Association between Hearing Aid Use and Cognitive Function in Persons with Hearing Impairment Stratified by Cardiovascular Risk.

The purpose of this study was to conduct a cross-sectional analysis of the association between hearing aid use and cognitive decline in community-dwelling older adults with hearing impairment, stratified by cardiovascular risk level. This cross-sectional study covers 1857 hearing-impaired individuals selected among 10,674 community-dwelling older adults (≥65 years of age) in Japan. We investigate the association between hearing aid use and cognitive decline stratified by cardiovascular risk level, by assessing self-reported hearing impairment and hearing aid use, absolute cardiovascular risk, cognitive function, and potential confounding factors. The association between hearing impairment severity and increased cardiovascular risk, and the benefit of hearing aid use in preventing cognitive decline, were examined in a binomial logistic regression analysis, with the presence of cognitive decline as the objective variable. In the low cardiovascular risk group, hearing aid users had a lower odds ratio for decline in executive function than non-users (odds ratio = 0.61, 95% confidence interval: 0.39-0.98). However, there was no significant association between hearing aid use and cognitive decline in the high cardiovascular risk group (p > 0.05). Among older adults with hearing impairment, hearing aid use was associated with the maintenance of executive function in individuals of low cardiovascular risk.

Association between perceived value of adopting new behaviors and incident disability among Japanese community-dwelling older adults.

OBJECTIVES: This longitudinal observational cohort study aimed to clarify the relationship between perceived value (PV) to adopt new behaviors and incident disability in community-dwelling older adults. METHOD: Participants were 5073 community-dwelling older adults aged ≥65 years in Japan (Mage = 74.0 ± 5.6 years; female = 55.1%). The mean follow-up time was 34.5 months. Baseline data were collected during health checkups in a prospective cohort study. Measurements included engagement in physical activity (PA), cognitive activity (CA), and social activity (SA), PV, health and physical conditions, and demographic characteristics. PV was assessed by asking whether participants thought it was valuable to adopt new behaviors related to PA, CA, and SA. Participants were classified as having higher/lower PV, PA, CA, and SA. Cox proportional hazard models were used to analyze the association between PV and incident disability. PV was examined both as an independent variable and in combination as follows: higher PV and higher PA/CA/SA (high/high); lower PV and higher PA/CA/SA (low/high); higher PV and lower PA/CA/SA (high/low); and lower PV and lower PA/CA/SA (low/low). RESULTS: Higher PV was significantly associated with a lower hazard ratio (HR) for incident disability. The low/high, high/low, and low/low significantly increased the HR compared to high/high in the analyses of PV & PA and CA. The analysis of PV & SA showed that only low/low increased the HR compared to high/high. CONCLUSION: Having both higher PV and higher activity engagement may contribute to preventing disability development. Both support for activities and value education in older adults may be needed.

Estimating the Effect of Engagement in Community-Based Going-Out Program on Incidence Disability in Older Adults.

OBJECTIVES: Although going out has been reported to be associated with the incidence of disability, few studies have investigated the effect of community-based programs to promote going out on the incidence of disability. This study aimed to estimate the effects of a program fostering going-out on the incidence of disability in community-dwelling older adults. DESIGN: Longitudinal, observational study. SETTING AND PARTICIPANTS: Nonengaged (n = 1086) and engaged older adults (n = 1086) enrolled in the National Center for Geriatrics and Gerontology Study of Geriatric Syndrome by using a one-to-one nearest neighbor propensity score-matching scheme. METHODS: After the baseline assessments, participants in the community-based going-out program received a specialized physical activity tracker, monitored their daily physical activity, and received personalized feedback on going out to community facilities with a system for reading the device for 12 months. Disability onset was defined as a new case of long-term care under the public insurance certification in Japan within 48 months of program completion. The absolute risk reduction and the number needed to treat for the incidence of disability were calculated for the nonengaged and engaged groups. Cox proportional hazard regression analysis, using inverse probability weighting was used to obtain the hazard ratio. RESULTS: Disabilities occurred in 112 individuals in the matched nonengaged group and 51 individuals in the engaged group. The absolute risk reduction was 5.67% (95% CI 3.46%-7.88%). The number needed to treat was 18 (95% CI 13-29). The hazard ratio, with the nonengaged group as the reference, was 0.49 (95% CI 0.36-0.67). CONCLUSIONS AND IMPLICATIONS: This longitudinal observational study suggested that a community-based program could prevent 1 disability in every 18 participants. This program does not require a professional instructor, only the distribution of devices and system installation, and it could be beneficial as a population-based approach to preventing disabilities.

