BACKGROUND:Health status in old age can be influenced by financial disadvantages both at present and in earlier life stages; however, few studies have focused on the long-term individual patterns of financial disadvantage over the life course. This study examined the relationship between trajectories of financial disadvantage over the life course and depressive mood among community-dwelling older Japanese adults. METHODS:Data were obtained from the 2012 National Survey of the Japanese Elderly using a two-stage stratified random sampling method. The sample consisted of 1,324 adults aged ≥60 years. We retrospectively assessed financial disadvantage at four life-course benchmark periods: ≤18 years old, 25-35 years old, 35-50 years old, and current age. Depressive mood was measured using the 8-item Center for Epidemiologic Studies Depression Scale. RESULTS:We identified five distinct life-course financial disadvantage trajectories using group-based mixture modeling: "persistently affluent" (22.1%), "increasing affluence" (21.7%), "consistently modest" (28.0%), "decreasing affluence" (11.3%), and "persistently poor" (17.0%). A logistic regression analysis showed that people in the "increasing affluence" subgroup were less likely to have a depressive mood than those in the "persistently poor" subgroup, after adjusting for potential covariates, including current income and parental educational attainment. This association was more prominent in women than in men. CONCLUSION:The experience of escaping from financial disadvantages may bolster the mental health of older adults, regardless of sociodemographic characteristics, health behaviors, and health conditions. The mental health benefits of increasing affluence throughout the life course may be even stronger than the benefits of experiencing persistent affluence.

Background:Nutritional Profiling Systems (NPSs) are designed to classify foods by nutritional quality, but most validations occur at the food level. Their applicability to diet-level data from dietary questionnaires-commonly used in epidemiology-remains unclear. Objectives:The study aims to evaluate the construct and convergent validity of the Meiji NPS for Older Adults (MNPS-OA), the first NPS developed for older populations, when applied to diet-level data. Methods:Cross-sectional data from the Hatoyama Cohort Study and the Kusatsu Cohort Study involving 1102 Japanese adults aged ≥65 y were utilized. Dietary data were analyzed using a validated Brief Dietary History Questionnaire. Four MNPS-OA specifications were tested: 1) original, 2) without energy limits (WEL), 3) without nutrient caps (WC), and 4) without energy limit and nutrient caps (WEL-WC). Construct validity was assessed by intermodel correlations; convergent validity was evaluated against Healthy Eating Index-2015 (HEI-2015) and Nutrient-Rich Food Index 9.3 (NRF9.3). Results:Median MNPS-OA scores ranged from 124.5 (original) to 391.6 (WEL-WC). Correlations with HEI-2015 improved from r = 0.27 (original) to 0.58 (WEL-WC), and with NRF9.3 from r = 0.26 to 0.61. Removing nutrient caps substantially enhanced convergence, whereas removing energy limits had minimal effect. Conclusions:MNPS-OA can be adapted for diet-level assessment with targeted modifications. Eliminating nutrient caps markedly improves alignment with established diet quality indices, supporting its potential use in large-scale epidemiological studies and public health applications.

BACKGROUND:Dietary diversity is associated with enhanced cognitive function and reduced dementia risk among older adults; however, its relationship with structural brain ageing remains unclear. We examined cross-sectional and longitudinal associations between dietary variety score (DVS) and brain volume among older Japanese adults. METHODS:We analysed data from the Neuron to Environmental Impact across Generations (NEIGE) cohort, a population-based longitudinal study of community-dwelling Japanese adults aged 65-84 years. The analysis included 279 participants with baseline and follow-up magnetic resonance imaging (MRI) data. Dietary diversity was assessed at baseline using the DVS based on the consumption frequency of 10 food groups. Hippocampal and total grey matter volumes were measured using MRI at baseline (2017) and follow-up (2021). Cross-sectional associations were examined using multivariable linear regression models, and longitudinal associations were assessed using linear mixed-effects models adjusting for confounders. RESULTS:Mean follow-up was 4.1-year (SD 0.2). In cross-sectional analyses, DVS was not significantly associated with brain volume. In longitudinal mixed-effects models, the interaction between baseline DVS and duration was not significantly associated with changes in total grey matter volume (-128.11 mm3/year per 1-point increase in DVS; 95% CI, -267.86 to 11.65; p = 0.07). Similarly, no significant association was observed for hippocampal volume (-0.44 mm3/year per 1-point DVS; 95%CI, -3.52 to 2.65; p=0.78). CONCLUSIONS:Dietary diversity was not significantly associated with brain volume or with the rate of change in brain volume over time among older Japanese adults.

