Subjective Cognitive Decline and Frailty Trajectories and Influencing Factors in Japanese Community-Dwelling Older Adults: A Longitudinal Study.

We studied frailty and subjective cognitive decline (SCD) trajectories in older Japanese adults and evaluated the influence of various factors on these trajectories. We analyzed data from 1157 non-demented adults aged 70 and above from 2013 to 2019. Frailty was assessed using the self-administered Kihon Checklist (KCL), a Japanese frailty index. SCD was evaluated using the questionnaire of the Subjective Memory Complaints scale. Through group-based joint trajectory models, we discerned three frailty trajectories: non-progressive (n = 775), moderate progressive (n = 312), and rapid progressive (n = 70); and three SCD trajectories: non-progressive (n = 302), moderate progressive (n = 625), and rapid progressive (n = 230). Individuals in the rapid progressive SCD trajectory had a 32.2% probability of also being in the rapid progressive frailty trajectory. In contrast, those in the non-progressive SCD trajectory had zero probability of being in the rapid progressive frailty trajectory. Both the rapid progressive frailty and SCD groups combined had a higher incidence of depressive symptoms and slow gait speed. Our results have found that frailty and SCD share a similar trajectory in Japanese older adults. Additionally, rapid progressive frailty and SCD were associated with the highest risk of depressive symptoms and slow gait speed. Thus, interventions targeting both frailty and cognitive decline should prioritize mental health enhancement and gait speed improvement.

Nonlinear Associations between Physical Function, Physical Activity, Sleep, and Depressive Symptoms in Older Adults.

The purpose of this study is to examine how physical function, physical activity, and sleep are related to depressive symptoms in older adults using a nonlinear model. The participants were 283 Korean older adults aged 65 and older who met the study inclusion criteria. Depressive symptoms were measured using the shortened version of the Geriatric Depression Scale in Korean (SGDS-K). Physical activity and sleep time were objectively quantified by continuously monitoring participants over 20 consecutive days using a triaxial accelerometer. Physical function was evaluated using five distinct measurements: grip strength, gait speed, the Timed Up and Go Test (TUG), the Six-Minute Walk Test (SMWT), and the Five Times Sit to Stand Test (FTSST). The SMWT, gait speed, and MVPA exhibited a nonlinear relationship with depressive symptoms. However, other physical functions showed linear relationships. Also, sleep time showed a U-shaped trend starting at approximately 390 min. After adjusting for age, sex, drinking, and smoking in the logistic regression model, SMWT, MVPA, and sleep time were significantly associated with depressive symptoms. The outcomes highlight the importance of considering multiple factors in understanding depression among the elderly, particularly the intricate interactions between these elements and biological rhythms.

Differential effects of lifestyle activities on disability incidence based on neighborhood amenities.

BACKGROUND: This study examined the effect of neighborhood amenities on disability risk among community-dwelling older adults in Japan, based on lifestyle activities. METHOD: This was an observational prospective cohort study. Participants comprised 13,258 older adults from the National Center for Geriatrics and Gerontology-Study of Geriatric Syndromes. We calculated participants' Walk Score using their home addresses and divided them into three groups: "car-dependent," "somewhat walkable," and "very walkable." We then calculated the average value of lifestyle activities. We divided the neighborhood amenity groups into two groups, "fewer lifestyle activities" and "more lifestyle activities," for a total of six groups. After identifying interactions between neighborhood amenities and lifestyle activities, Cox proportional hazard models to calculate hazard ratios for incident disability risk, based on neighborhood amenities and lifestyle activities. RESULTS: An interaction occurred between neighborhood amenities and lifestyle activities (p < 0.05). Survival probabilities for incident disability based on lifestyle activities were estimated for each neighborhood amenity group: car-dependent, 1.62 (95% CI 1.07 to 2.46); somewhat walkable, 1.08 (95% CI 0.84 to 1.40); and very walkable, 1.05 (95% CI 0.87 to 1.27). Those with fewer lifestyle activities in the car-dependent group exhibited the highest risk of incident disability in the unadjusted and adjusted models. CONCLUSION: Given that the aging population is increasing steadily, considering older adults' neighborhood amenities and lifestyle activities in their day-to-day lives can help clinicians to deliver more older adult-centered care. Incorporating the lifestyle activities and neighborhood amenities of older adults into care planning will lead to the design and development of integrated clinical and community screening programs.

