Incident Functional Disability Research Articles

Developing a battery of physical performance tests to predict functional disability in Japanese older adults: A longitudinal study from the Kasama study.

Preventing functional disability benefits the quality of life of older adults and mitigates the economic burden of an aging society. However, the most effective physical performance tests and optimal cut points for identifying older adults at risk of functional disability remain unclear, and Japan lacks physical function-based assessment tools. We aimed to identify the physical performance tests related to functional disability and to develop a predictive test battery for it. We included 975 older adults (mean 72.8 ± 5.2 years, 55.4% women) in Kasama City, Japan. Functional disability was defined as certification of care level 2 or above based on the long-term care insurance system. Cox proportional hazards analysis examined the association between physical performance tests and incident functional disability. During a mean follow-up of 8.6 years (maximum 14 years), 236 participants (24.2%) developed functional disability. After adjusting for covariates, higher performances in grip strength, single-leg balance with eyes open (SLB), timed up-and-go (TUG), five-repetition sit-to-stand (5-STS), and 5-m habitual walk were significantly associated with a lower risk of functional disability. In a stepwise model, SLB, TUG, and 5-STS were key predictors of functional disability. Receiver operating characteristic analysis determined optimal cut points of 32.6/32.7 s for SLB, 6.5/6.6 s for TUG, and 7.8/7.9 s for 5-STS. We developed a predictive battery combining these cut points (area under the curve = 0.78). The developed battery of physical performance tests predicts future functional disability and is useful for screening older adults at high risk. Geriatr Gerontol Int 2024; ••: ••-••.

Cut-off point of the risk assessment scale for the 9-year risk of functional disability

Objectives This study aimed to examine the cut-off point of the Risk Assessment Scale (RAS) for predicting the 9-year risk of functional disability among older Japanese adults.Methods This prospective, 9-year follow-up study used data from the Sasaguri Genkimon Study in Fukuoka. Of the 2,629 older adults who did not have functional disabilities and participated in the baseline survey in 2011, 2,254 with complete data were included in the analysis. The RAS was assessed using a questionnaire that showed good predictive and external validity for the 3-year risk of functional disability. The outcome was the incidence of functional disability during follow-up, which was defined as a new certification for the need for support or care. The cut-off point of the RAS was estimated as the point indicating the maximum χ2 value of the log-rank test. The predictive validity of the RAS for functional disability was examined using C-statistics for the total score, and sensitivity and specificity for the cut-off point, respectively. Participants were then categorized into two groups according to the cut-off point (high-score and low-score groups). Hazard ratio (HR) and 95% confidence interval (95% CI) of the 9-year risk of functional disability for the high-score group compared with the low-score group were calculated using the Cox proportional hazard model. In the multivariate model, HR was adjusted for living alone, education, economic status, drinking, smoking, and multimorbidity.Results New functional disability was certified in 647 participants (28.7%) during a median follow-up period of 8.75 years. The cut-off point for functional disability was 13/14. The C-statistic was 0.774, and the sensitivity and specificity were 0.726 and 0.712, respectively. Compared to the low-score group (0-13 points), the HR (95% CI) of the high-score group (≥ 14 points) for incident functional disability in 9 years was 5.50 (4.62-6.54) in the crude model, and 4.81 (4.00-5.78) in the multivariate model (P<.001).Conclusion This study, with its long follow-up period of 9 years, demonstrated that the 13/14 cut-off point of the RAS is suitable for the long-term assessment of functional disability risk. Our results suggest the possibility of using the 13/14 cut-off point of the RAS as a promising tool to grasp the risk of functional disability over a longer time frame, highlighting the potential for early prevention and intervention.

Prevention of Age-Related-Increases in the Risks of Incident Functional Disability and Dementia by Home-Delivered Functional Dairy Product Consumption in Japanese Older Adults.

