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.

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.

Association between Gut Microbiota and Muscle Strength in Japanese General Population of the Iwaki Health Promotion Project.

The association between the gut microbiota and muscle strength has garnered attention in the context of mitigating muscle decline. However, many study subjects have been individuals with existing illnesses or the elderly only. This study aims to elucidate the association between the gut microbiota and muscle strength indicators using grip strength/BMI in a large-scale study of community residents. The mean age of men (n = 442) and women (n = 588) was 50.5 (15.3) and 51.2 (15.9) years, respectively. The muscle strength indicator used was grip/BMI. The association between total read count and genus-level gut microbiota and muscle strength was analyzed. The mean grip/BMI was 1.8 (0.3) for men and 1.2 (0.2) for women. The genus of the gut microbiota that showed an association in both sexes was Eggerthella (men: ß = 0.18, CI: 0.04-0.31, p = 0.009; women: ß = 0.07, CI: 0.00-0.12, p = 0.028). Blautia, Eggerthella and Faecalibacterium were found to be significantly associated with grip/BMI in both the multiple regression analysis and Spearman's correlation analysis after the multiple comparison adjustment. These results suggest that an increase in Blautia and Eggerthella, coupled with a decrease in Faecalibacterium, may contribute to muscle strengthening or the suppression of muscle weakness.

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.

Correction: Kanda et al. Body Compression Corrective Garment and Eating Behavioural Change for Weight Reduction: The Mutsu City Randomised Controlled Trial. Healthcare 2023, 11, 942.

In the original publication [...].

Prenatal exposure to environmental heavy metals and newborn telomere length: A systematic review and meta-analysis.

Exposure to environmental heavy metals is associated with telomere length (TL) alteration. Available information regarding the effect of prenatal exposure to environmental pollutants on newborn TL is controversial. The aim of this study is to systematically review and conduct a meta-analysis of the existing epidemiological studies on the associations between prenatal metal exposure and newborn TL. A comprehensive literature search was performed using the online databases of PubMed, Web of Science, and ScienceDirect from their inception to December 1, 2023. Thirteen eligible studies were included from the overall initial identification of 3559 records. The effect size was expressed as standardized beta coefficients with 95% confidence intervals (CIs) by the restricted maximum-likelihood approach with a weighted random-effects model. Prenatal exposure to environmental heavy metals was associated with a shorter newborn TL (standardized beta = -0.04; 95% CI: -0.08, 0.00; p = 0.05). Subgroup analysis showed that prenatal exposure to cadmium was significantly, negatively associated with TL in newborns (standardized beta = -0.05; 95% CI: -0.10, -0.01; p = 0.021). Heavy metal exposure during the third trimester was significantly associated with a shorter TL in newborns (standardized beta = -0.05; 95% CI: -0.11, -0.01; p = 0.045). No significant association was found between the newborn's sex and exposure sample type. This study provides evidence for the negative effect of prenatal exposure to heavy metals on newborn TL. In particular, cadmium exposure and exposure during the third trimester of pregnancy are critical factors associated with heavy metal-induced TL shortening.

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.

Does the Protective Effect of Zinc on Telomere Length Depend on the Presence of Hypertension or Type 2 Diabetes? Results from the Iwaki Health Promotion Project, Japan.

Telomeres, repeated TTAGGG sequences at chromosomal ends, shorten with age and indicate cellular lifespan. Zinc can protect against telomere damage through its anti-oxidative effect. Meanwhile, telomere shortening was correlated with metabolic diseases of hypertension and type 2 diabetes. The objective of this study was to investigate whether the association between zinc and telomere length differs by the presence or absence of hypertension/type 2 diabetes. This is a cross-sectional study with 1064 participants of the Iwaki area, Japan. Multiple linear regression models were performed to test the hypothesis. A higher serum zinc concentration was significantly associated with a longer G-tail length (ß = 48.11, 95% confidence intervals [CI]: 25.69, 70.54, p < 0.001). By multivariate linear regression analysis, there was a significant positive association between zinc and G-tail length in both hypertensive (ß = 46.84, 95%CI: 9.69, 84.0, p = 0.014) and non-hypertensive groups (ß = 49.47, 95%CI: 20.75, 78.18, p = 0.001), while the association was significant only in the non-diabetes group (ß = 50.82, 95%CI: 27.54, 74.11, p < 0.001). In conclusion, higher zinc concentration was significantly associated with longer G-tail length. The protective effect of zinc on G-tail did not differ by hypertension status; however, it disappeared in individuals with type 2 diabetes.

