Dose-response associations between physical activity and sedentary time with functional disability in older adults with or without frailty: a prospective cohort study.

Purpose: Evidence regarding the dose-response curve shapes of physical activity (PA) and sedentary time (ST) in older adults with functional disability (FD) is extremely limited. Moreover, these associations may differ depending on with/without frailty. We examined the dose-response associations between moderate-to-vigorous PA (MVPA) and ST with FD among older adults with/without frailty. Methods: We included 7,480 initially nondisabled adults (3,795 men and 3,685 women) aged 65-84 years in Ota City, Tokyo, Japan. MVPA and ST were evaluated using the International Physical Activity Questionnaire-Short Form. FD was prospectively identified using a nationally unified database of the long-term care insurance system. Frailty was determined using Check-List 15, validated against Fried's frailty criteria. Multivariate-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) of MVPA and ST for FD were calculated, and dose-response curves were examined using restricted cubic splines. Results: During 3.6 years of follow-up, 1,001 (13.4%) participants had FD. Among all participants, compared with no MVPA, the HRs for FD reduced linearly up to approximately 2000 metabolic equivalents (METs)■min/week of MVPA, and the lowest HR (HR: 0.61, 95% CI: 0.51-0.74) was reached at around 3,000-4,000 METs■min/week. Although the shape of this association was consistent regardless of with/without frailty, the magnitude of the association tended to be stronger in frail older adults than in non-frail older adults. Compared with those for the median (300 min/day) of ST, the HRs for FD increased linearly as ST reached approximately 600 min/day or more, independent of MVPA, with a maximum HR of 1.31 (95% CI: 1.01-1.71) for 1,080 min/day among all participants. This association was more pronounced among non-frail older adults but not statistically significant among frail older adults. Conclusion: Higher MVPA levels consistently reduced the incidence of FD regardless of frailty in a significant inverse nonlinear dose-response manner. A significant positive nonlinear dose-response association between ST and FD risk was identified among non-frail older adults but not among frail older adults. Increasing MVPA and reducing prolonged ST are important for preventing FD among non-frail older adults. However, reducing ST alone may be insufficient; increasing MVPA, even if by only small increments, is highly recommended for frail older adults.

[A framework for promoting and evaluating "Kayoi-no-ba" initiatives according to the Plan-Do-Check-Action cycle: The ACT-RECIPE framework].

Objective　In 2019, the Ministry of Health, Labour and Welfare emphasized the importance of promoting "Kayoi-no-ba" (or "places to go") initiatives according to the Plan-Do-Check-Action (PDCA) cycle. However, it proposed no specific promotion measures or standardized evaluation frameworks. This study is intended to propose a framework for local government officials to promote and evaluate "Kayoi-no-ba" initiatives according to the PDCA cycle.Methods　The working group (WG) conducted a narrative review of research and extracted evaluation models and indicators that could be used to create the framework. The co-researcher review committee discussed a draft framework prepared by the WG, and the WG revised it based on the discussion; this process was repeated four times. Using the completed framework, we calculated the score of the "Kayoi-no-ba" initiatives in 50 Tokyo municipalities and conducted regional correlation analyses on the relationship between the score of the "Kayoi-no-ba" initiatives in 50 Tokyo municipalities and the number of "Kayoi-no-ba" per 1,000 older persons.Results　The completed framework (named "ACT-RECIPE" by rearranging the underlined characters below) comprised the following six evaluation phases: (1) Comprehension: understanding the key lessons around disability and frailty prevention, and the necessity for "Kayoi-no-ba"; (2) Research and Planning: clarifying the current status of "Kayoi-no-ba," the strengths of the community, and the issues to be addressed through a community assessment, and developing a plan to resolve the issues; (3) Team Building and Collaboration: building a team by collaborating with organizations to solve problems; (4) Implementation: implementing the initiatives necessary to solve problems; (5) Evaluation: verifying changes in output and outcome indicators from the initiatives; and (6) Adjustment and Improvement: re-examining plans, teams, content, and goals based on the evaluation results. In these six phases, we designated 10 core items and accompanying subitems. The median score rate of the ACT-RECIPE framework in 50 municipalities was 75% for "Comprehension," 61% for "Research and Planning," 69% for "Team Building and Collaboration," 64% for "Implementation," 31% for "Evaluation," and 56% for "Adjustment and Improvement," and the mean ACT-RECIPE score rate was 57%. A significant positive correlation (rs=0.43, P=0.002) was observed between the ACT-RECIPE mean score rate and the number of "Kayoi-no-ba" per 1,000 older persons.Conclusion　We proposed the ACT-RECIPE as a framework for promoting and evaluating "Kayoi-no-ba" initiatives according to the PDCA cycle. We hope that this framework will lead to further progress in "Kayoi-no-ba" initiatives and facilitate evaluation of their effectiveness according to the PDCA cycle.