Dairy products formulated with bioactives are widely distributed in Japan, but it remains to be clear whether a regular consumption of these products would help reduce the risks of incidental functional disability and dementia in older adults. This study aimed to investigate Japanese subjects aged ≥65 y (n=629) that routinely consumed three functional dairy products, a calcium-enriched milk supplemented with Bifidobacterium longum BB536, a yogurt supplemented with lactoferrin, B. longum BB536 and heat-killed Lacticaseibacillus paracasei MCC1849, and a drinkable yogurt supplemented with lactoferrin, B. longum BB536 and heat-killed L. paracasei MCC1849, through a home delivery service. Intake frequency and intake duration of these functional dairy products were compared with the risk scores of incident functional disability and dementia, developed by the Japan Gerontological Evaluation Study. In the participants aged <75 y, the incident functional disability risk was significantly maintained or decreased in the participants with the long intake duration level compared with the short intake duration level (OR, 95% CI: 0.48, 0.25-0.93). In the participants aged ≥75 y, the dementia risk was significantly maintained or decreased in the participants with the high intake frequency level compared with the low intake frequency level (OR, 95% CI: 0.46, 0.22-0.95). A high intake frequency or long term duration of these functional dairy products may be effective in preventing an aging-related increase in the risks of incident functional disability and dementia in older adults, but this warrants further investigation using different products containing different bioactives.

Association between the incidence of functional disability and frequency of eating together among older adults living alone: a 6-year follow-up study from the Japan Gerontological Evaluation Study.

This study aimed to determine whether the frequency of eating together is associated with the incidence of functional disability in older adults who live alone. This 6-year observational prospective cohort study utilised self-reported questionnaires. Data were drawn from the participants of the Japan Gerontological Evaluation Study project between 2016 and 2022. The participants were independent older adults aged ≥65years living alone in Japan. The primary outcome was the incidence of functional disability during the follow-up period, with the self-reported frequency of eating together serving as the explanatory variable. Hazard ratios (HRs) and 95% confidence intervals (95% CIs) were estimated using Cox proportional hazards models after adjusting for confounders associated with incident functional disability. Among the 7167 participants, the mean age at baseline was 75.3 ± 6.5years and 69.2% were female. About, 12.8% of participants (n = 917) developed functional disabilities during the observation period. The incidence rates were 11.7% for 'every day', 11.3% for 'several times a week', 11.5% for 'several times a month', 12.7% for 'several times a year' and 19.0% for 'seldom'. The frequency of eating together 'seldom' was significantly associated with an increased incidence of functional disability (HR: 1.55, 95% CI: 1.10-2.18). Among older adults living alone, infrequent eating together ('seldom') was identified as a risk factor for developing functional disability.

Association between masticatory function, frailty, and functional disability: an observational study

BackgroundIncrease in functional disability in aging societies is an international medical and public health issue. Masticatory function may be a potential risk factor for functional disability, but the role of frailty in the association has not been clarified.MethodsForty thousand five hundred sixty-two community-dwelling older adults aged 65 years and over who were insured by public health insurance as of April 2018 were followed up for a median of 3.0 years. Masticatory function was categorized as good, moderate, or poor based on a self-reported questionnaire. The development of functional disability was defined as a new certification of the need for long-term care. A Cox proportional hazards model was used to calculate hazard ratios (HRs) and their 95% confidence intervals (CIs).ResultsDuring the follow-up period, 1,397 individuals experienced functional disability. After adjusting for age, sex, comorbidities, medical history, and lifestyle behaviors, the HR for incident functional disability was significantly higher in the moderate and poor groups compared to the good group (moderate, HR 1.21 [95% CI, 1.07–1.37]; poor, HR 1.64 [95% CI, 1.03–2.62]). However, after additional adjustment for frailty-related factors—namely, underweight, regular exercise, and gait speed—the association was attenuated in both the moderate group (HR 1.06 [95% CI, 0.94–1.21]) and the poor group (HR 1.51 [95% CI, 0.94–2.41]).ConclusionsMasticatory dysfunction was significantly associated with incident functional disability in a community-dwelling older Japanese population. Our findings suggest that masticatory dysfunction may be a surrogate of frailty rather than a direct cause of functional disability.

