Japan Gerontological Evaluation Study Research Articles

Sociodemographic Heterogeneity in the Associations of Social Isolation With Mortality

There are limited data on whether the vulnerabilities and impacts of social isolation vary across populations. To explore the association between social isolation and mortality due to all causes, cardiovascular diseases (CVD), and malignant neoplasms focusing on heterogeneity by sociodemographic factors. This cohort study used a moderator-wide approach to examine the heterogeneity in the association of social isolation with all-cause, CVD, and malignant neoplasm mortality using baseline data from the Japan Gerontological Evaluation Study in 2010 and 2011. Eligible participants were adults aged 65 years or older without heart disease, stroke, cancer, or impaired activity of daily living across 12 Japanese municipalities. Follow-up continued until December 31, 2017, identifying 6-year all-cause, cardiovascular disease (CVD), and malignant neoplasm mortality. Logistic regression assessed effect modification by age, gender, education, income, population density, marital status, and employment on mortality associations. Data analysis was performed from September 13, 2023, to March 17, 2024. Social isolation, determined by a 3-item scale (scores of 2 or 3 indicating isolation) was the primary exposure variable. Six-year all-cause, CVD, and malignant neoplasms mortality. This study included 37 604 older adults, with a mean (SD) age of 73.5 (5.9) years (21 073 women [56.0%]). A total of 10 094 participants (26.8%) were classified as experiencing social isolation. Social isolation was associated with increased all-cause (odds ratio [OR], 1.20 [95% CI, 1.09-1.32]), CVD (OR, 1.22 [95% CI, 0.98-1.52]), and malignant neoplasm mortality (OR, 1.14 [95% CI, 1.01-1.28]). Stratified analysis showed associations of social isolation with all-cause and malignant neoplasm mortality among people with high income (highest tertile all cause: OR, 1.27 [95% CI, 1.06-1.53]; malignant neoplasm: OR, 1.27 [95% CI, 1.02-1.60]), living in areas with high population density (highest tertile all cause: OR, 1.47 [95% CI, 1.26-1.72]; malignant neoplasm: OR, 1.38 [95% CI, 1.11-1.70]), not married (all cause: OR, 1.33 [95% CI, 1.15-1.53]; malignant neoplasm: OR, 1.25 [95% CI, 1.02-1.52]), and retirees (all cause: OR, 1.27 [95% CI, 1.14-1.43]; malignant neoplasm: OR, 1.27 [95% CI, 1.10-1.48]). Formal testing for effect modification indicated modification by population density and employment for all-cause mortality and by household income and employment for neoplasm mortality. Social isolation was associated with increased risks of all-cause, CVD, and malignant neoplasm mortality, with associations varying across populations. This study fills an important gap in research on social isolation, emphasizing its varied associations across demographic and socioeconomic groups.

Socioeconomic Status Transition Throughout Life and Risk of Dementia

Socioeconomic status (SES) is associated with dementia. However, the role of SES transitions in dementia is less explored; such evidence would be useful to understand whether social mobility is associated with healthy longevity at older ages. To investigate the association of lifetime SES transition with risk of dementia. This prospective cohort study, conducted from August 2010 to December 2016, used data from the Japan Gerontological Evaluation Study for participants aged 65 years or older from 31 different areas in Japan. Individuals with missing SES values, loss of follow-up, or new dementia onset 1 year or less from baseline were excluded. Data analysis was performed from April 2022 to April 2023. Transitions in SES across the life course. The main outcome was risk of dementia incidence and corresponding loss or gain of dementia-free periods in a lifespan. The incidence of dementia was identified with a national registry of long-term nursing care services. A total of 9186 participants (4703 men [51.2%]) were included. The mean (SD) age at baseline was 74.2 (6.0) years. Six SES transitions were identified: upward, stable-high, upper-middle, lower-middle, downward, and stable-low. During the follow-up period, 800 cases of dementia were identified. Many dementia risk factors, including lifestyle behaviors, comorbidities, and social factors, were associated with SES transition patterns. Compared with lower-middle SES, the lowest risk of dementia was observed for upward transition (hazard ratio [HR], 0.66; 95% CI, 0.57-0.74) followed by stable-high (HR, 0.77; 95% CI, 0.69-0.86), downward (HR, 1.15; 95% CI, 1.09-1.23), and stable-low (HR 1.45; 95% CI, 1.31-1.61) transition (P < .001 for linearity); there was no association of upper-middle transition with risk of dementia (HR, 0.91; 95% CI, 0.79-1.03). The greatest increases in dementia-free years in the lifespan were also associated with upward SES transition (eg, 1.8 years [95% CI, 1.4-2.2 years] at age 65 years), while the downward transition was associated with the largest loss in lifetime dementia-free years at 75 years or older (eg, -1.4 years [95% CI, -2.4 to -0.4 years] at age 85 years). This cohort study of Japanese older adults identified that upward and downward SES transitions were associated with risk of dementia and the length of dementia-free periods over the lifespan. The results may be useful to understand the association between social mobility and healthy longevity.

