Combined Social Frailty and Life-Space Activities Associated with Risk of Disability: A Prospective Cohort Study

OBJECTIVES

To examine the association between social frailty and life-space activities, and determine whether a combined status of life-space activities and social frailty is associated with risk of disability among older adults.

DESIGN

A prospective cohort study.

SETTING AND PARTICIPANTS

The participants were 8,301 older adults (mean age 72.9 ± 5.6 years, women [53.3%]) from a community setting.

METHODS

Life-space activities were evaluated using the Active Mobility Index (AMI) to assess activities in each life-space (distance from the respondent's home: up to 1 km, 1-10 km, or greater than 10 km) during the past 1 month. Activities were also assessed according to physical or social activity. Social frailty and characteristics were measured at the baseline. Incident disability was assessed according to long term care insurance.

RESULTS

The lowest scoring group was based on the quartile in each of the AMI scores (Q1), with reference to the highest scoring group, which had a higher odds ratios for social frailty (AMI total score Q1: OR 4.32, 95% CI 3.43-5.45, AMI physical score Q1: 2.19, 95% CI 1.79-2.69, AMI social score Q1: 5.04, 95% CI 3.94-6.44). During the follow-up (mean 23.5 months), 330 participants had incident disability. Incident disability was associated with social frailty. Combined status of social frailty and low AMI increased the risk of disability (HR 2.15, 95% CI 1.52-3.03), with reference to non-frailty and higher AMI scores.

CONCLUSIONS AND IMPLICATIONS

Social frailty or reduced activity in life-space assessment were identified as risk factors for incident disability. To decrease the risk of disability, the development of an intervention program to enhance activities and cope with social frailty is required.

Predictive Validity of Different Walking Measures to Identify the Incident Long-Term Care Needs in Older Adults

OBJECTIVES

A comfortable walking speed is a suitable measurement of functional status in older adults. In addition to assessing their comfortable walking speed, two complex walking tests were administered to a cohort of older people, assuming that these tests would be a more sensitive predictor of the incident long-term care needs than comfortable walking speed.

DESIGN

A prospective observational study was conducted to collect data.

SETTING AND PARTICIPANTS

Among the initial 5,563 community-dwelling independent older adults (aged ≥ 65 years), 935 were excluded and the data of 4,628 (mean age, 73.9 ± 5.5 years, 65-94 years; 2,052 men, 2,576 women) older adults were finally analyzed.

METHODS

Three walking tasks were administered: comfortable, complicated balance, and Go-stop walking. Complicated balance walking was measured under comfortable walking conditions, with participants having to walk with their hands crossed at the shoulder joint at 90°. For the Go-stop walking test, the time taken to walk 2 meters was measured using a stopwatch. For two years following baseline assessments, participants received monthly follow-ups for incident certification of the need for care under the long-term care insurance (LTCI) system.

RESULTS

Low performance in comfortable, complicated balance, and Go-stop walking were 29.8%, 37.7%, and 35.1%, respectively. During the 24-month follow-up period, 246 participants (5.3%) required LTCI certification. The Youden Index was used to determine the cut-points of the incident long-term care needs in the comfortable, complicated balance, and Go-stop walking conditions, which were 1.055 m/s, 0.936 m/s, and 3.205 seconds, respectively. Participants classified as exhibiting low performance included 1,381 (29.8%) under comfortable walking, 1,746 (37.7%) under complicated balance walking, and 1,623 (35.1%) under the Go-stop walking tests. The C-indices of the comfortable, complicated balance, and Go-stop walking tests were 0.72 (95% confidence interval (CI) 0.69-0.76), 0.71 (95% CI 0.67-0.74), and 0.65 (95% CI 0.61-0.69), respectively. Cox proportional hazards regression model revealed significant relationships between the incident long-term care needs and the comfortable (hazard ratio (HR) 2.14, 95% CI 1.62-2.84), complicated balance (1.81, 1.36-2.41), and Go-stop (1.46, 1.12-1.91) walking conditions.

