Associations between information and communication technology use and frailty in community-dwelling old-old adults: results from the ILSA-J.

OBJECTIVES: Frailty is a significant cause of adverse health events including long-term care and hospitalization. Although information and communication technology (ICT) has become an integral part of modern life, it remains unclear whether ICT use is associated with frailty. DESIGN: A cross-sectional study (Integrated Longitudinal Studies on Aging in Japan, ILSA-J). SETTING AND PARTICIPANTS: Aged 75 and older data from the ILSA-J in 2017 (n = 2893). METHODS: ICT use was measured using the technology usage sub-items of the Japan Science and Technology Agency Index of Competence. Specifically, the use of mobile phones, ATMs, DVD players, and sending e-mails were rated as "yes" (able to do) or "no" (unable to do), with the first quintile (≤1 point) defined as ICT non-users. Frailty was assessed using the Japanese version of the Cardiovascular Health Study criteria based on the phenotype model (e.g., weight loss, slowness, weakness, exhaustion, and low activity). Further, multivariate logistic regression analysis analyzed its association with ICT use. Subgroup analyses were stratified according to gender, years of education, and living arrangements. RESULTS: Higher ICT use was not associated with frailty after adjusting for covariates (odds ratio [OR]: 0.53; 95%CI 0.39-0.73). Similar associations were found in the sub-groups of women (OR 0.45, 95%CI 0.30-0.66), <13 years of education (OR 0.48, 95%CI 0.34-0.67), living alone (OR 0.46, 95%CI 0.27-0.79), and living together (OR 0.57, 95%CI 0.38-0.85). No association existed between using ICT and frailty in the sub-groups of men and ≥13 years of education. CONCLUSIONS AND IMPLICATIONS: Higher ICT use is associated with the absence of frailty in individuals 75 years and older. Such benefits may be particularly pronounced in women, those with lower levels of education, and older adults living alone or with others.

Oral frailty, appetite and dietary variety in late-stage older adults: A cross-sectional study (the STudy of lAte-stage oldeR adulTs in Tottori; START Tottori).

AIM: Efforts to combat frailty and preserve good health in older adults have highlighted oral frailty as an early indicator of overall frailty. Individuals showing oral frailty are at an elevated risk of insufficient nutritional intake compared with those without oral frailty; however, underlying mechanisms remain poorly explored. In this cross-sectional study, we aimed to examine the link between oral frailty and undernutrition, especially regarding poor appetite and low dietary diversity. METHODS: The analysis included 2727 late-stage older adults (mean age 79.9 ± 4.3 years) who underwent dental checkups in a prefecture in Japan from 2016 to 2020. The examination involved a questionnaire survey (covering basic information, frailty screening index, appetite index: Simplified Nutritional Appetite Questionnaire; and dietary variety: Dietary Variety Score) and a measurement survey (including intraoral confirmation, oral diadochokinesis and masticatory efficiency test). Individuals with three or more indications of poor oral function, identified through oral function assessment, were defined as showing oral frailty. Binomial logistic regression and path analyses examined associations among oral frailty, Simplified Nutritional Appetite Questionnaire and Dietary Variety Score. RESULTS: Among those analyzed, 1208 (44.3%) participants were categorized into the oral frailty group. Binomial logistic regression analysis showed that Simplified Nutritional Appetite Questionnaire (odds ratio for oral frailty per 1-point increase 0.88, 95% confidence interval 0.84-0.93) and Dietary Variety Score (odds ratio 0.95, 95% confidence interval 0.92-0.98) were significantly associated with oral frailty. The path analysis showed individual associations between each examined factor. CONCLUSIONS: Oral frailty was associated with decreased appetite and dietary variety in late-stage older adults. Geriatr Gerontol Int 2024; ••: ••-••.

Feasibility of Oral Function Evaluation According to Dementia Severity in Older Adults with Alzheimer's Disease.

Oral function evaluation in older adults with dementia is important for determining appropriate and practical dietary support plans; however, it can be challenging due to their difficulties in comprehending instructions and cooperating during assessments. The feasibility of oral function evaluation has not been well studied. This cross-sectional study aimed to determine the feasibility of oral function evaluation in older adults with Alzheimer's disease (AD) according to Functional Assessment Staging of Alzheimer's Disease (FAST) stages. In total, 428 older adults with AD (45 men and 383 women; mean age: 87.2 ± 6.2 years) were included. Multilevel logistic regression models were used to examine the prevalence of participants who were unable to perform oral function evaluations, including oral diadochokinesis (ODK), repeated saliva swallow test (RSST), and modified water swallow test (MWST). In comparison to the reference category (combined FAST stage 1-3), FAST stage 7 was associated with the infeasibility of ODK (adjusted odds ratio, 95% confidence interval = 26.7, 4.2-168.6), RSST (5.9, 2.2-16.1), and MWST (8.7, 1.6-48.5, respectively). Oral function evaluation is difficult in older adults with severe AD. Simpler and more practical swallowing function assessments and indicators that can be routinely observed are required.

