.1 years, mass: 71.8 ± 12.4 kg, height: 158 ± 6 cm) volunteered to participate in this study. The subjects completed a 3-m walk test at their own gait velocity. Kinematic data were acquired from a tri-axial inertial orientation tracker.

Findings

The spatio-temporal and frequency parameters measured in this study with an inertial sensor are related to gait disorders and showed significant differences among groups (frail, pre-frail and robust). A selection of those parameters improves frailty classification obtained to gait velocity, compared to classification model based on gait velocity solely.

Interpretation

Gait parameters simultaneously used with gait velocity are able to provide useful information for a more accurate frailty classification. Moreover, this technique could improve the early detection of pre-frail status, allowing clinicians to perform measurements outside of a laboratory environment with the potential to prescribe a treatment for reversing their physical decline.

Wearable sensor-based in-home assessment of gait, balance, and physical activity for discrimination of frailty status: baseline results of the Arizona frailty cohort study

BACKGROUND

Frailty is a geriatric syndrome resulting from age-related cumulative decline across multiple physiologic systems, impaired homeostatic reserve, and reduced capacity to resist stress. Based on recent estimates, 10% of community-dwelling older individuals are frail and another 41.6% are prefrail. Frail elders account for the highest health care costs in industrialized nations. Impaired physical function is a major indicator of frailty, and functional performance tests are useful for the identification of frailty. Objective instrumented assessments of physical functioning that are feasible for home frailty screening have not been adequately developed.

OBJECTIVE

To examine the ability of wearable sensor-based in-home assessment of gait, balance, and physical activity (PA) to discriminate between frailty levels (nonfrail, prefrail, and frail).

METHODS

In an observational cross-sectional study, in-home visits were completed in 125 older adults (nonfrail: n=44, prefrail: n=60, frail: n=21) living in Tucson, Ariz., USA, between September 2012 and November 2013. Temporal-spatial gait parameters (speed, stride length, stride time, double support, and variability of stride velocity), postural balance (sway of hip, ankle, and center of mass), and PA (percentage of walking, standing, sitting, and lying; mean duration and variability of single walking, standing, sitting, and lying bouts) were measured in the participant's home using validated wearable sensor technology. Logistic regression was used to assess the most sensitive gait, balance, and PA variables for identifying prefrail participants (vs. nonfrail). Multinomial logistic regression was used to identify variables sensitive to discriminate between three frailty levels.

RESULTS

Gait speed (area under the curve, AUC=0.802), hip sway (AUC=0.734), and steps/day (AUC=0.736) were the most sensitive parameters for the identification of prefrailty. Multinomial regression revealed that stride length (AUC=0.857) and double support (AUC=0.841) were the most sensitive gait parameters for discriminating between three frailty levels. Interestingly, walking bout duration variability was the most sensitive PA parameter for discriminating between three frailty levels (AUC=0.818). No balance parameter discriminated between three frailty levels.

CONCLUSION

Our results indicate that unique parameters derived from objective assessment of gait, balance, and PA are sensitive for the identification of prefrailty and the classification of a subject's frailty level. The present findings highlight the potential of wearable sensor technology for in-home assessment of frailty status.

Wearable sensor-based in-home assessment of gait, balance, and physical activity for discrimination of frailty status: baseline results of the Arizona frailty cohort study

BACKGROUND

Frailty is a geriatric syndrome resulting from age-related cumulative decline across multiple physiologic systems, impaired homeostatic reserve, and reduced capacity to resist stress. Based on recent estimates, 10% of community-dwelling older individuals are frail and another 41.6% are prefrail. Frail elders account for the highest health care costs in industrialized nations. Impaired physical function is a major indicator of frailty, and functional performance tests are useful for the identification of frailty. Objective instrumented assessments of physical functioning that are feasible for home frailty screening have not been adequately developed.

OBJECTIVE

To examine the ability of wearable sensor-based in-home assessment of gait, balance, and physical activity (PA) to discriminate between frailty levels (nonfrail, prefrail, and frail).