Higher-level competence: Results from the Integrated Longitudinal Studies on Aging in Japan (ILSA-J) on the shape of associations with impaired physical and cognitive functions.

AIM: This study aimed to examine the relationships between levels of competence and impaired physical and cognitive functions in older adults. METHODS: We used a data set of the Integrated Longitudinal Studies on Aging in Japan for 2017 including 5475 community-dwelling older adults. Levels of competence were assessed using the Japan Science and Technology Agency Index of Competence (JST-IC). Grip strength (low grip strength: <28 kg for men and <18 kg for women) and gait speed (slow gait speed: <1.0 m/s for both sexes) were evaluated as physical function measurements, and the Mini-Mental State Examination (cognitive decline: <24 on the Mini-Mental State Examination) was used to assess cognitive function. RESULTS: The JST-IC had areas under the curve estimated from receiver operating characteristic analysis ranging from 0.65 to 0.73 for detecting low function as assessed by these tests. Restricted cubic spline curves showed that the shape of the association between the JST-IC and impaired function depended on sex and the test used. The comparison between perfect and imperfect JST-IC scores showed significant differences in the prevalence of low grip strength in both sexes, slow gait speed in women, and cognitive decline in men. CONCLUSIONS: It may be insufficient to identify those with impaired physical or cognitive function using the JST-IC. The shape of the association with the JST-IC varies across their measurements. Our findings can help interpret JST-IC scores in the context of low physical and cognitive functions. Geriatr Gerontol Int 2024; 24: 352-358.

The relationship between working status in old age and cause-specific disability in Japanese community-dwelling older adults with or without frailty: A 3.6-year prospective study.

AIM: To examine the effects of employment engagement, classified by frailty and working status, on the incidence of disability in urban community-dwelling older adults. METHODS: We used data from 6386 initially nondisabled residents aged 65-84 years from Ota City, Tokyo, Japan, in 2016. The observation duration was 3.6 years. Self-administered questionnaires applied the Cox proportional hazard model by assessing the existence of frailty through Check-List 15 (with a score ≥4 indicating the state of frailty), controlling for age, sex, living situation, education level, equivalent income, chronic conditions, body mass index, instrumental activities of daily living, self-rated health, drinking and smoking status, and social activities. We evaluated the predictive value of working status (full-time, part-time, temporary, or nonworker) at baseline for cause-specific disability (dementia-type vs. non-dementia-type) incidence, identified using the long-term care insurance system's nationally unified database. RESULTS: Of the 6386 participants, 806 (63/1134 full-time workers; 58/1001 part-time workers; 61/547 temporary workers; 624/3704 nonworkers) presented with disabilities during the 3.6-year-long duration. Adjustments for conventional covariates showed that nonfrail full-time and part-time workers, as well as frail full-time workers, had significantly lower risks of all-cause disability incidence. Furthermore, nonfrail and frail full-time workers had significantly lower risks of dementia-type and nondementia-type disabilities, respectively. CONCLUSIONS: The incidence of disability in older adults was influenced by working and frailty status. Engaging in full-time work thus prevents disabilities in older adults, regardless of their frailty status. Meanwhile, nonfrail older adults are able to avoid disabilities even when engaging in part-time work. Geriatr Gerontol Int 2023; 23: 855-863.

Accelerometer-measured sedentary behavior and risk of functional disability in older Japanese adults: a 9-year prospective cohort study.

