Risk factors for post-coronavirus disease condition in the Alpha-, Delta-, and Omicron-dominant waves among adults in Japan: A population-based matched case-control study.

Vaccination is associated with a reduced risk of post-coronavirus disease (COVID-19) condition (PCC). Here, risk factors including vaccination for PCC in the Omicron-dominant waves among Japanese adults were investigated. This was a registry-based matched case-control study of individuals aged 18-79 years diagnosed with COVID-19 registered in a National database between March 2021 and April 2022 and matched noninfected individuals living in Yao City, Japan. A self-administered questionnaire was used to assess persistent symptoms and their risk factors. The COVID-19 vaccination status was obtained from the Vaccination Registry. PCC risk factors were analyzed using logistic regression after adjusting for potential confounding factors. Overall, 4185 infected (cases) and 3382 noninfected (controls) individuals were included in the analysis. The mean ages and proportions of women were 44.7 years and 60.2% and 45.5 years and 60.7% for cases and controls, respectively. A total of 3805 (90.9%) participants had asymptomatic or mild acute symptoms at the median (range) follow-up of 271 (185-605) days. The prevalence of PCC was 15.0% for cases while that of persistent symptoms was 4.4% for controls; among the cases, it was 27.0% in the Alpha- and Delta-dominant waves and 12.8% in the Omicron-dominant wave. Female sex, comorbidities, and hospitalization were positively associated with PCC. One or more vaccine doses of vaccination were inversely associated with PCC; the inverse association was stronger in the Alpha- and Delta-dominant waves (adjusted odds ratio [aOR]: 0.29, 95% confidence interval [CI]: 0.12-0.73) than in the Omicron-dominant wave (aOR: 0.79, 95% CI: 0.59-1.07).

Mushroom intake and risk of incident disabling dementia: the Circulatory Risk in Communities Study (CIRCS).

It is uncertain whether dietary intake of mushrooms rich in dietary fibre and several antioxidants is associated with a lower risk of dementia. We sought to examine prospectively the association between mushroom intake and the risk of disabling dementia. We performed a prospective study involving 3750 people aged 40 to 64 years residing in three communities who participated in an annual cardiovascular risk survey from 1985 to 1999. Cases of incident disabling dementia were surveyed from 1999 to 2020. We calculated the hazard ratios (HR) and 95 % CI for incident total dementia according to mushroom intake among participants with or without a history of stroke. During a mean 16·0 years' follow-up in 3739 eligible participants, 670 people developed disabling dementia. For women, mushroom intake was inversely associated with the risk of total dementia and the association was confined to dementia without a history of stroke. The multivariable HR (95 % CI) for total dementia in women were 0·81 (0·62, 1·06) for mushroom intake of 0·1-14·9 g/d and 0·56 (0·42, 0·75) for mushroom intake above 15·0 g/d (Pfor trend = 0·003) compared with no intake. The corresponding HR (95 % CI) for dementia without a history of stroke were 0·66 (0·47, 0·93) and 0·55 (0·38, 0·79) (Pfor trend = 0·01). In men, no associations were observed between mushroom intake and the risk of disabling dementia. Among Japanese women, dietary mushroom intake was associated with a lower risk of disabling dementia.

Development of a Brief Assessment Tool to Evaluate Early Low Nutrition Risk in Community Elderly. Creation of the tool and examination of its reliability and criterion-related validity.