Environmental DNA unveils deep phylogeographic structure of a freshwater fish.

Phylogeography bears an important part in ecology and evolution. However, current phylogeographic studies are largely constrained by limited numbers of individual samples. Using an environmental DNA (eDNA) assay for phylogeographic analyses, this study provides detailed information regarding the history of Siberian stone loach Barbatula toni, a primary freshwater fish across the whole range of Hokkaido, Japan. Based on an eDNA metabarcoding on 293 river water samples, we detected eDNA from B. toni in 189 rivers. A total of 51 samples, representing the entire island, were then selected from the B. toni eDNA-positive sample set for the subsequent analyses. To elucidate the phylogeographic structure of B. toni, newly developed eDNA metabarcoding primers (Barba-cytb-F/R) were applied to these samples, specifically targeting their haplotypic variation in cytochrome b. After a bioinformatic processing to mitigate haplotypic false positives, a total of 50 eDNA haplotypes were identified. Two regionally restricted, genetically distinct lineages of the species were revealed as a result of phylogeographic analyses on the haplotypes and tissue-derived DNA from B. toni. According to a molecular clock analysis, they have been genetically isolated for at least 1.5 million years, suggesting their ancient origin and colonisation of Hokkaido, presumably in the glacial periods. These results demonstrate how freshwater fishes can alter their distributions over evolutionary timescales and how eDNA assay can deepen our understanding of phylogeography.

Social participation in the neighborhood community prevents onset of disability in community-dwelling older adults whose life space with activities is limited: A 2-year prospective cohort study.

AIMS: For older adults with limited life space and activity, social participation in the neighborhood community is essential to ensure social interaction and activity levels. This study examined the association between social participation in the neighborhood community and the onset of disability in older adults with different life spaces and activities. METHODS: The participants were 9513 older adults from a cohort study conducted at the National Center for Geriatrics and Gerontology Study of Geriatric Syndromes (NCGG-SGS). Social participation in the neighborhood community was assessed by participating in the community meetings. Life space with activities was evaluated using the Activity Mobility Index (AMI) developed in the NCGG-SGS, with higher scores indicating better mobility and movement. The participants were divided into four groups based on the quartiles of their AMI scores (Q1-Q4). Cox proportional hazard models were used to calculate hazard ratios (HRs) with 95% confidence intervals (CIs) for disability incidence by social participation in each quartile. RESULTS: Over the 2-year follow-up period, disability occurred in 4.3% of the participants (n = 409). In the Q1 group, participants who participated in the neighborhood community had a significantly lower risk of developing a disability than those who did not (HR, 0.47; 95% CI, 0.28-0.76). There were no significant differences in onset of disability between the presence and absence of social participation for groups Q2, Q3, and Q4. CONCLUSIONS: Social participation in the neighborhood community was associated with the onset of disability in the lowest life space group. Social participation within a limited life space with activities may prevent disability onset. Geriatr Gerontol Int 2024; ••: ••-••.

Association between the perceived value of adopting new behaviors and depressive symptoms among older adults.

Early preventive measures against depression have become important with unprecedented global aging. Increase in one's perceived value (PV) may correspond to better mental health outcomes. This cross-sectional observation study aimed to clarify whether the PV of adopting new behaviors is associated with depressive symptoms. The participants were 5266 community-dwelling older adults aged ≥ 65 years. We developed a questionnaire to measure the PV of adopting new behaviors, specifically activities beneficial for preventing depressive symptoms (physical, cognitive, and social activities) in older adults. The questionnaire asked whether adopting the ten selected behaviors was valuable. The scores were added, and the total score ranged from - 20 to 20. The odds ratios (OR) of depressive symptoms were calculated using binomial logistic regression according to the PV score quartiles. Depressive symptoms were reported by 595 (11.3%) participants. After adjusting for potential confounders, higher quartiles of PV scores were significantly associated with lower prevalence of depressive symptoms: vs Q1; Q2 OR 0.76 (95% confidence interval: 0.59-0.97); Q3 0.67 (0.51-0.87); Q4 0.54 (0.40-0.73) (P for trend < .001). Having a higher PV of adopting new behaviors may prevent depressive symptoms among older adults. Healthcare professionals need to pay attention to poor value orientation among older adults.