CONCLUSIONS AND IMPLICATIONS

The findings suggest that slow walking speed has a considerably greater impact on the incident long-term care needs in older adults. However, the complex walking task did not improve the predictive performance. Comfortable walking speed tests, which can easily be measured to predict the future incident long-term care needs, are effective tools in community health promotion and primary care.

Association between Sarcopenia, Its Defining Indices, and Driving Cessation in Older Adults

OBJECTIVES

Driving a car is essential for older adults to support their activities of daily living and maintain their quality of life. However, physical function - which often declines with age - is a key factor to determine whether older adults can continue driving safely. As such, we sought to examine the association between sarcopenia and driving cessation in older adults.

DESIGN

A prospective study.

SETTING

A community setting.

PARTICIPANTS

We conducted a study including 2,874 older adult participants from the community (mean age: 71.0 ± 4.7 years [range: 65-93 years], women: 36.3%).

MEASUREMENTS

We assessed whether they were still driving at baseline examination as well as their degree of sarcopenia. Sarcopenia was assessed according to the clinical definition provided by the EWGSOP2 by measuring muscle mass, muscle strength, and physical performance represented by gait speed. Driving cessation was determined based on driving status at the initial visit and at a follow-up examination approximately 15 months later.

RESULTS

At the baseline assessment, there were 62 participants (2.2%) with confirmed sarcopenia and 23 participants (0.8%) with severe sarcopenia. Participants were classified into either the ongoing driving (n = 2816) or driving cessation (n = 58) group. Low muscle strength and low muscle mass were associated with driving cessation (low muscle strength: odds ratio [OR] 2.09, 95% confidence interval [CI] 1.13-3.87; low muscle mass: OR 2.00, 95% CI 1.04-3.85). Slow gait was not associated with driving cessation (OR 1.35, 95% CI 0.68-2.69). Significantly, sarcopenia was associated with driving cessation (confirmed sarcopenia: OR 4.48, 95% CI 1.63-12.29; severe sarcopenia: OR 4.46, 95% CI 1.21-16.41).

CONCLUSIONS

Sarcopenia is associated with an increased likelihood of driving cessation in community-dwelling older adults. Evaluation of physical function related to sarcopenia would be useful for judgment of the ability to drive safely among older adults.

Cognitive Frailty as a Risk Factor for Incident Disability During Late Life: A 24-Month Follow-Up Longitudinal Study

OBJECTIVES

Association between cognitive frailty as identified by a new operational definition and incident disability in the community setting remains unclear. This will be the catalyst for preventive interventions designed to treat adverse health problems among elderlies.

DESIGN

A 24-month follow-up longitudinal study on a community-based cohort.

SETTING

Community-setting.

PARTICIPANTS

Participants included a total of 9,936 older adults aged 65 years or older.

MEASUREMENTS

Frailty was characterized as slow walking speed or/and muscle weakness represented by grip strength. Cognitive function was assessed according to several tests. Cognitive impairment was defined below the age-education reference threshold. Participants were categorized into the four groups: robust, cognitive impairment alone, frailty alone, and cognitive frailty (both frail and cognitive impairment). Incident disability data was extracted from the Japanese Long-Term Care system.

RESULTS

The prevalence of cognitive frailty was 11.2%. The cumulative incidence rates of incident disability in each group were also estimated (robust, 9.6/1,000 person-years (95% CI 7.9 to 11.7); cognitive impairment, 21.3/1,000 person years (95% CI 16.3 to 27.7); frailty, 45.4/1,000 person years (95% CI 39.5 to 52.3); and cognitive frailty, 79.9/1,000 person years (95% CI 68.6 to 93.1)). Adjusted Cox proportional hazard model revealed that the cognitive frailty group had the highest hazard ratio (HR 3.86, 95%CI 2.95 - 5.05, P < 0.001).

CONCLUSIONS

A proper operational definition was developed to determine cognitive frailty among elderlies. Cognitive frailty is more associated with incident disability in community-setting than cognitive impairment or physical frailty alone.

Cognitive Frailty and Incidence of Dementia in Older Persons

BACKGROUND

Cognitive frailty may be a preventive or therapeutic target for preventing dementia and functional decline with age.