BACKGROUND: The associations of sedentary time and patterns with functional disability among older adults remain unclear, and few studies have accounted for the co-dependency of sedentary behavior and physical activities when modeling sedentary behavior with risk of functional disability. We aimed to examine the associations between sedentary time and patterns and risk of incident functional disability, and assess whether replacing sedentary time with light physical activity (LPA) or moderate-to-vigorous intensity physical activity (MVPA) is associated with reduced risk of functional disability in community-dwelling older adults. METHODS: A total of 1,687 Japanese adults aged ≥ 65 years without functional disability at baseline were prospectively followed-up for 9 years (2011-2020). Functional disability was ascertained using the national database of Japan's Long-term Care Insurance System. Sedentary time and patterns, LPA, and MVPA were measured using a tri-axial accelerometer secured to participants' waists. RESULTS: During follow-up, 466 participants developed functional disability. Compared with the lowest quartile of total sedentary time, the multivariable-adjusted hazard ratios (95% confidence intervals) of functional disability for the second, third, and top quartiles were 1.21 (0.91‒1.62), 1.45 (1.10‒1.92), and 1.40 (1.05‒1.88) (p for trend = 0.01). After further adjusting for MVPA, total sedentary time was no longer significantly associated with the risk of functional disability (p for trend = 0.41). Replacing 10 min/day of sedentary time with the same amount of MVPA (but not LPA) was significantly associated with a 12% reduced risk of functional disability (hazard ratio [95% confidence interval]: 0.88 [0.84‒0.92]). No significant association was observed between sedentary bout length and functional disability. CONCLUSION: Higher levels of total sedentary time were associated with an increased risk of incident functional disability. However, this association was not independent of MVPA. Replacing sedentary time with MVPA, but not LPA, was associated with reduced risk of functional disability in older adults.

Longitudinal Changes in Moderate to Vigorous Physical Activity in Community-Dwelling Older Men and Women: A 2-Year Prospective Cohort Study in Japan.

BACKGROUND: To examine longitudinal changes in accelerometer-measured moderate to vigorous physical activity (MVPA) and associated factors of changes in MVPA among community-dwelling older Japanese men and women over 2 years of follow-up. METHODS: In total, 601 participants (72.2 [5.4] y, 40.6% men) were included. MVPA was assessed at baseline (2011) and follow-up (2013) using triaxial accelerometers. Sex-stratified multiple linear regression models were used to identify associated factors of changes in MVPA. RESULTS: On average, a significant decrease in MVPA over 2 years was observed only in women (P < .001). Higher baseline MVPA levels and older age were significantly associated with a decrease in MVPA over 2 years in both men and women. Men who were currently drinking (vs no) and had faster maximum gait speed showed statistically significant increases in MVPA. Women who had very poor/poor economic status (vs fair/good) and were socially isolated (vs no) showed statistically significant increases in MVPA over 2 years, while those who had fear of falling (vs no) and poor/fair self-rated health (vs good/very good) showed statistically significant decreases in MVPA over 2 years. CONCLUSIONS: Our findings showed different associated factors of changes in MVPA by sex, suggesting the importance of accounting for sex differences in terms of developing specific intervention strategies for promoting MVPA among older men and women.

Association of dietary variety with the risk for dementia: the Yabu cohort study.

OBJECTIVE: The consumption of various foods is internationally recommended in healthy diet although the association between dietary variety and incident dementia is unknown. We aimed to examine the association between dietary variety and the incidence of disabling dementia in older Japanese adults. DESIGN: We conducted a prospective cohort study. Dietary variety was assessed based on the Dietary Variety Score (DVS). DVS was assessed by counting the number of ten food components (meat, fish/shellfish, eggs, milk, soyabean products, green/yellow vegetables, potatoes, fruit, seaweed and fats/oils) that were consumed almost daily using a FFQ. Participants were categorised into low (0-2 points), middle (3-4 points) and high (5-10 points) groups based on the DVS. Data on newly diagnosed disabling dementia were retrieved from the public long-term care insurance database. Cox proportional hazards regression was used to estimate hazard ratios (HR) with 95 % CI. SETTING: Yabu cohort study, Japan. PARTICIPANTS: A total of 4972 community-dwelling adults aged 65 years or older. RESULTS: During the median follow-up of 6·8 years, 884 participants were newly diagnosed with disabling dementia. After adjusting for confounders, the multivariable-adjusted HR for incident disabling dementia was 0·82 (95 % CI, 0·69, 0·97) for participants in the highest DVS category compared with those in the lowest DVS category (Pfor trend = 0·019). CONCLUSIONS: A higher dietary variety is associated with a reduced risk of disabling dementia in older Japanese adults. These results have potential implications for the development of effective public nutritional approaches to prevent dementia in older adults.