Position Statement: Exercise Guidelines for Osteoporosis Management and Fall Prevention in Osteoporosis Patients.

BACKGROUND: The effectiveness of exercise for improving osteoporosis and fall prevention in patients diagnosed with osteoporosis or osteopenia has not been fully summarized. The Korean Society for Bone and Mineral Research and the Korean Society of Exercise Physiology has developed exercise guidelines for patients with osteoporosis or osteopenia and provide evidence-based recommendations. METHODS: A systematic review identified randomized controlled trials (RCT) assessing the effect of resistance, impact, balance, aerobic training, and physical activity in osteoporosis and osteopenia on bone quality, physical performance, quality of life, and fall prevention. PubMed, Embase, KoreaMed, and RISS were searched from January 2000 to August 2022. Ten key questions were established to review the evidence and formulate recommendations. RESULTS: The 50 RCTs reported that even with osteoporosis and osteopenia, resistance and impact training consistently maximized bone strength, improved body strength and balance, and eventually reduced fall incidences. Resistance exercise combining 3 to 10 types of free weight and mechanical exercise of major muscle groups performed with an intensity of 50% to 85% 1-repetition maximum, 5 to 12 repetitions/set, 2 to 3 days/week, for 3 to 12 months is recommended. Impact exercises such as jumping chin-ups with drop landings and jump rope performed 50 jumps/session for at least 6 months with 3 or more days/week are recommended. CONCLUSIONS: A multi-component exercise mainly comprised of resistance and impact exercise seems to be an effective strategy to attenuate the risk factors of osteoporosis and osteopenia. The integration of exercise guidelines and individualized exercise plans has significant potential to reduce the morbidity and mortality of osteoporosis.

Association between COVID-19 emergency declarations and physical activity among community-dwelling older adults enrolled in a physical activity measurement program: Evidence from a retrospective observational study using the regression discontinuity design.

BACKGROUND: The current study examines the negative impact of the coronavirus disease 2019 (COVID-19) emergency declarations on physical activity among the community-dwelling older adults, the participants of a physical activity measurement program, in Japan. METHODS: This retrospective observational study included 1,773 community-dwelling older adults (aged 74.6 ± 6.3 years, 53.9% women) who had participated in the physical activity measurement project from February 2020 to July 2021. We measured physical activity using a tri-axial accelerometer during 547 consecutive days. Three emergency declarations, requesting people to avoid going outside, occurred during the observational period. We multiply-imputed missing values for daily physical activity, such as steps, light physical activity (LPA), and moderate-to-vigorous physical activity (MVPA) for several patterns of datasets according to the maximum missing rates on a person level. We mainly report the results based on less than 50% of the maximum missing rate (n = 1,056). Other results are reported in the supplemental file. Changes in physical activity before and after the start of each emergency declaration were examined by the regression discontinuity design (RDD) within 14-, 28-, and 56-day bandwidths. RESULTS: For all the participants in the multiply-imputed data with the 14-day bandwidth, steps (coefficients [[Formula: see text]][Formula: see text] 964.3 steps), LPA ([Formula: see text] 5.5 min), and MVPA ([Formula: see text] 4.9 min) increased after the first emergency declaration. However, the effects were attenuated as the RDD bandwidths were widened. No consistent negative impact was observed after the second and third declarations. After the second declaration, steps ([Formula: see text]-609.7 steps), LPA ([Formula: see text]-4.6 min), and MVPA ([Formula: see text]-2.8 min) decreased with the 14-day bandwidth. On the other hand, steps ([Formula: see text] 143.8 steps) and MVPA ([Formula: see text] 1.3 min) increased with the 56-day bandwidth. For the third declaration, LPA consistently decreased with all the bandwidths ([Formula: see text]-2.1, -3.0, -0.8 min for the 14, 28, 56-day bandwidth), whereas steps ([Formula: see text]-529 steps) and MVPA ([Formula: see text]-2.6 min) decreased only with the 28-day bandwidth. CONCLUSIONS: For the community-dwelling older adults who regularly self-monitor their physical activity, the current study concludes that there is no evidence of consistently negative impacts of the emergency declarations by the COVID-19 pandemic.