METHODS

In an observational cross-sectional study, in-home visits were completed in 125 older adults (nonfrail: n=44, prefrail: n=60, frail: n=21) living in Tucson, Ariz., USA, between September 2012 and November 2013. Temporal-spatial gait parameters (speed, stride length, stride time, double support, and variability of stride velocity), postural balance (sway of hip, ankle, and center of mass), and PA (percentage of walking, standing, sitting, and lying; mean duration and variability of single walking, standing, sitting, and lying bouts) were measured in the participant's home using validated wearable sensor technology. Logistic regression was used to assess the most sensitive gait, balance, and PA variables for identifying prefrail participants (vs. nonfrail). Multinomial logistic regression was used to identify variables sensitive to discriminate between three frailty levels.

RESULTS

Gait speed (area under the curve, AUC=0.802), hip sway (AUC=0.734), and steps/day (AUC=0.736) were the most sensitive parameters for the identification of prefrailty. Multinomial regression revealed that stride length (AUC=0.857) and double support (AUC=0.841) were the most sensitive gait parameters for discriminating between three frailty levels. Interestingly, walking bout duration variability was the most sensitive PA parameter for discriminating between three frailty levels (AUC=0.818). No balance parameter discriminated between three frailty levels.

CONCLUSION

Our results indicate that unique parameters derived from objective assessment of gait, balance, and PA are sensitive for the identification of prefrailty and the classification of a subject's frailty level. The present findings highlight the potential of wearable sensor technology for in-home assessment of frailty status.

Sensor-based detection of gait speed in older adults: an integrative review

Gait speed is an indicator of functional change in older adults. One approach to support older adults' preferences to "age in place" is through the use of technology to monitor gait speed in everyday life. The authors of the current article conducted an integrative review of the scientific literature to summarize the current state of gait speed detection technologies. A total of 539 articles were returned from searches, and 16 were included in the review. Technologies were categorized as body-worn or home-installed sensors. Evidence was classified as emerging (n = 8) or promising (n = 8). Gait speed technology research has advanced beyond the use of customized research hardware prototypes, and consumer technologies are now commonly used in gait speed research. However, a need exists for software systems that integrate data for analysis and presentation to stakeholders with different information needs. Future research should focus on approaches to integrate disparate data sources and visualizations of gait speed data.

Motoric cognitive risk syndrome: multicountry prevalence and dementia risk

OBJECTIVES

Our objective is to report prevalence of motoric cognitive risk syndrome (MCR), a newly described predementia syndrome characterized by slow gait and cognitive complaints, in multiple countries, and its association with dementia risk.

METHODS

Pooled MCR prevalence analysis of individual data from 26,802 adults without dementia and disability aged 60 years and older from 22 cohorts from 17 countries. We also examined risk of incident cognitive impairment (Mini-Mental State Examination decline ≥4 points) and dementia associated with MCR in 4,812 individuals without dementia with baseline Mini-Mental State Examination scores ≥25 from 4 prospective cohort studies using Cox models adjusted for potential confounders.

RESULTS

At baseline, 2,808 of the 26,802 participants met MCR criteria. Pooled MCR prevalence was 9.7% (95% confidence interval [CI] 8.2%-11.2%). MCR prevalence was higher with older age but there were no sex differences. MCR predicted risk of developing incident cognitive impairment in the pooled sample (adjusted hazard ratio [aHR] 2.0, 95% CI 1.7-2.4); aHRs were 1.5 to 2.7 in the individual cohorts. MCR also predicted dementia in the pooled sample (aHR 1.9, 95% CI 1.5-2.3). The results persisted even after excluding participants with possible cognitive impairment, accounting for early dementia, and diagnostic overlap with other predementia syndromes.

CONCLUSION

MCR is common in older adults, and is a strong and early risk factor for cognitive decline. This clinical approach can be easily applied to identify high-risk seniors in a wide variety of settings.