Effects of community-based frailty-preventing intervention on all-cause and cause-specific functional disability in older adults living in rural Japan: A propensity score analysis.

Preventing frailty is crucial in aging societies. We examined the effectiveness of a community-based frailty-prevention program for delaying the onset of functional disability among community-dwelling older adults. From 2014 to 2019, 48 community-based frailty prevention classes (FPC, 60 min/session, once a week), comprising resistance exercise and nutritional or psychosocial programs, were established in Yabu City, Japan. We conducted a baseline survey in 2012 and followed up with participants for up to 6.8 years (4.8 years from establishing the first FPC). We analyzed data from 3350 older people. The primary and secondary outcomes were the onset of functional disability and cause-specific functional disability (including dementia and cardiovascular and orthopedic diseases), respectively. In addition to crude Cox proportional hazard regression, inverse probability of treatment weighting (IPTW) and propensity score matching (PSM; 918 nonparticipants and 459 participants) were used to adjust for confounders. Participants were more likely to be female and have a healthy lifestyle than nonparticipants. During the follow-up, 690 individuals developed a functional disability. The hazard ratio of incident functional disability in the participants was significantly lower than that in nonparticipants in the IPTW (hazard ratio 0.53, 95% confidential interval 0.38-0.75) and PSM (0.52, 0.37-0.71) analyses. In age-stratified analysis, significant associations were observed only in the ≥75-year-old subgroup. In a cause-specific analysis, participation significantly and consistently reduced incident functional disability caused by dementia (IPTW 0.47, 0.25-0.86; PSM 0.45, 0.25-0.83). Community-based FPC may be effective for preventing functional disability, especially caused by dementia, in this population.

Modifiable healthy behaviours and incident disability in older adults: Analysis of combined data from two cohort studies in Japan.

Healthy behaviours reduce the risk of incident disability; however, their components require further consideration. Specifically, little evidence exists on healthy behaviours that comprise modifiable factors, including social aspects, and their effects on those who do not engage in them. This study aimed to examine the association between engaging in healthy behaviours with modifiable factors and incident disability among community-dwelling older adults; as well as identify factors associated with nonengagement in healthy behaviours. We analysed data obtained from 1357 older adults aged 65 years and more without disabilities at baseline. The outcome was incident disability, which was defined based on the long-term care insurance certification in Japan. This study included regular exercise (≥1 day/week), favourable eating habits (≥4 dietary variety score), and social participation (engaging in two or more social activities) as components of healthy behaviours. We used the Cox proportional hazards model to calculate hazard ratios (HR) for incident disabilities. The proportion of those who satisfied all healthy behaviours was 21 %. During the follow-up period (median: 6.3 years), 282 incident disabilities were confirmed. Compared to those who engaged in one healthy behaviour, those who satisfied all healthy behaviours showed a 31 % (95 % confidence interval: 0.48, 0.98) lower HR of incident disability after adjusting for covariates. Current smoking and depressive mood were associated with non-engagement in healthy behaviours. This study found that having physically and socially active lifestyles and favourable eating habits are effective in reducing the risk of incident disability. Meanwhile, several older adults lack the components of a healthy lifestyle. Approaches that focus on multiple healthy behaviours are necessary to enhance the benefits of healthy lifestyles.

Relationship between the urinary Na/K ratio, diet and hypertension among community-dwelling older adults.