Determining the most appropriate socioeconomic status indicator for describing inequalities in dental visits by Japanese older people.

This study examined the association between various socioeconomic status (SES) indicators and dental visits among older Japanese. When examining health inequalities, an adequate indicator of SES should be applied. In older adults, wealth and pensions are considered more appropriate indicators of SES than education and income, but few studies have examined. This cross-sectional study used data from 12 391 individuals aged 65 years or older from the 2016 Japan Gerontological Evaluation Study (JAGES). The Slope Index of Inequality (SII) and the Relative Index of Inequality (RII) were applied to examine the association of education, income, wealth and pensions with dental visits for treatment and check-up adjusting for covariates. The mean age of the participants was 74.0 ± 6.2 years. In the previous year, 56.3% of participants had visited a dentist for a check-up, and 65.9% had visited for treatment. Inequalities in dental treatment visits were observed for wealth, pensions and income rather than education. Income was not significantly associated with check-up visits. Wealth showed the largest association with dental visits for treatment [(SII 0.09, 95% CI 0.06 to 0.13), (RII 1.14, 95% CI 1.09 to 1.21)] and check-up [(SII 0.08, 95% CI 0.05 to 0.12), (RII 1.16, 95% CI 1.09 to 1.23)]. When measuring inequalities in access to dental care among the older population, wealth and pensions could be important indicators of SES.

The Purpose of Internet Use and Face-To-Face Communication With Friends and Acquaintances Among Older Adults: A JAGES Longitudinal Study.

Internet use influences social interactions in society. However, there is no consensus on whether and what kind of Internet use increases face-to-face communication (FFC). This study investigated the mode of Internet use that increases FFC among older adults after three years. Participants were 8734 adults aged 65 or older who responded to the Japan Gerontological Evaluation Study (JAGES) surveys in 2016 and 2019. The exposures were the purposes of Internet use in 2016. The outcome was the frequency of FFC with friends or acquaintances in 2019. The confounders included 13 demographic, socioeconomic, and psychological variables. We performed modified Poisson regression analyses and found that Internet use for communication in 2016 increased FFC in 2019, especially for low-frequency FFC in 2016. Internet-based non-FFC may help promote FFC and prevent social isolation among older adults who are less likely to interact with others.

Community-level group sports participation and all-cause, cardiovascular disease, and cancer mortality: a 7-year longitudinal study

BackgroundCommunity-level group sports participation is a structural aspect of social capital that can potentially impact individual health in a contextual manner. This study aimed to investigate contextual relationship between the community-level prevalence of group sports participation and the risk of all-cause, cardiovascular disease (CVD), and cancer mortality in older adults.MethodsIn this 7-year longitudinal cohort study, data from the Japan Gerontological Evaluation Study, a nationwide survey encompassing 43,088 functionally independent older adults residing in 311 communities, were used. Cause of death data were derived from the Japanese governmental agency, The Ministry of Health, Labour and Welfare, for secondary use. “Participation” was defined as engaging in group sports for one or more days per month. To analyze the data, a two-level survival analysis was employed, and hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated.ResultsAmong the participants, 5,711 (13.3%) deaths were identified, with 1,311 related to CVD and 2,349 to cancer. The average group sports participation rate was 28.3% (range, 10.0–52.7%). After adjusting for individual-level group sports participation and potential confounders, a higher community-level group sports participation rate was found to be significantly associated with a lower risk of both all-cause mortality (HR: 0.89, 95% CI: 0.83–0.95) and cancer mortality (HR: 0.89, 95% CI: 0.81–0.98) for every 10% point increase in the participation rate. For CVD mortality, the association became less significant in the model adjusted for all covariates (HR: 0.94, 95% CI: 0.82–1.09).ConclusionsOur findings support the existence of a preventive relationship between community-level group sports participation and the occurrence of all-cause and cancer mortality among older individuals. Promoting group sports within communities holds promise as an effective population-based strategy for extending life expectancy, regardless of individual participation in these groups.