Association of objectively measured physical activity with incidence disability in older adults with/without social isolation.

PURPOSE: This study aimed to investigate association between objectively measured physical activities with incidence disability in older adults with and without social isolation. METHODS: This 5-year longitudinal observational study used a population-based study from a sub-cohort of the National Center for Geriatrics and Gerontology Study of Geriatric Syndrome. In Japan, Incident disability is defined as a new case of public insurance certification for long-term care. As participants, we enrolled 5,257 community-dwelling older adults aged ≥ 70 years. The Participants on whom incomplete baseline physical activity assessments were performed; who required long-term care; had a history of dementia, Parkinson's disease, stroke, or depression; who lacked independence in basic ADL; who had Mini-Mental State Examination scores; or who had missing measurements; were excluded. Thus, 2,071 participants were included. RESULTS: Of the participants, 1,183 non-socially isolated participants had 151 (4.3%) cases of disability, while socially isolated participants had 150 (13%) cases. Cox proportional-hazards regression analysis presented the adjusted hazard ratio (HR) and 95% confidence interval (95%CI) of daily steps and low-intensity and moderate-to-vigorous physical activities-0.62(0.43-0.89), 0.84(0.60-1.18), 0.62(0.43-0.89) in participants with social isolation, and 0.58(0.40-0.85), 0.86(0.60-1.24), 0.70(0.49-1.01) in those with social isolation. CONCLUSIONS: Daily steps were significantly associated with a decreased risk of incidence disability, regardless of social isolation. These results suggest the greater importance of daily physical activity than its specific intensity in socially isolated older adults.

Lifetime Physical Activity and Late-Life Mild Cognitive Impairment in Community-Dwelling Older Adults.

OBJECTIVES: Regular physical activity throughout life is generally recommended to prevent dementia; however, there is little evidence regarding the association between lifetime physical activity and mild cognitive impairment (MCI), which often precedes dementia. This study aimed to examine the association of lifetime physical activity and their transitions with late-life MCI. DESIGN: A population-based case-control study. SETTING AND PARTICIPANTS: A total of 2968 Japanese community-dwelling older adults aged ≥70 years without dementia. METHODS: We evaluated the participants' early-, mid-, and late-life physical activity habits and categorized their transitions across life stages. Cognitive functions in late life were assessed for memory, attention, executive function, and processing speed; functional impairment in one or more cognitive domains was defined as MCI. RESULTS: Regular physical activity in early life was not significantly associated with late-life MCI [odds ratio (OR), 0.80; 95% CI, 0.63-1.02], although those in mid-life (OR, 0.64; 95% CI, 0.51-0.81) and late-life (OR, 0.74; 95% CI, 0.59-0.91) were associated with lower odds of late-life MCI. Compared with nonexercisers, participants who acquired new habits of physical activity during mid- or late-life (OR, 0.71; 95% CI, 0.55-0.91) and those who maintained physical activity throughout their life span (OR, 0.61; 95% CI, 0.42-0.87) had lower odds of late-life MCI; those who stopped regular activity during mid- or late-life did not (OR, 0.79; 95% CI, 0.58-1.06). CONCLUSIONS AND IMPLICATIONS: While physical activity throughout the life span is associated with the lowest odds of MCI, starting regular physical activity, even later in life, confers a benefit and should be encouraged as a "lifelong approach" to MCI risk reduction.

Neurophysiological markers in community-dwelling older adults with mild cognitive impairment: an EEG study.