The Association between Gut Microbiota and Depression in the Japanese Population.

Depression is a leading cause of disease worldwide. The association between gut microbiota and depression has barely been investigated in the Japanese population. We analyzed Iwaki health check-up data collected from 2017 to 2019 and constructed generalized linear mixed models. The independent variable was the relative abundance of each of the 37 gut microbiota genera that were reported to be associated with depression. The dependent variable was the presence of depression assessed by the Center for Epidemiologic Studies Depression Scale. Potential confounders, including grip strength, gender, height, weight, smoking, and drinking habits, were adjusted in the regression models. Nine genera's regression coefficients (Alistipes, Blautia, Coprococcus, Dorea, Faecalibacterium, Holdemania, Lactobacillus, Mitsuokella, and Oscillibacter) showed statistical significance after multiple comparisons adjustment. Among these nine gut bacteria genera, Alistipes, Blautia, Coprococcus, Dorea, Faecalibacterium, and Oscillibacter were reported to be associated with butyrate production in the intestine. Our results indicate that gut microbiotas may influence the depression condition of the host via the butyrate-producing process.

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.

Validation of self-reported articulatory oral motor skill against objectively measured repetitive articulatory rate in community-dwelling older Japanese adults: The Otassha Study.

AIM: To assess the validity of self-reported articulatory oral motor skill against objectively measured repetitive articulatory rate (oral diadochokinesis [oral-DDK]) as a gold standard index for articulatory oral motor skill in community-dwelling older Japanese adults. METHODS: This cross-sectional study included 607 Japanese adults (mean age = 73.9 years). A single-item self-report questionnaire for articulatory oral motor skill was developed. Study participants completed a 1-month-interval test-retest protocol to assess reliability of the questionnaire, and the protocol was tested by the kappa statistic. Oral-DDK with /ta/ (i.e., the number of repetitions of the monosyllable /ta/ per second) was measured during the on-site examination. Low oral-DDK performance was defined as <5.2 times/s in men and <5.4 times/s in women. Oral-DDK performance, oral functions other than articulatory oral motor skill, and physical frailty were compared in the groups with and without self-reported low articulatory oral motor skill as determined by the response to the questionnaire. RESULTS: Self-reported low articulatory oral motor skill was identified in 18.5% of the study population. The self-report questionnaire had good test-retest reliability, with a kappa statistic of 0.71. Self-reported low articulatory oral motor skill was significantly associated with a lower value of oral-DDK with /ta/ and a higher proportion of low oral-DDK performance, difficulties in chewing and swallowing, dry mouth, and physical frailty. Self-report had high specificity (83.1%) but low sensitivity (42.1%) for detecting low oral-DDK performance. CONCLUSIONS: A single-item self-report questionnaire for articulatory oral motor skill had acceptable test-retest reliability and was associated with objectively measured articulatory oral motor skill. Geriatr Gerontol Int 2023; 23: 729-735.

Development of a multiple masticatory function model based on the evaluation of sarcopenia: A cross-sectional survey of the Otassha study.

OBJECTIVE: The masticatory function is intricately linked to several factors like natural teeth count, occlusion, masticatory muscles, and tongue coordination. This study's goal was to formulate a comprehensive masticatory function model, considering sarcopenia's conceptual structure, and subsequently validate its measurement efficacy. DESIGN: The study encompassed 753 participants (59.1 % women; mean age: 73.0 ± 5.1 years) from an urban community. The model amalgamated masseter muscle mass, occlusal force, and mixing ability. Based on the Asian Working Group for Sarcopenia 2019 classification, participants were categorized into a multiple masticatory dysfunction (MMD) or severe MMD (S-MMD) group. Logistic regression analysis gauged the model's validity, using serum albumin levels and self-reported chewing difficulties as dependent variables. RESULTS: Of the total, 61 (8.1 %) participants exhibited MMD, while 24 (3.2 %) had S-MMD. S-MMD was correlated with low serum albumin levels (odds ratio: 3.62; 95 % confidence interval: 1.07-12.29) and heightened self-reported chewing difficulties (odds ratio: 2.82; 95 % confidence interval: 1.09-7.28). CONCLUSIONS: Our multiple masticatory function model offers a straightforward approach for assessing MMD. Furthermore, the study establishes a link between S-MMD, nutritional vulnerability, and self-reported chewing challenges, thus affirming the model's credibility.

Serum levels of vitamin D and periodontal inflammation in community-dwelling older Japanese adults: The Otassha Study.