BACKGROUND: To date simple assessment tool to evaluate early low nutrition risk in general older population has not been available. This study aimed to create such tool and examined its reliability and criterion-related validity. METHODS: 1,192 community elderly with a mean age of 74.7(5.8) years responded to a questionnaire consisting of 48 (Hatoyama) or 34 items (Kusatsu), which have been reported to be associated with nutritional state in older people. Item analysis was conducted on the 34 common items, and items were selected based on the following criteria: adequate pass rates and discriminative power, no gender and regional differences, and a certain level of commonality based on factor analysis. Next, the factor structure of the candidate items was examined through exploratory factor analysis, and confirmatory factor analysis was conducted as the final scale structure. Furthermore, Spearman's partial rank correlation coefficients (sex- and age-adjusted) between the created index and important health indicators were examined to determine the criterion-related validity. RESULTS: Finally, we obtained a semantic coherence of 4 factors (named health beliefs, dietary status, physical activity, and food-related quality of life) totaling 13 items; confirmatory factor analysis of the 4-factor solution yielded good model fit values, χ2 (59) =275.4 (p<0.001), CFI=0.930, and RMSEA=0.056. The factor loadings for each factor ranged from 0.43 to 0.82, indicating adequate loadings. The reliability of the index was shown to be high by Good-Poor analysis and Cronbach's α. The index showed statistically significant correlations with all health indicators. CONCLUSIONS: We have developed a simple assessment tool to evaluate early low nutrition risk in general older population.

Serum folate and risk of disabling dementia: a community-based nested case-control study.

PURPOSE: The aim of this study was to examine associations between serum folate levels and risk of disabling dementia that required care under the national insurance (disabling dementia). METHODS: We performed a nested case-control study in a community-based cohort, the Circulatory Risk in Communities Study, involving 13,934 Japanese individuals aged 40-84 years at the baseline period of 1984-2005. Serum folate was measured in 578 cases of incident disabling dementia, and in 1,156 controls whose age (±1 years), sex, area of residence, and baseline year were matched with the cases. The diagnosis of disabling dementia was performed by attending physicians under the National Long-Term Care Insurance System in Japan. Conditional odds ratios of disabling dementia according to quintiles of serum folate were calculated using conditional logistic regression models. RESULTS: After a 20.8-year follow-up, serum folate was inversely associated with risk of disabling dementia. The respective multivariable odds ratios (95% CIs) were 0.71 (0.51-0.99), 0.76 (0.54-1.06), 0.70 (0.49-1.00), and 0.62 (0.43-0.90) for persons with the second, third, fourth, and highest quintiles of serum folate as compared with the lowest quintile (P for trend = 0.03). A similar association was observed for dementia with or without stroke. CONCLUSION: In this nested case-control study with a long follow-up, low serum folate levels were associated with an increased risk of disabling dementia among Japanese individuals.

[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.

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.

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.

Dietary fiber intake and risk of incident disabling dementia: the Circulatory Risk in Communities Study.

OBJECTIVES: It has been hypothesized that dietary fiber intake has a beneficial impact on prevention of dementia, but the epidemiological evidence is scant. We sought to examine whether dietary fiber intake is inversely associated with risk of dementia requiring care under the national insurance (disabling dementia). METHODS: The study setting was the Circulatory Risk in Communities Study, involving 3739 Japanese individuals aged 40-64 years at the dietary surveys (1985-99). Dietary fiber intake was estimated using the 24-hour dietary recall method. Incident disabling dementia was followed up from 1999 through 2020. Disabling dementia was further classified into that with or without a history of stroke. Hazard ratios of disabling dementia according to quartiles of total, soluble, and insoluble fiber intake were calculated using the Cox proportional hazards model. RESULTS: During a median 19.7-year follow-up, a total of 670 cases of disabling dementia developed. Dietary fiber intake was inversely associated with risk of dementia: the multivariate hazards ratios (95% confidence intervals) were 0.83 (0.67-1.04), 0.81 (0.65-1.02), and 0.74 (0.57-0.96) for individuals with the second, third, and highest quartiles of dietary fiber intake, respectively, as compared with the lowest quartile (P for trend = 0.03). The inverse association was more evident for soluble fiber intake and was confined to dementia without a history of stroke. As for fiber-containing foods, potatoes, but not vegetables or fruits, showed a similar association. CONCLUSIONS: Dietary fiber intake, especially soluble fiber, was inversely associated with risk of disabling dementia in a general Japanese population.

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.

Sex- and age-specific impacts of smoking, overweight/obesity, hypertension, and diabetes mellitus in the development of disabling dementia in a Japanese population.