Muscle force and movement variability before and after total knee arthroplasty: A review

Variability in muscle force output and movement variability are important aspects of identifying individuals with mobility deficits, central nervous system impairments, and future risk of falling. This has been investigated in elderly healthy and impaired adults, as well as in adults with osteoarthritis (OA), but the question of whether the same correlations also apply to those who have undergone a surgical intervention such as total knee arthroplasty (TKA) is still being investigated. While there is a growing body of literature identifying potential rehabilitation targets for individuals who have undergone TKA, it is important to first understand the underlying post-operative impairments to more efficiently target functional deficits that may lead to improved long-term outcomes. The purpose of this article is to review the potential role of muscle force output and movement variability in TKA recipients. The narrative review relies on existing literature in elderly healthy and impaired individuals, as well as in those with OA before and following TKA. The variables that may predict long-term functional abilities and deficits are discussed in the context of existing literature in healthy older adults and older adults with OA and following TKA, as well as the role future research in this field may play in providing evidence-based data for improved rehabilitation targets.

The effect of three different types of walking aids on spatio-temporal gait parameters in community-dwelling older adults

BACKGROUND AND AIMS

Gait and balance impairments lead to falls and injuries in older people. Walking aids are meant to increase gait safety and prevent falls, yet little is known about how their use alters gait parameters. This study aimed to quantify gait in older adults during walking without and with different walking aids and to compare gait parameters to matched controls.

METHODS

This retrospective study included 65 older (≥60 years) community dwellers who used a cane, crutch or walker and 195 independently mobile-matched controls. Spatio-temporal gait parameters were measured with an electronic walkway system during normal walking.

RESULTS

When walking unaided or aided, walking aid users had significantly worse gait than matched controls. Significant differences between the walking aid groups were found for stride time variability (cane vs. walker) in walking unaided only. Gait performances significantly improved when assessed with vs. without the walking aid for the cane (increased stride time and length, decreased cadence and stride length variability), crutch (increased stride time and length, decreased cadence, stride length variability and double support) and walker (increased gait speed and stride length, decreased base of support and double support) users.

CONCLUSION

Gait in older adults who use a walking aid is more irregular and unstable than gait in independently mobile older adults. Walking aid users have better gait when using their walking aid than when walking without it. The changes in gait were different for the different types of walking aids used. These study results may help better understand gait in older adults and differentiate between pathological gait changes and compensatory gait changes due to the use of a walking aid.

Association between nutritional status (MNA®-SF) and frailty (SHARE-FI) in acute hospitalised elderly patients

OBJECTIVE

This study aimed to explore the association between the impaired nutritional status and frailty in acute hospitalised elderly patients by using two tools, the MNA®-SF (Mini Nutritional Assessment® short-form) and the SHARE-FI (Frailty Instrument for Primary Care of the Survey of Health, Ageing and Retirement in Europe).

DESIGN

Cross-sectional study.

SETTING

Acute hospitalised, community-dwelling elderly patients were recruited at internal medicine wards in Vienna, Austria.

PARTICIPANTS

133 men (39%) and women (61%) aged 74 (65-97) years.

MEASUREMENTS

MNA®-SF was used to investigate malnutrition (<7 points) and patients at risk of malnutrition (8 to 11 points). By using the SHARE-FI, subjects were classified as frail, pre-frail or robust. A factor analysis was applied to identify overlaps between the MNA®-SF and SHARE-FI items. Internal consistency of different dimensions was assessed by using Cronbach's Alpha.

RESULTS

Malnutrition or risk of malnutrition was found in 76.7% of the total sample and in 46.8% of robust, in 69.0% of pre-frail, and in 93.0% of frail participants. Frailty or prefrailty was found in 75.9% of the total sample and in 45.1% of the subjects with no risk of malnutrition, in 80.9% of subjects at risk of malnutrition, and in 94.1% of malnourished patients. The two used tools show overlaps in three dimensions: (1) nutrition problems, (2) mobility problems and (3) anthropometric items with a moderate to strong internal consistency (Cronbach's Alpha of 0.670, 0.834 and 0.946, respectively). 64.7% of the total sample (79.5% of frail and 87.9% of malnourished subjects) would participate in a home-based muscle training and nutritional intervention program.