Proposal and validation of an equation to identify sarcopenia using bioelectrical impedance analysis-derived parameters.

OBJECTIVE: This study aimed to develop a simpler approach for diagnosing sarcopenia by using only bioelectrical impedance vector analysis parameters. METHODS: The study design was a cross-sectional study. The research was conducted based on the Itabashi Longitudinal Study on Aging, a community-based cohort study, with data collected from the 2022 and 2023 surveys in Itabashi Ward, Tokyo, Japan. The development cohort consisted of 1146 participants from the 2022 survey, and the validation cohort included 656 participants from the 2023 survey. Both cohorts were comprised of community-dwelling older adults with similar inclusion criteria. Sarcopenia was defined according to the Asian Working Group for Sarcopenia 2019 criteria. The logistic model utilized height divided by impedance at 50 kHz and phase angle to establish a new regression equation to identify sarcopenia. Regression equations were generated for the development cohort and validated for the validation cohort. Discriminatory ability was assessed using the area under the receiver operating characteristic curve (AUC) for men and women. RESULTS: The prevalence of sarcopenia was 20.7% and 14.8% in the development and validation cohort, respectively. The AUC (95% confidence interval) of the logistic model in discriminating sarcopenia was 0.92 (0.88, 0.95) for men and 0.82 (0.78, 0.86) for women in the development cohort and 0.85 (0.78, 0.91) for men and 0.90 (0.86, 0.95) for women in the validation cohort. CONCLUSION: The study demonstrated that a simple formula using bioelectrical parameters at 50 kHz proved useful in identifying sarcopenia in the older adult population.

Social isolation, regardless of living alone, is associated with mortality: the Otassha study.

Introduction: Social isolation has been recognized as a contributing factor to negative health outcomes. Although living alone is associated with health-related outcomes, existing findings are inconsistent. It is not the act of living alone that may predict poor health, but rather social isolation that can lead to increased mortality risk. This study investigated the combined associations of social isolation and living alone with mortality among community-dwelling older adults. Methods: We included older adults from Itabashi ward, Tokyo, who participated in comprehensive health checkups. Participants were categorized into four groups based on their social isolation status and living alone. The primary outcome was all-cause mortality, analyzed using Cox proportional hazards models. Results: Of the 1,106 participants (mean age 73, 42% male), 4.5% experienced both social isolation and living alone. This combination was associated with a worse prognosis regarding all-cause mortality (hazard ratio (HR): 2.08 [95% confidence interval (CI), 1.08-4. 00]). Those who were socially isolated but not living alone also showed a trend towards higher mortality risk (HR: 1.41 [95% CI, 0.90-2.20]). Contrastingly, those who were not socially isolated and lived alone did not show an increased mortality risk (HR: 0.81 [95% CI, 0.44-1.49]). Discussion and conclusion: Living alone is not inherently associated with a poor prognosis in older adults; however, social isolation was associated with a higher mortality risk. Healthcare providers should focus on enhancing social interactions and support for older adults because of their effects on health rather than solely addressing living arrangements to prevent adverse health events.

Sex-specific factors associated with acceptance of smartwatches among urban older adults: the Itabashi longitudinal study on aging.