A non-pharmacological multidomain intervention of dual-task exercise and social activity affects the cognitive function in community-dwelling older adults with mild to moderate cognitive decline: A randomized controlled trial.

The present study aimed to determine the impact of a 10-month multidomain program using dual-task exercise and social activity conducted at a community-based facility on improved cognitive function in older adults with mild to moderate cognitive decline. The participants included 280 community-dwelling older adults (age 71-91 years) with mild to moderate cognitive decline. The intervention group exercised for 90 min/day, once a week. Their routine included aerobic exercise and dual-task training which cognitive tasks were performed in combination with exercise. The control group attended health education classes thrice. Before and after the intervention, we measured their cognitive function, physical function, daily conversation, and physical activity. The mean adherence rate of the intervention class was 83.0%. According to a repeated-measures multivariate analysis of covariance in an intent-to-treat analysis, logical memory and 6-min walking distance demonstrated a significant time and group interaction effect. Regarding daily physical activities, we observed significant differences in the daily step count and moderate-to-vigorous physical activity in the intervention group. Our non-pharmacological multidomain intervention resulted in a modest improvement in the cognitive or physical function and building health behavior. It may be a helpful program with a potential role in preventing dementia. Clinical Trial Registration: http://clinicaltrials.gov Identifier ID: UMIN000013097.

Associations between the Timing and Nutritional Characteristics of Bedtime Meals and Sleep Quality for Nurses after a Rotating Night Shift: A Cross-Sectional Analysis.

The purpose of this study was to investigate the associations of the timing and nutritional characteristics of bedtime meals with sleep quality in nurses after rotating night shifts. In total, 128 nurses from a university hospital in South Korea participated in this cross-sectional study. Data were collected on the first night of two or three consecutive routine night shifts. Participants recorded all food eaten before going to bed after work. An accelerometer was used to objectively measure sleep quality, and subjective sleep quality was assessed by self-report using the Korean version of the Verran and Snyder-Halpern Sleep Scale. The associations of timing and nutritional characteristics of bedtime meals with sleep quality after night shifts were analyzed using multivariate linear regression. A short time interval between meals and sleep was associated with longer objectively measured total sleep time (ß = -0.37, p = 0.002), and the proportion of protein in meals was associated with better objectively measured sleep efficiency (ß = 0.31, p = 0.007). The shorter the time interval, the better the subjective sleep quality (ß = -0.23, p = 0.048), and high-calorie meals were positively associated with subjective sleep quality (ß = 0.23, p = 0.043). Based on our findings, we encourage nurses to have protein-rich meals after night shifts and reduce the delay between meals and sleep. Although high-calorie meals were shown to have a positive effect on subjective sleep quality, it is necessary to confirm this effect through additional research.

Association between simple test assessing hand dexterity and mild cognitive impairment in independent older adults.