BACKGROUND:As the global population ages, understanding factors influencing structural brain aging is crucial for dementia prevention. Social networks have emerged as important social factors; however, longitudinal evidence linking specific structural characteristics of social networks to brain volume change remains limited. This study examined whether social network homogeneity and heterogeneity were related to longitudinal changes in brain volume (hippocampus, gray matter, and prefrontal cortex) among community-dwelling older Japanese adults. METHODS:Data were obtained from the Neuron to Environmental Impact Across Generations (NEIGE) study. Participants aged 65-84 years were randomly selected from Tokamachi City, Japan. Of the 527 older adults surveyed at baseline, 279 who underwent magnetic resonance imaging at both baseline (2017) and follow-up (2021) were included. Social relationship (dis)similarities were assessed using ten items, and network homogeneity and heterogeneity domains were derived through factor analysis. Covariates included sociodemographic factors, health behaviors, health conditions, and apolipoprotein E genotype. RESULTS:Participants were 47.6% male, with a mean age of 73.2 years (SD = 5.1). Multiple linear regression analyses with inverse probability weighting indicated no association between homogeneous social networks and brain volume changes. However, lower network heterogeneity was significantly associated with a greater decline in hippocampal volume. This was particularly pronounced in the right hippocampus. CONCLUSION:Greater social network heterogeneity may attenuate age-related hippocampal volume loss in older adults, highlighting potential benefits of social network heterogeneity for structural brain aging and cognitive aging in later life. Further studies are warranted to clarify the underlying mechanisms.

BACKGROUND:Employment among older adults has been increasing; however, its association with daily activities remains unclear. This study examined the associations between working condition categories and nonoccupational physical activity among older workers in Japan. METHODS:This cross-sectional study used the baseline data from the Wako Cohort Study conducted in 2023. Of the 6429 older respondents, we analyzed 1689 older workers (age range: 65-91). They were categorized by their paid work hours (full time: ≥20 h/wk, part time: <20 h/wk) and the presence or absence of occupational physical activity. A questionnaire combining the Global Physical Activity Questionnaire and International Physical Activity Questionnaire long form was used to assess occupational, leisure-time, household, and transport-related physical activity. A 2-part model was fitted to analyze the binary (engagement vs nonengagement) and continuous outcomes of nonoccupational physical activity. RESULTS:Compared with part-time work involving occupational physical activity, full-time work with and without occupational physical activity showed significantly lower odds of engaging in leisure-time physical activity (odds ratio: 0.62; 95% CI, 0.42-0.91 and 0.54; 95% CI, 0.35-0.84, respectively). Full- and part-time work hours without occupational physical activity had a lower odds ratio of engaging in household physical activity (odds ratio: 0.35; 95% CI, 0.22-0.56 and 0.31; 95% CI, 0.19-0.50, respectively). In addition, they were associated with lower levels of total nonoccupational physical activity (mean ratio: 0.83; 95% CI, 0.71-0.98 and 0.72; 95% CI, 0.61-0.86, respectively). CONCLUSION:Working condition categories can reflect the physical activity characteristics of older workers outside their work hours.