Regional Inequalities in Oral Frailty and Social Capital.

Oral frailty leads to poor nutritional status, which, in turn, leads to frailty. This cross-sectional study aimed to determine regional differences in the prevalence of oral frailty and to identify factors associated with oral frailty using 3-level multilevel models. This study comprised 165,164 participants aged ≥65 y without long-term care requirements in the Japan Gerontological Evaluation Study. The dependent variable was oral frailty, which was calculated based on age, number of teeth, difficulty in eating tough foods, and choking. The individual-level independent variables included sociodemographics, present illness, social participation, frequency of meeting friends, and social capital. The local district-level independent variable was social capital (n = 1,008) derived from exploratory factor analyses. The municipality-level independent variable was population density (n = 62). Three-level multilevel Poisson regression analysis was performed to calculate the prevalence ratios (PRs). The prevalence of oral frailty in municipalities ranged from 39.9% to 77.6%. Regarding district-level factors, higher civic participation was significantly associated with a lower probability of oral frailty. At the municipality level, the PR of the rural-agricultural area was 1.17 (95% confidence interval, 1.11-1.23) (reference: metropolitan). These results highlight the usefulness of oral frailty prevention measures in encouraging social participation in rural areas. The results of the present study showed regional differences in oral frailty. In particular, rural-agricultural areas show higher prevalence rates of oral frailty than those in metropolitan cities. Promoting measures of social participation among older adults may help prevent oral frailty in rural areas.

Social participation among residents of serviced housing for older people versus community-dwelling older people in Japan: a propensity score matching analysis

Abstract Aim Housing has a significant impact on the health, safety, and social participation of older individuals. Japan’s Serviced Housing for Older People (SHOPs) is one such model that provides supportive services and accessible living spaces. Method This cross-sectional study examined the relationship between living in SHOPs with social activity programs (SAPs) and levels of social participation. We conducted a self-reported survey of SHOP residents and compared the proportions of participants who participated in social activities in the SHOP with a control group of community-dwelling older people selected from the Japan Gerontological Evaluation Study using propensity score matching. Results The survey obtained responses from 189 eligible participants. SHOP residents were primarily female, older, educated, unmarried, and had a better financial status than the control group. SHOP residents (n = 143) were 2.57 times more likely to exercise (p &lt; 0.001), 1.62 times more likely to participate in hobbies (p = 0.004), and 4.37 times more likely to participate in learning activities (p &lt; 0.001) than the control group (n = 398). However, volunteering, senior citizen clubs, neighborhood associations, and community gathering places participation did not differ significantly between the SHOP and control groups. Conclusion The findings suggest that SHOPs with SAPs have the potential to promote social participation and healthy aging among older people.

The association between objective and subjective oral health conditions and the presence of anorexia of aging among Japanese older Adults1