OBJECTIVES: This study aimed to clarify the association between hand function, including grip strength and hand dexterity, assessed using snap fasteners, and mild cognitive impairment (MCI) in older adults with normal global cognitive function. METHODS: A total of 228 functionally independent older adults (mean age 77.7 ± 6.1 years) participated in this study. None of the participants had a history of dementia diagnosis, and all the participants had a Mini-Mental State Examination score of ≥24. Participants were evaluated for hand function using grip strength and snap fastener tests, and for cognitive function using the National Center for Geriatrics and Gerontology-Functional Assessment Tool. RESULTS: A total of 72 participants (31.6%) were diagnosed with MCI. The slow snap fastener test group had a higher proportion of participants with MCI (p < 0.001) and impairments in memory (p = 0.010), attention (p = 0.043), executive function (p < 0.001), and processing speed (p = 0.044) compared to the fast snap fastener test group. The slow speed of fastening snap fasteners was significantly associated with MCI and impairment in memory, attention, executive function, and processing speed (MCI: adjusted odds ratio (AOR) = 3.88, 95% confidence interval (CI) = 1.64-9.19; memory: AOR = 5.73, 95% CI = 1.58-20.82; attention: AOR = 3.95, 95% CI = 1.10-14.11; executive function: AOR = 7.22, 95% CI = 1.78-29.24; processing speed: AOR = 7.52, 95% CI = 1.19-47.66) according to the multiple logistic regression analysis. Grip strength was not significantly associated with cognitive impairment. CONCLUSIONS: Thus, hand dexterity assessed using the snap fastener test was associated with MCI in older adults with normal global cognitive function. Hand dexterity assessment using the snap fastener test is useful for detecting MCI in apparently healthy older adults.

Association between driving a car and retention of brain volume in Japanese older adults.

BACKGROUND: Driving cessation is a major negative life event that has been associated with a decline in health conditions including dementia. The increase in activity owing to the expansion of life space is a possible explanation for the positive relationship between driving and brain health. The present study examined the association between driving, life space, and structural brain volume in older individuals. METHODS: High-resolution magnetic resonance imaging was employed to examine the brain volume in 1063 older adults. Participants were classified as non-drivers, those who drove <7 days a week, and everyday drivers. They were further classified into a non-driving group, an active group (drove 10 km at least once a week), and a less-active group (drove 10 km less than once a week). RESULTS: The hippocampal volume was greater in drivers than in non-drivers. Occipital cortex volume was greater in low-frequency drivers than in non-drivers and high-frequency drivers. Active drivers exhibited larger temporal cortex volumes than less-active drivers, larger cingulate cortex volumes than non-drivers and less-active drivers, and larger hippocampal volumes than non-drivers. CONCLUSION: Driving was associated with hippocampal brain atrophy attenuation, with active drivers exhibiting decreased brain atrophy in the temporal and cingulate cortices.

Differences in Subjective and Objective Cognitive Decline Outcomes Are Associated with Modifiable Protective Factors: A 4-Year Longitudinal Study.

Subjective cognitive decline (SCD) in older adults has been identified as a risk factor for dementia. However, the literature is inconsistent, and the underlying mechanisms are not well understood. We aimed to determine whether older adults with SCD had more modifiable protective factors against the risk of dementia and a lower risk of developing objective cognitive decline (OCD). We included 4363 older adults (71.7 ± 5.3 [mean ± standard deviation] years of age; 2239 women) from the National Center for Geriatrics and Gerontology Study of Geriatric Syndromes. SCD, OCD, and protective factors against dementia, such as lifestyle and activity, were assessed using interviews and objective cognitive-assessment tools. Based on initial cognitive status, participants were categorized into normal cognition, SCD-only, OCD-only, and both SCD and OCD groups. After 4 years, participants were classified as having either no impairment or mild or global cognitive impairment (i.e., OCD). Binomial logistic regression analyses were performed with the cognitive statuses of the groups at follow-up and baseline as the dependent and independent variables, respectively. After adjusting for potential confounding factors, we found that the SCD-only group had more modifiable protective factors against the risk of dementia than the OCD-only group. Community-dwelling older adults with normal cognition or those part of the SCD-only group had a lower risk of developing OCD during the 4-year follow-up, which may have been due to having more modifiable protective factors against the risk of dementia. Additionally, these factors may contribute to the inconsistencies in the literature on SCD outcomes.

The association between social activity and physical frailty among community-dwelling older adults in Japan.