Smartwatches (SW) are wearable devices that support daily life and monitor an individual's health and activity status. This information is utilized to promote behavior modification, which could help prevent chronic diseases and manage the health of older adults. Despite being interested in SWs, older adults tend to decrease their SW usage as they age. Therefore, understanding the acceptance of SWs among older individuals can facilitate individual health management through digital health technology. This study investigated the factors associated with the acceptance of SWs among older adults in Japan and the variations in the factors by sex. This study utilized data from the 2022 Itabashi Longitudinal Study on Aging, an ongoing cohort study conducted by the Tokyo Metropolitan Institute for Geriatrics and Gerontology. We included 899 eligible individuals aged ≥65 years. Participants were classified into three groups: possessing SW (possessor group), not possessing SW but interested in possession in the future (interest group), and not interested in possession in the future (non-interest group) using a self-administered questionnaire. The level of SW acceptance was operationally defined as follows: low (non-interest group), medium (interest group), and high (possessor group). Further, we evaluated the association of acceptance and purchase intentions of SWs with sociodemographic variables, technology literacy, and health variables. Among the participants, 4.2% possessed SWs, with no significant sex difference (men, 4.2%; women, 4.3%). Among men, age < 75 years, obesity, diabetes, and dyslipidemia were significantly associated with SW acceptance level. Contrastingly, among women, age < 75 years, living alone, higher household income, and a high score for new device use in the technology literacy category were significantly associated with SW acceptance level. Health-related factors were associated with SW acceptance in men, while technology literacy and sociodemographic factors were associated with SW acceptance in women. Our findings may inform the development of sex-specific interventions and policies for increasing SW utilization among older adults in Japan.

Association Between Ego-Resilience and Social Isolation Among Urban Older People.

Social isolation among older adults affects their physical and mental health. Ego-resilience is associated with flexible adaptation to various environments and acceptable behaviors. However, its association with social isolation among older people is unclear. Therefore, a health survey was conducted with 510 adults aged 65 years or older to assess social isolation, its associated factors, and ego resilience. The results showed that the social isolation group had a lower median ego-resiliency scale score (42.0) compared to the non-social isolation group (38.0). The social isolation group were mostly males without spouses, took time to move, had more depressive moods, and poorer subjective health status. The non-social isolated group had faster maximum walking speed. Low ego-resilience was newly identified as a factor associated with social isolation among older people, as were being male, having no spouse, and depressive symptoms. Mediation analysis revealed that ego-resilience affected social isolation and was partially mediated by depressive symptoms.

Three-year trajectories of social networks, face-to-face interactions, and non-face-to-face interactions among community-dwelling older adults in Japan during the COVID-19 pandemic: Otassha study.

OBJECTIVES: To investigate the trajectories of social networks and interactions among older Japanese individuals during the COVID-19 pandemic. STUDY DESIGN: We used data from a cohort of community-dwelling older individuals from the Otassha study's 2019-2022 survey. Participants comprised 606 older individuals who participated in the 2019 survey and were followed up at least once. MAIN OUTCOME MEASURES: Social networks were assessed using the Lubben Social Network Scale-6 (LSNS-6), whereas social interactions were assessed by the frequency of face-to-face or non-face-to-face contact with non-resident family members and friends. Trajectories of the LSNS-6 and face-to-face and non-face-to-face interactions were identified using group-based semiparametric mixture modeling. The trajectories of change in the LSNS-6 from 2019 were also identified. The factors associated with the changes in trajectory patterns were examined using logistic regression analysis. RESULTS: Three LSNS-6 trajectories were identified, with slightly decreasing patterns over time. Specifically, face-to-face interactions tended to decrease over time, whereas non-face-to-face interactions exhibited almost no change. The reduction in LSNS-6 in the decreased pattern failed to recover to its pre-pandemic level. The group of participants with the decreased pattern had a significantly higher proportion of people participating in group activities [odds ratio (95 % confidence interval): 2.27 (1.12-4.59)] and performing calisthenics twice a week than the group with the maintained pattern [2.08 (1.18-3.68)]. CONCLUSIONS: During the three years of the pandemic, no changes were observed in the social networks of community-dwelling older Japanese individuals.

Prevalence of oral frailty and its association with dietary variety, social engagement, and physical frailty: Results from the Oral Frailty 5-Item Checklist.

AIM: This cross-sectional study had two aims: to assess the prevalence of oral frailty (OF), according to the Oral Frailty 5-Item Checklist (OF-5), among community-dwelling older adults; and to examine the associations among oral frailty, dietary variety, social engagement, and physical frailty. METHODS: We pooled data from two population-based studies (the Otassha Study and the Itabashi Longitudinal Study on Aging). With the OF-5, OF is characterized by the presence of two or more of the following: (i) fewer teeth, (ii) difficulty in chewing, (iii) difficulty in swallowing, (iv) dry mouth, and (v) low articulatory oral motor skills. We calculated the OF prevalence for each sex. We assessed dietary variety, social engagement, and physical frailty. Generalized structural equation modeling was employed to investigate the associations among oral frailty, low dietary variety (dietary variety score ≤3), social isolation (Lubben Social Network Scale score <12), and physical frailty (Japanese version of the Cardiovascular Health Study score ≥3). RESULTS: A total of 1206 individuals (626 women and 580 men) with a mean age of 74.7 years were included. The prevalence of OF was 36.7%, and it increased with age; however, there was no significant sex difference. OF was significantly indirectly associated with physical frailty via low dietary variety (odds ratio, 1.43; 95% confidence interval, 1.04-1.97) and social isolation (odds ratio, 1.42; 95% confidence interval, 1.04-1.94). CONCLUSIONS: Two of five community-dwelling older adults exhibited OF. Low dietary variety and social isolation are potential underlying mechanisms through which OF is indirectly associated with physical frailty. Geriatr Gerontol Int 2024; 24: 371-377.