Dynapenic abdominal obesity and incident functional disability: Results from a nationwide longitudinal study of middle-aged and older adults in China

BackgroundThere is little epidemiological evidence on the relationship of dynapenic abdominal obesity (DAO) and the development of functional disability, particularly in Asian populations. We aimed to investigate the association of DAO with new-onset functional disability in Chinese adults. MethodsA total of 7881 participants aged ≥45 years from China Health and Retirement Longitudinal Study (CHARLS) in 2011 and 2015 were included in the study. Dynapenia and abdominal obesity were respectively defined based on handgrip strength (<28 kg for male and <18 kg for female) and waist circumference (≥ 90 cm for male and ≥85 cm for female). The sample was divided into four groups: non-dynapenic/non-abdominal obesity (ND/NAO), non-dynapenic/abdominal obesity (ND/AO), dynapenic/non-abdominal obesity (D/NAO) and dynapenic/abdominal obesity (D/AO). Functional status was assessed by basic activities of daily living (BADL) or instrumental activities of daily living (IADL). Logistic regression model was used to explore the longitudinal association between dynapenic abdominal obesity and incident functional disability. ResultsAfter a 4-year follow-up, 1153 (14.6 %) developed BADL disability and 1335 (16.9 %) developed IADL disability. The multivariable-adjusted odds ratios (95 % CIs) for the D/AO versus ND/NAO were 2.21 (1.61–3.03) for BADL disability, and 1.68 (1.23–2.30) for IADL disability. In addition, DAO was associated with an increased risk for functional dependency severity (odds ratio, 2.08 [95 % CI, 1.57–2.75]). ConclusionsDAO was significantly associated with greater risk of functional disability among Chinese middle-aged and older adults. Our findings indicated that interventions targeted DAO might be effective in the primary prevention of functional disability.

Impact of a history of cardiovascular disease and physical activity habits on the incidence of functional disability

We examined the impact of a history of coronary artery disease (CAD) or cerebrovascular disease (CVD) and physical activity habits on functional disability among community-dwelling Japanese adults. This population-based retrospective cohort study included 10,661 people aged 39–98 years in Japan (5054, men). Median follow-up was 3.7 years. During the study period, 209 functional disabilities occurred in the overall study population. In multivariable analysis, a history of CVD (hazard ratio [HR] 1.57 [95% CI: 1.00–2.45]) and no physical activity habit (HR 1.74 [1.27–2.39]) presented increased risks for functional disability. HRs for functional disability among patients with a CVD history with and without a physical activity habit were 1.68 (0.75–3.74) and 2.65 (1.49–4.71), respectively, compared with individuals without a history of CVD with a physical activity habit. Similar results were observed for CAD. We found no significant difference in the incidence of functional disability between the group with a history of CAD or CVD and physical activity habits and the group with no history of CAD or CVD and without physical activity habits. Physical activity habits had a favorable influence on avoiding functional disability regardless of a history of CAD or CVD. Future prospective studies are needed to clarify these associations.

Accelerometer-measured sedentary behavior and risk of functional disability in older Japanese adults: a 9-year prospective cohort study

BackgroundThe associations of sedentary time and patterns with functional disability among older adults remain unclear, and few studies have accounted for the co-dependency of sedentary behavior and physical activities when modeling sedentary behavior with risk of functional disability. We aimed to examine the associations between sedentary time and patterns and risk of incident functional disability, and assess whether replacing sedentary time with light physical activity (LPA) or moderate-to-vigorous intensity physical activity (MVPA) is associated with reduced risk of functional disability in community-dwelling older adults.MethodsA total of 1,687 Japanese adults aged ≥ 65 years without functional disability at baseline were prospectively followed-up for 9 years (2011–2020). Functional disability was ascertained using the national database of Japan’s Long-term Care Insurance System. Sedentary time and patterns, LPA, and MVPA were measured using a tri-axial accelerometer secured to participants’ waists.ResultsDuring follow-up, 466 participants developed functional disability. Compared with the lowest quartile of total sedentary time, the multivariable-adjusted hazard ratios (95% confidence intervals) of functional disability for the second, third, and top quartiles were 1.21 (0.91‒1.62), 1.45 (1.10‒1.92), and 1.40 (1.05‒1.88) (p for trend = 0.01). After further adjusting for MVPA, total sedentary time was no longer significantly associated with the risk of functional disability (p for trend = 0.41). Replacing 10 min/day of sedentary time with the same amount of MVPA (but not LPA) was significantly associated with a 12% reduced risk of functional disability (hazard ratio [95% confidence interval]: 0.88 [0.84‒0.92]). No significant association was observed between sedentary bout length and functional disability.ConclusionHigher levels of total sedentary time were associated with an increased risk of incident functional disability. However, this association was not independent of MVPA. Replacing sedentary time with MVPA, but not LPA, was associated with reduced risk of functional disability in older adults.