BACKGROUND: Physical frailty is associated with social activity. However, the relationship between physical frailty and levels of engagement with other people during social activities remains unclear. Thus, we aimed to clarify the relationship between physical frailty and social activity using a taxonomy of activity levels among community-dwelling older adults in Japan. METHODS: This cross-sectional observational study analyzed data from 12,788 older adults (7001 women, mean age: 73.8 years, standard deviation = 5.9; range: 60-96 years) from the National Center for Geriatrics and Gerontology-Study of Geriatric Syndromes. Physical frailty was assessed using the following components: slow walking speed, muscle weakness, exhaustion, low activity, and weight loss. We asked participants about seven social activities that included social participation and engagement and examined their relationship to physical frailty. RESULTS: Physical frailty was independently associated with all social activities. Exercise circle activity, which includes a level of social participation, was strongly associated with physical pre-frailty and physical frailty. Results of sub-analyses indicated that the level of social engagement was independently associated with physical frailty in the older group (over 75 years) but not in the younger group (60-74 years). CONCLUSIONS: Our results indicate that the strength of the association between social activity and physical frailty differs by the level of social participation. Given the increasingly high prevalence of physical frailty in Japan and its strong association with numerous adverse health outcomes, the relationship between physical frailty and levels of social participation may assist in developing measures to prevent the incidence and progression of physical frailty.

Virtual Reality and Exercise Training Enhance Brain, Cognitive, and Physical Health in Older Adults with Mild Cognitive Impairment.

We investigated the effectiveness of virtual-reality-based cognitive training (VRCT) and exercise on the brain, cognitive, physical and activity of older adults with mild cognitive impairment (MCI). METHODS: This study included 99 participants (70.8 ± 5.4) with MCI in the VRCT, exercise, and control groups. The VRCT consisted of a series of games targeting different brain functions such as executive function, memory, and attention. Twenty-four sessions of VRCT (three days/week) were performed, and each session was 100 min long. Exercise intervention consisted of aerobic and resistance trainings performed in 24 sessions for 60 min (2 times/week for 12 weeks). Global cognitive function was measured using the Mini-Mental State Examination (MMSE) test. Resting-state electroencephalography (EEG) of the neural oscillatory activity in different frequency bands was performed. Physical function was measured using handgrip strength (HGS) and gait speed. RESULTS: After the intervention period, VRCT significantly improved the MMSE scores (p < 0.05), and the exercise group had significantly improved HGS and MMSE scores (p < 0.05) compared to baseline. One-way analysis of variance (ANOVA) of resting-state EEG showed a decreased theta/beta power ratio (TBR) (p < 0.05) in the central region of the brain in the exercise group compared to the control group. Although not statistically significant, the VRCT group also showed a decreased TBR compared to the control group. The analysis of covariance (ANCOVA) test showed a significant decrease in theta band power in the VRCT group compared to the exercise group and a decrease in delta/alpha ratio in the exercise group compared to the VRCT group. CONCLUSION: Our findings suggest that VRCT and exercise training enhances brain, cognitive, and physical health in older adults with MCI. Further studies with a larger population sample to identify the effect of VRCT in combination with exercise training are required to yield peak benefits for patients with MCI.

Associations of fall history and fear of falling with multidimensional cognitive function in independent community-dwelling older adults: findings from ORANGE study.

BACKGROUND: Falls and fear of falling (FoF) inhibit healthy longevity and have been suggested to be associated with cognitive function. However, the domains of cognitive function that are associated with them remain controversial. It is speculated that clarifying this will help in the assessment of health status and interventions in the community. AIM: To analyse the associations between fall history and FoF and multidimensional cognitive function in independent community-dwelling older adults. METHODS: The data from 9759 (73.3 ± 5.4 years, 59.9% women) older individuals enrolled in the cross-sectional ORANGE study were analysed. Simple questions were used to assess fall history in the past year and current FoF. Assessments of multidimensional cognitive function were performed using the National Center for Geriatrics and Gerontology-Functional Assessment Tool (NCGG-FAT) to evaluate memory, attention, executive function, and processing speed. The independent associations of fall history and FoF with multidimensional cognitive function were assessed using multivariate linear regressions adjusted for potential confounding variables. RESULTS: A total of 18.3% and 35.4% of participants presented with fall history and FoF, respectively. Fall history (p = 0.008) and FoF (p = 0.002) were significantly associated with memory. FoF, but not fall history was associated with attention (p = 0.004), executive function (p < 0.01), and processing speed (p < 0.01). CONCLUSION: In independent community-dwelling older adults, fall history was associated only with the memory domain; in contrast, fear of falling was associated with multidimensional cognitive function. This study provides weak evidence suggesting the need to assess falls and FoF in all situations involving independent community-dwelling older adults.