BACKGROUND: Sex- and age-specific impacts of cardiovascular risk factors on the development of dementia have not been well evaluated. We investigated these impacts of smoking, overweight/obesity, hypertension, and diabetes mellitus on the risk of disabling dementia. METHODS: The study participants were 25,029 (10,134 men and 14,895 women) Japanese aged 40-74 years without disabling dementia at baseline (2008-2013). They were assessed on smoking status (non-current or current), overweight/obesity (body mass index ≥25 kg/m2 and ≥30 kg/m2, respectively), hypertension (systolic blood pressure ≥140 mmHg, diastolic blood pressure ≥90 mmHg or any antihypertensive medication use), and diabetes mellitus (a fasting serum glucose ≥126 mg/dL, non-fasting glucose ≥200 mg/dL, hemoglobin A1c ≥6.5% by the National Glycohemoglobin Standardization Program or glucose-lowering medication use) at baseline. Disabling dementia was identified as the level of care required ≥1 and cognitive disability grade ≥IIa according to the National Long-term Care Insurance Database. We used a Cox proportional regression model to estimate hazard ratios and 95% confidence intervals (95% CIs) of disabling dementia according to the cardiovascular risk factors and calculated the population attributable fractions (PAFs). RESULTS: During a median follow-up of 9.1 years, 1,322 (606 men and 716 women) developed disabling dementia. Current smoking and hypertension were associated with a higher risk of disabling dementia in both sexes, whereas overweight or obesity was not associated with the risk in either sex. Diabetes mellitus was associated with a higher risk only in women (p for sex interaction = 0.04). The significant PAFs were 13% for smoking and 14% for hypertension in men and 3% for smoking, 12% for hypertension, and 5% for diabetes mellitus in women. The total PAFs of the significant risk factors were 28% in men and 20% in women. When stratified by age, hypertension in midlife (40-64 years) was associated with the increased risk in men, while diabetes mellitus in later-life (65-74 years) was so in women. CONCLUSIONS: A substantial burden of disabling dementia was attributable to smoking, and hypertension in both sexes and diabetes mellitus in women, which may require the management of these cardiovascular risk factors to prevent dementia.

Total protein intake and subsequent risk of chronic kidney disease: the Circulatory Risk in Communities Study.

BACKGROUND: Whether dietary protein intake worsens renal function in the general population has been discussed but not yet determined. We aimed to examine the longitudinal association between dietary protein intake and risk of incident chronic kidney disease (CKD). METHODS: We conducted a 12-year follow-up study with 3,277 Japanese adults (1,150 men and 2,127 women) aged 40-74 years, initially free from CKD, who participated in cardiovascular risk surveys from two Japanese communities under the Circulatory Risk in Communities Study. The development of CKD was defined by the estimated glomerular filtration rate (eGFR) during the follow-up period. Protein intake was measured at baseline by using the brief-type self-administered diet history questionnaire. We estimated sex-, age-, community- and multivariate-adjusted hazard ratios (HR) for incident CKD were calculated using the Cox proportional hazards regression models according to quartiles of percentage of energy (%energy) from protein intake. RESULTS: During 26,422 person-years of follow-up, 300 participants developed CKD (137 men and 163 women). The sex-, age-, and community-adjusted HR (95% confidence interval, CI) for the highest (≥16.9%energy) versus lowest (≤13.4%energy) quartiles of total protein intake was 0.66 (0.48-0.90), p for trend = 0.007. The multivariable HR (95%CI) was 0.72 (0.52-0.99), p for trend = 0.016 after further adjustment for body mass index, smoking status, alcohol drinking status, diastolic blood pressure, antihypertensive medication use, diabetes mellitus, serum total cholesterol levels, cholesterol-lowering medication use, total energy intake, and baseline eGFR. The association did not vary by sex, age, and baseline eGFR. When examining animal and vegetable protein intake separately, the respective multivariable HRs (95%CIs) were 0.77 (0.56-1.08), p for trend = 0.036, and 1.24 (0.89-1.75), p for trend = 0.270. CONCLUSIONS: Higher protein intake, more specifically animal protein intake was associated with a lower risk of CKD.