BACKGROUND: Neurodegeneration and structural changes in the brain due to amyloid deposition have been observed even in individuals with mild cognitive impairment (MCI). EEG measurement is considered an effective tool because it is noninvasive, has few restrictions on the measurement environment, and is simple and easy to use. In this study, we investigated the neurophysiological characteristics of community-dwelling older adults with MCI using EEG. METHODS: Demographic characteristics, cognitive function, physical function, resting-state MRI and electroencephalogram (rs-EEG), event-related potentials (ERPs) during Simon tasks, and task proportion of correct responses and reaction times (RTs) were obtained from 402 healthy controls (HC) and 47 MCI participants. We introduced exact low-resolution brain electromagnetic tomography-independent component analysis (eLORETA-ICA) to assess the rs-EEG network in community-dwelling older adults with MCI. RESULTS: A lower proportion of correct responses to the Simon task and slower RTs were observed in the MCI group (p < 0.01). Despite no difference in brain volume between the HC and MCI groups, significant decreases in dorsal attention network (DAN) activity (p < 0.05) and N2 amplitude of ERP (p < 0.001) were observed in the MCI group. Moreover, DAN activity demonstrated a correlation with education (Rs = 0.32, p = 0.027), global cognitive function (Rs = 0.32, p = 0.030), and processing speed (Rs = 0.37, p = 0.010) in the MCI group. The discrimination accuracy for MCI with the addition of the eLORETA-ICA network ranged from 0.7817 to 0.7929, and the area under the curve ranged from 0.8492 to 0.8495. CONCLUSIONS: The eLORETA-ICA approach of rs-EEG using noninvasive and relatively inexpensive EEG demonstrates specific changes in elders with MCI. It may provide a simple and valid assessment method with few restrictions on the measurement environment and may be useful for early detection of MCI in community-dwelling older adults.

Motoric Cognitive Risk Syndrome and Traffic Incidents in Older Drivers in Japan.

Importance: To prevent motor vehicle collisions by older drivers, the increased risk of collisions should be considered early. Cognitive decline increases the risk of car collisions. Motoric cognitive risk syndrome (MCR), characterized by the presence of cognitive concerns and slow gait, can be assessed conveniently and is useful to assess the risk of dementia. Objective: To examine the association between MCR assessment findings and car collisions among older drivers in Japan. Design, Setting, and Participants: This cross-sectional study used data from a community-based cohort study, the National Center for Geriatrics and Gerontology-Study of Geriatric Syndromes, conducted in Japan from 2015 to 2018. Participants were community-dwelling older adults aged at least 65 years. Data were analyzed from February to March 2023. Exposure: MCR was defined as having subjective memory concerns (SMC) and slow gait. Participants were classified into 4 groups: no SMC or slow gait, only SMC, only slow gait, and MCR. Main Outcomes and Measures: Participants were asked about the experience of car collisions during the last 2 years and near-miss traffic incidents during the previous year through face-to-face interviews. Odds of experiencing a collision or near-miss traffic incident were assessed using logistic regression. Results: Among a total of 12 475 participants, the mean (SD) age was 72.6 (5.2) years, and 7093 (56.9%) were male. The group with only SMC and the group with MCR showed a higher proportion of both car collisions and near-miss traffic incidents than the other groups (adjusted standardized residuals > 1.96; P < .001). Logistic regression analysis showed the only SMC and MCR groups had increased odds of car collisions (only SMC group: odds ratio [OR], 1.48; 95% CI, 1.27-1.72; MCR group: OR, 1.73; 95% CI, 1.39-2.16) and near-miss traffic incidents (only SMC group: OR, 2.07; 95% CI, 1.91-2.25; MCR group: OR, 2.13; 95% CI, 1.85-2.45) after adjusting for confounding factors. After stratifying MCR assessments by objective cognitive impairment, significant associations were still observed. In the only slow gait group, objective cognitive impairment was associated with increased odds of car collisions (OR, 1.96; 95% CI, 1.17-3.28). Conclusions and Relevance: In this cross-sectional study of community-dwelling older drivers in Japan, SMC and MCR were associated with car collisions and near-miss traffic incidents independent from objective cognitive impairment. Future studies should examine the mechanism of these associations in more detail.

Difference in employment status and onset of disability among Japanese community-dwelling older adults: a prospective cohort study.