Light intensity physical activity is beneficially associated with brain volume in older adults with high cardiovascular risk.

Background: Older people with high cardiovascular risk, including those without cardiovascular diseases, are an at-risk population for dementia. Regular physical activity is generally recommended to maintain brain health; however, the optimal intensity of physical activity for maintaining brain volume in older adults with cardiovascular risk remains unclear. We examined the associations between intensity-specific physical activity and brain volume stratified by absolute cardiovascular risk level in older adults without cardiovascular diseases. Methods and results: This cross-sectional study involved 725 community-dwelling older Japanese adults without cardiovascular diseases. We estimated absolute cardiovascular risk using the World Health Organization risk estimation charts, which include variables such as age, sex, diabetes mellitus, smoking, systolic blood pressure, and total cholesterol, and stratified cardiovascular risk level into three risk categories: low (≤ 9%), moderate (10-14%), and high (≥15%). We measured daily physical activity using a triaxial accelerometer, and calculated the average time spent in moderate-to-vigorous intensity physical activity (MVPA) and light intensity physical activity (LPA). We performed brain T1-weighted magnetic resonance imaging and calculated the volume of the cortical gray matter, subcortical gray matter, and cerebral white matter, using the FreeSurfer software. In the overall sample, multivariable linear regression analysis showed that greater MVPA was significantly associated with greater volume of the cortical gray matter and cerebral white matter, and greater LPA was significantly associated with greater volume of the cerebral white matter. Additionally, in the analysis of the sample stratified by absolute cardiovascular risk level, cerebral white matter volume was significantly associated with both MVPA and LPA in the high cardiovascular risk group. Conclusions: The association between physical activity and brain volume differed according to cardiovascular risk level in community-dwelling older adults. In a population at high cardiovascular risk, maintaining or increasing LPA might be a practical and achievable strategy for healthy brain aging.

Association of dual sensory impairment with changes in life space: A longitudinal study with two-year follow-up.

OBJECTIVES: Dual sensory impairment (DSI) of hearing and vision in older adults may limit lifestyle activities of daily living and contribute to a reduced life space. This study aimed to investigate how DSI is associated with specific lifestyle activities and predicts changes in mobility in life space. STUDY DESIGN: Participants comprised 4214 older adults (52.3 % female, mean age 75.8 years) who met the study's inclusion criteria. The participants were divided into three groups according to the number of sensory impairments: (1) no sensory impairment (NSI), (2) single sensory impairment (SSI), and (3) DSI. MAIN OUTCOME MEASURE: We investigated the association between DSI and specific lifestyle activities at baseline. The Active Mobility Index (AMI) was used to assess life-space. Two years later, the association between DSI and life-space mobility was verified using multinomial logistic regression analysis. RESULTS: DSI was more likely to have limited people's instrumental activities of daily living and cognitive, social, and productive activities at baseline (P < 0.05). In the adjusted model with potential covariates, people with DSI had a lower life-space score at 2 years than people with NSI (odds ratio [OR] = 1.40, 95 % confidence interval [CI]: 1.01-1.95), but the difference was not significant for SSI (OR = 0.98, 95 % CI: 0.78-1.24). CONCLUSIONS: This study suggested that DSI was a factor that limited various activities and narrowed the life-space mobility of older adults. Prevention of DSI may be important for community-dwelling older adults to maintain a more active lifestyle.

Gait Speed and Sleep Duration Is Associated with Increased Risk of MCI in Older Community-Dwelling Adults.