Brief self-exercise education for adults with chronic knee pain: A randomized controlled trial.

OBJECTIVES: Effective brief instructions for self-management of chronic knee pain are needed. METHODS: Forty-six participants with chronic knee pain were randomly allocated into two programmes: material-based education alone or brief self-exercise education (brief-See), which comprised a 100-minute instruction for self-exercise combined with compact pain education. Total function (KOOS4, 4-subscale average of knee injury and osteoarthritis outcome score), pain intensity (NRS, numeric rating scale), self-efficacy (PSEQ, pain self-efficacy questionnaire), and health-related quality of life (EQ-5D, European quality of life-5 dimensions) were evaluated at baseline and 4 and 12 weeks after the initial intervention. A generalized mixed linear model estimated average group differences in changes from baseline and 95% confidence intervals (95% CIs) using intention-to-treat principle. RESULTS: Compared to material-based education alone, the brief-See provided significant additional improvements of 9.4% (95% CI: 2.3 to 16.4) on the KOOS4 and 5.4 points (0.3 to 10.4) on the PSEQ at 12 weeks but did not on the NRS and EQ-5D. Adherence and satisfaction were favourable in the brief-See without any notable adverse event. CONCLUSIONS: Adding the brief-See to material-based education could be more acceptable and restore total function and self-efficacy, which could contribute to the self-management of chronic knee pain in primary care.

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 Kesennuma Study in Miyagi, Japan: Study Design and Baseline Profiles of Participants.

BACKGROUND: To clarify the association between psychosocial problems and frailty in the areas affected by the Great East Japan Earthquake, and to develop strategies for preventive long-term care in the community, we launched the Kesennuma Study in 2019. This report describes the study design and the participants' profiles at baseline. METHODS: The prospective study comprised 9,754 people (4,548 men and 5,206 women) randomly selected from community-dwelling independent adults aged 65 to 84 who were living in Kesennuma City, Miyagi. The baseline survey was conducted in October 2019. It included information on general health, socio-economic status, frailty, lifestyle, psychological factors (eg, personality, depressive moods), and social factors (eg, social isolation, social capital). A follow-up questionnaire survey is planned. Mortality, incident disability, and long-term care insurance certifications will also be collected. RESULTS: A total of 8,150 questionnaires were returned (83.6% response rate), and 7,845 were included in the analysis (80.4%; mean age 73.6 [standard deviation, 5.5] years; 44.7% male). About 23.5% were considered frail. Regarding psychological and social functions, 42.7% had depressive moods, 29.1% were socially isolated, and only 37.0% participated in social activities at least once a month. However, 82.5% trusted their neighbors. CONCLUSION: While local ties were strong, low social activity and poor mental health were revealed as issues in the affected area. Focusing on the association between psychological and social factors and frailty, we aim to delay the need for long-term care for as long as possible, through exercise, nutrition, social participation, and improvement of mental health.

Associations Between Occupational Status, Support at Work, and Salivary Cortisol Levels.