Anorexia of aging is a risk factor for malnutrition among older adults. This study aimed to evaluate the association between objective and subjective oral health and anorexia among independent older adults. This cross-sectional study targeted independent older adults aged ≥65 years who participated in the Japan Gerontological Evaluation Study conducted in 2022. The outcome variable was the presence of anorexia, as assessed by the Simplified Nutritional Appetite Questionnaire. Exposure variables were dental status (≥20 teeth, 10–19 teeth with/without dentures, and 0–9 teeth with/without dentures) as objective oral health and oral health-related quality of life measured by five items of the short version of the Oral Impacts on Daily Performances (OIDP) (eating, speaking, smiling, emotional stability, and enjoying with others) as subjective oral health. We fitted the Poisson regression model, including possible confounders, and estimated prevalence ratios (PRs) and 95% confidence intervals. Among 19,787 participants (mean age: 74.6 years [1SD = 6.2], male: 48.5%), 9.0% were classified as having anorexia. After adjusting possible confounders, those with ≤19 teeth had a higher proportion of experiencing anorexia compared to those with ≥20 teeth; however, the association was less pronounced among those with dentures (0−9 teeth with dentures: PR = 1.48 [1.31−1.68], and 0−9 teeth without dentures: PR = 2.08 [1.65−2.63]). Even after adjusting for dental status, each item of OIDP was significantly associated with the presence of anorexia (all p < 0.05). The results showed that both objective and subjective poor oral health were significantly associated with a higher probability of developing anorexia of aging. Therefore, improving both objective and subjective oral health through appropriate dental care could contribute to maintaining appetite in later life.

Living in public rental housing is healthier than private rental housing a 9-year cohort study from Japan Gerontological Evaluation Study

Housing tenure is an important aspect to determine health. However, even though renters tend to have more socioeconomic disadvantages than homeowners, mortality risk between private and public renters compared with homeowners remains unclear. Japanese public rented housing, such as the Urban Renaissance Agency, has been developed for supplying an adequate living environment since 1950s. This study aimed to examine the mortality risk among older Japanese residents living in private and public rented houses compared with those living in owner-occupied houses using 9-year follow-up data. This study drew upon a 9-year follow-up of participants in the Japan Gerontological Evaluation Study, a population-based cohort study of Japanese independent adults aged ≥ 65 years. Mortality from 2010 to 2019 was analyzed for 44,007 respondents. Housing tenure was defined by a questionnaire. Cox regression models were used for calculating the hazard ratio for mortality. Bonferroni correction was used to account for multiple testing between rental houses. Overall, 10,638 deaths occurred during the follow-up period. Compared with housing owners, all rental housing groups had a significantly higher risk of mortality. Among renters, participants who lived in public rental housing had the lowest risk of mortality even after adjusting for sociodemographic characteristics, health status, social status, and environmental status. Multiple testing among renters with Bonferroni correction showed that public renters had 0.80 times (95% CI 0.72–0.89) lower mortality risk than private renters. Although Japanese older adults living in public rental housing had a higher mortality risk than homeowners, this risk was lower than that among private renters. A positive neighborhood environment based on well-planned urban development may have contributed to this result. The results suggest that planned urban development lowers the risk of mortality in older renters in Japan.

Do changes in the frailty score differ by the type of group sports and exercises participated in? A 3-year longitudinal study

BackgroundOlder adults who engage in group sports and exercises achieve greater health benefits than those who exercise by themselves. The benefits of group participation may vary depending on the type of sports/exercise they engage in. The present study aimed to identify the association between specific sports and exercise types performed in groups and evaluate the longitudinal changes in multidimensional frailty scores among community-dwelling older adults in Japan.MethodsWe used 3-year follow-up data from the Japan Gerontological Evaluation Study and analyzed 33,746 men and 36,799 women aged ≥ 65 years. To elucidate the relationship between participation in 20 types of group sports/exercises in 2016 (baseline) and the change in frailty score (using the Kihon Checklist, KCL) from 2016 to 2019, we performed linear regression analyses through multivariate adjustments for age group, self-rated health, marital status, living alone, occupational status, years of education, alcohol drinking status, smoking status, equivalent income, and disease status using an inverse probability weighting method. P < 0.05 was considered statistically significant.ResultsThe mean change in KCL scores over 3 years was + 0.62 and + 0.61 points in men and women, respectively, implying the degree of frailty worsened. The sports/exercise types that significantly prevented increments in KCL scores for both sexes compared to non-participants were hiking (men: B, − 0.36; women: B, − 0.29), walking (men: B, − 0.26; women: B, − 0.24), tennis (men: B, − 0.23; women: B, − 0.24), ground golf (men: B, − 0.21; women: B, − 0.19), and weight exercises (men: B, − 0.19; women: B, − 0.16).ConclusionParticipation in specific sports and exercise groups offer significant physical and psychological benefits for frailty prevention among older adults in Japan. The results of this study may offer substantive evidence to encourage older adults to participate in group activities for the prevention of multidimensional frailty. It will also help public health stakeholders to decide which type of sports and exercise groups to promote in a community.