Japan is experiencing unprecedented population aging, with adults' aged 65 years and older accounting for nearly 30% of its total population. In this context, employment has attracted increasing attention as an important form of social participation in later life. However, despite increased labor force participation among older adults, suitable employment opportunities remain limited. Moreover, Japan is simultaneously facing a serious workforce shortage in the long-term care sector, raising concerns about care system sustainability in super-aging societies. This review aims to not only provide an overview of later-life employment in Japan but also introduce the older assistant care worker model as a concrete and socially acceptable form of older adults' employment in long-term care settings. Drawing on nationwide surveys of geriatric health service facilities in Japan, this review examines how older adults' involvement in non-professional, peripheral tasks can generate multidimensional benefits. The findings indicate that the older assistant care worker model-adopted across prefectures-reflects its practical feasibility and social acceptance within geriatric health service facilities. For older assistant care workers, employment was associated with perceived health maintenance, meaningful use of time, and enhanced social participation and social connection, which, in turn, were associated with lower emotional exhaustion. For care staff, the presence of older assistant care workers was related to reduced workload and lower burnout risk. Overall, the older assistant care worker model represents an age-friendly employment approach that benefits older adults, care staff, and care facilities, potentially contributing to sustainable long-term care systems in aging societies.

AIM:Dynapenia-loss of muscle strength despite preserved muscle mass-is a clinical concern linked to functional decline in older adults. Diabetes may contribute to dynapenia; however, few studies have examined whether this association varies by sex and age. Clarifying these differences may help inform targeted prevention strategies. This study investigated the association between diabetes and dynapenia in community-dwelling older adults in Japan, focusing on sex- and age-specific differences. METHODS:We conducted a cross-sectional analysis using pooled data from four geriatric cohorts in Japan. Participants were classified into three groups: (1) established diabetes (treatment or HbA1c ≥ 6.5%), (2) prediabetes (HbA1c 5.7%-6.4%, no treatment), and (3) non-diabetes (HbA1c < 5.7%, no treatment). Dynapenia was defined per Asian Working Group for Sarcopenia 2019 cutoffs as low grip strength with preserved muscle mass. Sex-stratified logistic regression examined the association between diabetes status and dynapenia, adjusting for age, body fat, comorbidities, lifestyle factors, and cohort. Analyses were also stratified by age group (65-74 and ≥ 75 years). RESULTS:Among 3085 participants (34.8% men; median age: 70 years), the prevalence of dynapenia was 13.0% in both sexes. In women, dynapenia prevalence increased with glycemic status; adjusted ORs were 1.32 (95% CI: 0.97-1.78) for prediabetes and 1.86 (1.27-2.71) for established diabetes. Stratified analyses showed significant associations in men aged 65-74 and women aged ≥ 75. CONCLUSIONS:Diabetes was associated with dynapenia, with distinct patterns by sex and age. Targeted strategies may be needed for younger-old men and older-old women with diabetes.

OBJECTIVE:Approaching the "population that is indifferent to health" is important for reducing health disparities. This also applies to individuals with mild cognitive impairment (MCI). Raising health awareness is essential for preventing further cognitive decline and the onset of various diseases, including dementia. This study examined the association between MCI and interest in health among community-dwelling older adults. METHODS:We performed a cross-sectional analysis using baseline data from the Wako Cohort Study conducted in Wako City, Saitama Prefecture. A community survey was conducted in September-October 2023, and 1,004 individuals aged 65 years or older participated. Among them, 1,000 participants who completed the cognitive assessments were included in the analysis. The cognitive function of the participants was assessed using the Japanese version of the Montreal Cognitive Assessment, with scores ≤25 classified as MCI. Interest in health was measured using the 12-item Interest in Health Scale (score range: 12-48). The covariates included sex, age, marital status, household composition, work status, years of education, economic status, self-rated health, number of chronic diseases, and depressive symptoms. We analyzed the data of the total sample and subsamples stratified by sex and age. Moreover, we also conducted the analyses by setting three subscales ("health consciousness," "health motivation," and "health value") as the outcomes. RESULTS:Of the participants, 48.2% were men, and the mean age was 75.3±6.4 years. The prevalence of MCI was 65.0%. The mean scores of the Interest in Health Scale were 38.4±4.6 in the non-MCI group and 38.1±4.9 in the MCI group. A multiple regression analysis with adjustment for covariates indicated that MCI was significantly associated with a lower interest in health (b=-0.67, 95% confidence interval: -1.31, -0.04). Stratified analyses showed that this association was evident among men and those aged 75 years or older. In subscale analyses, a significant difference between groups was observed only in "health value" (b=-0.45, 95% confidence interval: -0.75, -0.15). CONCLUSIONS:Older adults with MCI showed a lower interest in health than their cognitively normal peers, and this tendency was more pronounced among men and those aged 75 years or older. Moreover, a significant difference was found only in the "health value" subscale, suggesting that a diminished valuation of health may be a characteristic of MCI. Strategies to enhance health interests in this population are therefore needed to support preventive behaviors.

