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.

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.

Effects of Radio-Taiso on Health-Related Quality of Life in Older Adults with Frailty: A Randomized Controlled Trial.

BACKGROUND: Radio-Taiso could be a sustainable public health strategy for maintaining quality of life (QoL) in older adults with frailty. This study aimed to investigate whether Radio-Taiso provided greater benefits for health-related quality of life (HR-QoL) and to identify the mechanisms underlying the effectiveness in this population. METHODS: A 12-week randomized controlled trial enrolled 226 older Japanese adults with pre-frailty or frailty, assessed using the modified frailty phenotype. Participants were randomly allocated to the intervention (Radio-Taiso + nutrition program) or control (nutrition program) groups. The Radio-Taiso program comprised five 60-min group sessions and daily practice at the participants' homes. The primary outcome was the change in the mental domain of HR-QoL, assessed using the SF-36®. The secondary outcomes included six physical fitness items and exercise self-efficacy. RESULTS: Overall, 104 and 105 participants in the intervention and control groups, respectively, were analyzed based on the intention-to-treat principle. The median (interquartile range) daily practice rate of Radio-Taiso was 94.1% (73.2-98.8%). Although general linear models adjusted for baseline values and allocation stratification factors showed that the intervention group obtained greater benefits (adjusted mean differences [95% confidence intervals]) in the up-and-go (0.3 [0.1, 0.6] s), 2-min step-in-place (-3.2 [-6.2, -0.2] steps) tests, and exercise self-efficacy scale (-1.4 [-2.6, -0.1] points) than the control group, there were no group differences in changes in the mental domain score of HR-QoL. CONCLUSIONS: Radio-Taiso provided greater benefits for agility/dynamic balance, aerobic endurance, and exercise self-efficacy in older adults with frailty; however, these changes do not improve HR-QoL.

Identification of a novel biomarker for sarcopenia diagnosis using serum metabolomic analysis: a pilot study.

PURPOSE: This pilot study compared serum metabolites in participants with and without sarcopenia. METHODS: Metabolomic techniques were applied to identify serum metabolites and novel biomarkers specific to patients with sarcopenia. In accordance with AWGS2019 criteria, sarcopenia was defined as low muscle mass plus either low muscle strength/low physical function, and severe sarcopenia was defined as low muscle mass, low muscle strength, and low physical function all together. RESULTS: The sarcopenia group had higher hypoxanthine, galactose, and mannose levels but lower triethanolamine and homogentisic acid levels than the non-sarcopenia group. The severe sarcopenia group had lower levels of alpha-tocopherol than the mild and moderate sarcopenia groups. CONCLUSION: This study is the first to identify hypoxanthine as a potential biomarker for sarcopenia in humans and provides new insights into the pathophysiology of sarcopenia. Furthermore, the identified metabolites may be useful for the early detection of sarcopenia.

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.

Dose-Response Relationship of Physical Activity with All-Cause Mortality among Older Adults: An Umbrella Review.