Combined impacts of physical activity, dietary variety, and social interaction on incident functional disability in older Japanese adults.

This 3.6-year prospective study examined combined impacts of physical activity, dietary variety, and social interaction on incident disability and estimated population-attributable fraction for disability reduction in older adults. Participants were 7,822 initially non-disabled residents (3,966 men; 3,856 women) aged 65-84 years of Ota City, Tokyo, Japan. Sufficiency of moderate-to-vigorous-intensity physical activity (MVPA) ≥150 min/week, dietary variety score (DVS) ≥3 (median), and social interaction (face-to-face and/or non-face-to-face) ≥1 time/week was assessed using self-administered questionnaires. Disability incidence was prospectively identified using the long-term care insurance system's nationally unified database. During a follow-up of 3.6 years, 1,046 (13.4%) individuals had disabilities. Independent multivariate-hazard ratios (HRs) and 95% confidence intervals of MVPA, DVS, and social interaction sufficiency for incident disability were 0.68 (0.59-0.78), 0.87 (0.77-0.99), and 0.91 (0.79-1.03), respectively. Incident disability HRs (95% CIs) gradually reduced with increased frequency of satisfying these behaviors (any one: 0.82, 0.65-1.03; any two: 0.65, 0.52-0.82; and all three behaviors: 0.54, 0.43-0.69), in an inverse dose-response manner (P < 0.001 for trend). Population-attributable fraction for disability reduction in satisfying any one, any two, and all three behaviors were 4.0% (-0.2, 7.9), 9.6% (4.8-14.1), and 16.0% (8.7-22.8), respectively. Combining active physical activity, dietary variety, and social interaction substantially enhances the impacts on preventing disability among older adults, with evidence of an inverse dose-response manner. Adding the insufficient behavior element to individual habits and preexisting social group activities may be effective in preventing disability in the community.

Lifestyle factors and incident functional disability among a rural ageing population in South Africa.

The study aimed to assess the relationship between lifestyle factors and incident functional disability in South Africa. Longitudinal data (N = 4113) from two consecutive waves in 2014/2015 and 2018/2019 in Agincourt, South Africa, were analysed. Moderate sedentary behaviour (AOR: 1.84, 95% CI: 1.31-2.58) and being overweight (AOR: 1.61, 95% CI: 1.10-2.36) increased the odds of incident functional disability among men. Moderate and high sedentary behaviour (AOR: 1.83, 95% CI: 1.31, 2.57, and AOR: 1.83, 95% CI: 1.08-3.10) increased the odds, and frequent fruit intake (AOR: 0.41, 95% CI: 0.19-0.91) and moderate physical activity (AOR: 0.47, 95% CI: 0.30-0.75) decreased the odds of incident functional disability among women. Sedentary behaviour and being overweight increased odds, and physical activity and frequent fruit intake decreased odds of incident functional disability among ageing men and/or women in South Africa.

Oral status and incident functional disability: A 9-year prospective cohort study from the JAGES

IntroductionThe population-attributable risk of oral status for incident functional disability remains unknown. We investigated the impact of a range of oral statuses (number of remaining teeth, chewing difficulty, dry mouth, and choking) on incident functional disability. MethodsParticipants (n = 44,083) aged ≥ 65 years from the Japan Gerontological Evaluation Study were evaluated. The outcome variable was incident functional disability, and the explanatory variables were four select oral statuses. The possible confounders were included as covariates. Using the Cox proportional hazards model, we calculated hazard ratios (HRs), 95% confidence intervals (CIs), and their population-attributable fractions (PAFs). ResultsThe mean age of the participants was 73.7 (standard deviation=6.0) years at baseline, and 53.2% were women. A total of 8,091 participants (18.4%) developed functional disabilities during the follow-up period. Among the four oral statuses, the incidence rate of functional disability was the highest in those with chewing difficulty (3.27/100 person-years), followed by those with dry mouth (3.20/100 person-years), choking (3.10/100 person-years), and ≤19 remaining teeth (2.89/100 person-years). After adjusting for all covariates, chewing difficulty showed the highest risk of functional disability (HR=1.22, 95%CI=1.16–1.28), followed by ≤19 remaining teeth (HR=1.18, 95%CI=1.12–1.25), dry mouth (HR=1.18, 95%CI=1.12–1.24), and choking (HR=1.10, 95%CI=1.04–1.17). Regarding PAF, ≤19 remaining teeth (12.0%) were the largest, followed by chewing difficulty (7.2%), dry mouth (4.6%), and choking (1.9%). ConclusionsMaintaining a good oral status may reduce the risk of functional disability later in life. Given its population contribution, tooth loss had the largest impact among the four oral conditions.