Objectives　Health Japan 21 (Third Term) emphasizes measures targeting individuals who are indifferent to their health. We examined associations between health interest levels and the practice of the three key elements of frailty prevention (regular exercise, food intake diversity, and participation in social activities). We further investigated whether this association differed by participant characteristics.Methods　We obtained data from a mailed survey conducted in 2023 targeting 14,013 residents aged ≥65 years living in Wako City, Saitama Prefecture, who had not been certified as requiring level 3 or higher long-term care. We analyzed data from 6,429 valid respondents. We assessed the implementation status of each of the three key elements of frailty prevention: regular exercise (at least once per week), food intake diversity (Dietary Variety Score ≥ 4), and participation in social activities (participation in at least one of the following: employment, volunteer groups, sports groups or clubs, hobby groups, learning or cultural groups, groups for preventing long-term care, senior citizens' clubs, or neighborhood associations). Health interest levels were assessed using the Health Interest Scale (score range: 12-48 points). Participants were categorized into five groups according to the quintiles of their health interest scores. Modified Poisson regression analysis adjusted for major confounding factors was performed to estimate prevalence ratios with 95% confidence intervals (CIs). We also assessed the interactions between health interests and basic respondent characteristics (sex and age group).Results　Among all respondents, 22.9% practiced all three elements of frailty prevention, and the mean Health Interest Scale score was 36.6 ± 5.2. Compared with the group with the highest health interest level (5th quintile), the group with the lowest level (1st quintile) had fewer people who regularly exercised (prevalence ratio = 0.64, [95%CI = 0.59-0.68]), consumed various foods (0.65 [0.59-0.71]), or participated in social activities (0.83 [0.78-0.90]), and fewer people who practiced all three elements (0.45 [0.38-0.53]). Additionally, a significant interaction was observed between health interest and age group with respect to participation in social activities (P = 0.031). The association between low health interest and non-participation in social activities was stronger among those aged ≥75 years than among those aged 65-74 years.Conclusion　Individuals with low health interests were less likely to engage in frailty prevention behaviors. Frailty prevention interventions should consider an individual's health awareness level.

BACKGROUND AND PURPOSE:This study examined the relation between sarcopenia and the replacement of sedentary behavior (SB) with physical activity (PA) of varying intensities using the isotemporal substitution (IS) model. We explored effective intensities and time substitution patterns that may contribute to the prevention of sarcopenia through increased PA and reduced SB. METHODS:A total of 527 community-dwelling adults aged 65-84 years in Tokamachi city, Niigata, wore accelerometers for 7 consecutive days to measure time spent in SB, light PA (LPA), and moderate-to-vigorous PA (MVPA). Sarcopenia was assessed based on the criteria of the Asian Working Group for Sarcopenia, using skeletal muscle mass index, gait speed, and grip strength. Three analytical approaches were applied: the single-factor model, partition model, and IS model. The IS model specifically evaluated the effects of reallocating time among SB, LPA, and MVPA. RESULTS AND DISCUSSION:The prevalence of sarcopenia in this population was 6.3%. The IS model revealed that reallocating 10 minutes per day of either SB or LPA to MVPA was significantly associated with improved gait speed. Furthermore, replacing SB with MVPA was linked to a reduced prevalence of sarcopenia. CONCLUSION:These findings suggest that preventing sarcopenia requires not only reducing SB but also replacing sitting or lying time with MVPA. Physical therapists should therefore encourage older adults to decrease prolonged sitting and engage in more active movements, such as brisk walking or structured exercise.