OBJECTIVES: To examine the dose-response relationship between physical activity (PA) and all-cause and cardiovascular disease (CVD) mortality, specifically among older adults. DESIGN: Umbrella review. SETTING AND PARTICIPANTS: Eligible studies included systematic reviews with meta-analyses that investigated the association of aerobic PA, muscle-strengthening activity, and multicomponent PA, including exercise programs (such as aerobic, muscle strengthening, and balance training), with all-cause and CVD mortality among older adults aged ≥60 years. METHODS: We performed a literature search in PubMed, CINAHL, and the Cochrane Library for eligible studies published between January 2017 and March 2023 to update an umbrella review initially conducted by the United States 2018 PA Guidelines Advisory Committee. Studies included in the 2018 US PA and 2020 World Health Organization (WHO) Guidelines were also reviewed. In addition, meta-analyses that reported effect sizes stratified by age and recruiting older adults (aged ≥60 years) were included. RESULTS: Overall, 16 relevant systematic reviews (10 from our review and 6 from the US and WHO guidelines) met the inclusion criteria. All these reviews showed that 7.5 to 15.0 metabolic equivalents (METs)-hours/week (around the recommended PA levels outlined in the US and WHO guidelines) substantially reduced mortality risks among older adults (approximately 19%-30% for all-cause mortality and 25%-34% for CVD mortality). Moreover, 15.0 to 22.5 MET-hours/week, exceeding the guideline-recommended PA levels, resulted in greater reductions in mortality risks by 35% to 37% and 38% to 40%, respectively. CONCLUSIONS AND IMPLICATIONS: PA substantially reduced all-cause and CVD mortality risks among older adults. Larger risk reductions may be achieved by engaging in PA levels higher than those recommended by the current international PA guidelines. Our findings suggest that recommending higher PA levels beyond the current guidelines may benefit older adults when developing future international PA guidelines.

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.

Association between dynapenia and cognitive decline in community-dwelling older Japanese adults: The IRIDE Cohort Study.

AIM: Muscle mass and strength correlate with cognitive function; however, it remains unclear whether dynapenia (i.e., muscle weakness with preserved muscle mass) is relevant. This study aimed to explore whether dynapenia is associated with global cognitive function in community-dwelling older Japanese adults. METHODS: This cross-sectional study used data from the Integrated Research Initiative for Living Well with Dementia Cohort Study, which pooled data from five community-based geriatric cohorts. Dynapenia was defined as muscle weakness without muscle mass loss according to the Asian Working Group for Sarcopenia criteria. Cognitive function was assessed using the Mini-Mental State Examination (MMSE). An ordered logistic regression analysis was conducted with dynapenia as the exposure and with cognitive decline stages, defined as an MMSE score of 27-30 for normal cognition, 24-26 for possible cognitive decline, and <24 for cognitive decline, as the outcome, stratified by sex and adjusted for age, muscle mass, education, alcohol consumption, smoking habits, living alone, and non-communicable diseases. RESULTS: We analyzed data for 3338 participants (2162 female) with preserved muscle mass. Of these, 449 (13.5%) had dynapenia, and 79 (2.4%) exhibited cognitive decline. Multivariate odds ratios (95% confidence interval) for cognitive decline among those with dynapenia, compared with those without dynapenia, were 1.51 (1.02-2.24) for males and 2.08 (1.51-2.86) for females. CONCLUSIONS: Muscle weakness is associated with cognitive decline, even in individuals with preserved muscle mass. Further studies are needed to better understand the association between muscle weakness and cognitive decline over time in order to develop dementia prevention strategies for those with dynapenia. Geriatr Gerontol Int 2024; 24: 123-129.

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 2023; ••: ••-••.

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.

Predictive Capability of 5 Sarcopenia Diagnostic Criteria for Fall Incidents in Older Japanese Women: The Otassha Study.