Effect of social participation on the association between frailty and disability

ObjectivesTo examine whether social participation affects the association between frailty and disability. MethodsA baseline survey conducted from December 1 to 15, 2006, included 11,992 participants who were classified based on the Kihon Checklist into three categories and based on the number of activities in which they socially participated into four categories. The study outcome, incident functional disability, was defined as in Long-Term Care Insurance certification. A Cox proportional hazards model was used to calculate hazard ratios (HRs) for incident functional disability according to frailty and social participation categories. Combination analysis was performed between the nine groups using the above-mentioned Cox proportional hazards model. ResultsDuring the 13-year follow-up (107,170 person-years), 5,732 incident cases of functional disability were certified. Compared with the robust group, the other groups had significantly higher incident functional disability. However, the HRs for those participating in social activities were lower than that for those not participating in any activity [1.52 (pre-frail + none group); 1.31 (pre-frail + one activity group); 1.42 (pre-frail + two activities group); 1.37 (pre-frail + three activities group); 2.35 (frail + none group); 1.87 (frail + one activity group); 1.85 (frail + two activities group); and 1.71 (frail + three activities group)]. ConclusionsThe risk of functional disability for those participating in social activities was lower than that for those not participating in any activity, irrespective of being pre-frail or frail. Comprehensive social systems for disability prevention need to focus on social participation in frail older adults.

Effects of community-based frailty-preventing intervention on all-cause and cause-specific functional disability in older adults living in rural Japan: A propensity score analysis

Preventing frailty is crucial in aging societies. We examined the effectiveness of a community-based frailty-prevention program for delaying the onset of functional disability among community-dwelling older adults. From 2014 to 2019, 48 community-based frailty prevention classes (FPC, 60 min/session, once a week), comprising resistance exercise and nutritional or psychosocial programs, were established in Yabu City, Japan. We conducted a baseline survey in 2012 and followed up with participants for up to 6.8 years (4.8 years from establishing the first FPC). We analyzed data from 3350 older people. The primary and secondary outcomes were the onset of functional disability and cause-specific functional disability (including dementia and cardiovascular and orthopedic diseases), respectively. In addition to crude Cox proportional hazard regression, inverse probability of treatment weighting (IPTW) and propensity score matching (PSM; 918 nonparticipants and 459 participants) were used to adjust for confounders. Participants were more likely to be female and have a healthy lifestyle than nonparticipants. During the follow-up, 690 individuals developed a functional disability. The hazard ratio of incident functional disability in the participants was significantly lower than that in nonparticipants in the IPTW (hazard ratio 0.53, 95% confidential interval 0.38–0.75) and PSM (0.52, 0.37–0.71) analyses. In age-stratified analysis, significant associations were observed only in the ≥75-year-old subgroup. In a cause-specific analysis, participation significantly and consistently reduced incident functional disability caused by dementia (IPTW 0.47, 0.25–0.86; PSM 0.45, 0.25–0.83). Community-based FPC may be effective for preventing functional disability, especially caused by dementia, in this population.

Association between Social Isolation and the Risk of Incident Functional Disability in Elderly Survivors after the Great East Japan Earthquake.