OBJECTIVE: This prospective cohort study investigates the relationship between the onset of disability and employment status. METHODS: We investigated 3,741 community-dwelling adults aged 70 or older, who participated in a population-based cohort study in Japan. Their onset of disability was monitored monthly using the long-term care insurance certification registration system, for five years from baseline. Based on an employment status questionnaire, we categorized participants into three groups: (1) employee, (2) self-employed, and (3) not working. Covariates included demographic information, medical history, number of medications, educational level, living alone, social group engagement, smoking status, walking speed, instrumental activities of daily living, global cognitive function, and depressive symptoms. Missing values were managed using multiple imputation. Cox proportional hazard models were used to calculate hazard ratios (HRs) with 95% confidence intervals (CIs) for incident disability risk by employment status. RESULTS: The disability incidence rates were 15.3/1,000 (95% CIs: 10.7-22.0) person-years among employees, and 33.0/1000 (95% CIs: 24.4-44.6) and 39.6/1000 (95% CIs: 36.5-43.0) person-years among self-employed and non-working participants, respectively. The adjusted HRs for the onset of disability among non-working and self-employed participants were 1.69 (95% CIs: 1.16-2.46, p = 0.007) and 1.63 (95% CIs: 1.01-2.62, p = 0.044) compared with employees, respectively. Similar results were found among men. Among women, disability onset was not associated with employment status. CONCLUSIONS: Older adults' risk of disability onset differed according to their employment status. Older employees had a lower risk of disability onset than those not working or self-employed.

Reciprocal relationship between physical and social frailty among community-dwelling older adults.

OBJECTIVE: Both physical and social frailty are risk factors for major adverse health-related outcomes and influence each other. However, the longitudinal causal relationship between physical and social frailty has not been clarified. This study aimed to determine the reciprocal relationship between physical and social frailty by age group. METHODS: This study analyzed longitudinal data from a cohort study of older adults aged 65 years or older living in Obu City, Aichi Prefecture, Japan. The study included 2568 participants who participated in both a baseline assessment in 2011 and a follow-up assessment four years later. Participants participated in assessments of physical and cognitive function. Physical frailty was assessed using the Japanese version of the Cardiovascular Health Study criteria. Social frailty was assessed with five questions about daily social activities, social roles, and social relationships. A total frailty score was calculated for each frailty type and used in the cross-lagged panel analysis. The reciprocal relationship between physical and social frailty status was analyzed using a cross-lagged panel model in each of the young-old (n = 2006) and old-old (n = 562) groups. RESULTS: In the old-old group, baseline physical frailty status predicted social frailty status four years later, and social frailty status at baseline predicted physical frailty status four years later. In the young-old group, the effect of social frailty status at baseline on physical frailty at four years was significant; however, the cross-lag effect from baseline physical frailty status to social frailty status at four years was insignificant, indicating that social frailty preceded physical frailty. CONCLUSION: The reciprocal relationship between physical and social frailty differed by age group. The results of this study suggest the importance of considering age when planning strategies to prevent frailty. Although a causal relationship between both physical and social frailty was observed in old-old, social frailty preceded physical frailty in the young-old, suggesting that early prevention of social frailty is important for the prevention of physical frailty.

Sarcopenic Obesity and Risk of Disability in Community-Dwelling Japanese Older Adults: A 5-Year Longitudinal Study.

OBJECTIVES: Previous studies have indicated that sarcopenic obesity is a risk factor for disability onset. However, these studies had disparities in terms of criteria for sarcopenia, study design, or study population. No longitudinal study has investigated the effect of sarcopenic obesity on disability onset in an Asian population using the Asian Working Group for Sarcopenia 2019 criteria for sarcopenia definition. Herein, we aimed to investigate the longitudinal effect of sarcopenic obesity on disability onset in Japanese older adults and extend the generalizability of results to other populations. DESIGN: Longitudinal cohort study. SETTING AND PARTICIPANTS: A total of 4197 Japanese older adults (mean age 74.6 ± 5.0 years, 54.2% women) formed our study population. MEASUREMENTS: Sarcopenia was identified using the Asian Working Group for Sarcopenia 2019 algorithm. Obesity was determined when body fat percentage was ≥25%, or when visceral fat content was ≥100 cm2 for either sex. Disability onset was defined as a new case of long-term care insurance system certification for 5 years from baseline. Missing values were managed with multi-imputation. Cox proportional hazard regression analysis was used with disability onset as dependent variable and group (nonsarcopenia/nonobesity as a reference, nonsarcopenia/obesity, sarcopenia/non-obesity, possible sarcopenia/obesity, possible sarcopenia/non-obesity, sarcopenic obesity) as explanatory variable, and was adjusted for potential confounding factors. RESULTS: When the nonsarcopenia/nonobesity group was used as the reference category, other groups such as possible-sarcopenia/nonobesity [hazard ratio (HR) 1.38, 95% confidential interval (95% CI) 1.29‒1.47, P < .028], possible-sarcopenia/obesity (HR 1.54, 95% CI 1.46‒1.62 P < .001), sarcopenia/nonobesity (HR 2.09, 95% CI 1.96‒2.23, P < .001), and sarcopenic obesity (HR 2.48, 95% CI 2.24‒2.75, P < .001) showed significantly increased HRs. CONCLUSIONS AND IMPLICATIONS: The risk of disability onset because of sarcopenic obesity was exceedingly higher compared with sarcopenia alone among community-dwelling older adults in Japan The health providers should consider assessing the co-existence of sarcopenia and obesity to screen for the risk of disability onset in the community-dwelling population.