This study aimed to examine the linear and nonlinear associations between sleep duration and gait speed and the risk of developing mild cognitive impairment (MCI) in community-dwelling older adults. Participants were 233 older adults who met the study inclusion criteria. The MCI diagnosis was based on medical evaluations through a clinical interview conducted by a dementia specialist. Self-reported sleep duration was evaluated using the Pittsburgh Sleep Quality Index. The usual gait speed was calculated from the time taken to walk along a 4 m walkway. Multivariate logistic regression analysis was used to calculate the odds ratio (OR) and the 95% confidence interval (95% CI) of developing MCI in relation to sleep duration and gait speed. Generalized additive models were used to examine the dose−response relationships between sleep duration, gait speed, and the risk of developing MCI. Slower gait speed (OR: 1.84, 95%; CI: 1.00−3.13) and poor sleep duration (OR: 1.76, 95%; CI: 1.00−3.35) were associated with the risk of developing MCI, compared with their optimal status. In addition, the combination of poor sleep and slower gait was associated with a higher risk of developing MCI than optimal sleep duration and gait speed (OR: 3.13, 95%; CI: 1.93−5.14). Furthermore, gait speed and sleep duration were non-linearly associated with the risk of developing MCI. These results highlight the complex interplay and synergism between sleep duration and gait abilities on the risk of developing MCI in older adults. In addition, our results suggest that slower gait speed (<1.0 m/s) and short (<330 min) and long (>480 min) sleep duration may be linked to MCI risks through underlying pathways.

A simple algorithm to predict disability in community-dwelling older Japanese adults.

BACKGROUND: With a worldwide aging population, the prevention of disability in older adults has become an important issue. Therefore, the purpose of this study was to develop a model for predicting disability risk in older adults based on multiple factors, using a decision tree analysis. This model may be used with a mobile application when it is difficult to interview older adults, and to obtain individualized information for prioritizing interventions. METHODS: We examined the data from a cohort study conducted by the National Center for Geriatrics and Gerontology-Study of Geriatric Syndromes. We included 12,000 older adults without a disability and performed a decision tree analysis using the Chi-square automatic interaction detection (CHAID) algorithm. RESULTS: Among the 12,000 participants without a disability, 11,503 and 497 participants remained disability-free and developed disability, respectively. The CHAID analysis identified 24 end nodes with five levels of partition and 16 partitioning variables for 34 questionnaire variables, with incident disability probabilities ranging from 0.0% to 96.7%. The classification accuracy and area under the curve of the CHAID model were 73.4% and 0.76, respectively. We found that maintaining mental health was important for older adults in their 80s and older, and that lifestyles and geriatric syndromes were important factors for those in their 70s. CONCLUSIONS: The magnitude of the influences on the risk of developing a disability differ by age group. The results of this study may provide useful information for the development of mobile applications that predict the risk of developing disability and create tailor-made interventions.

Association of Dual Sensory Impairment with Cognitive Decline in Older Adults.

INTRODUCTION: The prevalence of hearing and visual impairment (HI and VI) and dual sensory impairment (DSI), which is a combination of both, is increasing as the population ages. These sensory impairments are expected to increase the cognitive load of information processing from hearing and vision and impair appropriate cognitive processing. Although an association between DSI and cognitive decline has been reported, a more detailed study of the effects on each cognitive domain is required. This study aimed to investigate the prevalence of self-reported sensory impairment in community-dwelling older adults and to examine the impact of DSI on the severity of mild cognitive impairment (MCI) and on each cognitive domain (memory, attention, executive function, and processing speed). METHODS: The participants were recruited from a sub-cohort of the National Center for Geriatric Gerontology-Study on Geriatric Syndromes (NCGG-SGS) conducted by the National Center for Geriatrics and Gerontology. We included 4,471 community-dwelling older adults (age: 75.9 ± 4.3 years; females: 52.3%) who fulfilled the inclusion criteria. The HI and VI were identified using a self-report questionnaire. Cognitive and other parameters were also assessed by trained staff. Logistic regression analysis was used to evaluate the relationship between the presence of HI and VI and the severity of MCI, and functional decline in each cognitive domain. RESULTS: DSI was identified in 11.4% of community-dwelling older adults. Regarding sensory impairment and MCI severity, the odds ratio (OR) for single-domain MCI was significantly higher in VI (OR: 1.31; 95% CI: 1.06-1.61), and the OR for multiple-domain MCI was significantly higher in DSI (OR: 1.58; 95% CI: 1.10-2.29). In relation to the four cognitive domains, ORs for impaired executive function were higher for VI and DSI (VI, OR: 1.37; 95% CI: 1.09-1.72. DSI, OR: 1.39; 95% CI: 1.06-1.81). DSI also exhibited a higher odds ratio for reduced processing speed (OR: 2.03; 95% CI: 1.42-2.91). DISCUSSION/CONCLUSION: DSI is predicted to increase as the population ages and is associated with various health problems. Further, DSI has been reported to decrease quality of life, which needed to establish appropriate treatment and prevention measures.