BACKGROUND:Frailty is a growing public health concern, with emerging evidence highlighting the importance of social determinants, including external and intra-household isolation. This study examined the association between intra-household isolation and frailty among community-dwelling older adults in Japan and explored whether external social connections modified this association. METHODS:Data were obtained from the 2023 baseline survey of the Wako Cohort Study, including 6,429 participants aged ≥65 years in Wako City, Saitama Prefecture, without long-term care certification levels 3-5 (men: 45.0%; mean age: 76.5 years). Intra-household isolation was defined as living with others but having minimal interaction (talking <15 min/day and spending most time alone at home). Frailty was assessed using the 25-item Kihon Checklist. Modified Poisson regression analysis estimated the associations, adjusting for sociodemographic factors, health behaviors, health conditions, and external social connections. RESULTS:Intra-household isolation was observed in 5.3% of participants, while 21.0% lived alone. Frailty was observed in 28.3% of participants. Individuals with intra-household isolation were more likely to be frail than non-isolated individuals (prevalence ratio [95% confidence interval]: 1.42 [1.26-1.59]). This association remained significant when compared with individuals living alone (1.34 [1.16-1.54]) and was stronger among those aged 65-74 years than those aged ≥75 years. No significant interaction was observed between intra-household isolation and external social connections. CONCLUSION:Intra-household isolation among cohabiting older adults was independently associated and showed a stronger association with frailty than living alone. These findings suggest that living with others does not necessarily have protective effects unless meaningful interactions exist.

Background: In Japan, community-driven dining spaces known as children’s cafeterias (kodomo shokudo) have increased rapidly. Despite their rapid expansion, the role of social environmental factors in the development of children’s cafeterias, particularly social capital, has received limited empirical attention. We examined the association between social capital and changes in the number of children’s cafeterias in Japan. Methods: We conducted a longitudinal ecological study. The outcome was the change in the number of children’s cafeterias per municipality between 2020 and 2022. Social capital indicators (trust in neighbors, norm of reciprocity, trust in the national government, neighborhood ties, and social participation) were derived from a nationwide internet survey. Results: A total of 512 local municipalities were analyzed. Multiple regression analyses showed that higher neighborhood trust was positively associated with increases in the number of children’s cafeterias, whereas denser neighborhood ties were inversely associated with such increases. Conclusions: The findings suggest that cognitive and structural dimensions of social capital may operate differently in the diffusion of children’s cafeterias. These results indicate that community social contexts are associated with the spread of child-focused initiatives.

BACKGROUND & AIMS:The phase angle may serve as a clinically relevant indicator of skeletal muscle health beyond conventional muscle mass assessments; however, reference intervals for community-dwelling older adults remain scarce. This study aimed to establish sex- and age-specific reference intervals for bioelectrical impedance analysis-derived phase angles in older adults in Japan. METHODS:This cross-sectional study used pooled data from four community-based cohorts within the Tokyo Longitudinal Study on Aging, with available bioelectrical impedance analysis measurements. Data were collected between 2022 and 2024. The phase angle was measured using an InBody 770. Individuals without functional impairments were included, whereas those undergoing cancer treatment were excluded. After stratification by sex and 5-year age groups, the percentile values (at quartiles as well as at 2.5%, 10%, 90%, and 97.5%) for the phase angles were calculated. Phase-angle distributions were parameterized using a generalized additive model for the location, scale, and shape algorithms. The Jonckheere-Terpstra test was used to examine whether the phase angle decreases monotonically with increasing age. RESULTS:A total of 4484 adults aged 65-96 years (1885 men, 2599 women; mean age 76.2 years) were included. According to Schwarz's criteria, the phase angle follows a normal distribution in both sexes. For whole-body phase angles, the median ranged from 5.2 to 4.2 in men and from 4.4 to 3.9 in women across age groups from 65 to 69 and 85-89 years, showing a consistent decline with age. CONCLUSIONS:This study established sex- and age-specific reference intervals for phase angles among community-dwelling older adults in Japan, including those aged ≥80 years. These intervals may facilitate clinical interpretation of the phase angle and support the assessment of skeletal muscle health in older populations.