Association of Loneliness With the Incidence of Disability in Older Adults With Hearing Impairment in Japan.

Importance: Loneliness is suggested to negatively affect physical and mental health and influence the development of disability; however, a consensus on the relationship between loneliness and disability has not been reached. Age-related hearing impairment worsens the daily-life activities of older adults, and the association between loneliness and the incidence of disability may be influenced by hearing impairment. Objective: To examine the association between loneliness and the incidence of disability among older adults stratified by hearing impairment. Design, Setting, and Participants: This prospective observational cohort study included 5563 community-dwelling adults 65 years or older who participated in functional health examinations in Tokai City, Aichi Prefecture, Japan, between September 2017 and June 2018. Data analysis was conducted from August 2022 to February 2023. Main Outcomes and Measures: Cox proportional hazards regression models were used to examine the association between loneliness and the incidence of disability stratified by hearing impairment. Results: Among the 4739 participants who met the inclusion criteria (mean [SD] age, 73.8 [5.5] years; 2622 [55.3%] female), 3792 (80.0%) were without hearing impairment and 947 (20.0%) were with hearing impairment. Of those who reported experiencing loneliness, 1215 (32.0%) were without hearing impairment, and 441 (46.6%) were with hearing impairment. After 2 years, the number of individuals with disabilities was 172 (4.5%) without hearing impairment and 79 (8.3%) with hearing impairment. Cox proportional hazards regression analysis showed no statistically significant association between loneliness and the incidence of disability in a model adjusted for potential confounding factors among community-dwelling older adults without hearing impairment (hazard ratio, 1.10; 95% CI, 0.80-1.52). Among community-dwelling older adults with hearing impairment, a model adjusted for potential confounding factors showed a statistically significant association between loneliness and the incidence of disability (hazard ratio, 1.71; 95% CI, 1.04-2.81). Conclusions and Relevance: This cohort study found that the association between loneliness and the incidence of disability was moderated by the presence or absence of hearing impairment. Hearing impairment is the most common symptom of geriatric syndromes, showing that among the various risk factors, loneliness may require special attention in the prevention of disability in people with hearing impairment.

Association of sarcopenia and systolic blood pressure with mortality: A 5-year longitudinal study.

PURPOSE: Whether the combination of sarcopenia and systolic blood pressure (SBP) changes the risk of all-cause mortality is unknown. Thus, this study aimed to examine the association between sarcopenia and SBP in community-dwelling older adults and determine whether this association changes the mortality risk. METHODS: Older adults aged ≥65 years participated in the baseline assessment. The participants were classified into six groups according to a combination of the presence or absence of sarcopenia (sarcopenia, non-sarcopenia) and SBP (low SBP, ≤119 mmHg; normal SBP, 120-139 mmHg; high SBP, ≥140 mmHg). The participants were followed for the occurrence of death for 5 years after baseline assessment. Muscle mass, grip strength, and walking speed as indicators of sarcopenia, SBP, and all-cause mortality data for 5 years from baseline assessment were evaluated. RESULTS: This study included 13,569 community-dwelling older adults. During the 5-year follow-up period, 830 participants (6.6%) died. In the Cox proportional hazards models, the risk of all-cause mortality was higher in other non-sarcopenia groups than in the non-sarcopenia/normal SBP group. In particular, those with sarcopenia had a higher mortality risk. CONCLUSIONS: Low or high SBP increased the mortality risk in community-dwelling older adults. In those with sarcopenia, low or high SBP was associated with an even higher mortality risk. Older adults with sarcopenia and low/high blood pressure should be monitored as a population at a higher mortality risk.