AIM: To evaluate the association between vitamin D status and periodontal inflammation as determined by the periodontal inflamed surface area (PISA) in community-dwelling older adults. MATERIALS AND METHODS: This cross-sectional study included 467 Japanese adults (mean age = 73.1 years) who underwent full-mouth periodontal examinations and measurements of serum levels of 25-hydroxyvitamin D (25(OH)D). We used linear regression and restricted cubic spline models to analyse the association between exposure (serum 25(OH)D) and outcome (PISA). RESULTS: The linear regression model showed that, after adjusting for potential confounders, participants in the lowest quartile of serum 25(OH)D had 41.0 mm2 more PISA (95% confidence interval [CI]: 4.6-77.5) than the reference group (the highest quartile of serum 25(OH)D). The spline model showed that the association between serum 25(OH)D and PISA was non-linear and restricted to the low 25(OH)D range. PISA initially sharply decreased as serum 25(OH)D increased, and then the decreasing trend slowed and plateaued. The inflection point with the minimum PISA value was a serum 25(OH)D level of 27.1 ng/mL, above which there was no decreasing trend in PISA with increasing serum 25(OH)D levels. CONCLUSIONS: Low vitamin D status had an L-shaped association with periodontal inflammation in this cohort of Japanese adults.

Impact of combinations of subscale declines in higher-level functional capacity on 8-year all-cause mortality among community-dwelling older Japanese adults.

BACKGROUND: The frequency of combined declines in domains of multi-faceted frailty and their impact on adverse health outcomes have not been adequately investigated. We aimed to examine the association between combined subscale declines in higher-level functional capacity and 8-year all-cause mortality among community-dwelling older Japanese individuals and the impact of multi-faceted frailty on mortality. MATERIALS AND METHODS: We administered a questionnaire to 7015 community-dwelling older adults aged 65-85 years. The higher-level functional capacity of the 3381 respondents was assessed using the Tokyo Metropolitan Institute of Gerontology Index of Competence. Subscale decline was defined as (1) none, (2) only social role (SR), (3) only intellectual activity (IA), (4) SR and IA, (5) only instrumental activities of daily living (IADL), (6) IADL and SR, (7) IADL and IA, and (8) all. Associations between combined subscale declines and mortality were examined using adjusted Cox proportional hazards models. Follow-up was conducted from October 1, 2012, to death or November 1, 2020. RESULTS: The mortality rate was 16.7/1000 person-years. Moreover, 44% of respondents had declined SR, and half of them had multiple declines. Compared with no decline, SR (adjusted hazard ratio [HR]: 1.49, 95% confidence interval [CI]: 1.14-1.93), SR and IA (HR: 1.59, 95% CI: 1.16-2.17), IADL and SR (HR: 1.97, 95% CI: 1.31-2.99), and all-domain (HR: 2.72, 95% CI: 1.98-3.74) declines were significantly associated with higher mortality risks. CONCLUSIONS: Overlapping SR and IADL declines increased mortality risk, suggesting the importance of measuring social frailty and overlapping physical and social frailty.

Activity diversity is associated with the prevention of frailty in community-dwelling older adults: The Otassha Study.

Introduction: A prior study showed an association between diversity in daily activities (type, frequency, evenness) and frailty in older adults. However, the causality of this relationship is unclear. Therefore, this study aimed to clarify the relationship between activity diversity and frailty through a 2-year longitudinal study conducted among community-dwelling older adults. Methods: We evaluated data from the 2018 and 2020 waves of the Otassha Study. Frailty was assessed using the Cardiovascular Health Study criteria, with pre-frail and frail participants defined as frail and the other participants categorized into the robust group. We enrolled a total of 207 participants who were not frail at baseline. Activity type, frequency, and evenness scores were calculated using an Activity Diversity Questionnaire. The association between each activity diversity score and the incidence of frailty was evaluated using logistic regression modeling (each diversity score was entered the model after Z-transformation). Results: Of the 207 enrolled participants (median age, 73 years; age range, 65-91 years; 60.4% women), 64 (30.9%) had incident frailty during the follow-up period. A logistic regression analysis adjusting for sociodemographic and psychosomatic factors revealed odds ratios for activity type and evenness scores of 0.64 and 0.61, respectively (P < 0.05). These factors were significantly associated with the incidence of frailty. Discussion: Activity type and evenness (except frequency) within daily activities were predictors of frailty during 2 years of follow-up. Engagement in diverse activities appears to be more effective in preventing frailty than does engagement in a few activities.