OBJECTIVES: The association between sarcopenia diagnosis according to various diagnostic criteria and falls is unclear. We examined the association between sarcopenia defined by 5 different international criteria, and fall and injurious fall numbers among older community-dwelling Japanese women. DESIGN: Prospective observational study. SETTING AND PARTICIPANTS: Two population-based cohort studies in Itabashi, Japan, were integrated, including 552 community-dwelling Japanese women >75 years of age. METHODS: Muscle mass, muscle strength, and physical performance were assessed by bioimpedance analysis, handgrip strength, and gait speed, respectively. We recorded the fall and injurious fall numbers for 1 year using a diary. The association between sarcopenia diagnosis defined by the Asian Working Group for Sarcopenia (AWGS) 2019, European Working Group on Sarcopenia in Older People 2, Foundation for the National Institutes of Health (FNIH), International Working Group on Sarcopenia, and Society on Sarcopenia, Cachexia, and Wasting Disorders, and fall numbers was assessed by Poisson regression analysis to estimate the incidence rate ratio (IRR) and 95% CI for the presence or absence of sarcopenia. RESULTS: Of 470 participants (mean age 77.1 ± 8.1 years), 144 reported a combined 352 falls. Overall, 80 individuals experienced a single fall, 64 experienced multiple falls, and 91 experienced injurious falls. Sarcopenia defined by the AWGS 2019 (IRR 1.39, 95% CI 1.10-1.76) and FNIH (IRR 2.55, 95% CI 1.99-3.26) was significantly associated with the number of falls. In addition, sarcopenia defined by the FNIH (IRR 2.72, 95% CI 1.84-4.03) was significantly associated also with the number of injurious falls. No significant association was observed between sarcopenia diagnosis based on the other definitions and fall outcomes. CONCLUSIONS AND IMPLICATIONS: The AWGS 2019 and FNIH sarcopenia definitions were associated with the fall and injurious fall numbers in older Japanese women, indicating they can help in predicting falls in this population.

Fluctuations in Cognitive Test Scores and Loss to Follow-Up in Community-Dwelling Older Adults: The IRIDE Cohort Study.

INTRODUCTION: We examined the relationship between previous fluctuations in Mini-Mental State Examination (MMSE) scores, future changes in MMSE scores, and attrition from follow-up surveys, which helps in a more comprehensive interpretation of repeatedly collected MMSE scores. METHODS: This 4-year longitudinal study included 2,073 community-dwelling older adults aged ≥65 years in Japan. The MMSE was administered at baseline (T0), 2 years (T1), and 4 years (T2) follow-up. We performed multinomial logistic regression analysis with the dependent variable, indicating the change in MMSE score from T1 to T2 (categorized as increase, no change [reference category], and decrease) and attrition at T2. The independent variables included the change in MMSE scores from T0 to T1 and MMSE scores at T0 and T1. RESULTS: The mean MMSE score was 29 across the three time points. A one-point decrease in MMSE score from T0 to T1 was associated with 79% (95% confidence interval: 1.62, 1.97) higher odds of an increase in MMSE score from T1 to T2 and 28% (1.17, 1.40) higher odds of attrition at T2. A one-point decrement in the MMSE score at T0 and T1 was also associated with an increase in the MMSE score from T1 to T2 and attrition at T2. CONCLUSION: Focusing on cognitive fluctuation for 2 years, rather than cognitive function at a point in time, would have no remarkable advantage when focusing on future cognitive function and attrition. Our results emphasize the need for further studies to identify factors that distinguish between those who continue to attend follow-up surveys and show improvements in cognitive test scores and those who drop out.

Vitamin K insufficiency predicts incidence of frailty in community-dwelling older adults: The Otassha Study.

INTRODUCTION: Vitamin K is a fat-soluble vitamin discovered as an essential factor for blood coagulation. It is suggested that vitamin K can benefit several aging-related diseases, including osteoporosis, osteoarthritis, and dementia. We previously reported the cross-sectional association of vitamin K insufficiency with frailty in community-dwelling older adults. MATERIALS AND METHODS: In October 2020, a health examination of community-dwelling older adults (The Otassha Study) was performed, including frailty evaluation and blood tests. We used a ucOC and OC ratio (ucOC/OC) to indicate vitamin K insufficiency. One year later, we conducted a follow-up evaluation of frailty on 518 people who were not frail at baseline. The serum ucOC/OC at the baseline examination was divided into quartiles (Q1, Q2, Q3, and Q4). Odds ratio (OR) and 95% confidence interval (CI) were calculated using multivariate binary logistic regression for each quartile of ucOC/OC to determine the risk of incident frailty in the follow-up study, with the lowest quartile (Q1) as the reference. RESULTS: Among the 518 older adults who were not frail at baseline, 66 people (12.7%) became frail in the follow-up study. In the multivariate binary logistic regression analysis, setting the lowest quartile of ucOC/OC (Q1) as a reference, the OR of the incident frailty in the highest quartile (Q4) was 2.53 (95% CI 1.07, 4.92) which was significantly different from Q1. CONCLUSION: The findings of this longitudinal study suggest that vitamin K insufficiency has nutritional importance in predicting the future incidence of frailty in the Japanese older adult population.