CONCLUSIONS

This study underlines the association and the overlap between frailty and impaired nutritional status. There is a high readiness to participate in a program to tackle the problems associated with malnutrition and frailty, especially in those, who would benefit most from it.

Prevention of neuromusculoskeletal frailty in slow-aging ames dwarf mice: longitudinal investigation of interaction of longevity genes and caloric restriction

Ames dwarf (Prop1^df/df) mice are remarkably long-lived and exhibit many characteristics of delayed aging and extended healthspan. Caloric restriction (CR) has similar effects on healthspan and lifespan, and causes an extension of longevity in Ames dwarf mice. Our study objective was to determine whether Ames dwarfism or CR influence neuromusculoskeletal function in middle-aged (82 ± 12 weeks old) or old (128 ± 14 w.o.) mice. At the examined ages, strength was improved by dwarfism, CR, and dwarfism plus CR in male mice; balance/ motor coordination was improved by CR in old animals and in middle-aged females; and agility/ motor coordination was improved by a combination of dwarfism and CR in both genders of middle-aged mice and in old females. Therefore, extension of longevity by congenital hypopituitarism is associated with improved maintenance of the examined measures of strength, agility, and motor coordination, key elements of frailty during human aging, into advanced age. This study serves as a particularly important example of knowledge related to addressing aging-associated diseases and disorders that results from studies in long-lived mammals.

Evaluation of age-related differences in the stride-to-stride fluctuations, regularity and symmetry of gait using a waist-mounted tri-axial accelerometer

PURPOSE

To compare the stride-to-stride fluctuations, regularity and symmetry of gait using a body-fixed accelerometer in a group of healthy young and healthy older adults.

METHODS

Forty-one healthy young adults (24 ± 3 years) and forty-one healthy older adults (76 ± 5 years) completed a 10-min walk at a self-selected, normal walking speed while wearing a single waist-mounted tri-axial accelerometer. The following gait parameters were compared between age groups: mean step and stride time, step and stride time variability, stride time fractal scaling index and the regularity and symmetry of the acceleration pattern in the vertical, mediolateral and anteroposterior directions (unbiased autocorrelation procedure).

RESULTS

Older adults displayed significantly greater step and stride time variability (p<0.05) and a lower stride time fractal scaling index (p<0.01), as well as significantly less regularity (p<0.05) and symmetry (p<0.05) of the anteroposterior accelerations.

CONCLUSION

The results show that healthy older adults possess greater temporal gait variability, as well as a less-organized and repeatable pattern of variability and acceleration in the direction of motion, than younger adults. The findings also suggest the presence of an age-related decline in the anteroposterior control of gait, but not in the vertical and mediolateral control of gait.

Frailty and technology: a systematic review of gait analysis in those with frailty

BACKGROUND

New technologies for gait assessment are emerging and have provided new avenues for accurately measuring gait characteristics in home and clinic. However, potential meaningful clinical gait parameters beyond speed have received little attention in frailty research.

OBJECTIVE

To study gait characteristics in different frailty status groups for identifying the most useful parameters and assessment protocols for frailty diagnosis.

METHODS

We searched PubMed, Embase, PsycINFO, CINAHL, Web of Science, Cochrane Library, and Age Line. Articles were selected according to the following criteria: (1) population: individuals defined as frail, prefrail, or transitioning to frail, and (2) outcome measures: quantitative gait variables as obtained by biomechanical analysis. Effect sizes (d) were calculated for the ability of parameters to discriminate between different frailty status groups.

RESULTS

Eleven publications met inclusion criteria. Frailty definitions, gait protocols and parameters were inconsistent, which made comparison of outcomes difficult. Effect sizes were calculated only for the three studies which compared at least two different frailty status groups. Gait speed shows the highest effect size to discriminate between frailty subgroups, in particular during habitual walking (d = 0.76-6.17). Gait variability also discriminates between different frailty status groups in particular during fast walking. Prominent parameters related to prefrailty are reduced cadence (d = 1.43) and increased step width variability (d = 0.64), whereas frailty (vs. prefrail status) is characterized by reduced step length during habitual walking (d = 1.32) and increased double support during fast walking (d = 0.78). Interestingly, one study suggested that dual-task walking speed can be used to predict prospective frailty development.