The association between the urinary sodium (Na)/potassium (K) ratio and hypertension is well recognized. We investigated whether the urinary Na/K ratio might be associated with hypertension in community-dwelling older adults and whether the association was influenced by habitual dietary patterns. We enrolled a total of 684 older adults (mean age, 76.8 years) and conducted health examinations at Kusatsu, Japan, in 2021. The urinary Na/K ratio was found to be independently associated with systolic blood pressure (SBP) (p < 0.0001), years of education (p = 0.0027), number of cohabitants (p = 0.0175), estimated glomerular filtrate rate (eGFR) (p = 0.0244), and Geriatric Depression Scale short-version (GDS15) score (p = 0.0366). In addition, an unsupervised hierarchical clustering analysis revealed a spectrum of habitual dietary patterns for higher and lower values of the urinary Na/K ratio. The decision tree indicated that the urinary Na/K ratio was associated with the history of milk consumption. A positive history of daily milk consumption predicted a mean urinary Na/K ratio of 2.8, and a negative history of daily milk consumption predicted a mean urinary Na/K ratio of 3.3. Furthermore, the frequency of fruit and vegetable consumption also predicted the urinary Na/K ratio. The relationship between the urinary Na/K ratio and hypertension was influenced by the frequency of consumption of milk, fruits, and vegetables in the subjects. This finding might be due to the influence of education and/or depression. The results suggested the importance of nutritional education in the development of hypertension.

Role of personality traits in determining the association between social participation and mental health: A cross-sectional study in Japan.

The role of personality in determining the association between social participation and mental health was examined by a cross-sectional study. We analyzed data from 4981 older adults aged 65-84 years who were recruited via a mail survey in one region of Japan. We defined poor mental health using a score ≤12 points on the World Health Organization-Five Well-Being Index-Japanese. Personality traits were measured by 10 Item Personality Inventory-Japanese. In women, higher openness positively moderated the association between private group participation (volunteering, sports, hobby, and learning) and mental health, while higher neuroticism negatively moderated it. This study contributes to knowledge about mental health, personality, and participation. The findings provide provisional evidence about recommending private group participation for women with high openness but not those with high neuroticism.

Combined Impacts of Physical Activity, Dietary Variety, and Social Interaction on Incident Functional Disability in Older Japanese Adults.

BACKGROUND: This 3.6-year prospective study examined combined impacts of physical activity, dietary variety, and social interaction on incident disability and estimated population-attributable fraction for disability reduction in older adults. METHODS: Participants were 7,822 initially non-disabled residents (3,966 men and 3,856 women) aged 65-84 years of Ota City, Tokyo, Japan. Sufficiency of moderate-to-vigorous-intensity physical activity (MVPA) ≥150 min/week, dietary variety score (DVS) ≥3 (median), and social interaction (face-to-face and/or non-face-to-face) ≥1 time/week was assessed using self-administered questionnaires. Disability incidence was prospectively identified using the long-term care insurance system's nationally unified database. RESULTS: During a follow-up of 3.6 years, 1,046 (13.4%) individuals had disabilities. Independent multivariate-hazard ratios (HRs) and 95% confidence intervals (CIs) of MVPA, DVS, and social interaction sufficiency for incident disability were 0.68 (95% CI, 0.59-0.78), 0.87 (95% CI, 0.77-0.99), and 0.90 (95% CI, 0.79-1.03), respectively. Incident disability HRs gradually reduced with increased frequency of satisfying these behaviors (any one: HR 0.82; 95% CI, 0.65-1.03; any two: HR 0.65; 95% CI, 0.52-0.82; and all three behaviors: HR 0.54; 95% CI, 0.43-0.69), in an inverse dose-response manner (P < 0.001 for trend). Population-attributable fraction for disability reduction in satisfying any one, any two, and all three behaviors were 4.0% (95% CI, -0.2 to 7.9%), 9.6% (95% CI, 4.8-14.1%), and 16.0% (95% CI, 8.7-22.8%), respectively. CONCLUSION: Combining physical activity, dietary variety, and social interaction substantially enhances the impacts on preventing disability among older adults, with evidence of an inverse dose-response manner. Improving insufficient behavior elements through individual habits and preexisting social group activities may be effective in preventing disability in the community.

Population-based reference values for tongue pressure in Japanese older adults: A pooled analysis of over 5,000 participants.