Body Compression Corrective Garment and Eating Behavioural Change for Weight Reduction: The Mutsu City Randomised Controlled Trial.

Affordable and accessible behaviour-based interventions that do not overwhelm or demoralise overweight/obese individuals are needed. Combining clothing with behaviour change techniques might be an option. This is because clothing is a social norm, and clothing and motivation for weight loss are associated with the common desire to look better. Therefore, we conducted a single-blind randomised controlled trial to examine the effect of an intervention that combined behaviour change techniques, including simplified goal setting and self-monitoring, with a body compression corrective garment (BCCG), which exerts continuous but minimal tactile pressure on the hips and abdomen. We enrolled healthy community-dwelling adults with a body mass index ≥ 25 kg/m2 and assigned 35 and 34 participants to the intervention and control groups, respectively. The reduction in body weight was 1.3 kg more in the intervention group than in the control group after the 12-week intervention period (p < 0.05, repeated-measures mixed model). In addition, eating behaviour and body appreciation showed significant improvement in the intervention group compared with the control group. Our newly developed intervention improved eating behaviour and body appreciation and reduced the body weight of overweight/obese participants. Wearing a BCCG seems to facilitate behavioural changes and lead to weight loss.

Annual stability of the plasma Aß40/42 ratio and associated factors.

OBJECTIVE: The plasma Aß40/42 ratio is a biomarker of brain amyloidosis. However, the threshold difference between amyloid positivity and negativity is only 10-20% and fluctuates with circadian rhythms, aging, and APOE-ε4 during the decades of evolution of Alzheimer's disease. METHODS: Plasma Aß40 and Aß42 levels in 1472 participants aged between 19 and 93 years in the Iwaki Health Promotion Project for 4 years were statistically analyzed. RESULTS: The means and standard deviations of annual inter-individual coefficients of variation were 5.3 ± 3.2% for Aß40, 7.8 ± 4.6% for Aß42, and 6.4 ± 4.1% for the Aß40/42 ratio. No significant age-dependent changes were observed in inter-individual coefficients of variation. Age-dependent increases in Aß42 levels were suppressed, whereas those in the Aß40/42 ratio were enhanced in APOE-ε4 carriers. The change points of Aß42, Aß40, and the Aß40/42 ratio were 36.4, 38.2, and 43.5 years, respectively. In the presence of APOE-ε4, the Aß40/42 ratio increased in middle-aged and elderly subjects while Aß42 levels decreased in elderly subjects. INTERPRETATION: Individual values for Aß40, Aß42, and the Aß40/42 ratio did not fluctuate annually or in an age-dependent manner. If the plasma Aß40/42 ratio changes by more than 14.7% (+2 standard deviations) relative to age- and APOE-ε4-adjusted normal annual fluctuations, other biomarkers also need to be examined.

Effects of body compositions on the associations between ferritin and diabetes parameters among Japanese community dwellers.

BACKGROUND: Ferritin is associated with an increased prevalence of diabetes mellitus. Moreover, the ferritin levels differ across the body compositions. Although there were studies reporting the association of ferritin and diabetes, the alteration in ferritin-diabetes association by body composition differences is rarely explained. Thus, the aim of this study is to identify the effects of body compositions on the association between ferritin and diabetes parameters among the Japanese population. METHODS: This study analyzed the data of a cross-sectional study with 1065 subjects aged over 19 years in the Iwaki area, Japan. Independent variables were ferritin and body compositions, while dependent variables were blood sugar, HbA1c, and diabetes mellitus. Correlations between serum ferritin and blood sugar and HbA1c were analyzed using Spearman's Rank Correlation. Multivariate linear or logistic regressions were used to investigate the effects of body compositions (body fat percentage, muscle mass, or visceral fat level) on the ferritin-diabetes associations by adjusting the confounders. RESULTS: There were significant positive correlations between ferritin and blood sugar in both sexes (p < 0.05), while a significant correlation between ferritin and HbA1c was found only in females (p < 0.001). Higher ferritin was significantly associated with an increase in blood sugar in individuals with normal body fat percentage (lowest vs. highest quartile group, coefficient=5.07, 95 % confidence intervals [CI]: 1.48-8.65), normal visceral fat level (lowest vs. highest quartile group, coefficient=4.84, 95 % CI: 1.74-7.94), and very high muscle mass (lowest vs. highest quartile group, coefficient=14.14, 95 % CI: 5.00-23.29). CONCLUSIONS: By our study findings, individuals' body composition notably influenced the associations of serum ferritin and diabetes parameters, and the association was attenuated in obese individuals.