CONCLUSION

Gait characteristics in people with frailty are insufficiently analyzed in the literature and represent a major area for innovation. Despite the paucity of work, current results suggest that parameters beyond speed could be helpful in identifying different categories of frailty. Increased gait variability might reflect a multisystem reduction and may be useful in identifying frailty. In addition, a demanding task such as fast walking or adding a cognitive distractor might enhance the sensitivity and specificity of frailty risk prediction and classification, and is recommended for frailty assessment using gait analysis.

Location and activity tracking with the cloud

Helping elderly people to live independently within their homes for as long as possible, before transitioning to higher levels of care, can significantly reduce healthcare expenditures. However, achieving this vision requires continuous monitoring of the condition of elderly adults within their homes. In particular, activity, gait velocity, movement, and location of elderly adults are critical biomarkers for healthy aging. We present a prototype integrating a wearable location-tracking sensor with back-end cloud-based data processing, thereby enabling real-time tracking and analysis of a large number of people simultaneously. The resulting vertically-integrated prototype provides a basic infrastructure for future work, including new products and services that offer real-time monitoring and early disease diagnosis to help elderly people live independently for as long as possible.

Measures of frailty in population-based studies: an overview

Background

Although research productivity in the field of frailty has risen exponentially in recent years, there remains a lack of consensus regarding the measurement of this syndrome. This overview offers three services: first, we provide a comprehensive catalogue of current frailty measures; second, we evaluate their reliability and validity; third, we report on their popularity of use.

Methods

In order to identify relevant publications, we searched MEDLINE (from its inception in 1948 to May 2011); scrutinized the reference sections of the retrieved articles; and consulted our own files. An indicator of the frequency of use of each frailty instrument was based on the number of times it had been utilized by investigators other than the originators.

Results

Of the initially retrieved 2,166 papers, 27 original articles described separate frailty scales. The number (range: 1 to 38) and type of items (range of domains: physical functioning, disability, disease, sensory impairment, cognition, nutrition, mood, and social support) included in the frailty instruments varied widely. Reliability and validity had been examined in only 26% (7/27) of the instruments. The predictive validity of these scales for mortality varied: for instance, hazard ratios/odds ratios (95% confidence interval) for mortality risk for frail relative to non-frail people ranged from 1.21 (0.78; 1.87) to 6.03 (3.00; 12.08) for the Phenotype of Frailty and 1.57 (1.41; 1.74) to 10.53 (7.06; 15.70) for the Frailty Index. Among the 150 papers which we found to have used at least one of the 27 frailty instruments, 69% (n = 104) reported on the Phenotype of Frailty, 12% (n = 18) on the Frailty Index, and 19% (n = 28) on one of the remaining 25 instruments.

Conclusions

Although there are numerous frailty scales currently in use, reliability and validity have rarely been examined. The most evaluated and frequently used measure is the Phenotype of Frailty.

Nutritional status according to the mini nutritional assessment (MNA®) and frailty in community dwelling older persons: a close relationship

OBJECTIVE

This study investigates the association between MNA results and frailty status in community-dwelling older adults. In addition the relevance of singular MNA items and subscores in this regard was tested.

DESIGN

Cross-sectional study.

SETTING

Community-dwelling older adults were recruited in the region of Nürnberg, Germany.

PARTICIPANTS

206 volunteers aged 75 years or older without cognitive impairment (Mini Mental State Examination >24 points), 66.0% female.

MEASUREMENTS

Frailty was defined according to Fried et al. as presence of three, pre-frailty as presence of one or two of the following criteria: weight loss, exhaustion, low physical activity, low handgrip strength and slow walking speed. Malnutrition (<17 points) and the risk of malnutrition (17-23.5 points) were determined by MNA®.