Inverse Association between Cheese Consumption and Lower Cognitive Function in Japanese Community-Dwelling Older Adults Based on a Cross-Sectional Study.

Diet modification may contribute to the prevention of age-related cognitive decline. The association between dairy product consumption and cognitive function in older people remains unknown. We investigated whether cheese intake is associated with lower cognitive function (LCF) in community-dwelling older adults. This cross-sectional study included 1503 adults aged over 65 years. The analyzed data were obtained through face-to-face interviews and functional ability measurement. Cognitive function was assessed using the mini-mental state examination (MMSE), and a score ≤23 was defined as LCF. The prevalence of LCF was 4.6%, and this group had smaller calf circumference, slower usual walking speed, and a more frequent history of anemia than subjects with MMSE scores >23. After adjusting for confounding factors, logistic regression analysis revealed cheese intake (odds ratio (OR) = 0.404, 95% confidence interval (CI) = 0.198-0.824), age (OR = 1.170, 95% CI = 1.089-1.256), usual walking speed (OR = 0.171, 95% CI = 0.062-0.472) and calf circumference (OR = 0.823, 95% CI = 0.747-0.908) to be significant factors associated with LCF. Although the present study was an analysis of cross-sectional data of Japanese community-dwelling older adults, the results suggest that cheese intake is inversely associated with LCF.

Age- and sex-specific associations between sarcopenia severity and poor cognitive function among community-dwelling older adults in Japan: The IRIDE Cohort Study.

Introduction: This study examined whether the association between sarcopenia severity and cognitive function differed according to sex and age in community-dwelling older adults in Japan. Methods: This is a cross-sectional study of older adults (age ≥ 65 years) consisting of five regional cohorts integrated as the Integrated Research Initiative for Living Well with Dementia (IRIDE) Cohort Study. Sarcopenia severity was determined based on the Asian Working Group for Sarcopenia 2019, which assessed grip strength, walking speed, and skeletal muscle mass index. Poor cognitive function was defined as a Mini-Mental State Examination score of ≤ 23. Odds ratios (ORs) and 95% confidence intervals (CIs) for poor cognitive function were calculated by sex and age group (65-74 and ≥75 years) using binomial logistic regression models, which were adjusted for age, educational attainment, history of non-communicable diseases, smoking and drinking habits, living alone, frequency of going outdoors, exercise habits, and depressive symptom. Results: Of the 8,180 participants, 6,426 (1,157 men aged 65-74 and 1,063 men aged 75 or older; 2,281 women aged 65-74 and 1,925 women aged 75 or older) were analyzed. The prevalence ratio of sarcopenia and severe sarcopenia were 309 (13.9%) and 92 (4.1%) among men and 559 (13.3%) and 166 (3.7%) among women, respectively. A total of 127 (5.8%) men and 161 (3.9%) women had a poor cognitive function. Setting non-sarcopenia as a reference, the adjusted ORs (95% CI) of poor cognitive function were 2.20 (1.54, 3.15) for sarcopenia and 3.56 (2.20, 5.71) for severe sarcopenia. A similar trend was observed in analyses stratified by sex and age, with linear associations (P for trend <0.05) in both categories. Furthermore, there was a significant interaction (P < 0.05) between sex and sarcopenia severity, indicating a stronger linear association of sarcopenia severity with poor cognitive function in women compared with men. Discussion and conclusion: Sarcopenia severity was linearly associated with poor cognitive function in adults aged ≥ 65 years, with a stronger association in women compared with men.