Association of social isolation and smartphone use on cognitive functions.

BACKGROUND: The number of socially isolated older adults has increased owing to the coronavirus disease pandemic, thus leading to a decrease in cognitive functions among this group. Smartphone use is expected to be a reasonable preventive measure against cognitive decline in this social context. Thus, this study aimed to investigate the influence of social isolation and smartphone use on cognitive functions in community-dwelling older adults. METHODS: We divided 4,601 community-dwelling older adults into four groups based on their levels of social isolation and smartphone use. Then, we conducted cognitive functions tests including a word list memory task, trail-making test, and symbol digit substitution task. Social isolation was defined when participants met two or more of the following measures: domestic isolation, less social contact, and social disengagement. We used an analysis of covariance adjusted by background information to measure between-group differences in levels of cognitive functions and social isolation. A linear regression model was used to analyze the association of standardized scores of cognitive function tests with smartphone use. RESULTS: Smartphone users' scores of the symbol digit substitution task were superior compared with both non-users with social isolation and without. All cognitive functions were associated with smartphone use among non-socially and socially isolated participants. Socially isolated older adults showed an association only between trail making test- part A and smartphone use. CONCLUSIONS: Smartphone use was associated with cognitive functions (memory, attentional function, executive function, and processing speed) even in socially isolated community-dwelling older adults.

Isotemporal Substitution of Sedentary Behavior With Moderate to Vigorous Physical Activity Is Associated With Lower Risk of Disability: A Prospective Longitudinal Cohort Study.

OBJECTIVE: The purpose of the study was to estimate, using an isotemporal substitution model, the effect of replacing sedentary behavior (SB) with physical activity on the incidence of disability in community-dwelling older adults. METHODS: This 2-year longitudinal cohort study enrolled 3691 community-dwelling older adults (57.2% women; mean age = 74.0 [SD = 5.0] years). Individuals with dementia, stroke, Parkinson disease, depression, low Mini-Mental State Examination scores, dependence on basic activities of daily living, and missing data were excluded. Physical activity and potential confounding factors were investigated as a baseline survey of disability incidence, defined by Japanese long-term care insurance certification, for 2 years in 2 regions. Physical activity data (SB, light-intensity physical activity, and moderate- to vigorous-intensity physical activity [MVPA]) were measured using triaxial accelerometers for 14 days, and daily mean time spent in each physical activity parameter was computed in increments of 10 minutes. The relationship between baseline physical activity and disability incidence adjusted for potential confounders was analyzed using multilevel Cox proportional hazards regression analyses with an isotemporal substitution model. RESULTS: The disability incidence rate was 3.8%, excluding individuals who could not be followed-up. Replacing 10 minutes of SB per day with MVPA was associated with a decreased disability incidence (hazard ratio = 0.870; 95% CI = 0.766-0.988), whereas no evidence was found for replacing SB with light-intensity physical activity (hazard ratio = 0.980; 95% CI = 0.873-1.10). CONCLUSIONS: Replacing SB with MVPA was associated with a lower risk of disability. These findings are helpful for establishing disability prevention strategies. IMPACT: These results suggest that feasible changes in daily behavior, such as replacing 10 minutes of SB with MVPA daily, might have a protective effect on disability incidence. Clarifying these associations is useful for developing disability prevention strategies and may help reduce the incidence of disability in community-dwelling older adults.