RESULTS

15.1% of the participants were at risk of malnutrition, no participant was malnourished. 15.5 % were frail, 39.8% pre-frail and 44.7% non-frail. 46.9% of the frail, 12.2% of the pre-frail and 2.2% of the non-frail participants were at risk of malnutrition (p<0.001). Hence, 90% of those at risk of malnutrition were either pre-frail or frail. For the anthropometric, dietary, subjective and functional, but not for the general MNA subscore, frail participants scored significantly lower than pre-frail (p<0.01), and non-frail participants (p<0.01). Twelve of the 18 MNA items were also significantly associated with frailty (p<0.05).

CONCLUSIONS

These results underline the close association between frailty syndrome and nutritional status in older persons. A profound understanding of the interdependency of these two geriatric concepts will represent the basis for successful treatment strategies.

Nutritional status according to the mini nutritional assessment (MNA®) and frailty in community dwelling older persons: a close relationship

OBJECTIVE

This study investigates the association between MNA results and frailty status in community-dwelling older adults. In addition the relevance of singular MNA items and subscores in this regard was tested.

DESIGN

Cross-sectional study.

SETTING

Community-dwelling older adults were recruited in the region of Nürnberg, Germany.

PARTICIPANTS

206 volunteers aged 75 years or older without cognitive impairment (Mini Mental State Examination >24 points), 66.0% female.

MEASUREMENTS

Frailty was defined according to Fried et al. as presence of three, pre-frailty as presence of one or two of the following criteria: weight loss, exhaustion, low physical activity, low handgrip strength and slow walking speed. Malnutrition (<17 points) and the risk of malnutrition (17-23.5 points) were determined by MNA®.

RESULTS

15.1% of the participants were at risk of malnutrition, no participant was malnourished. 15.5 % were frail, 39.8% pre-frail and 44.7% non-frail. 46.9% of the frail, 12.2% of the pre-frail and 2.2% of the non-frail participants were at risk of malnutrition (p<0.001). Hence, 90% of those at risk of malnutrition were either pre-frail or frail. For the anthropometric, dietary, subjective and functional, but not for the general MNA subscore, frail participants scored significantly lower than pre-frail (p<0.01), and non-frail participants (p<0.01). Twelve of the 18 MNA items were also significantly associated with frailty (p<0.05).

CONCLUSIONS

These results underline the close association between frailty syndrome and nutritional status in older persons. A profound understanding of the interdependency of these two geriatric concepts will represent the basis for successful treatment strategies.

Vascular depression and frailty: a compound threat to longevity among older-old women

OBJECTIVES

The vascular depression hypothesis posits that cerebrovascular burden contributes to the development of depression symptoms in late life. Building on work that suggests that vascular depression is a prodrome for frailty, this paper tests a theoretical framework that vascular depression symptoms are an early marker of a broader pattern of decline characterized by more frailty symptoms and shortened lifespan, and that vascular depression symptoms predict mortality through frailty.

METHODS

The sample was drawn from the Health and Retirement Study and included 1361 stroke-free women over the age of 80. Data were included from six biannual waves from 1998 to 2008 (waves 4-9). A vascular depression symptomatology variable was based on Center for Epidemiological Studies Depression Scale (CES-D) scores and number of cerebrovascular risk factors (hypertension, diabetes, cardiac disease, and smoking). Frailty was measured based on wasting, slowness, weakness, fatigue, and falls. Vascular depression and frailty symptoms were modeled using slope and intercept terms. Mortality was modeled using a discrete-time survival term.

RESULTS

The data supported the proposed model (RMSEA = 0.051; CFI = 0.971; X² = 234.84, p < 0.001). Higher vascular depression symptom slope and intercept scores significantly predicted higher frailty slope and intercept scores, respectively. Frailty intercept scores significantly predicted mortality. The vascular depression symptoms indirectly predicted mortality through frailty symptoms. A second model testing the competing hypothesis - that frailty symptoms lead to vascular depression symptoms and indirectly to mortality - was not supported by the data.

CONCLUSIONS

Results suggest that vascular depression symptoms are associated with a clinical trajectory that includes greater frailty and shortened remaining lifespan.

Vascular depression: an early warning sign of frailty

OBJECTIVES

Frailty is a common geriatric disorder associated with activities of daily living (ADL) impairment, hospitalization, and death. Phenomenological evidence suggests that late-life depression (Katz, 2004 ), particularly vascular depression, may be a risk factor for frailty. This study tests that hypothesis.