Amid rapid population aging, declining fertility, and a shrinking workforce, employment in later life has become a critical issue in Japan. Older adults are no longer viewed solely as care recipients; many remain engaged in paid work, making employment a key form of social participation. This review synthesizes epidemiological evidence on the health benefits, challenges, and future directions of late-life employment, drawing on the authors' previous studies and domestic and international cohort research from a health and welfare policy perspective. Longitudinal evidence indicates that continued employment is associated with reduced mortality, better self-rated health, preserved cognitive function, and maintained activities of daily living. However, these benefits vary by sex, employment type, and frailty status. Notably, full-time employment may offer protective effects even among frail older adults, particularly in reducing risks related to dementia and physical decline, whereas irregular or sporadic work provides limited benefits. The motivation and meaning of work also play a crucial role. Employment driven solely by financial necessity is linked to poorer health outcomes and greater social isolation, while nonfinancial motivations-such as maintaining health, purpose in life, and social contribution-are associated with more favorable outcomes. Finally, the study underscores the importance of community-based intermediaries and emerging approaches such as social prescribing to connect older adults with meaningful, ability-appropriate work. Effective support requires integrating employment assistance with frailty assessment, safety management, and multidisciplinary coordination.

Objectives In Japan, resident-led prevention care activities (Kayoi-no-ba) are promoted, and many older individuals are expected to participate in these activities to prevent isolation and declining functional disability and support their daily lives. However, as older adults' travel ranges reduce with age, access to activity hubs is a barrier to participation. This study aimed to examine the association between road distance from home to activity hubs and participation in resident-led preventive care activities in locations in which hubs were established within walking distance in each administrative district.Methods Mail surveys were sent in 2017 and 2022 to individuals aged ≥65 years in Yabu City, Hyogo Prefecture, Japan. Of the respondents, the analysis included 1,369 individuals living in 53 districts in which activity hubs were established in the period between the two surveys. Modified Poisson regression analysis was performed with participation in resident-led preventive care activities by 2022 as the objective variable, road distance from home to activity hubs calculated using Geographic Information Systems (GIS) as the explanatory variable, and baseline demographic variables, socioeconomic status, health concerns, health status, social interaction, car use, the year the hub was established, and mean slope angle to the activity hub (calculated using GIS) as covariates. Restricted cubic splines were used to examine the dose-response relationship between distance and participation.Results In the period between the two surveys, 478 (34.2%) residents participated in the resident-led preventive care activities. Adjusted analyses revealed that participants residing in the highest tertile of road distance (≥327 m) were less likely to participate in the activities compared to those in the lowest tertile (<171 m) (PR = 0.66, 95% CI; 0.55-0.79, P < 0.001). In sex-stratified analyses, distance and participation were significantly associated only in women. In spline analysis, using the shortest distance as the reference, the PR decreased as the distance increased. A statistically significant difference emerged at distances >350 m.Conclusions Even in areas in which activity hubs were established within walking distance, the road distance from home to activity hubs was a barrier to participation in resident-led preventive care activities, and a closer hub placement was important for promoting participation. This effect was observed regardless of car use. These findings provide scientific evidence to support the development of activity environments that enable continued participation among older adults.