Associations of polypharmacy with frailty severity and each frailty phenotype in community-dwelling older adults: Itabashi Longitudinal Study on Aging.

AIM: Although polypharmacy and frailty are concerns in older adults, there is limited understanding of their association, particularly regarding frailty severity and its phenotypes within this population. This study aimed to examine the association between polypharmacy and frailty severity or frailty phenotypes in community-dwelling older Japanese adults. METHODS: This cross-sectional study included 1021 older adults from the Itabashi Longitudinal Study on Aging. Men accounted for 45.4%, and the mean age (standard deviation) was 77.9 (5.1) years. Participants were classified into frail (n = 67), pre-frail (n = 543), and robust (n = 411) groups using the revised Japanese Cardiovascular Health Study criteria. Polypharmacy was defined as using five or more self-reported prescription drugs. Ordinal and binomial logistic regression analyses examined the association between polypharmacy and frailty severity or frailty phenotypes (weight loss, weakness, exhaustion, slowness, and low activity). These models were adjusted for age, sex, body mass index, number of comorbidities, living status, employment status, years of education, as well as drinking and smoking habits. RESULTS: The prevalence of frailty in participants with and without polypharmacy was 10.1% and 5.0%, respectively. Participants with polypharmacy were more likely to have frailty (adjusted odds ratio [95% confidence interval], 1.89 [1.40-2.57]), weight loss (1.81 [1.00-3.27]), weakness (1.50 [1.08-2.09]), and slowness (2.25 [1.29-3.94]) compared with the no-polypharmacy group. CONCLUSIONS: Polypharmacy was associated with frailty severity and three frailty phenotypes. Longitudinal studies are required to investigate whether polypharmacy can predict the development and progression of frailty. Geriatr Gerontol Int 2024; 24: 196-201.

Predicting the incidence of mild cognitive impairment with a computer-based cognitive assessment tool in community-dwelling older adults: The Otassha study.

This study examined the ability of a computer-based cognitive assessment tool (CompBased-CAT) to predict mild cognitive impairment (MCI) in community-dwelling older adults. A two-year longitudinal study was conducted using data from 2016 to 2018 from the Otassha study cohort of community-dwelling older adults. MCI was defined as a Mini-Mental Status Examination (MMSE) score of <27. The CompBased-CAT was used at baseline, with each subtest score converted into a Z-score. Subsequently, the total Z-scores were calculated. Participants were divided into robust and MCI groups, and all variables were compared using the t-test or χ2 test. Receiver operating characteristic (ROC) curves and logistic regression analyses were conducted, with MCI and total Z-scores as dependent and independent variables, respectively. Among the 455 participants (median age, 72 years; range, 65-89 years; 282 women and 173 men), 32 developed MCI after two years. The participants in the MCI group were significantly older. They had lower maximal gait speed, baseline MMSE scores, subtest Z-scores, and total Z-scores than those in the robust group. The area under the ROC curve was 0.79 (95% confidence interval: 0.70-0.87; P <0.01). The sensitivity was 0.76, and the specificity was 0.75. The logistic regression analysis showed an odds ratio of 1.34 (95% confidence interval: 1.18-1.52; P <0.01). This study showed that CompBased-CAT can detect MCI, which is an early stage of dementia. Thus, CompBased-CAT can be used in future community health checkups and events for older adults.

Questionnaire for Medical Checkup of Old-Old is non-inferior to the Kihon Checklist in screening frailty among independent older adults aged 75 years and older: The Itabashi Longitudinal Study on Aging.