PURPOSE: To establish age- and sex-specific population reference values for tongue pressure (TP) in community-dwelling Japanese older adults. METHODS: For this analysis, we pooled four population-based studies on community-dwelling adults aged ≥65 years that measured TP using a JMS tongue pressure measuring device. We calculated the means and deciles of TP per 5-year age group for each sex. We also estimated age trends in TP for men and women. RESULTS: In total, 5,083 individuals (2,150 men and 2,933 women, with a mean [standard deviation] age of 75.2 [6.5] years) were included in the present analysis. In male participants, the mean (standard deviation) TPs for ages 65-69, 70-74, 75-79, 80-84, and ≥85 years were 34.0 (8.4), 32.2 (8.1), 30.8 (8.3), 28.4 (8.9), and 24.4 (8.2) kPa, respectively. In female participants, the corresponding values were 31.5 (7.1), 30.5 (7.5), 29.6 (7.3), 28.4 (8.0), and 26.4 (7.6) kPa, respectively. For both sexes, there were significant declining trends in TP with advanced age. In addition, the interaction between age and sex had a significant effect on TP (regression coefficient [95% confidence interval] = -0.18 [-0.25 to -0.11] when age was modeled as a continuous variable and sex was modeled as a categorical variable [coded as 0=women, 1=men]). CONCLUSIONS: This study determined age- and sex-specific reference values for TP, presented as means and deciles, in community-dwelling Japanese older adults aged ≥65 years. This study also demonstrated sex differences in age-related declines in TP.

Dose-Response Associations of Physical Activity and Sitting Time with All-Cause Mortality in Older Japanese Adults.

PURPOSE: Although examining the dose-response curves of physical activity (PA) and sitting time with health-related outcomes is an important research agenda, the results for older Japanese adults are extremely limited. We examined the dose-response associations of PA and sitting time with all-cause mortality among older Japanese. METHODS: Initially, 8,069 non-disabled residents (4,073 men; 3,996 women) aged 65-84 years of Ota City, Japan, were recruited. Moderate-to-vigorous PA (MVPA) and sitting time were evaluated using the International Physical Activity Questionnaire-Short Form. Multivariate-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) of MVPA and sitting time for all-cause mortality were calculated, and the dose-response curves were examined using restricted cubic splines (RCS). RESULTS: During 4.1 years of follow-up, 458 participants (5.7%; 331 men and 127 women) died. Compared with the low MVPA (<600 metabolic equivalents [METs]·minutes/week) group, HR for mortality gradually reduced in moderate (600-3000 METs·minutes/week) and high (>3000 METs·minutes/week) MVPA groups (moderate: HR 0.66; 95% CI, 0.54-0.82; high: HR 0.58; 95% CI, 0.45-0.75; P <0.001 for trend). RCS showed that the HR for mortality reduced linearly up to approximately 2000 METs·minutes/week of MVPA, and maximal risk reduction was seen at approximately 3000-4500 METs·minutes/week of MVPA. No significant dose-response association of sitting time with mortality was observed. CONCLUSIONS: Higher MVPA levels reduced all-cause mortality risk, in a significant inverse non-linear dose-response manner. Sitting time was not significantly associated with all-cause mortality. It is important to disseminate the significance of even a slight increase in the MVPA.

The effect of a multicomponent intervention on occupational fall-related factors in older workers: A pilot randomized controlled trial.

OBJECTIVES: Multicomponent interventions reduce falls among community-dwelling older adults. However, whether this strategy helps reduce occupational falls among older workers is unclear. This pilot trial tested the safety, adherence, and potential effectiveness of a multicomponent intervention for older workers. METHODS: An assessor-blind, parallel-designed randomized controlled trial was conducted in five public employment agencies for seniors in Saitama, Japan. In total, 69 older adults who worked ≥4 days/month were randomly assigned to the intervention (n = 35) or control (n = 34) groups. The intervention group was provided a multicomponent intervention consisting of exercise, nutrition, and psychosocial programs once a week for 8 weeks. Safety was evaluated for all adverse events reported by participants. Adherence was assessed by rates for withdrawal/dropout, exercise practice, and nutritional diary completion. The primary outcome was a change in functional strength related to occupational falls. Secondary outcomes included changes in agility, balance, executive function, visuospatial ability, exercise self-efficiency, dietary variety, social network, and functional capacity. RESULTS: No adverse events were reported by participants. The median withdrawal/dropout, exercise practice, and nutritional diary completion rates were 0%, 80.4%-93.7%, and 100%, respectively. In the adjusted general linear model, the intervention group showed a non-significant but clinically important improvement in functional strength (P value: .081, Cohen's d: 0.57) and significant improvements in agility, balance, and dietary variety compared to the control group. CONCLUSIONS: A multicomponent intervention for older workers would be a safe, acceptable, and effective strategy for improving risk factors for occupational falls.