Social isolation is frequently observed among survivors of disaster. However, there is limited evidence regarding the association between social isolation and adverse health outcomes among survivors of disaster. The purpose of this study was to investigate the association between social isolation and the risk of incident functional disability (IFD) among survivors of the 2011 Great East Japan Earthquake (GEJE). We conducted a prospective cohort study of 1,039 residents aged ≥ 65 years who lived in four areas affected by the GEJE. Information regarding social isolation and other lifestyle factors was collected between June and November 2011 via a self-reported questionnaire. Social isolation was assessed using the Lubben Social Network Scale-6 (LSNS-6). Data regarding the incidence of functional disability were retrieved from the Long-term Care Insurance database. The Cox model was used to calculate multivariate hazard ratios (HRs) and 95% confidence intervals (CIs) for IFD. During 7,030 person-years of follow-up, 300 cases of IFD were certified (42.7disability events per 1,000 person-years). Social isolation was associated with increased risk of IFD in disaster survivors (HR = 1.32, 95% CI = 0.98-1.76). In addition, this association tended to be more remarkable among men and those whose houses were completely/seriously damaged. The present results suggest us that it would be possible to identify those who are more likely to be affected by social isolation after disaster. This finding would be useful in screening and supporting high risk group right after the occurrence of disaster.

Acceptable walking and cycling distances and functional disability and mortality in older Japanese adults: An 8-year follow-up study

We prospectively investigated the association between acceptable travel distances (i.e., walking and cycling) and the incidence of functional disability and mortality among older Japanese adults. A baseline survey was conducted in 2013 among 7618 individuals aged ≥65 years in Kasama City, Japan, and they were tracked through the city's database until 2021. Acceptable travel distances were assessed using a questionnaire. Outcomes (i.e., functional disability and mortality) were gathered as binary (incident or not) with survival time. A multivariable-adjusted Cox proportional-hazards model indicated that shorter acceptable walking and cycling distances were markedly linked with higher risks of functional disability and mortality. In conclusion, acceptable distances of ≤500m for walking and ≤1km for cycling were associated with higher risks of functional disability and mortality among older adults.

Bidirectional association between functional disability and multimorbidity among middle-aged and older adults in Thailand.

The purpose of this study was to assess the bidirectional association between multimorbidity (MM) and functional disability among middle-aged and older adults in a longitudinal study in Thailand. We analyzed longitudinal data of participants aged 45 years and older from two consecutive waves (in 2015 and 2017) of the Health, Aging, and Retirement in Thailand (HART). Functional disability was assessed with a 4-item activity of daily living (ADL) scale. Logistic regression analysis was conducted to assess the association between baseline functional disability and incident MM (≥2), and baseline morbidity and incident functional disability. The results indicate that a total of 1,716 individuals without morbidity at baseline and 3,529 without functional disability at baseline were included. At follow-up, 16.7 and 20.0% of functional disability cases and 7.1 and 3.6% of nonfunctional disability cases developed 2 morbidities and 3 or more morbidities, respectively, and 6.6% of MM cases and 4.0% of non-MM cases developed a functional disability. In the final logistic regression model adjusted for education, income, age, marital status, sex, smoking tobacco, body mass index (BMI), alcohol use, physical activity, and social engagement, functional disability at baseline was positively associated with incident MM (≥2) (adjusted odds ratio [aOR]: 2.58, 95% CI: 1.42-4.72), and MM (≥3) at baseline was positively associated with incident functional disability (aOR: 1.97, 95% CI: 1.13-3.43). Multimorbidity and functional disability were bidirectionally associated.

Mental distress and incident functional disability among a rural ageing population in South Africa.

The aim of the study was to investigate the association between mental symptoms and incident functional disability among middle-age and older adults in South Africa. Longitudinal data from two consecutive population surveys (2014/2015-2018/2019) in Agincourt, South Africa, were analysed. In total, 298 of 3813 participants without functional disability in wave 1 (8.8%) had functional disability in wave 2. The prevalence of baseline functional disability was 9.1%. In the fully adjusted models for people without functional disability at baseline, depressive symptoms (AOR: 1.74, 95% CI: 1.08-2.80) among men and lower life satisfaction among men (AOR: 0.86, 95% CI: 0.80-0.93) and among women (AOR: 0.90, 95% CI: 0.83-0.98) increased the odds of incident functional disability. Posttraumatic stress disorder symptoms, poor sleep quality, restless sleep, and loneliness were not significantly associated with incident functional disability. Depressive symptoms among men and lower life satisfaction among both sexes were independently associated with incident functional disability in ageing rural South Africans.

Fast walking and physical activity are independent contributors to improved physical function.