METHODS

We identified a sample of stroke-free women over the age of 80 from the Health and Retirement Survey. The sample included 984 respondents in 2000 (incidence sample). Of these, 459 were non-frail at baseline and still alive in 2004 (prevalence sample). Frail respondents experienced at least three of the following: wasting, exhaustion, weakness, slowness, and falls. Vascular depression was represented using two dummy variables. The first represented respondents with either high cerebrovascular burden (CVB; at least two cerebrovascular risk factors) or probable depression (score ≥3 on the 8-item Center for Epidemiological Studies Depression Scale (CES-D)), and the second represented respondents with both high CVB and probable depression.

RESULTS

At baseline, the prevalence of frailty was 31.5%. Over four years the incidence of frailty was 31.8%. After controlling for age, education, ADL and IADL disability, arthritis, pulmonary disorders, cancer, and self-rated health, respondents with either high CVB or probable depression were more likely to be frail at baseline, and those with both were at even higher risk. Of those who were not frail at the 2000 wave, respondents who reported both high CVB and probable depression were more likely to become frail by 2004.

DISCUSSION

These findings suggest that vascular depression is a prodrome for frailty.

Gait and cognition: a complementary approach to understanding brain function and the risk of falling

Until recently, clinicians and researchers have performed gait assessments and cognitive assessments separately when evaluating older adults, but increasing evidence from clinical practice, epidemiological studies, and clinical trials shows that gait and cognition are interrelated in older adults. Quantifiable alterations in gait in older adults are associated with falls, dementia, and disability. At the same time, emerging evidence indicates that early disturbances in cognitive processes such as attention, executive function, and working memory are associated with slower gait and gait instability during single- and dual-task testing and that these cognitive disturbances assist in the prediction of future mobility loss, falls, and progression to dementia. This article reviews the importance of the interrelationship between gait and cognition in aging and presents evidence that gait assessments can provide a window into the understanding of cognitive function and dysfunction and fall risk in older people in clinical practice. To this end, the benefits of dual-task gait assessments (e.g., walking while performing an attention-demanding task) as a marker of fall risk are summarized. A potential complementary approach for reducing the risk of falls by improving certain aspects of cognition through nonpharmacological and pharmacological treatments is also presented. Untangling the relationship between early gait disturbances and early cognitive changes may be helpful in identifying older adults at risk of experiencing mobility decline, falls, and progression to dementia.

The frailty syndrome: a comprehensive review

The frailty syndrome is defined as unintentional weight and muscle loss, exhaustion, and declines in grip strength, gait speed, and activity. Evidence with respect to the clinical definition, epidemiology, mechanisms, interactions, assessment, prevention, and treatment of frailty in the older adult is reviewed.

A comparison of the relationship of 14 performance-based measures with frailty in older women

The purpose of this study was to determine which performance measures of physical function are most closely related to frailty and whether physical function is different across levels of frailty. Fifty-three community-dwelling Greek women (63-100 years) participated in this study. Participants were divided into 3 tertiles based on level of frailty as calculated from a frailty index (FI): lowest FI group (<0.19 FI), intermediate FI group (0.19-0.36 FI), and highest FI group (>0.36 FI). Performance measures tested were handgrip and knee extension muscle strength and fatigue, upper and lower body muscular endurance, walking performance, agility, and dynamic balance. The greatest proportion of variance in the FI was explained by combining all performance-based measures of physical function. The performance measures that were most closely related to frailty yet different across levels of frailty were ambulatory mobility, lower body muscular endurance, and nondominant handgrip strength. Walking at a preferred pace had the strongest relationship to frailty rather than walking at maximal pace. Grip strength of the nondominant hand had a stronger correlation with frailty compared with the dominant hand. The FI was a better predictor of physical function than chronological age. The decline in physical function accelerated after the intermediate FI tertile. Definitions of frailty need to combine performance-based measures that can identify impairments in various domains of physical function. The assessment protocols of these measures are important.