Association between social support and ambulance use among older people in Japan: an empirical cross-sectional study

BackgroundAmbulance service demand and utilization are increasing worldwide. To address this issue, the factors that affect ambulance use must be identified. Few studies have examined factors that can intervene and thus reduce the frequency of ambulance use. This study aimed to examine the association between social support and ambulance use among older adults in Japan. We hypothesize that social support is associated with reduced ambulance use.MethodsThis cross-sectional study was conducted as part of the Japan Gerontological Evaluation Study. In December 2019 and January 2020, we collaborated with individuals aged 65 years or above with no long-term care needs. A total of 24,581 participants were included in the analysis. The objective and explanatory variables were ambulance use and social support, respectively. Binomial regression analysis was used to calculate the odds ratios (ORs) and 95% confidence intervals (CIs).ResultsSocial support was associated with ambulance use. People who had no one to listen to their complaints or worries were significantly more likely to use ambulance services than those who did (OR [95% CI] = 1.26 [1.03–1.53]). People with no one to take care of them when they were ill were also significantly more likely to use ambulance services than those who had someone to provide care (1.15 [1.01–1.31]). Moreover, the results of binomial logistic regression analysis indicated that individuals who called an ambulance but were not hospitalized had significantly lower social support compared to those who did not call an ambulance.ConclusionsThe results suggest that the presence and quality of social support play a significant role in ambulance use among older adults in Japan. Our findings can help policymakers to plan and implement strategies for reducing the burden on emergency medical care.

Frequency of Going Outdoors and Risk of Poor Oral Health Among Older Japanese Adults: A Longitudinal Cohort From the Japan Gerontological Evaluation Study.

The association between the frequency of going outdoors and the risk of poor oral health has been reported in several studies; however, the findings have been inconclusive. We conducted a 3-year longitudinal study of 19,972 Japanese adults aged ≥65 years who reported no poor oral condition at baseline in 2013. The respondents rated their frequency of going outdoors in three categories (≤1, 2-3, or ≥4 times/week), and the oral conditions reported in 2016 included tooth loss, chewing difficulty, swallowing difficulty, dry mouth, and composite outcomes. The associations between the frequency of going outdoors and the risk of poor oral health were examined as relative risk ratios (RRs) and 95% confidence intervals (CIs) using multivariable Poisson regression, while mediation analysis was performed to investigate indirect effects. During the follow-up, 32.5% of participants developed poor oral health. In the mediation analysis, indirect effects were observed through low instrumental activities of daily living, depressive symptoms, little social network diversity, and underweight. Compared to going outdoors ≥4 times/week, the multivariable RRs of composite poor oral health conditions were 1.12 (95% CI, 1.05-1.20) for 2-3 times/week and 1.22 (95% CI, 1.07-1.39) for ≤1 time/week (P-trend < 0.001). Similar associations were observed for tooth loss, chewing difficulty, and swallowing difficulty; the corresponding RRs were 1.07 (95% CI, 0.97-1.19) and 1.36 (95% CI, 1.13-1.64) (P-trend = 0.002), 1.18 (95% CI, 1.06-1.32) and 1.30 (95% CI, 1.05-1.60) (P-trend < 0.001), and 1.15 (95% CI, 1.01-1.31) and 1.38 (95% CI, 1.08-1.77) (P-trend = 0.002), respectively. The frequency of going outdoors was inversely associated with the risk of poor oral health through several modifiable risk factors in the older population.