OBJECTIVE: The present study investigated associations between occupation, job stress, and salivary cortisol levels after psychological tasks. METHODS: We examined 766 (273 men and 493 women) healthy employed Japanese participants aged 21 to 68 years (mean age = 46.4 years, standard deviation = 8.5) with three types of occupation: manager, teacher, and general worker. The Brief Job Stress Questionnaire was used to evaluate participants' job stress levels, including job demand, job control, support from supervisors, and support from coworkers. Salivary cortisol levels were measured at pre-session, post-stressful tasks, and post-relaxation. All samples were assayed using an enzyme-linked immunosorbent assay test. Natural log transformation was applied before statistical analyses. A multiple regression analysis and a repeated measures analysis of covariance were conducted to test associations between occupation and salivary cortisol levels, adjusting for confounding factors. Statistical analyses were conducted separately for men and women. RESULTS: Among both men and women, general workers had higher cortisol levels than managers throughout the experimental session (men 0.6 µg/dL and 0.4 µg/dL, respectively; women 0.5 µg/dL and 0.4 µg/dL, respectively). Job control was positively associated with cortisol levels measured in all sessions, after adjusting for confounding factors (standardized beta 0.15, 0.21, and 0.18 for pre-session, post-stressful-tasks, and post-relaxation, respectively, all p < 0.05). Men with low support from coworkers had higher cortisol levels than those with high support through the sessions (0.6 µg/dL and 0.4 µg/dL, respectively). CONCLUSION: Socioeconomic disparity according to occupational status was related to cortisol levels in Japanese workers. Support from coworkers may be effective for reducing cortisol secretion in men.

[Development of a risk prediction model and a sample risk chart for long-term care certification based on the functional health of older adults].

Objectives　The first aim of this study was to develop risk prediction models based on age, sex, and functional health to estimate the absolute risk of the 3-year incidence of long-term care certification and to evaluate its performance. The second aim was to produce risk charts showing the probability of the incident long-term care certification as a tool for prompting older adults to engage in healthy behaviors.Methods　This study's data was obtained from older adults, aged ≥65 years, without any disability (i.e., they did not certify≥care level 1) and residing in Yabu, Hyogo Prefecture, Japan (n=5,964). A risk prediction model was developed using a logistic regression model that incorporated age and the Kihon Checklist (KCL) score or the Kaigo-Yobo Checklist (KYCL) score for each sex. The 3-year absolute risk of incidence of the long-term care certification (here defined as≥care level 1) was then calculated. We evaluated the model's discrimination and calibration abilities using the area under the receiver operating characteristic curves (AUC) and the Hosmer-Lemeshow goodness-of-fit test, respectively. For internal validity, the mean AUC was calculated using a 5-fold cross-validation method.Results　After excluding participants with missing KCL (n=4) or KYCL (n=1,516) data, we included 5,960 for the KCL analysis and 4,448 for the KYCL analysis. We identified incident long-term care certification for men and women during the follow-up period: 207 (8.2%) and 390 (11.3%) for KCL analysis and 128 (6.6%) and 256 (10.2%) for KYCL analysis, respectively. For calibration, the χ2 statistic for the risk prediction model using KCL and KYCL was: P=0.26 and P=0.44 in men and P=0.75 and P=0.20 in women, respectively. The AUC (mean AUC) in the KCL model was 0.86 (0.86) in men and 0.83 (0.83) in women. In the KYCL model, the AUC was 0.86 (0.85) in men and 0.85 (0.85) in women. The risk charts had six different colors, suggesting the predicted probability of incident long-term care certification.Conclusions　The risk prediction model demonstrated good discrimination, calibration, and internal validity. The risk charts proposed in our study are easy to use and may help older adults in recognizing their disability risk. These charts may also support health promotion activities by facilitating the assessment and modification of the daily behaviors of older adults in community settings. Further studies with larger sample size and external validity verification are needed to promote the widespread use of risk charts.

[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.

Development of risk prediction models for incident frailty and their performance evaluation.

There is currently no tool to predict incident frailty despite various frailty assessment tools. This study aimed to develop risk prediction models for incident frailty and evaluated their performance on discrimination, calibration, and internal validity. This 2-year follow-up study used data from 5076 non-frail older adults (51% women) living in Tokyo at baseline. We used the Kaigo-Yobo checklist, a standardised assessment instrument, to determine frailty. Twenty questionnaire-based variables that include sociodemographic, medical, behavioural, and subjective factors were entered into binary logistic regression analysis with stepwise backward elimination (p < 0.1 for retention in the model). Discrimination and calibration were assessed by area under the receiver operating characteristic curve (AUC) and the Hosmer-Lemeshow test, respectively. For the assessment of internal validity, we used a 5-fold cross-validation method and calculated the mean AUC. At the follow-up survey, 15.0% of men and 10.2% of women were frail. The frailty risk prediction model was composed of 10 variables for men and 11 for women. AUC of the model was 0.71 in men and 0.72 in women. The P-value for the Hosmer-Lemeshow test in both models was more than 0.05. For internal validity, the mean AUC was 0.71 in men and 0.72 in women. Probability of incident frailty rose with an increasing risk score that was calculated from the developed models. These results demonstrated that the developed models enable the identification of non-frail older adults at high risk of incident frailty, which could help to implement preventive approaches in community settings.