To clarify whether the presence or absence of fast walking and habitual physical activity are independently associated with the incidence of functional disability. This historical cohort study was comprised of 9,652 (4,412 men, mean age 65 years) individuals aged 39-98 years without functional disability at baseline. Functional disability was determined based on the Japanese long-term care insurance system, which specified requirements for assistance in the activities of daily living. The impact of fast walking and habitual physical activity on the incidence of functional disability was analysed by Cox proportional hazards models. The follow-up period was a median of 3.7 years during which 165 patients were newly certified as having functional disability. In the multivariate analysis, baseline age in 5-year increments (hazard ratio 2.42 [95% confidence interval 2.18-2.69]), no habitual physical activity (1.56 [1.07-2.27]), and not fast walking (1.89 [1.32-2.69]) significantly increased the risk of functional disability after adjustment for covariates. The stratified analysis showed that compared with physical activity (+), the impact of physical activity (-) on the incidence of functional disability was observed in those aged ≥75 years regardless of fast walking (+). Fast walking (-) significantly increased the risk of disability compared with fast walking (+) in those aged <75 years regardless of a physical activity habit. In Japanese, slow walking speed and lack of a physical activity habit were shown to be independent risk factors for incident functional disability, with their impact differing according to age.

Interaction of Eating Status and Dietary Variety on Incident Functional Disability among Older Japanese Adults.

ObjectivesTo examine whether eating status and dietary variety were associated with functional disability during a 5-year follow-up analysis of older adults living in a Japanese metropolitan area.DesignA 5-year follow-up study.SettingOta City, Tokyo, Japan.ParticipantsA total of 10,308 community-dwelling non-disabled adults aged 65–84 years.MeasurementsEating status was assessed using a self-reported questionnaire. Dietary variety was assessed using the dietary variety score (DVS). Based on the responses, participants were classified according to eating alone or together and DVS categories (low: 0–3; high: 4–10). Functional disability incidence was prospectively identified using the long-term care insurance system’s nationally unified database. Multilevel survival analyses calculated the adjusted hazard ratio (HR) and 95% confidence interval (CI) for incident functional disability.ResultsDuring a 5-year follow-up, 1,991 (19.3%) individuals had functional disabilities. Eating status or DVS were not independently associated with incident functional disability. However, interaction terms between eating status and DVS were associated with functional disability; HR (95% CI) for eating together and low DVS was 1.00 (0.90–1.11), eating alone and high DVS was 0.95 (0.77–1.17), and eating alone and low DVS was 1.20 (1.02–1.42), compared to those with eating together and high DVS.ConclusionOlder adults should avoid eating alone or increase dietary variety to prevent functional disability. This can be ensured by providing an environment of eating together or food provision services for eating a variety of foods in the community.Electronic Supplementary MaterialSupplementary material is available for this article at 10.1007/s12603-022-1817-5 and is accessible for authorized users.

Association of Arterial Stiffness with Functional Disability and Mobility Limitation: The Rugao Longitudinal Ageing Study.

Arterial stiffness is a common issue that may represent an indicator of vascular ageing. We aimed to investigate the association of arterial stiffness with the risk of functional disability and mobility limitation in older adults. Prospective cohort study. A total of 1699 older adults from the Rugao Longitudinal Ageing Study were included and analysed. Arterial stiffness was assessed by brachial-ankle pulse wave velocity (baPWV). Functional disability and mobility limitation were evaluated by the activities of daily living and the Timed Up and Go test, respectively. The associations of baPWV and risk of functional disability and mobility limitation were analysed using logistic regression models. Restricted cubic spline regressions were applied to estimate the possible nonlinear relationships between them. During the 3.5-year follow-up, 97 (10.00%) and 285 (31.11%) individuals were defined as new-onset functional disability and mobility limitation, respectively. After adjusting for confounding factors, elevated baPWV was significantly associated with a higher risk of incident functional disability (odds ratio [OR] 1.18, 95% confidence interval [CI] 1.06-1.31) and mobility limitation (OR 1.08, 95% CI 1.01-1.16). Additionally, consistent results were obtained from the stratified analyses of the different subgroups. Multivariable restricted cubic spline regression analysis further demonstrated that a near-linear association occurred between baPWV and the risk of incident functional disability and mobility limitation (P-overall < 0.01, P-nonlinear >0.05). Arterial stiffness, as assessed by baPWV, was associated with the risk of functional disability and mobility limitation in this community-based cohort, and these associations were nearly linear.