Social participation and functional disability trajectories in the last three years of life: The Japan Gerontological Evaluation Study

BackgroundFunctional disability has various patterns from onset until death. Although social participation is a known protective factor against functional disability among older individuals, it is unclear whether social participation is associated with the trajectory patterns of functional disability prior to death. This study assessed the association between social participation, specifically in horizontal and vertical groups, and the trajectories of functional disability prior to death. MethodsWe used survey data from the 2010 Japan Gerontological Evaluation Study for functionally independent older adults combined with public long-term care insurance system data from 2010 to 2016 (n = 4,502). The outcome variables included five previously identified trajectory patterns using group-based trajectory modeling. As the explanatory variable, we used three definitions of social participation: any group, horizontal group (e.g., sports, hobbies), or vertical group (e.g., political, religious), at least once a month. We used a multinomial logistic regression analysis to calculate odds ratios with 95 % confidence intervals for the identified trajectory patterns. ResultsParticipation in any groups was significantly less likely to belong to “Accelerated disability” (OR=0.74 [95 % CIs 0.60–0.92]), “Persistently mild disability” (0.68 [0.55–0.84]), and “Persistently severe disability” (0.67 [0.50–0.83]) compared to “Minimum disability.” Although participation in horizontal groups was similarly associated with trajectories regardless of gender, vertical groups was not associated with trajectories among males. ConclusionsSocial participation among older adults may be associated with an extended period of living without disabilities before death. This association may differ by gender and social participation group and requires further research.

Socioeconomic status and incident depressive symptoms among older adults: A 3-year longitudinal study from the Japan Gerontological Evaluation Study.

The association between socioeconomic status (SES) and the onset of depressive symptoms has attracted considerable attention. However, few studies have simultaneously examined the association of multiple SES indicators, including "assets," with the onset of depressive symptoms. Therefore, this study examined the association of four SES indicators in old age ('years of education' 'equivalent income,' 'equivalent assets,' and 'the longest-held job') with new-onset depressive symptoms in a large Japanese dataset. This longitudinal study used panel data of cognitively and physically independent older adults from the Japan Gerontological Evaluation Study (JAGES) conducted in 2013 and 2016. Multivariate logistic regression analysis was conducted to examine the association of each SES indicator with new-onset depressive symptoms, and odds ratios and 95% confidence intervals (CIs) were calculated. We analyzed the data of 40,257 older adults, with a mean age (± standard deviation) of 72.9 (±5.5) years. In the follow-up survey, 4292 older adults had new-onset depression symptoms (10.7%). 39.3% had 10-12years of education. 36.9% had an equivalent income of up to JPY 1.99 million. 24.4% had equivalent assets of JPY 4-17.99 million. Most had a clerical job for the long time. Furthermore, fewer years of education (males: OR=1.42, 95% CI=1.22-1.64, p-value <0.001/females: 1.26, [1.09-1.47], p=0.002), lower income (males: 1.64, [1.34-2.01], p<0.001/females: 1.82, [1.49-2.22], p<0.001), and fewer assets (males: 1.40, [1.16-1.68], p<0.001/females: 1.21, [1.02-1.42], p=0.025) resulted in higher odds of having new-onset depressive symptoms, even when other SES indicators were entered simultaneously. All four SES indicators have an independent association with the development of new-onset depressive symptoms among older adults, reflecting different aspects of SES. The association between the "longest-held job" and new-onset depressive symptoms can be largely explained by other SES indicators. A multifaceted and lifetime approach is required to prevent the onset of depressive symptoms in old age.

Measuring functional ability in Healthy Ageing: testing its validity using Japanese nationwide longitudinal data.

The United Nations Decade of Healthy Ageing 2021-2030 suggests nations should monitor functional ability as an indicator of healthy ageing progress. Functional ability is the attribute of people to do something they value and consists of five domains. We examined its validity in terms of a construct, cross-validation across multiple waves' data, and predictivity for subsequent well-being. Using panel data from 35,093 community-dwelling adults aged ≥65years from the Japan Gerontological Evaluation Study, we performed factor analyses to explore the construct of functional ability domains in both 2013 and 2016. A modified Poisson regression analysis was employed to test their associations with well-being (subjective health and happiness) in 2019. The mean age (standard deviation) of participants was 72.1 (5.0) years, and 52.0% were women. A total of 85.0% reported good subjective health, and 50.6% reported high happiness levels. Factor analyses with 31 logically checked candidate items from 2016 data suggested a three-factor model comprising 24 items, which were compatible with the 2013 data results. Based on the World Health Organization's original domains, we named domains as domain #1: ability to build and maintain relationships; domain #2: ability to meet basic needs + ability to move around and domain #3: ability to learn, grow and make decisions + ability to contribute. All three domains predicted both subjective health and happiness in 2019. Empirical data from Japan supports the functional ability concept among older individuals. Validating this concept with data from other nations is warranted.