AIM: The Questionnaire for Medical Checkup of Old-Old (QMCOO) is a 15-item dichotomous questionnaire developed for the early detection and intervention of frailty in a nationwide health checkup program targeting the old-old (i.e. aged ≥75 years). The Kihon Checklist (KCL) is a 25-item questionnaire widely used for screening and self-monitoring frailty status in administrative settings. With fewer items than the KCL, the QMCOO might expedite the frailty screening process. This study tested whether the QMCOO shows noninferiority in detecting frailty compared with the KCL. METHODS: Overall, 645 participants aged ≥75 years in the Itabashi Longitudinal Study on Aging were assessed for their frailty status according to the revised Japanese version of the Cardiovascular Health Study criteria. They also completed the QMCOO and the KCL simultaneously. We compared the discriminative performance of the two questionnaires using non-inferiority testing with an operationally defined non-inferiority margin of 10% of the area under the receiver operating characteristic curve computed from the KCL. RESULTS: The prevalence of frailty was 8.8%. The area under the receiver operating characteristic curve for the QMCOO in determining frailty was 0.76 (95% CI 0.70, 0.82), and the corresponding area under the receiver operating characteristic curve for the KCL was 0.77 (95% CI 0.69, 0.84). The QMCOO was not inferior to the KCL for frailty discrimination (P for non-inferiority = 0.006). CONCLUSIONS: The accuracy of the QMCOO for determining frailty was not inferior to that of the KCL. The QMCOO might be more acceptable and useful, as it can be applied in a shorter time with fewer questions than the KCL. Geriatr Gerontol Int 2024; 24: 176-181.

Relationship between a gum-chewing routine and oral, physical, and cognitive functions of community-dwelling older adults: A Kashiwa cohort study.

AIM: As associations between oral function and general health have been reported in community-dwelling older adults, easily implementable preventive measures are urgently required. We focused on the health benefits of gum chewing, as no studies have been carried out on the impact of gum-chewing routines on the health of older adults. This cross-sectional study aimed to determine whether the gum-chewing routine is associated with oral, physical and cognitive functions in community-dwelling older adults. METHODS: This study included 1617 community-dwelling older participants in a health survey carried out in 2021. The gum-chewing routine and weekly chewing time were assessed using a self-administered questionnaire. The outcome measures, including actual measurements of oral function, physical function, cognitive function, dietary intake and lifestyle, were evaluated using self-administered questionnaires or health surveys. RESULTS: We analyzed 1474 (mean age 76.1 ± 5.8 years, 45% women) participants for whom all data were not missing, and 14% of them had a gum-chewing routine for more than 30 min weekly. Oral functions were significantly higher in older adults with a gum-chewing routine, and there were substantially fewer participants with oral frailty (adjusted odds ratio 0.581, 95% confidence interval 0.340-0.993). Additionally, cognitive and physical functions, including grip strength, were significantly higher in the gum-chewing routine group. CONCLUSIONS: Community-dwelling older adults with a gum-chewing routine have higher oral, physical and cognitive functions. These findings indicate that a gum-chewing routine might contribute to maintaining oral function and preventing frailty. Geriatr Gerontol Int 2024; 24: 68-74.

Towards an operational definition of oral frailty: A e-Delphi study.

OBJECTIVES: Building upon our recently developed conceptual definition of oral frailty (the age-related functional decline of orofacial structures), this e-Delphi study aims to develop an operational definition of oral frailty by identifying its components. METHODS: We used a modified e-Delphi study to reach a consensus among international experts on the components of oral frailty. Twelve out of fifteen invited experts in the field of gerodontology participated. Experts responded to three rounds of an online 5-point scale questionnaire of components to be included or excluded from the operational definition of oral frailty. After each round, scores and rationales were shared with all experts, after which they could revise their position. A consensus was reached when at least 70% of the experts agreed on whether or not a component should be included in the operational definition of oral frailty. RESULTS: The experts achieved a high level of agreement (80 - 100%) on including eight components of oral frailty and excluding nineteen. The operational definition of oral frailty should include the following components: 1) difficulty eating hard or tough foods, 2) inability to chew all types of foods, 3) decreased ability to swallow solid foods, 4) decreased ability to swallow liquids, 5) overall poor swallowing function, 6) impaired tongue movement, 7) speech or phonatory disorders, and 8) hyposalivation or xerostomia. CONCLUSION: This e-Delphi study provided eight components that make up the operational definition of oral frailty. These components are the foundation for the next stage, which involves developing an oral frailty assessment tool.

Relationship between phase angle and lower-extremity function in older adults: Itabashi Longitudinal Study on Aging.