Effectiveness of a community-wide intervention for population-level frailty and functional health in older adults: A 2-year cluster nonrandomized controlled trial.

This cluster nonrandomized controlled trial examined the effectiveness of a 2-year community-wide intervention (CWI) on population-level frailty and functional health among older adults. We allocated 18 districts in Ota City, Tokyo, Japan, to intervention (3 districts, A-C) and control (15 districts) groups. Of the 15,500 stratified randomly sampled residents aged 65-84 years, 11,701 (6009 in intervention and 5692 in control groups) gave valid responses to the baseline survey and were followed for 2 years. Using participatory action research framework, we developed an evidence-based CWI to promote frailty prevention. The outcomes were changes in frailty (primary), functional health (secondary, i.e., physical, nutritional, and psychosocial variables), and awareness. Primary analyses showed no significant group by time interactions in frailty prevalence (difference in multivariate-adjusted change between groups, 1.8 percentage points [PP] [95% CI, -0.1, 3.6]). Although changes in functional health were similar between groups, prespecified subgroup analyses showed a benefit for ≥150 min/week of walking (3.9 PP [1.9-5.8]) in district A, and for exercise ≥1 time/week (2.1 PP [0.1-4.0]), Motor Fitness Scale (0.10 points [0.01-0.20]), Dietary Variety Score (DVS) (0.10 points [0.01-0.18]), DVS of ≥7 (2.0 PP [0.01-4.1]), and going outdoors ≥1 time/day (2.1 PP [0.1-4.1]) in district C. Awareness of our CWI was significantly higher in the intervention group (multivariate-adjusted difference between groups, 5.8 PP [3.9-7.8]). This CWI increased awareness in intervention group and improved population-level functional health in intervention subgroups in the short term but was not effective for population-level frailty prevention at 2 years. Trial registration: UMIN-CTR (UMIN000026515).

Salt taste perception and blood pressure levels in population-based samples: the Circulatory Risk in Communities Study (CIRCS).

To examine the associations of salt perception with salt intake and blood pressure levels in general populations, we performed a cross-sectional study in two communities where salt intake level is different, Akita and Osaka in Japan. Taste perception (detection for certain taste and recognition for salt taste) was determined using a Na-impregnated test strip for 1024 Akita and 1199 Osaka adults aged 30-74 years. The proportions of detection for 0·1 % salt were 61, 62, 79, and 79 % in Akita men, Osaka men, Akita women and Osaka women, respectively. The corresponding proportions of not recognising of 1·6 % salt taste (>1·6 %) were 34, 30, 16 and 21 %. Detection threshold was higher in Akita than in Osaka for women aged 60-74 years, and recognition threshold was lower in Akita than in Osaka for women aged 30-59 and 60-74 years. The high detection (≥0·4 %) and recognition (>1·6 %) thresholds of salt taste were associated with higher salt intake scores for Akita men aged 30-59 years, whose detection and recognition thresholds tended be positively associated with systolic and diastolic blood pressures (SBP and DBP) after adjustment for potential confounders. Among Akita elderly men, detection threshold tended to be positively associated with SBP and DBP, while among Akita middle-aged women, recognition threshold was associated with SBP. In conclusion, the high thresholds of salt perception were inversely associated with salt intake for Akita middle-aged men and with blood pressure levels for Akita middle-aged and elderly men and middle-aged women.