Dental prosthesis use moderates association between tooth loss and risk of depressive symptoms in older adults with severe tooth loss: The JAGES cohort trial.

Depression is a leading cause of disability. Although tooth loss increases the risk of depressive symptoms, it is unclear whether dental prosthesis use moderates this risk. This study aimed to investigate whether dental prosthesis use moderates the association between tooth loss and new depressive symptoms in older adults. This cohort study used data from the 2016 and 2019 Japan Gerontological Evaluation Study (JAGES). The participants were independent older adults aged ≥65 years without depressive symptoms in 2016. The onset of depressive symptoms in 2019 was the outcome variable. The explanatory variables were dental status (≥20 teeth, 10-19 teeth with or without dental prostheses, and 0-9 teeth with or without dental prostheses) in 2016. Risk ratios (RRs) and 95% confidence intervals (CIs) were estimated using Poisson regression models with potential confounders as covariates. The analysis included 50,169 participants (mean age: 72.8 [standard deviation, 5.4] years). During follow-up, the incidence of depressive symptoms was 11.3%. Compared to those who had ≥20 teeth, the RR of depressive symptom onset was highest among those who had 0-9 teeth without dental prostheses (RR, 1.27; 95% CI, 1.04-1.56), after the adjustment for confounders. However, this risk was lower in those with 0-9 teeth and dental prostheses (RR, 1.08; 95% CI, 1.01-1.15). These data highlight the potential of dental prostheses as an important factor in reducing the risk of depressive symptoms among individuals with severe tooth loss.

Poor oral health and dementia risk under time-varying confounding: A cohort study based on marginal structural models.

Bidirectional association between oral health, including tooth loss and oral hypofunction, and cognitive impairment can induce time-varying confounding in association with dementia. This study aimed to investigate the association between oral health and the development of dementia among older adults, considering cognitive impairment as a time-varying confounder. This nine-year follow-up cohort study targeted independent older adults aged ≥65 years who participated in the Japan Gerontological Evaluation Study. The exposure variables were self-reported poor oral health (≤19 remaining teeth, edentulousness, chewing difficulty, swallowing problems, and xerostomia), which were assessed in 2010 and 2013. The outcome variable was the incidence of dementia between 2013 and 2019, which was obtained from the municipalities' administrative database. Furthermore, in 2010 and 2013, we considered cognitive impairment as a time-varying confounder and treated it based on a marginal structural model (MSM), including possible baseline confounders. Oral health and cognitive impairment were assessed using the items of Kihon checklist. We employed a Cox proportional hazards model with a stabilized inverse probability weight and estimated hazard ratios (HRs) and 95% confidence intervals (CIs). Among 37,556 participants (mean age: 72.8 years [1 SD = 5.5], males: 46.8%), the dementia incidence rate was 2.2/100 person-year. The proportions of those with ≤19 remaining teeth, edentulousness, chewing difficulty, swallowing problems, and xerostomia were 61.3%, 11.0%, 24.4%, 14.7%, and 19.2%, respectively. From the regression analysis based on MSM, ≤19 remaining teeth (HR = 1.12, 95% CI = 1.03-1.23), edentulousness (HR = 1.20, 95% CI = 1.09-1.32), chewing difficulty (HR = 1.11, 95% CI = 1.02-1.21), and xerostomia (HR = 1.10, 95% CI = 1.01-1.20) were significantly associated with an increased risk of dementia; however, swallowing problems were not significantly associated with dementia onset (p > 0.05). Even after considering time-varying confounding by cognitive function at baseline and follow-up, we observed significant associations between poor oral health and increased risk of dementia among older adults.

Does eating with others promote happiness among older adults living alone? A 3-year longitudinal study of the Japan gerontological evaluation study.