Information and Communication Technology Use for Alleviation of Disability Onset in Socially Isolated Older Adults: A Longitudinal Cohort Study.

INTRODUCTION: Delaying the onset of disability is important for maintaining independence and quality of life in community-dwelling older adults. Given that social isolation is a significant risk factor for disability, effective means associated with social isolation are needed to alleviate disability. Although information and communication technology (ICT) may be a reasonable measure considering the recent social contexts due to the coronavirus disease 2019 pandemic, further insights are required. This study aimed to investigate whether ICT use can alleviate the onset of disability in community-dwelling older adults with and without social isolation. METHODS: This longitudinal cohort study on 4,346 community-dwelling independent Japanese older adults (mean age, 73.5 ± 5.3 years) was conducted between 2017 and 2018. Participants were classified into four groups based on social isolation (the condition where two or more of the following measures were met: domestic isolation, less social contact, and social disengagement) and ICT users (those who had recently used a computer or a smartphone) and followed up to assess disability incidence for 24 months after baseline assessments. Cox proportional-hazards regression models were used to identify the effect of social isolation and ICT use on the risk of disability onset by adjusting for age, sex, education history, number of medications, eye disease, level of annual income, Mini-Mental State Examination, Geriatric Depression Scale 15, and gait speed. RESULTS: The group comprised nonsocial isolation and ICT users (44.7%), social isolation and ICT users (5.4%), nonsocial isolation and ICT nonusers (41.7%), and social isolation and ICT nonusers (8.2%). At the follow-up, 2.2%, 2.4%, 5.5%, and 12.4% of the participants in the above order developed disability (p < 0.01). Cox regression models revealed a significantly higher risk of disability onset in the social isolation and ICT nonusers group than in the social isolation and ICT users group (HR = 2.939; 95% confidence interval (CI) 1.029-8.397; p = 0.044). In the subgroup analysis stratified by social isolation, ICT use significantly reduced the risk of disability onset in the socially isolated group (HR = 0.320; 95% CI 0.109-0.943; p = 0.039), although the same association was not observed in the nonsocially isolated group (HR = 0.845; 95% CI 0.565-1.264; p = 0.411). CONCLUSION: ICT use can alleviate the onset of disability in socially isolated older adults in a community setting. Considering ICT-applied methods for alleviating disability is beneficial for older adults in social isolation.

Bioadhesive and biodissolvable hydrogels consisting of water-swellable poly(acrylic acid)/poly(vinylpyrrolidone) complexes.

Films that can form bioadhesive hydrogels on wet biotissues absorbing blood or body fluids are useful for medical devices such as hemostats, adhesion barriers, wound dressings, and drug release devices. We focused on a hydrogen-bonding polymer complex consisting of poly(acrylic acid) (PAA) and poly(vinylpyrrolidone) (PVP). PAA is known as a tissue-adhesive polymer. However, simple mixing of aqueous PAA and PVP solutions resulted in the formation of an insoluble nonadhesive precipitate. We developed a novel solid/solution interface complexation method to afford a PAA/PVP complex that forms a strongly bioadhesive hydrogel with low cytotoxicity. The complex hydrogel can be slowly dissociated and dissolved in the body. The formation of the complexes as well as their swelling and degradation behavior depended strongly on the molecular weights and cross-linking densities of the component polymers. When the complex film was applied to a clipped incised jugular vein of a rat, it immediately formed a hydrogel and closed the incision. After removal of the clip, blood flowed through the vessel without any leakage. Application of the complex film to the surface of an incised mouse liver resulted in firm adhesion and the hemorrhage was effectively stopped. Such bioadhesive and biodissolvable materials consisting of low-toxicity synthetic polymers have high potential for implantable medical devices.

New endovascular perforation subarachnoid hemorrhage model for investigating the mechanisms of delayed brain injury.