OBJECTIVE: Evaluating muscle quality instead of its mass has gained attention in diagnosing sarcopenia. The aim of this study was to examine whether phase angle (PhA) as a bioelectrical impedance analysis (BIA)-derived muscle quality indicator is associated with overall lower extremity function better than appendicular skeletal muscle mass index (ASMI) in community-dwelling older adults. METHODS: This cross-sectional study used data from the Itabashi Longitudinal Study on Aging, a community-based cohort study. A sex-stratified multivariate logistic regression analysis was conducted using PhA and ASMI as exposures, and low physical function defined as short physical performance battery score <10 as the outcome, adjusted for age, being overweight, knee pain, and non-communicable diseases. Discrimination of low physical function was compared using the receiver operating characteristic curve. RESULTS: This study included 1464 participants (age 76 [73-80] y; 757 women), with 58 men (8%) and 66 women (9%) exhibiting low physical function. The multivariate odds ratio (OR; 95% confidence interval [CI]) for low physical function among the highest quartile, compared with the lowest quartile were significant in PhA in multiple sites (e.g., OR, 0.09; 95% CI, 0.03-0.32] for men and 0.12; 95% CI, 0.04-0.33 for women in the left leg) but not in ASMI (OR, 0.51; 95% CI, 0.19-1.34 for men and 0.56; 95% CI, 0.21-1.47 for women). Legs and whole-body PhA outperformed the ASMI in discriminating low physical function (P < 0.001). CONCLUSION: PhA reflected physical function better than ASMI; using PhA instead of ASMI in BIA-based morphometric evaluation may add information on low physical function and enhance the diagnostic value of sarcopenia.

Development and validation of a rapid sarcopenia screening questionnaire: The Otassha study.

AIM: To develop a rapid and easy screening tool to detect sarcopenia. METHODS: In total, 683 community-dwelling older adults who participated in our cohort study, the "Otassha Study," in 2019, completely responded to a questionnaire, and were diagnosed with sarcopenia were included. Participants responded to a nine-item questionnaire, including candidate items for a new sarcopenia screening tool named rapid sarcopenia screening, based on items of the Strength, Assistance with walking, Rising from a chair, Climbing stairs, and Falls (SARC-F) questionnaire. To select appropriate items for the new screeening tool, multiple logistic regression analyses were performed, with sarcopenia as the dependent variable and questionnaire responses as independent variables. The area under the curve using 10 000 bootstraps was used to assess the rapid sarcopenia screening diagnostic ability for detecting sarcopenia. RESULTS: Responses to question nos 2 (how much can you squeeze a wet towel?), 5 (how much muscle strength do you think you have compared with that of people of your age and sex?), 7 (how fast do you usually walk?), and 9 (age-related item) were related to sarcopenia in multiple logistic regression analysis. The area under the curve of the total score of rapid sarcopenia screening was 0.82, 0.80, and 0.81 for men, women, and overall, respectively. At a cut-off value of 14/15, the sensitivity and specificity for sarcopenia detection were 0.73 and 0.73, respectively. CONCLUSIONS: The newly developed sarcopenia screening tool has a better diagnostic ability for sarcopenia than the SARC-F. Rapid sarcopenia screening does not require physical function measurements, making it a useful and accessible tool among older adults to detect sarcopenia. Geriatr Gerontol Int 2023; 23: 945-950.

Social interaction trajectories and all-cause mortality in older adults: the Otassha study.

Introduction: This longitudinal study aimed to identify aging trajectory patterns of social interaction by sex and determine the association between these patterns and all-cause mortality. Methods: Participants were 4,065 community-dwelling older adults (1849 men) in Japan, aged 65-89 years, who responded twice or more to a mail survey conducted between 2012 and 2020. Social interaction was examined through the frequency of face-to-face and non-face-to-face contact with non-resident family and friends. The aging trajectories of the social interaction scores were identified using group-based trajectory modeling. Results: Two groups were identified among both men and women. Among men with high-frequency interaction, a rapid decrease in the frequency of social interaction was observed after 80 years of age. Conversely, among women, the frequency tended to remain the same, even after 80 years of age. The social interaction score among those aged 65 years in the low-frequency group was approximately 4 points for men and 6 points for women. Among men, no decrease was observed; however, it tended to decline after 85 years of age among women. Among men, the factors associated with the low-frequency group were instrumental activities of daily living score, perceived financial status, and social participation, while among women, they were self-rated health and social participation. The adjusted hazard ratio in the low-frequency group for all-cause mortality was 1.72 (95% confidence interval, 1.27-1.72) for men and 1.45 (95% confidence interval, 0.98-2.14) for women. Discussion: In the low-frequency group, men had a higher risk of all-cause mortality than women. Daily social interaction from mid-age is important to reduce the risk of social isolation and all-cause mortality in later life.