Living a happy life is an essential issue for old adults. However, how eating with others contributes to happiness and whether this association is different by living arrangements or not is unknown. The current study examined the relationship between the frequency of eating with others and happiness among older adults according to their living arrangements using 3-year longitudinal data. The analyzed sample comprised 18,727 people (10,920 males and 7807 females) with low happiness (0-7 points on score of 0-10 points) from Japan Gerontological Evaluation Study (JAGES) in 2016. Our exposure was the frequency of eating with others: rarely, a few times a year, a few times a month, and a few times a week or more. We performed Modified Poisson Regression to examine the association between the frequency of eating with others and high happiness (8-10 points) in 2019 stratified by living arrangement (living alone/with others). A total of 4352 (23.2%) people showed high happiness in 2019. After adjusting for age, sex, marital status, education, household income, social participation, illnesses under treatment, and depressive symptoms in 2016, the cumulative incidence ratio (CIR) for high happiness in 2019 among people living alone was more significant, that is, 1.28 (95% confidence intervals: 0.88-1.87), 1.50 (1.05-2.14), and 1.82 (1.26-2.63), than 1.28 (1.11-1.48), 1.30 (1.12-1.50), and 1.33 (1.16-1.52) among people living with others for those who ate with others a few times a year, a few times a month, and a few times a week or more compared to those who rarely ate with others, respectively. The interaction between the frequency of eating with others and living arrangements was statistically significant. The trend test showed that higher frequency of eating with others was significantly associated with high happiness. Eating with others was associated with improved happiness among older adults, with such an association being stronger among people living alone.

Cooking skills, living alone, and mortality: JAGES cohort study

BackgroundLiving alone without someone to cook meals for them can happen more frequently in aging due to bereavement, divorce, or other family changes. Health risks to older adults due to poor cooking skills may be more pronounced among those living alone. We aimed to examine whether cooking skills are associated with mortality according to cohabitation status in older Japanese people.MethodsParticipants in the Japan Gerontological Evaluation Study, a population-based cohort of independent older adults, were followed for three years (n = 10,647). Cooking skill was assessed using a scale with good validity and modified for Japanese people in the baseline survey. After stratification by living alone or together, participants with high and low cooking skills were matched on demographic, socioeconomic, health-related factors, and availability of food stores using propensity score matching. All-cause mortality risks were compared between high and low cooking skills using Cox regression models.ResultsDuring the follow-up, 520 of the 10,647 participants died. One hundred and seventy-one pairs of high and low cooking skills were matched among those living alone, and 2,161 pairs among those living with others were matched as well. The hazard ratio of the low level of cooking skills (vs. high) was 2.50 (95% confidence interval [CI]: 1.10–5.68) among those living alone, while 1.05 (95% CI: 0.82–1.33) among those living with others.ConclusionLower cooking skills were associated with a higher risk of mortality only among those living alone. Cooking skills may be important for older adults who live alone to reduce mortality risk.

Community gender norms, mental health, and suicide ideation and attempts among older Japanese adults: a cross-sectional study.

Gender norms embedded in communities may restrict opportunities and harm the mental health of older adults, yet this phenomenon has received little attention. This study investigates the connection between older adults' perceptions of community gender norms and mental health and suicide-related outcomes. Cross-sectional. This study analyzed data from the 2019 wave of the Japan Gerontological Evaluation Study. In total, 25,937 participants aged 65 years or older in 61 municipalities. Perceptions of community gender norms were assessed by the respondents' perceptions of the gender-differentiating language used by those around them such as "You should/should not do XXX, because you are a man/woman." The prevalence of all mental health outcomes was higher among both men and women who perceived community gender norms as restrictive. These associations remained in fully adjusted multivariable analyses. Prevalence ratios for men were 1.36 [95% confidence interval: 1.13, 1.65] for psychological resistance to obtaining help, 1.85 [1.54, 2.23] for depressive symptoms, 1.99 [1.34, 2.96] for suicidal ideation, and 2.15 [1.21, 3.80] for suicide attempts. The corresponding figures for women were 1.39 [1.17, 1.65], 1.80 [1.55, 2.10], 2.13 [1.65, 2.74], 2.62 [1.78, 3.87]. There was a more pronounced association between perceiving community gender norms as restrictive and depressive symptoms and suicidal behaviors among those with nonconventional gender role attitudes compared to those with conventional attitudes. Considering the effects of community gender norms, in addition to individual gender role attitudes, may be critical in designing effective public health interventions for improving mental health.