OBJECTIVE: Delayed brain injury (DBI) is considered one of the most important causes of mortality and morbidity after subarachnoid hemorrhage (SAH). However, no suitable experimental rat endovascular perforation (EVP) SAH model was available for investigating DBI. The authors added early cerebral hypoperfusion to a mild EVP SAH model by unilateral common carotid artery occlusion (UCCAO) 24 hours after induction of SAH to mimic the clinical course of early cerebral hypoperfusion after SAH. METHODS: A total of 109 adult male Sprague-Dawley rats were randomly divided into 2 groups: no SAH and SAH. Next, no-SAH rats were randomly divided on day 1 into 2 groups: sham and UCCAO. SAH rats with a neurological score of 15 or greater were randomly divided into 2 groups: SAH - UCCAO and SAH + UCCAO group. RESULTS: The mild SAH model had a lower mortality rate of 5.4% within the first 24 hours. No rat died in the SAH + UCCAO group until day 7. DBI as well as early brain injury (EBI), reactive astrogliosis, and cerebral vasospasm significantly worsened in the SAH + UCCAO group. CONCLUSIONS: The present SAH + UCCAO model can simulate EBI with aggravation of reactive astrogliosis, cerebral vasospasm, and DBI but without high mortality.

Environmental DNA metabarcoding for fish community analysis in backwater lakes: A comparison of capture methods.

The use of environmental DNA (eDNA) methods for community analysis has recently been developed. High-throughput parallel DNA sequencing (HTS), called eDNA metabarcoding, has been increasingly used in eDNA studies to examine multiple species. However, eDNA metabarcoding methodology requires validation based on traditional methods in all natural ecosystems before a reliable method can be established. To date, relatively few studies have performed eDNA metabarcoding of fishes in aquatic environments where fish communities were intensively surveyed using multiple traditional methods. Here, we have compared fish communities' data from eDNA metabarcoding with seven conventional multiple capture methods in 31 backwater lakes in Hokkaido, Japan. We found that capture and field surveys of fishes were often interrupted by macrophytes and muddy sediments in the 31 lakes. We sampled 1 L of the surface water and analyzed eDNA using HTS. We also surveyed the fish communities using seven different capture methods, including various types of nets and electrofishing. At some sites, we could not detect any eDNA, presumably because of the polymerase chain reaction (PCR) inhibition. We also detected the marine fish species as sewage-derived eDNA. Comparisons of eDNA metabarcoding and capture methods showed that the detected fish communities were similar between the two methods, with an overlap of 70%. Thus, our study suggests that to detect fish communities in backwater lakes, the performance of eDNA metabarcoding with the use of 1 L surface water sampling is similar to that of capturing methods. Therefore, eDNA metabarcoding can be used for fish community analysis but environmental factors that can cause PCR inhibition, should be considered in eDNA applications.

[A Case of Retro-Odontoid Pseudotumor in a Very Elderly Individual].

Retro-odontoid pseudotumors are mainly caused by aging or rheumatoid arthritis. We treated a very elderly patient with retro-odontoid pseudotumor. A 92-year-old man was admitted with the chief complaints of difficulty walking and progressive numbness in the right upper and lower extremities. Neurological examination revealed muscle weakness and exaggerated tendon reflexes of the right upper and lower extremities, and disturbance in skilled motor activities of the fingers, bilaterally. He had no bladder or rectal disturbances. The Japanese Orthopaedic Association(JOA)score for cervical myelopathy was 10/17. Rheumatoid arthritis was interpreted as negative. Radiography of the neck showed no atlanto-axial instability. Cervical magnetic resonance(MR)imaging revealed a mass located posterior to the C2 odontoid process, severely compressing the cervical cord. The patient underwent a C1 laminectomy and C2 half laminectomy without fixation to achieve cord decompression. Postoperatively, muscle weakness in the right upper and lower extremities was remarkably improved, and gait disturbance was also improved. However, skilled motor activities of the fingers on the right hand during tasks such as writing letters, holding a cup, and using chopsticks, were not improved. JOA score was improved to 14/17. Postoperative radiography revealed no atlanto-axial instability and MR imaging revealed adequate decompression of the spinal canal. Laminectomy without fixation is recommended as an effective and less invasive treatment for retro-odontoid pseudotumor, especially in very elderly patients without atlanto-axial instability.