Abstract　In rapidly aging Japan, supporting older adults in maintaining meaningful social roles is an important public health priority for extending healthy life expectancy and preventing the need for long-term care. In response, the Work-like Activity (Shuro-teki Katsudo) Support Coordinator Placement Program was introduced in 2020 to promote role-based social participation among older adults. Within this policy framework, this paper clarifies the concepts of work-like activities and work-like activity support. By reviewing diverse definitions and practices and examining their alignment with documents issued by the Ministry of Health, Labour and Welfare, we identify key conceptual issues related to work-like activities and emphasize their significance as meaningful forms of social participation, particularly regarding paid activities outside formal employment. Two central perspectives on work-like activity support are highlighted: (1) aligning activities with older adults' preferences and functional conditions and (2) developing and expanding opportunities that accommodate diverse health and functional states. This conceptual framework may support the planning and implementation of municipal programs while providing a common foundation for future research on the prevalence and effects of work-like activities.

Objectives　To examine the effects of a multifactorial intervention for improving frailty-comprising resistance exercise and nutritional and psychosocial programs-on the risk of long-term care insurance (LTCI) certification, death, and long-term care (LTC) cost among community-dwelling older adults.Methods　Seventy-seven individuals (47 in 2011 and 30 in 2013) from the Hatoyama Cohort Study (742 individuals) participated in a multifactorial intervention. Non-participants were from the same cohort (including people who were invited to participate in the multifactorial intervention but declined). We performed propensity score matching with a ratio of 1 : 2 (intervention group vs. non-participant group). Afterward, 70 individuals undergoing the multifactorial intervention and 140 non-participants were selected. The risk of LTCI certification and/or death and the mean LTC cost during the follow-up period (32 months) were compared using the Cox proportional hazards model and generalized linear model (gamma regression model).Results　The incidence of new LTCI certification (per 1,000 person-years) tended to be lower in the intervention group than in the non-participant group (1.8 vs. 3.6), but this was not statistically significant as per the Cox proportional hazards model (hazard ratio=0.51, 95% confidence interval [CI]=0.17-1.54). Although the incidence of LTC cost was not significant, the mean cumulative LTC cost during the 32 months and the mean LTC cost per unit during the follow-up period (1 month) were 375,308 JPY and 11,906 JPY/month, respectively, in the intervention group and 1,040,727 JPY and 33,460 JPY/month, respectively, in the non-participant group. Cost tended to be lower in the intervention group than in the non-participant group as per the gamma regression model (cumulative LTC cost: cost ratio=0.36, 95%CI=0.11-1.21, P=0.099; LTC cost per unit follow-up period: cost ratio=0.36, 95%CI=0.11-1.12, P=0.076).Conclusions　These results suggest that a multifactorial intervention comprising resistance exercise, nutritional, and psychosocial programs is effective in lowering the incidence of LTCI certification, consequently saving LTC cost, although the results were not statistically significant. Further research with a stricter study design is needed.

Adequate protein intake is crucial for preventing frailty and sarcopenia in older adults, but conventional dietary assessments are time-consuming. Developing a rapid screening tool for identifying those at risk of low protein intake is essential; however, no such tool exists for Asian populations. This study developed a prediction model to identify older adults in Japan at risk of low protein intake using a simple food intake questionnaire. The model was developed using data from 4,085 older adults aged ≥65 years from the 2013 and 2017 National Health and Nutrition Surveys. Protein intake was assessed using a one-day dietary record with a semi-weighted method. A multivariable logistic regression model was developed to predict low protein intake (<1.0 g/kg adjusted body weight/day), incorporating sex, age, adjusted body weight, and food intake frequency of nine food groups. Model performance was evaluated using the area under the receiver operator characteristic (ROC) curve and a calibration plot, both adjusted for optimism through bootstrap resampling. Participants had a mean age of 74.1 years (standard deviation = 6.6), and 55.5% of all participants were female. The prevalence of low protein intake was 21.8%. Internal validation showed a bootstrap optimism-corrected ROC area of 0.695 and a calibration slope of 0.921. We developed a 12-item prediction model for identifying older adults at risk of low protein intake. The model provides a practical tool to identify older adults at high risk of low protein intake and is expected to be used in public health settings.