OBJECTIVES

To examine the relationship between physical and cognitive frailty and the incidence of dementia in community-living older persons.

DESIGN

A prospective cohort study.

SETTING

General community in Japan.

PARTICIPANTS

A total of 4072 persons aged ≥ 65 years.

SETTING

A community in Japan.

PARTICIPANTS

A total of 4072 community-dwelling older persons aged ≥ 65 years participated in the study.

MEASUREMENTS

We characterized physical frailty as ≥ 3 of the following criteria: slow walking speed, muscle weakness, exhaustion, low physical activity, and weight loss. We used the National Center for Geriatrics and Gerontology-Functional Assessment Tool, which includes tests of word list memory, attention, and executive function, and processing speed to screen for cognitive frailty. The presence of ≥ 2 cognitive impairments, indicated by an age-adjusted score of at least 1.5 standard deviations below the reference threshold, was defined as cognitive frailty. The incidence of dementia was determined using data collected by the Japanese Health Insurance System over 24 months.

RESULTS

The overall prevalence rates of physical frailty, cognitive impairment, and cognitive frailty (i.e., coexistence of frailty and cognitive impairment) were 5.1%, 5.5%, and 1.1%, respectively. During the follow-up period, 81 participants (2.0%) developed dementia. We found significant relationships between the incidence of dementia and cognitive impairment (hazard ratio (HR): 3.85, 95% confidence interval (95% CI): 2.09-7.10) and cognitive frailty (HR: 6.19, 95% CI: 2.7-13.99). However, the association between dementia and physical frailty did not reach significance (HR: 1.95, 95% CI: 0.97-3.91).

CONCLUSIONS

Individuals with cognitive frailty had the highest risk of dementia. Future research should implement dementia prevention strategies among older persons with cognitive frailty.

Associations of Skeletal Muscle Mass, Lower-Extremity Functioning, and Cognitive Impairment in Community-Dwelling Older People in Japan

OBJECTIVE

We examined whether skeletal muscle mass and lower extremity functioning are closely associated with multiple cognitive domains, including global cognition, memory, attention, executive functioning, and processing speed, in community-dwelling older Japanese adults.

DESIGN

A cross-sectional, population-based community study.

SETTING

This study was conducted among community-living older people enrolled in the Obu Study of Health Promotion for the Elderly.

PARTICIPANTS

Participants comprised 5,104 adults (≥ 65 years, mean age: 71 years).

MEASUREMENTS

Data from 4273 participants were analyzed. Appendicular skeletal muscle mass was estimated from bioelectrical impedance analysis and expressed as appendicular skeletal muscle mass index (ASMI). Lower-extremity functioning was assessed by the Five-Times-Sit-to-Stand test (FTSS) and Timed Up and Go test (TUG). Cognitive functions were assessed by the Mini Mental State Examination, word list memory, Trail Making Test parts A and B, and Symbol Digit Substitution Task. Logistic regression analysis were performed to calculate odds ratios (ORs) of cognitive impairment in various domains among skeletal muscle mass, lower-extremity functioning levels adjusted for important demographic variables, and comorbidities.

RESULTS

Participants with lower ASMI and slower FTSS and TUG groups had lower cognitive functioning scores than did participants with higher ASMI and faster FTSS and TUG. The slowest quartiles (Q4) of FTSS and TUG were significantly associated with impaired global functioning (MMSE score < 24) compared to the fastest quartile (Q1) after multivariate adjustment (FTSS, OR = 1.46, 95% confidence interval (CI) = 1.12-1.90; TUG, OR = 1.65, 95% CI = 1.25-2.17). In other dimensions of cognitive functioning, FTSS and TUG were significantly associated with all cognitive impairment in the full adjustment model.

CONCLUSION

Lower-extremity functioning, rather than skeletal muscle mass, is closely related to multiple cognitive domains. This study suggests that maintaining lower-extremity functioning, rather than skeletal muscle mass, may be required for detecting and preventing cognitive impairment.

Long and Short Sleep Duration and Physical Frailty in Community-Dwelling Older Adults

OBJECTIVE

The objective of this study was to investigate whether older adults who have a particularly long sleep duration are likely to exhibit physical frailty, similar to those with a particularly short sleep duration.

DESIGN

Cross-sectional study.

SETTING

The National Center for Geriatrics and Gerontology - Study of Geriatric Syndromes.

PARTICIPANTS

A total of 9,824 older adults (mean age: 73.6 ± 5.5 years, 4,812 men and 5,012 women) met the entry criteria for this study.

MEASUREMENTS

We divided the participants into three groups according to self-reported sleep duration (Short: ≤6 h, Mid: 6.1-8.9 h (control), Long: ≥ 9 h). Physical frailty was characterized based on the criteria from the Cardiovascular Health Study. Multinomial logistic regression analysis was performed to evaluate the effect of sleep duration on physical frailty by sex.

RESULTS

Among all participants, the prevalence of physical frailty was higher in the Short (10.5%) and Long (17.9%) groups than in the Mid (7.4%) group (p < 0.001). Multinomial logistic regression analysis showed that both Short and Long groups had a significantly higher odds ratio (OR) for physical frailty than the Mid group [Short: OR 1.53, 95% confidence interval (CI) 1.26-1.87; Long: OR 2.39, 95% CI 1.90-3.00], even after adjusting for age, educational level, number of medications, body mass index, Mini Mental State Examination score, current smoking and alcohol habits, self-perceived health, and medical history.

CONCLUSION

Both long and short sleep durations were associated with physical frailty. Further studies are required to confirm the effect of sleep duration on the incidence or worsening of physical frailty in older adults.

Cognitive Frailty is Associated with Fall-Related Fracture among Older People

OBJECTIVE

Cognitive frailty refers to cognitive impairment and physical frailty. Both cognitive impairment and physical frailty include risks of falling. The purpose of the study is to examine cognitive frailty and falling with/without a fracture.

DESIGN

Cross-sectional observation study.

SETTING

General communities in Japan.

PARTICIPANTS

Data of 10,202 older adults aged ≥ 65 years were collected.

MEASUREMENTS

Physical frailty was characterized as slow walking speed and/or muscle weakness. Assessment of cognitive function included word lists memory, attention, executive function, and processing speed. Cognitive impairment refers to one or more cognitive decline indicated by at least 1.5 standard deviations below the threshold after adjusting for age and education. We operationally defined cognitive frailty as having both cognitive impairment and physical frailty. Participants were interviewed about their falling, history of fall-related fractures, and several potentially confounding factors such as demographic characteristics.

RESULTS

Multinomial logistic regression analysis revealed that functional decline in all groups, as compared to the robust group, was significantly associated with falling without fractures, after adjusting for the covariates; cognitive impairment group (P = .017), physical frailty group (P = .002), and cognitive frailty group (P < .001). Only the cognitive frailty group had a significant association with fall-related fracture after adjusting for the covariates (OR 1.92, 95% CI: 1.20-3.08, P = .007).

CONCLUSION

Cognitive frailty is associated with not only falling but also fall-related fractures. Cognitive frailty may have a greater risk for fall-related fractures than cognitive impairment or physical frailty alone. Future research should examine causal the relationship between fall-related fractures and cognitive frailty.

Association between Insulin-Like Growth Factor-1 and Frailty among Older Adults

OBJECTIVES

Frailty is a course experienced in advanced aging. Identification of a biological factor associated with frailty is required. Although serum insulin-like growth factor-1 (IGF-1) is a potential factor related with frailty, consensus has not been reached regarding this relationship. This study aimed to investigate the association between IGF-1 and frailty in older adults.

DESIGN

Cross-sectional study.

SETTING

Cohort study that was part of the "National Center for Geriatrics and Gerontology - Study of Geriatric Syndromes."

PARTICIPANTS

The study participants were 4133 older adults (mean age, 71.8 ± 5.4 years).

MEASUREMENTS

We assessed serum IGF-1 levels and frailty status and collected demographic variables, including cognitive function, as covariates.

RESULTS

Frailty and pre-frailty were present in 274 subjects (7%) and 1930 subjects (47%), respectively. Subjects were divided into four groups based on quartiles of IGF-1 levels. Multinomial logistic analysis showed that the lowest group had significant odds of pre-frailty (crude model: odds ratio [OR] 1.58, 95% confidence interval [CI] 1.30-1.90, p < .001; adjusted model: OR 1.38, 95% CI 1.13-1.68, p = .002) and frailty (crude model: OR 3.42, 95% CI 2.38-4.92, p < .001; adjusted model: OR 1.54, 95% CI 1.02-2.32, p = .039), compared with the highest group.

CONCLUSION

Lower serum IGF-1 levels were independently related with frailty in older adults.

Impact of Cognitive Frailty on Daily Activities in Older Persons

OBJECTIVES

To identify the relationships between physical and/or cognitive frailty and instrumental activities of daily living (IADL) functioning in community living older persons.

DESIGN

Cross sectional observation study.

SETTING

Data extracted from the 2011-2013 of the National Center for Geriatrics and Gerontology-Study of Geriatric Syndromes (NCGG-SGS) database.

PARTICIPANTS

A total of 8,864 older adults aged ≥ 65 years who were enrolled in the NCGG-SGS.

MEASUREMENTS

We characterized physical frailty as limitations in three or more of the following five domains: slow walking speed, muscle weakness, exhaustion, low activity and weight loss. To screen for cognitive impairment, we used the National Center for Geriatrics and Gerontology-Functional Assessment Tool (NCGG-FAT) which included tests of word list memory, attention and executive function (tablet version of the Trail Making Test, part A and B), and processing speed (tablet version of the Digit Symbol Substitution Test). Two or more cognitive impairments indicated by an age-adjusted score of at least 1.5 standard deviations below the reference threshold was characterized as cognitive impairment. Each participant reported on their IADL status (use of public transportation, shopping, management of finances, and housekeeping) and several potential confounders such as demographic characteristics.

RESULTS

The overall prevalence of physical frailty, cognitive impairment, and cognitive frailty, i.e. co-occurrence of frailty and cognitive impairment, was 7.2%, 5.2%, and 1.2%, respectively. We found significant relationships between IADL limitations and physical frailty (Odds Ratio (OR) 1.24, 95% confidence interval (95% CI) 1.01 to 1.52), cognitive impairment (OR 1.71, 95% CI 1.39 to 2.11), and cognitive frailty (OR 2.63, 95% CI 1.74 to 3.97).

CONCLUSION

Using the NCGG-SGS frailty criteria, we found more participants with physical frailty than with cognitive frailty. The individuals with cognitive frailty had the highest risks of IADL limitations. Future investigation is necessary to determine whether this population is at increased risk for incidence of disability or mortality.

Structural comparison of three types of staphylococcal cassette chromosome mec integrated in the chromosome in methicillin-resistant Staphylococcus aureus

The beta-lactam resistance gene mecA of Staphylococcus aureus is carried by a novel mobile genetic element, designated staphylococcal cassette chromosome mec (SCCmec), identified in the chromosome of a Japanese methicillin-resistant S. aureus (MRSA) strain. We now report identification of two additional types of mecA-carrying genetic elements found in the MRSA strains isolated in other countries of the world. There were substantial differences in the size and nucleotide sequences between the elements and the SCCmec. However, new elements shared the chromosomal integration site with the SCCmec. Structural analysis of the new elements revealed that they possessed all of the salient features of the SCCmec: conserved terminal inverted repeats and direct repeats at the integration junction points, conserved genetic organization around the mecA gene, and the presence of cassette chromosome recombinase (ccr) genes responsible for the movements of SCCmec. The elements, therefore, were considered to comprise the SCCmec family of staphylococcal mobile genetic elements together with the previously identified SCCmec. Among 38 epidemic MRSA strains isolated in 20 countries, 34 were shown to possess one of the three typical SCCmec elements on the chromosome. Our findings indicated that there are at least three distinct MRSA clones in the world with different types of SCCmec in their chromosome.