Predictive ability of the total score of the Kihon checklist for the incidence of functional disability in older Japanese adults: An 8-year prospective study.

AIM: To investigate the association between the total score of the Kihon checklist (t-KCL score) and functional disability over an 8-year follow-up period, and to examine whether the t-KCL score in the basic model with risk factors contributes to the incremental predictive ability for functional disability among older adults. METHODS: We followed 2209 older adults aged ≥65 years without functional disability at baseline. The t-KCL score was determined using a baseline survey questionnaire. Functional disability was defined based on information from long-term care certifications. The association between the t-KCL score and functional disability was examined using the Cox proportional hazards model. The incremental predictive ability of the t-KCL score for functional disability was evaluated by the difference of the C-statistic, category-free net reclassification improvement (NRI), and integrated discrimination improvement (IDI). RESULTS: The median follow-up period was 7.8 years, and 557 participants developed functional disability. The adjusted hazard ratio (95% confidence interval [CI]) of functional disability for a 1-point increase of the t-KCL score was 1.08 (1.06-1.10). Adding the t-KCL score to the basic model significantly improved the C-statistic (95% CI) from 0.747 (0.728-0.768) to 0.760 (0.741-0.781). When the t-KCL score was added to the basic model, the NRI and IDI were 0.187 (95% CI: 0.095-0.287) and 0.020 (95% CI: 0.012-0.027), respectively. CONCLUSIONS: The t-KCL score had an independent positive association with functional disability over an 8-year follow-up. Furthermore, adding the t-KCL score to the basic model improved the predictive ability for functional disability. Geriatr Gerontol Int 2022; 22: 723-729.

[Development and evaluation of a modified version of the dietary variety score for community-dwelling older adults].

Objectives　The dietary variety score (DVS) was developed as an index to assess the variety of food intake among older Japanese adults and has been widely used in epidemiological studies and public health settings. However, this index has not been reviewed since its development in the 1990s and may not adequately reflect the current dietary habits of the older Japanese population. In this study, we developed a modified version of the DVS (MDVS) and examined its validity.Methods　We conducted a cross-sectional study of 357 community-dwelling adults aged ≥65 years (mean age: 76.2±4.6, men: 61.1%) who participated in the 2016 survey of the Hatoyama cohort study. The DVS and MDVS were assessed by the number of food groups eaten almost every day based on the weekly frequency of consumption. The DVS was calculated based on ten components: meat, fish/shellfish, eggs, milk, soybean products, green/yellow vegetables, potatoes, fruits, seaweed, and fats/oils. The components of the MDVS were determined by calculating the contribution of each food group to the total and nutrient intakes from the food groups comprising the main dish, side dish, and soup, based on the data from older adults aged ≥65 years who participated in the 2017 National Health and Nutrition Survey in Japan. Based on the contribution of each food group, we added "other vegetables" and "dairy products" in the MDVS. Dietary intake was assessed using a validated, self-administered diet history questionnaire. We calculated the probability of adequacy for each of the fourteen nutrients selected as per the estimated average requirement in the Dietary Reference Intake for Japanese 2020 and the mean probability of adequacy for all fourteen nutrients. In addition, we assessed the correlation between the DVS, MDVS, and each indicator and the significance of the difference between correlation coefficients.Results　The MDVS was significantly positively correlated with the energy ratios of protein and fat, dietary fiber, potassium, and the modified diet score based on the Japanese Food Guide Spinning Top (r=0.21-0.45) and negatively correlated with the carbohydrate energy ratio (r=-0.32). The MDVS was also correlated with the mean probability of nutrient adequacy (r=0.41). The correlation coefficients between the MDVS and each indicator were not significantly different from those of the DVS.Conclusions　Validity in terms of nutrient intake and diet quality was comparable between the DVS and MDVS. To revise the DVS, it is necessary to conduct nationwide studies based on highly accurate dietary surveys.