TRENDS IN THE PREVALENCE OF FRAILTY IN JAPAN: A META-ANALYSIS FROM THE ILSA-J.

OBJECTIVE: To examine whether age-specific prevalence of frailty in Japan changed between 2012 and 2017. DESIGN: This study performed meta-analyses of data collected from 2012 to 2017 using the Integrated Longitudinal Studies on Aging in Japan (ILSA-J), a collection of representative Japanese cohort studies. SETTING: The ILSA-J studies were conducted on community-living older adults. PARTICIPANTS: ILSA-J studies were considered eligible for analysis if they assessed physical frailty status and presence of frailty in the sample. Seven studies were analyzed for 2012 (±1 year; n = 10312) and eight studies were analyzed for 2017 (±1 year; n = 7010). Five studies were analyzed for both 2012 and 2017. MEASUREMENTS: The study assessed the prevalence of frailty and frailty status according to 5 criteria: slowness, weakness, low activity, exhaustion, and weight loss. RESULTS: The overall prevalence of physical frailty was 7.0% in 2012 and 5.3% in 2017. The prevalence of frailty, especially in people 70 years and older, tended to decrease in 2017 compared to 2012. Slight decreases were found in the prevalence of frailty subitems including weight loss, slowness, exhaustion, and low activity between 2012 and 2017, but change in the prevalence of weakness was weaker than other components. CONCLUSIONS: The prevalence of physical frailty decreased from 2012 to 2017. There are age- and gender-related variations in the decrease of each component of 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.

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.

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 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.

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.

Community-Based Intervention for Prevention of Dementia in Japan.

Population aging is accelerating, with prolonged life expectancy and a decrease in birth rate. As age is a significant risk factor for dementia, we are confronted with an ever-increasing prevalence of mild cognitive impairment (MCI)/dementia. Thus, the Japanese National Center for Geriatrics and Gerontology launched a project to promote community-based research, including the development of an effective screening system for high-risk groups and intervention for dementia prevention. This review introduces the project, the Obu Study of Health Promotion for the Elderly, with the following strategic triad: 1) Identification of the target population by population screening; we regarded patients with MCI as the target population, and developed a screening test battery to identify MCI in a population screening setting. 2) Scientific evaluation of community-based intervention; we developed an interventional method combining exercise and cognitive training ("cognicise"). In practical settings, "cognicise" is programmed into multicomponent exercise intervention, which was reported to have benefits of cognitive improvement and reduction of brain atrophy based on randomized controlled trials. 3) Standardization of the methods of population screening and community-based intervention for evidence-based policy making and widespread implementation. Dementia prevention, or at least delaying the onset of dementia and/or stopping/slowing the progression of dementia, should benefit the whole society as well as individuals. It is our continuing challenge to improve the screening system and community-based intervention for dementia prevention through accumulation of evidence.