AIM:Age-related functional decline in muscle strength is a major determinant of disability in older adults. Although kidney dysfunction has been implicated in sarcopenia, longitudinal evidence linking changes in kidney function with muscle strength decline in community-dwelling older adults remains limited. This study, part of the Kusatsu Cohort Study, aimed to examine whether 6-year changes in estimated glomerular filtration rate (eGFR) were associated with changes in handgrip strength and skeletal muscle mass index (SMI). METHODS:A total of 279 residents in Kusatsu Town, Gunma Prefecture, aged ≥ 65 years participated in municipal checkups in 2019, 2021, 2023, and 2025. Handgrip strength, SMI, and eGFR (uncorrected for body surface area) were assessed. Six-year changes (Δgrip, ΔSMI, ΔeGFR) were calculated. Associations were examined using Pearson correlation and multivariable linear regression. ROC analysis evaluated the discriminatory ability of ΔeGFR for grip-strength decline. RESULTS:Grip strength declined significantly over 6 years (28.5 ± 8.8-24.0 ± 7.6 kg, p < 0.001), whereas SMI remained stable (6.3 ± 1.0 to 6.2 ± 1.0 kg/m2, p = 0.10). Δgrip correlated positively with ΔeGFR (r = 0.30, p < 0.001). In multivariable analysis, ΔeGFR independently predicted Δgrip (β = 0.14, p = 0.03), along with sex and baseline grip strength. ROC analysis showed moderate discrimination (AUC 0.664), with an optimal ΔeGFR cutoff of -0.263 over 6 years (-4.4%/year). CONCLUSIONS:Preservation of kidney function was independently associated with a smaller decline in handgrip strength among community-dwelling older adults. These findings highlight kidney-muscle crosstalk as a key mechanism of functional aging and support the use of eGFR decline as a biomarker for early detection of strength deterioration.

OBJECTIVES:Disturbance of hearing or olfaction is known to be associated with cognitive impairment. Multisensory impairment-simultaneous dysfunction in multiple senses-is common among older adults. This study examined the relationship between cognitive impairment and the co-occurrence of olfactory and auditory dysfunctions in older adults. METHODS:Data were obtained from a population-based survey. Of 1346 randomly selected residents, 527 participated; after excluding 22 with incomplete data, 505 residents aged 65-84 years were enrolled. Cognitive function was assessed using the Japanese Quick Mild Cognitive Impairment Screen (Qmci-J). Olfactory and auditory function, assessed using the Open Essence test and pure-tone audiometry, respectively, were classified as normal, moderate, or severe, yielding nine combined groups. Associations with cognitive impairment (Qmci-J ≤ 60) were examined using modified Poisson regression to estimate the prevalence ratio (PR), adjusting for demographic, health-related, and socioeconomic covariates. RESULTS:Among 505 participants, 225 (44.6%) had cognitive impairment. Severe dysfunction in either olfaction or audition, combined with at least moderate dysfunction in the other, was significantly associated with cognitive impairment. The highest PR was observed in participants with severe dysfunction in both senses (PR = 1.90, 95% CI: 1.16-3.10). These associations remained significant even after adjustment for all covariates. Although no significant additive or multiplicative interaction was observed, the co-occurrence of severe olfactory and auditory dysfunctions showed the highest PR, consistent with an additive effect. CONCLUSION:Olfactory and auditory dysfunctions are additively associated with cognitive impairment, highlighting the importance of considering multisensory impairment in older adults. TECHNICAL EFFICACY:The technical efficacy of this study is high. The study design, data collection procedures, and statistical analyses are clearly described and reproducible. In addition, all key assessments used in this study, including the Quick Mild Cognitive Impairment Screen (Qmci), the Open Essence Test, and pure-tone audiometry, are standardized, validated, and widely accepted measures, as detailed in the manuscript. LEVEL OF EVIDENCE: 3: