Dose-response associations between physical activity and sedentary time with functional disability in older adults with or without frailty: a prospective cohort study

Purpose

Evidence regarding the dose-response curve shapes of physical activity (PA) and sedentary time (ST) in older adults with functional disability (FD) is extremely limited. Moreover, these associations may differ depending on with/without frailty. We examined the dose-response associations between moderate-to-vigorous PA (MVPA) and ST with FD among older adults with/without frailty.

Methods

We included 7,480 initially nondisabled adults (3,795 men and 3,685 women) aged 65-84 years in Ota City, Tokyo, Japan. MVPA and ST were evaluated using the International Physical Activity Questionnaire-Short Form. FD was prospectively identified using a nationally unified database of the long-term care insurance system. Frailty was determined using Check-List 15, validated against Fried's frailty criteria. Multivariate-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) of MVPA and ST for FD were calculated, and dose-response curves were examined using restricted cubic splines.

Results

During 3.6 years of follow-up, 1,001 (13.4%) participants had FD. Among all participants, compared with no MVPA, the HRs for FD reduced linearly up to approximately 2000 metabolic equivalents (METs)■min/week of MVPA, and the lowest HR (HR: 0.61, 95% CI: 0.51-0.74) was reached at around 3,000-4,000 METs■min/week. Although the shape of this association was consistent regardless of with/without frailty, the magnitude of the association tended to be stronger in frail older adults than in non-frail older adults. Compared with those for the median (300 min/day) of ST, the HRs for FD increased linearly as ST reached approximately 600 min/day or more, independent of MVPA, with a maximum HR of 1.31 (95% CI: 1.01-1.71) for 1,080 min/day among all participants. This association was more pronounced among non-frail older adults but not statistically significant among frail older adults.

Conclusion

Higher MVPA levels consistently reduced the incidence of FD regardless of frailty in a significant inverse nonlinear dose-response manner. A significant positive nonlinear dose-response association between ST and FD risk was identified among non-frail older adults but not among frail older adults. Increasing MVPA and reducing prolonged ST are important for preventing FD among non-frail older adults. However, reducing ST alone may be insufficient; increasing MVPA, even if by only small increments, is highly recommended for frail older adults.

Dose-response Associations of Physical Activity and Sitting Time With All-cause Mortality in Older Japanese Adults

PURPOSE

Although examining the dose-response curves of physical activity (PA) and sitting time with health-related outcomes is an important research agenda, the results for older Japanese adults are extremely limited. We examined the dose-response associations of PA and sitting time with all-cause mortality among older Japanese.

METHODS

Initially, 8,069 non-disabled residents (4,073 men; 3,996 women) aged 65-84 years of Ota City, Japan, were analyzed. Moderate-to-vigorous PA (MVPA) and sitting time were evaluated using the International Physical Activity Questionnaire-Short Form. Multivariate-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs) of MVPA and sitting time for all-cause mortality were calculated, and the dose-response curves were examined using restricted cubic splines (RCS).

RESULTS

During 4.1 years of follow-up, 458 participants (5.7%; 331 men and 127 women) died. Compared with the low MVPA (<600 metabolic equivalents [METs]·minutes/week) group, HR for mortality gradually reduced in moderate (600-3,000 METs·minutes/week) and high (>3,000 METs·minutes/week) MVPA groups (moderate: HR 0.66; 95% CI, 0.54-0.82; high: HR 0.58; 95% CI, 0.45-0.75; P < 0.001 for trend). RCS showed that the HR for mortality reduced linearly up to approximately 2,000 METs·minutes/week of MVPA, and maximal risk reduction was seen at approximately 3,000-4,500 METs·minutes/week of MVPA. No significant dose-response association of sitting time with mortality was observed.

CONCLUSION

Higher MVPA levels reduced all-cause mortality risk, in a significant inverse non-linear dose-response manner. Sitting time was not significantly associated with all-cause mortality. It is important to disseminate the significance of even a slight increase in the MVPA for reducing mortality risk.

Protective effects of dog ownership against the onset of disabling dementia in older community-dwelling Japanese: A longitudinal study

This prospective study examined the associations of dog/cat ownership with incident disabling dementia using propensity score matching based on the physical, social, and psychological characteristics of dog and cat owners. We also examined associations of the interaction between dog/cat ownership and exercise habit and social isolation with dementia. Overall, 11,194 older adults selected using stratified and random sampling strategies in 2016 were analyzed. Dog/cat ownership was defined as "current" or "past and never". Disabling dementia was defined according to physicians' rating in the long-term care insurance system in Japan during the approximately 4-year follow-up period. Statistical analysis was weighted by the inverse of the propensity score in the generalized estimating equation after adjusting for follow-up period. Current dog owners (8.6 %) had an odds ratio (OR) of 0.60 (95 %CI: 0.37-0.977) of having disabling dementia compared to past and never owners. For cat ownership, the corresponding OR was 0.98 (95 %CI: 0.62-1.55). Current dog owners with a regular exercise habit had an OR of 0.37 (0.20-0.68) compared to past and never dog owners with no exercise habit. Further, current dog owners with no social isolation had an OR of 0.41 (0.23-0.73) compared to past and never dog owners with social isolation. Dog ownership had a suppressive effect on incident disabling dementia after adjusting for background factors over a 4-year follow-up period. Specifically, dog owners with an exercise habit and no social isolation had a significantly lower risk of disabling dementia.

Association of dietary variety with the risk for dementia: the Yabu cohort study

OBJECTIVE

The consumption of various foods is internationally recommended in healthy diet although the association between dietary variety and incident dementia is unknown. We aimed to examine the association between dietary variety and the incidence of disabling dementia in older Japanese adults.

DESIGN

We conducted a prospective cohort study. Dietary variety was assessed based on the Dietary Variety Score (DVS). DVS was assessed by counting the number of ten food components (meat, fish/shellfish, eggs, milk, soyabean products, green/yellow vegetables, potatoes, fruit, seaweed and fats/oils) that were consumed almost daily using a FFQ. Participants were categorised into low (0-2 points), middle (3-4 points) and high (5-10 points) groups based on the DVS. Data on newly diagnosed disabling dementia were retrieved from the public long-term care insurance database. Cox proportional hazards regression was used to estimate hazard ratios (HR) with 95 % CI.

SETTING

Yabu cohort study, Japan.

PARTICIPANTS

A total of 4972 community-dwelling adults aged 65 years or older.

RESULTS

During the median follow-up of 6·8 years, 884 participants were newly diagnosed with disabling dementia. After adjusting for confounders, the multivariable-adjusted HR for incident disabling dementia was 0·82 (95 % CI, 0·69, 0·97) for participants in the highest DVS category compared with those in the lowest DVS category (Pfor trend = 0·019).

CONCLUSIONS

A higher dietary variety is associated with a reduced risk of disabling dementia in older Japanese adults. These results have potential implications for the development of effective public nutritional approaches to prevent dementia in older adults.

The relationship between working status in old age and cause-specific disability in Japanese community-dwelling older adults with or without frailty: A 3.6-year prospective study

AIM

To examine the effects of employment engagement, classified by frailty and working status, on the incidence of disability in urban community-dwelling older adults.

METHODS

We used data from 6386 initially nondisabled residents aged 65-84 years from Ota City, Tokyo, Japan, in 2016. The observation duration was 3.6 years. Self-administered questionnaires applied the Cox proportional hazard model by assessing the existence of frailty through Check-List 15 (with a score ≥4 indicating the state of frailty), controlling for age, sex, living situation, education level, equivalent income, chronic conditions, body mass index, instrumental activities of daily living, self-rated health, drinking and smoking status, and social activities. We evaluated the predictive value of working status (full-time, part-time, temporary, or nonworker) at baseline for cause-specific disability (dementia-type vs. non-dementia-type) incidence, identified using the long-term care insurance system's nationally unified database.

RESULTS

Of the 6386 participants, 806 (63/1134 full-time workers; 58/1001 part-time workers; 61/547 temporary workers; 624/3704 nonworkers) presented with disabilities during the 3.6-year-long duration. Adjustments for conventional covariates showed that nonfrail full-time and part-time workers, as well as frail full-time workers, had significantly lower risks of all-cause disability incidence. Furthermore, nonfrail and frail full-time workers had significantly lower risks of dementia-type and nondementia-type disabilities, respectively.

CONCLUSIONS

The incidence of disability in older adults was influenced by working and frailty status. Engaging in full-time work thus prevents disabilities in older adults, regardless of their frailty status. Meanwhile, nonfrail older adults are able to avoid disabilities even when engaging in part-time work. Geriatr Gerontol Int 2023; 23: 855-863.

Association Between Serum GDF15 Concentration and Total Mortality in Community-Dwelling Japanese Older Populations: The Involvement of Renal Dysfunction

BACKGROUND

Serum growth differentiation factor 15 (GDF15) is associated with age-related adverse outcomes. However, renal function has not been thoroughly evaluated in studies addressing the association between GDF15 and mortality. We aimed to clarify whether GDF15 is associated with total mortality after carefully controlling renal function markers.

METHODS

We divided 1 801 community-dwelling Japanese older adults into quartiles according to their serum GDF15 concentrations. The correlation of GDF15 with renal function and inflammation markers was assessed by calculating Spearman correlation coefficients. Cumulative survival rates of the quartiles were estimated. In a Cox regression analysis adjusted for confounders, the association between GDF15 and mortality was evaluated. The discriminative capacity of GDF15 for the prediction of mortality was assessed with receiver-operating characteristic analysis.

RESULTS

GDF15 was correlated with cystatin C (r = 0.394), β2-microglobulin (r = 0.382), C-reactive protein (r = 0.124), and interleukin-6 (r = 0.166). The highest GDF15 quartile showed poor survival compared to the others. Older adults with higher GDF15 were associated with an increased mortality risk, independent of demographics and clinically relevant variables (hazard ratio [95% confidence interval]: 1.98 [1.09-3.59]). This significant association disappeared when additionally adjusted for cystatin C (1.65 [0.89-3.05]) or β2-microglobulin (1.69 [0.91-3.12]). The ability to predict mortality was approximately comparable between GDF15 (area under the curve: 0.667), cystatin C (0.691), and β2-microglobulin (0.715).

CONCLUSIONS

Serum GDF15 is associated with total mortality in older Japanese after adjustment for major confounders. The increased mortality risk in older adults with higher GDF15 may be partly attributed to decreased renal function.

Occupational Fall Risk Assessment Tool for older workers

BACKGROUND

No easy-to-use fall risk assessment tools have been devised to assess occupational fall risk in older workers.

AIMS

To develop an Occupational Fall Risk Assessment Tool (OFRAT) and report its predictive validity and reliability in older workers.

METHODS

The baseline fall risk assessment was completed by 1113 participants aged ≥60 years who worked ≥4 days/month in Saitama, Japan. Participants were followed up for falls during occupational activities for 1 year, and 30 participants were assessed twice for test-retest reliability. The following assessment measures were summed to form the OFRAT risk score: older age, male sex, history of falls, physical work participation, diabetes, use of medications increasing fall risk, reduced vision, poor hearing, executive dysfunction and slow stepping. The scores were then classified into four grades (0-2 points: very low, 3 points: low, 4 points: moderate and ≥5 points: high).

RESULTS

During follow-up, 112 participants fell 214 times during work. The negative binomial regression model showed that participants with higher grades had a higher incidence rate ratio [95% confidence interval] for falls than those with very low grades (low: 1.64 [1.08-2.47], moderate: 4.23 [2.82-6.34] and high: 6.12 [3.83-9.76]). The intraclass correlation coefficient for risk score was 0.86 [0.72-0.93], and the weighted kappa coefficient for grade assessment was 0.74 [0.52-0.95].

CONCLUSIONS

The OFRAT is a valid and reliable tool for estimating the occupational fall risk in older workers. It may assist occupational physicians implement strategies to prevent falls in this group.

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.

Relationship between the urinary Na/K ratio, diet and hypertension among community-dwelling older adults

The association between the urinary sodium (Na)/potassium (K) ratio and hypertension is well recognized. We investigated whether the urinary Na/K ratio might be associated with hypertension in community-dwelling older adults and whether the association was influenced by habitual dietary patterns. We enrolled a total of 684 older adults (mean age, 76.8 years) and conducted health examinations at Kusatsu, Japan, in 2021. The urinary Na/K ratio was found to be independently associated with systolic blood pressure (SBP) (p < 0.0001), years of education (p = 0.0027), number of cohabitants (p = 0.0175), estimated glomerular filtrate rate (eGFR) (p = 0.0244), and Geriatric Depression Scale short-version (GDS15) score (p = 0.0366). In addition, an unsupervised hierarchical clustering analysis revealed a spectrum of habitual dietary patterns for higher and lower values of the urinary Na/K ratio. The decision tree indicated that the urinary Na/K ratio was associated with the history of milk consumption. A positive history of daily milk consumption predicted a mean urinary Na/K ratio of 2.8, and a negative history of daily milk consumption predicted a mean urinary Na/K ratio of 3.3. Furthermore, the frequency of fruit and vegetable consumption also predicted the urinary Na/K ratio. The relationship between the urinary Na/K ratio and hypertension was influenced by the frequency of consumption of milk, fruits, and vegetables in the subjects. This finding might be due to the influence of education and/or depression. The results suggested the importance of nutritional education in the development of hypertension.

Association between sarcopenia and oral functions in community-dwelling older adults: A cross-sectional study

BACKGROUND

Few studies have examined the state of oral function in older adults with sarcopenia. We assessed the oral functions of community-dwelling older adults with sarcopenia from multiple perspectives to clarify their potentially low oral function.

METHODS

A total of 1517 (86.2%; 990 women, 527 men; mean age 76.1 ± 7.6 years) participants were included in this study. Grip strength, gait speed and skeletal muscle mass index were assessed, and sarcopenia was evaluated according to the criteria of the Asian Working Group for Sarcopenia 2019. The degree of tongue coating, oral moisture, occlusal force, tongue-lip motor function, tongue pressure, masticatory function and swallowing function were assessed. The criteria for oral hypofunction (a disease that is a combination of multiple low oral functions) were used to assess oral function. Statistical analyses were performed using Kolmogorov-Smirnov test, unpaired t-test, Mann-Whitney U test, χ² test, and univariate and multivariable logistic regression analyses, with each oral function as the dependent variable and sarcopenia as one of the independent variables. The significance level was set at P < 0.05.

RESULTS

The prevalence rates of sarcopenia and severe sarcopenia were 14.2% and 3.8%, respectively. The prevalence of oral hypofunction was 39.9%. Compared with the robust group, the sarcopenia and severe sarcopenia groups tended to have a higher frequency of the following components (all P < 0.01): low occlusal force, low tongue-lip motor function, low tongue pressure, low masticatory function, low swallowing function and oral hypofunction. Univariate logistic regression analysis showed that sarcopenia was associated with low occlusal force, low tongue-lip motor function, low tongue pressure, low masticatory function, low swallowing function and oral hypofunction. The odds ratios and 95% confidence intervals of sarcopenia for each oral function were 2.62 [2.00, 3.43], 2.21 [1.69, 2.89], 3.66 [2.79, 4.81], 3.23 [2.46, 4.25], 1.66 [1.26, 2.20] and 3.59 [2.72, 4.72], respectively. Multivariable logistic regression analysis showed that sarcopenia was associated with low occlusal force (1.63 [1.10, 2.40]), low tongue pressure (2.28 [1.65, 3.15]), low masticatory function, (1.94 [1.27, 2.97]), low swallowing function (1.64 [1.17, 2.28]) and oral hypofunction (2.17 [1.52, 3.09]).

CONCLUSIONS

This study demonstrated that multiple aspects of oral function were low among community-dwelling older adults with sarcopenia. The potential decline in oral functions in older adults with sarcopenia may have been overlooked until now. This study indicates the need for dental perspectives in intervening with older adults with sarcopenia and the need to encourage them to see dental professionals.

Population-based reference values for tongue pressure in Japanese older adults: A pooled analysis of over 5,000 participants

PURPOSE

To establish age- and sex-specific population reference values for tongue pressure (TP) in community-dwelling Japanese older adults.

METHODS

For this analysis, we pooled four population-based studies on community-dwelling adults aged ≥65 years that measured TP using a JMS tongue pressure measuring device. We calculated the means and deciles of TP per 5-year age group for each sex. We also estimated age trends in TP for men and women.

RESULTS

In total, 5,083 individuals (2,150 men and 2,933 women, with a mean [standard deviation] age of 75.2 [6.5] years) were included in the present analysis. In male participants, the mean (standard deviation) TPs for ages 65-69, 70-74, 75-79, 80-84, and ≥85 years were 34.0 (8.4), 32.2 (8.1), 30.8 (8.3), 28.4 (8.9), and 24.4 (8.2) kPa, respectively. In female participants, the corresponding values were 31.5 (7.1), 30.5 (7.5), 29.6 (7.3), 28.4 (8.0), and 26.4 (7.6) kPa, respectively. For both sexes, there were significant declining trends in TP with advanced age. In addition, the interaction between age and sex had a significant effect on TP (regression coefficient [95% confidence interval] = -0.18 [-0.25 to -0.11] when age was modeled as a continuous variable and sex was modeled as a categorical variable [coded as 0=women, 1=men]).

CONCLUSIONS

This study determined age- and sex-specific reference values for TP, presented as means and deciles, in community-dwelling Japanese older adults aged ≥65 years. This study also demonstrated sex differences in age-related declines in TP.

Cross-Sectional and Longitudinal Associations of Creatinine-to-Cystatin C Ratio with Sarcopenia Parameters in Older Adults

OBJECTIVES

Accumulating evidence from cross-sectional studies suggests that the serum creatinine-to-cystatin C ratio (CCR) may be a useful biomarker for sarcopenia. This study aimed to assess the cross-sectional and longitudinal associations of CCR with sarcopenia and its parameters in community-dwelling older adults.

DESIGN

Cross-sectional and longitudinal study.

SETTING AND PARTICIPANTS

This 6-year prospective cohort study included the repeated measurement data from 1,253 Japanese residents (662 males and 591 females) aged ≥65 years who underwent medical checkups in Kusatsu and Hatoyama, Japan. A total of 4,421 observations were collected.

MEASUREMENTS

The CCR was grouped into quartiles by sex (Q1-Q4) using Q4 as the reference category. Sarcopenia was defined according to the Asian Working Group for Sarcopenia 2019 algorithm. Skeletal muscle mass index (SMI) measured using segmental multifrequency bioelectrical impedance analysis, handgrip strength (HGS), usual gait speed (UGS), and maximal gait speed (MGS) were measured repeatedly as sarcopenia parameters. The association of the CCR with changes in sarcopenia, SMI, HGS, UGS, and MGS during the 6-year period were analyzed using a generalized linear mixed-effects model.

RESULTS

The prevalence of sarcopenia at baseline was 13.1% (11.9% in males and 14.5% in females). In a cross-sectional analysis, the CCR quartile was inversely associated with sarcopenia and was positively associated with SMI, HGS, and MGS (P for trend < 0.001). In a longitudinal analysis during the 6 years, a significant increase in sarcopenia in Q2 (B = 1.1% point/year; P = 0.026 for group-by-time interaction) and significant declines in SMI (B = -0.01 kg/m2/year; P = 0.044 for group-by-time interaction) and MGS (B = -0.008 m/sec/year; P = 0.041 for group-by-time interaction) in Q1 were observed compared with Q4. However, the dose-response relationship was significant only for MGS (P = 0.033 for trend). No significant group-by-time interaction was observed for HGS. CCR was not significantly associated with UGS either cross-sectionally or longitudinally.

CONCLUSIONS

CCR is a useful biomarker regarding the status of sarcopenia. It may be used for sarcopenia screening even in older adults whose physical function is difficult to assess. However, further longitudinal studies are needed to determine whether CCR can be a predictor of future sarcopenia.

Pet ownership-related differences in medical and long-term care costs among community-dwelling older Japanese

This study examined the differences in medical and long-term care costs over 18 months between pet owners and non-owners among community-dwelling older Japanese. Pet ownership data were collected from 460 community-dwelling adults age 65 years and older. These data were matched with data from the National Health Insurance, health insurance for older people, and Long-Term Care Insurance beneficiaries for 17 months back from the survey on pet ownership. Pet-ownership group-specific trajectories in monthly medical and long-term care costs were modeled by a generalized estimating equation. Among pet owners (n = 96, 20.9%) and non-pet owners (n = 364, 79.1%) there were no significant differences in baseline demographic or health characteristics including chronic disease and self-reported long-term care level. At baseline, pet owners had estimated monthly medical costs of ¥48,054 (SE = 0.11; $418), compared to ¥42,260 (SE = 0.06; $367) for non-pet owners. The monthly medical costs did not differ significantly between the two groups during the 18-month follow-up period. At baseline, estimated monthly long-term care costs of pet owners and non-pet owners were ¥676 (SE = 0.75; $6) and ¥1,420 (SE = 0.52; $12), respectively. During the follow-up period, the non-pet owner to owner ratio of monthly long-term care costs was 1.2 at minimum and 2.3 at maximum. This study showed that monthly long-term care costs for pet owners were approximately half those of non-pet owners. Pet owners might use long-term care services less frequently, or use lighter care services.

Role of personality traits in determining the association between social participation and mental health: A cross-sectional study in Japan

The role of personality in determining the association between social participation and mental health was examined by a cross-sectional study. We analyzed data from 4981 older adults aged 65-84 years who were recruited via a mail survey in one region of Japan. We defined poor mental health using a score ≤12 points on the World Health Organization-Five Well-Being Index-Japanese. Personality traits were measured by 10 Item Personality Inventory-Japanese. In women, higher openness positively moderated the association between private group participation (volunteering, sports, hobby, and learning) and mental health, while higher neuroticism negatively moderated it. This study contributes to knowledge about mental health, personality, and participation. The findings provide provisional evidence about recommending private group participation for women with high openness but not those with high neuroticism.

THE RELATIONSHIP BETWEEN EMPLOYMENT AND ALL-CAUSE MORTALITY IN JAPANESE COMMUNITY-DWELLING OLDER ADULTS

It is well known that social contribution such as working maintains the functional health and prevents frailty of older adults. However, the effect of employment in old age with frailty on health outcomes is not well-established.This 3.6-year prospective study examined the influence of working on all-cause mortality in urban community-dwelling Japanese older adults. Participants were 10,591 initially non-disabled residents (5,180 men; 5,411 women) aged 65–84 years of Ota City, Tokyo, Japan. We applied the Cox proportional hazard model by gender and with/without frailty, controlling for age, years of education, equivalent income, number of chronic diseases, body mass index, instrumental activities of daily living (IADLs), smoking and drinking status, exercise habits, social activities, and social interaction for evaluating the predictive value of working status (full-time worker, part time worker, occasional worker and non-worker) at baseline for all-cause mortality.During a follow-up of 3.6 years, 328 (3.1%) individuals died. Compared with non-workers, independent multivariate-hazard ratios (95% confidence intervals) of part-time workers for all-cause mortality in men with/without frailty were 0.35 (0.13–0.97) and 0.54 (0.28–1.01), respectively. Corresponding female multivariate-adjusted HRs with/without frailty were 1.21 (0.34–4.34) and 0.23 (0.05–0.99). Also, for both genders, full-time workers and occasional workers did not have significantly lower adjusted hazard ratios of all-cause mortality, compared to non-workers, regardless of frailty. In conclusion, moderate employment resulted in lower risk of all-cause mortality, even in frail older men.

TRAJECTORIES OF SKELETAL MUSCLE MASS AND FAT MASS AND THEIR IMPACTS ON MORTALITY IN OLDER JAPANESE ADULTS

Skeletal muscle mass and fat mass have differential impacts on mortality between men and women. We aimed to determine age-related trajectories of skeletal muscle mass index (SMI) and fat mass index (FMI) among men and women and to examined their impacts on mortality risks. This prospective study included 1,770 (863 men and 907 women) aged ≥65 years who participated in health check-ups; the total number of observations was 6,110. SMI and FMI were determined using segmental multi-frequency bioelectrical impedance analysis, and their age-related trajectories from age 65–90 years were examined using group-based semiparametric mixture models. SMI and FMI age-related trajectories for all-cause mortality were determined by multivariate-adjusted hazard ratios (HRs) and 95% confidence intervals (CIs). SMI and FMI trajectories were classified into three trajectories in both sexes: the low- (28.6% and 34.0%), middle- (56.0% and 47.5%), and high-trajectory (15.4% and 18.5%) groups in men and the low- (27.6% and 40.9%), middle- (51.6% and 48.1%), and high-trajectory (20.8% and 11.0%) groups in women. The median follow-up was 5.3 years; 101 (11.7%) men and 56 (6.2%) women died. Compared with the low-trajectory groups, male multivariate-adjusted HRs for mortality in the middle- and high-trajectory groups were 0.89 (95% CI: 0.57–1.39) and 0.34 (0.13–0.93) for SMI, and 0.76 (0.47–1.23) and 1.13 (0.60–2.14) for FMI, respectively. Corresponding female multivariate-adjusted HRs were 1.00 (0.50–2.02) and 1.64 (0.62–4.36) for SMI, and 0.74 (0.38–1.43) and 0.37 (0.12–1.14) for FMI. Maintaining high skeletal muscle mass is important for prolonging life expectancy, especially in men.

The Kesennuma Study in Miyagi, Japan: Study Design and Baseline Profiles of Participants

BACKGROUND

To clarify the association between psychosocial problems and frailty in the areas affected by the Great East Japan Earthquake, and to develop strategies for preventive long-term care in the community, we launched the Kesennuma Study in 2019. This report describes the study design and the participants' profiles at baseline.

METHODS

The prospective study comprised 9,754 people (4,548 men and 5,206 women) randomly selected from community-dwelling independent adults aged 65 to 84 who were living in Kesennuma City, Miyagi. The baseline survey was conducted in October 2019. It included information on general health, socio-economic status, frailty, lifestyle, psychological factors (eg, personality, depressive moods), and social factors (eg, social isolation, social capital). A follow-up questionnaire survey is planned. Mortality, incident disability, and long-term care insurance certifications will also be collected.

RESULTS

A total of 8,150 questionnaires were returned (83.6% response rate), and 7,845 were included in the analysis (80.4%; mean age 73.6 [standard deviation, 5.5] years; 44.7% male). About 23.5% were considered frail. Regarding psychological and social functions, 42.7% had depressive moods, 29.1% were socially isolated, and only 37.0% participated in social activities at least once a month. However, 82.5% trusted their neighbors.

CONCLUSION

While local ties were strong, low social activity and poor mental health were revealed as issues in the affected area. Focusing on the association between psychological and social factors and frailty, we aim to delay the need for long-term care for as long as possible, through exercise, nutrition, social participation, and improvement of mental health.

Impact of number of functional teeth on independence of Japanese older adults

AIM

To examine the relationship between the number of present and functional teeth at baseline and future incidence of loss of independence.

METHODS

Participants were community-dwelling older individuals who participated in a comprehensive geriatric health examination conducted in Kusatsu town, Japan, between 2009 and 2015. The primary endpoint was the incidence of loss of independence among participants, defined as the first certification of long-term care insurance in Japan. The numbers of present and functional teeth at baseline were determined via an oral examination. Demographics, clinical variables (e.g., history of chronic diseases and psychosocial factors), blood nutritional markers, physical functions, and perceived masticatory function were assessed.

RESULTS

This study included 1121 individuals, and 205 individuals suffered from loss of independence during the follow-up period. Kaplan-Meier estimates of loss of independence for participants with smaller numbers of present and functional teeth were significantly greater than for those with larger numbers of teeth. Cox proportional hazard analyses indicated that a smaller number of present teeth was not a significant risk factor after adjusting for demographic characteristics. However, the number of functional teeth was a significant risk factor after the adjustment (hazard ratio: 1.975 [1.168-3.340]). Additionally, higher hazard ratios were observed in other adjusted models, but they were not statistically significant.

CONCLUSIONS

The number of functional teeth may be more closely related to the future incidence of loss of independence than the number of present teeth. This novel finding suggests that prosthodontic rehabilitation for tooth loss possibly prevents the future incidence of this life-event. Geriatr Gerontol Int 2022; 22: 1032-1039.

[Development and evaluation of a modified version of the dietary variety score for community-dwelling older adults]

Objectives　The dietary variety score (DVS) was developed as an index to assess the variety of food intake among older Japanese adults and has been widely used in epidemiological studies and public health settings. However, this index has not been reviewed since its development in the 1990s and may not adequately reflect the current dietary habits of the older Japanese population. In this study, we developed a modified version of the DVS (MDVS) and examined its validity.Methods　We conducted a cross-sectional study of 357 community-dwelling adults aged ≥65 years (mean age: 76.2±4.6, men: 61.1%) who participated in the 2016 survey of the Hatoyama cohort study. The DVS and MDVS were assessed by the number of food groups eaten almost every day based on the weekly frequency of consumption. The DVS was calculated based on ten components: meat, fish/shellfish, eggs, milk, soybean products, green/yellow vegetables, potatoes, fruits, seaweed, and fats/oils. The components of the MDVS were determined by calculating the contribution of each food group to the total and nutrient intakes from the food groups comprising the main dish, side dish, and soup, based on the data from older adults aged ≥65 years who participated in the 2017 National Health and Nutrition Survey in Japan. Based on the contribution of each food group, we added "other vegetables" and "dairy products" in the MDVS. Dietary intake was assessed using a validated, self-administered diet history questionnaire. We calculated the probability of adequacy for each of the fourteen nutrients selected as per the estimated average requirement in the Dietary Reference Intake for Japanese 2020 and the mean probability of adequacy for all fourteen nutrients. In addition, we assessed the correlation between the DVS, MDVS, and each indicator and the significance of the difference between correlation coefficients.Results　The MDVS was significantly positively correlated with the energy ratios of protein and fat, dietary fiber, potassium, and the modified diet score based on the Japanese Food Guide Spinning Top (r=0.21-0.45) and negatively correlated with the carbohydrate energy ratio (r=-0.32). The MDVS was also correlated with the mean probability of nutrient adequacy (r=0.41). The correlation coefficients between the MDVS and each indicator were not significantly different from those of the DVS.Conclusions　Validity in terms of nutrient intake and diet quality was comparable between the DVS and MDVS. To revise the DVS, it is necessary to conduct nationwide studies based on highly accurate dietary surveys.

Normative Data of the Trail Making Test Among Urban Community-Dwelling Older Adults in Japan

Introduction

Population aging is likely to increase the number of people with dementia living in urban areas. The Trail Making Test (TMT) is widely used as a cognitive task to measure attention and executive function among older adults. Normative data from a sample of community-dwelling older adults are required to evaluate the executive function of this population. The purpose of this study was to examine the Trail Making Test completion rate and completion time among urban community-dwelling older adults in Japan.

Methods

A survey was conducted at a local venue or during a home visit (n = 1,966). Cognitive tests were conducted as a part of the survey, and TMT Parts A (TMT-A) and B (TMT-B) were completed after the completion of the Japanese version of the Mini-Mental State Examination (MMSE-J). Testers recorded TMT completion status, completion time, and the number of errors observed.

Results

In the TMT-A, 1,913 (99.5%) participants understood the instructions, and 1,904 (99.1%) participants completed the task within the time limit of 240 s. In the TMT-B, 1,839 (95.9%) participants understood the instructions, and 1,584 (82.6%) participants completed the task within the time limit of 300 s. The completion rate of TMT-B was 90.2 and 41.8% for participants with an MMSE-J score of >23 points and ≦23 points, respectively. Results of multiple regression analyses showed that age, education, and the MMSE-J score were associated with completion time in both TMTs.

Conclusion

In both TMTs, completion time was associated with age, education, and general cognitive function. However, not all participants completed the TMT-B, and the completion rate was relatively low among participants with low MMSE-J scores. These findings may help interpret future TMT assessments.

Modifiable intrinsic factors related to occupational falls in older workers

AIM

Identification of modifiable intrinsic factors for occupational falls is required for initiating effective fall prevention strategies for older workers. This study aimed to identify modifiable intrinsic factors related to falls during occupational activities among older workers.

METHODS

This retrospective study involved 1164 older workers (aged ≥60 years, workdays ≥4/month) sampled from 18 public employment agencies for seniors in Saitama, Japan. Participants were assessed regarding the following 10 modifiable intrinsic factors: multimorbidity, polypharmacy, fall-risk-increasing medication use, self-rated vision and hearing, functional strength, bilateral stepping, standing balance, executive function and visuospatial ability. The number of falls during occupational activities in the past year was also recorded.

RESULTS

In total, 111 falls occurred in 73 of the 1164 participants during occupational activities in the past year. A negative binomial regression model showed that use of fall-risk-increasing medications (incidence rate ratio [IRR]: 2.23, 95% confidence interval [CI]: 1.08, 4.60, P = 0.031), reduced functional strength (IRR: 1.81, 95% CI: 1.02, 3.21, P = 0.042), poor standing balance (IRR: 1.83, 95% CI: 1.09, 3.09, P = 0.023) and poor visuospatial ability (IRR: 1.56, 95% CI: 1.03, 2.36, P = 0.034) were independently associated with occupational falls.

CONCLUSIONS

Our findings suggest that the assessment of medication use, functional strength, standing balance and visuospatial ability in regular health checks in the workplace may be useful for screening older workers at risk of occupational falls. Geriatr Gerontol Int 2022; 22: 338-343.

Dose-response relationships of sarcopenia parameters with incident disability and mortality in older Japanese adults

BACKGROUND

Sarcopenia-related parameters may have differential impacts on health-related outcomes in older adults. We examined dose-response relationships of body composition, muscle strength, and physical performance with incident disability and mortality.

METHODS

This prospective study included 1765 Japanese residents (862 men; 903 women) aged ≥65 years who participated in health check-ups. Outcomes were incident disability and all-cause mortality. Fat mass index (FMI) and skeletal muscle mass index (SMI), determined using segmental multi-frequency bioelectrical impedance analysis, handgrip strength (HGS), and usual gait speed (UGS) were measured. We determined multivariate-adjusted hazard ratios (HRs) for disability and mortality relative to sex-specific reference values (FMI: medians; SMI: 7.0 kg/m² for men and 5.7 kg/m² for women; HGS: 28 kg for men and 18 kg for women; or UGS: 1.0 m/s for both sexes). Association shapes were examined using restricted cubic splines or fractional polynomial functions.

RESULTS

The median follow-up was 5.3 years; 107 (12.7%) men and 123 (14.2%) women developed disability, and 101 (11.7%) men and 56 (6.2%) women died. FMI did not impact any outcome in men and disability in women, while an FMI ≤ 7.3 kg/m² (median) was significantly associated with higher mortality risk in women, compared with median FMI. SMI did not impact disability in either sex and mortality in women, but showed a significant inverse dose-response relationship with mortality risk in men [HRs (95% confidence intervals) of minimum and maximum values compared with the reference value: 2.18 (1.07-4.46) and 0.43 (0.20-0.93), respectively], independent of HGS and UGS. HGS and UGS showed a significant inverse dose-response relationship with disability in both sexes [HGS: 1.71 (1.00-2.91) and 0.31 (0.09-0.99), respectively, in men, 2.42 (1.18-4.96) and 0.41 (0.20-0.85), respectively, in women; UGS: 2.14 (1.23-3.74) and 0.23 (0.08-0.67), respectively, in men, 3.26 (2.07-5.14) and 0.11 (0.05-0.26), respectively, in women] and mortality in women [HGS: 6.84 (2.84-16.47) and 0.06 (0.02-0.21), respectively; UGS: 2.67 (1.14-6.27) and 0.30 (0.11-0.85), respectively], independent of body composition, but did not impact mortality in men.

CONCLUSIONS

Disability risk was more dependent on muscle strength and physical performance in both sexes. Mortality risk in men was more dependent on muscle mass, and mortality risk in women was influenced by lower fat mass along with muscle strength and physical performance. Although improving muscle strength and physical performance should be the first target for health promotion, it is also necessary to pay attention to body composition to extend life expectancy in older adults.

Behavior changes and functional capacity Physical, social, and dietary behavioral changes during the COVID-19 crisis and their effects on functional capacity in older adults

Background

This two-year follow-up study aimed to identify factors associated with unhealthy behaviors during the COVID-19 pandemic and examine their impact on functional capacity in older adults.

Methods

Altogether, 536 adults aged ≥65 years participated in this study. The frequency of going out, exercise habits, face-to-face and non-face-to-face interactions, social participation, and eating habits were examined as behavioral factors before and after the first declaration of a state of emergency in Japan. Functional capacity was assessed using the Tokyo Metropolitan Institute of Gerontology Index of Competence.

Results

Using latent class analysis considering changes in the six behaviors, the participants were divided into healthy (n = 289) and unhealthy (n = 247) behavior groups. The male sex was associated with 2.36 times higher odds, diabetes with 2.19 times higher odds, depressive mood with 1.83 times higher odds, poor subjective economic status with 2.62 times higher odds, and living alone with 44% lower odds of being unhealthy. The unhealthy behavior group showed significantly decreased functional capacity (B =−1.56 [−1.98, −1.14]) than the healthy behavior group. For each behavior, negative changes in going out (B =−0.99 [−1.60, −0.37]), face-to-face interaction (B =−0.65 [−1.16, −0.13]), and non-face-to-face interactions (B =−0.80 [−1.36, −0.25]) were associated with a decline in functional capacity.

Conclusion

Our results showed four factors associated with engaging in unhealthy lifestyle behaviors and how behavioral changes affect functional capacity decline during the COVID-19 pandemic, which will help to develop public health approaches

Evidence that dog ownership protects against the onset of disability in an older community-dwelling Japanese population

Objectives

This study examined the association between dog and cat ownership, the onset of disability and all-cause mortality in an older population. Dog and cat owners take more regular exercise and have closer social relationships than non-owners. We further assess the beneficial effects of these moderating variables on the onset of disability and mortality.

Methods

Dog and cat ownership data were collected from 11233 community-dwelling adults age 65 years and older. These data were matched with data about the onset of disability held by the Japanese long-term care insurance system. Local registry data were used to ascertain all-cause mortality.

Results

During the approximately 3.5 year follow-up period, 17.1% of the sample suffered onset of disability, and 5.2% died. Logistic regression analysis indicated that, compared with a reference group of those who had never owned a dog (odds ratio fixed at 1.0), older adults who were currently dog owners had a significantly lower odds ratio of onset of disability (OR = 0.54 95% CI: 0.37–0.79). Our results further show that regular exercise interacts with dog ownership to reduce the risk of disability. The association of dog and/or cat ownership with all-cause mortality was not statistically significant.

Conclusions

Dog ownership appears to protect against incident disability among older Japanese adults. Additional benefits are gained from ownership combined with regular exercise. Daily dog care may have an important role to play in health promotion and successful aging.

Difference between "Physical Fitness Age" Based on Physical Function and Chronological Age Is Associated with Obesity, Hyperglycemia, Depressive Symptoms, and Low Serum Albumin

OBJECTIVES

This study aimed to (1) develop the physical fitness age, which is the biological age based on physical function, (2) evaluate the validity of the physical fitness age for the assessment of sarcopenia, and (3) examine the factors associated with the difference between physical fitness age and chronological age.

DESIGN

Cross-sectional study.

SETTING AND PARTICIPANTS

Community-dwelling older adults and outpatients.

MEASUREMENTS

A formula for calculating the physical fitness age was created based on the usual walking speed, handgrip strength, one-leg standing time, and chronological age of 4,076 older adults from the pooled data of community-dwelling and outpatients using the principal component analysis. For the validation of the physical fitness age, we also used pooled data from community-dwelling older adults (n = 1929) and outpatients (n = 473). Sarcopenia was diagnosed according to the Asian Working Group for Sarcopenia 2019 consensus. The association of D-age (the difference between physical and chronological ages) with cardiovascular risk factors, renal function, and cardiac function was examined.

RESULTS

The receiver operating characteristic analysis, with sarcopenia as the outcome, showed that the area under the curve (AUC) of physical fitness age was greater than that of chronological age (AUC 0.87 and 0.77, respectively, p < 0.001). Binomial logistic regression analysis revealed that the D-age was significantly associated with sarcopenia after adjustment for covariates (odds ratio 1.22, 95% confidence interval 1.19-1.26; p <0.001). In multivariate linear regression analysis with D-age as the dependent variable, D-age was independently associated with a history of diabetes mellitus (or hemoglobin A1c as a continuous variable), obesity, depression, and low serum albumin level. D-age was also correlated with estimated glomerular filtration rate derived from serum cystatin C, brain natriuretic peptide, and ankle-brachial index, reflecting some organ function and arteriosclerosis.

CONCLUSIONS

Compared to chronological age, physical fitness age calculated from handgrip strength, one-leg standing time, and usual walking speed was a better scale for sarcopenia. D-age, which could be a simple indicator of physical function, was associated with modifiable factors, such as poor glycemic control, obesity, depressive symptoms, and malnutrition.

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

OBJECTIVES

To 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.

DESIGN

A 5-year follow-up study.

SETTING

Ota City, Tokyo, Japan.

PARTICIPANTS

A total of 10,308 community-dwelling non-disabled adults aged 65-84 years.

MEASUREMENTS

Eating 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.

RESULTS

During 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.

CONCLUSION

Older 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.

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

BACKGROUND

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.

METHODS

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.

RESULTS

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.

CONCLUSION

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.

Identifying the specific associations between participation in social activities and healthy lifestyle behaviours in older adults

OBJECTIVES

To examine the longitudinal association between participation in social activities and healthy lifestyle behaviours.

STUDY DESIGN

This 2-year follow-up study used data from 6168 older adults (73.5 ± 5.3 years; 49% men). We studied participation in five types of social activities at baseline: participation in volunteer, sports, hobbies, senior clubs, and neighbourhood-association groups.

MAIN OUTCOME MEASURES

The healthy lifestyle behaviours were physical activity (time spent walking: ≥150 min/week; or less), eating habits (dietary variety score: ≥4 points; or less), and intellectual activity (subcomponents of the Tokyo Metropolitan Institute of Gerontology Index of Competence: 4 points; or less).

RESULTS

In the follow-up survey, 19% of participants were physically inactive, 53% had unfavourable eating habits, and 34% had diminished intellectual activity. Multilevel modified Poisson regression analysis showed that participation in sports groups was associated with a lower relative risk (RR) of physical inactivity (RR=0.82 [0.72, 0.93]) and unfavourable eating habits (RR=0.95 [0.90, 1.00]). Participation in hobby groups reduced the RR of unfavourable eating habits (RR=0.93 [0.90, 0.97]) and diminished intellectual activity (RR=0.90 [0.85, 0.96]). Participation in volunteering was associated with a lower RR of diminished intellectual activity (RR=0.84 [0.75, 0.95]). Relative to non-participation, participating in two or more social activities was associated with a 9% (95% CI: 0.83, 1.00) lower RR for physical inactivity, a 12% (95% CI: 0.82, 0.95) lower RR for unfavourable eating habits, and a 17% (95% CI: 0.77, 0.89) lower RR for diminished intellectual activity.

CONCLUSIONS

Both the nature and the number of social activities determine the longitudinal effects of social participation on healthy lifestyle behaviours.

Development of risk prediction models for incident frailty and their performance evaluation

There is currently no tool to predict incident frailty despite various frailty assessment tools. This study aimed to develop risk prediction models for incident frailty and evaluated their performance on discrimination, calibration, and internal validity. This 2-year follow-up study used data from 5076 non-frail older adults (51% women) living in Tokyo at baseline. We used the Kaigo-Yobo checklist, a standardised assessment instrument, to determine frailty. Twenty questionnaire-based variables that include sociodemographic, medical, behavioural, and subjective factors were entered into binary logistic regression analysis with stepwise backward elimination (p < 0.1 for retention in the model). Discrimination and calibration were assessed by area under the receiver operating characteristic curve (AUC) and the Hosmer-Lemeshow test, respectively. For the assessment of internal validity, we used a 5-fold cross-validation method and calculated the mean AUC. At the follow-up survey, 15.0% of men and 10.2% of women were frail. The frailty risk prediction model was composed of 10 variables for men and 11 for women. AUC of the model was 0.71 in men and 0.72 in women. The P-value for the Hosmer-Lemeshow test in both models was more than 0.05. For internal validity, the mean AUC was 0.71 in men and 0.72 in women. Probability of incident frailty rose with an increasing risk score that was calculated from the developed models. These results demonstrated that the developed models enable the identification of non-frail older adults at high risk of incident frailty, which could help to implement preventive approaches in community settings.

Nutritional status and body composition in cognitively impaired older persons living alone: The Takashimadaira study

OBJECTIVES

To investigate nutritional status and body composition in cognitively impaired older persons living alone.

METHODS

This cross-sectional study included 1051 older adults (633 women and 418 men, mean age: 77.1 years) from the Takashimadaira study. The study participants were categorized according to whether they lived alone, which was confirmed via questionnaire, and had cognitive impairment, which was defined as having a Mini Mental State Examination-Japanese score ≤23. Nutritional status was evaluated using the serum albumin level. The fat-free mass index (FFMI) was calculated based on anthropometric and body composition measurements. A logistic regression model with the outcome of a low serum albumin level (serum albumin <4 g/dL) and low FFMI (<16 kg/m2 in men and <14 kg/m2 in women) were used to analyze the data.

RESULTS

The percentages of participants in the living alone (-)/cognitive impairment (-) group, the living alone (+)/cognitive impairment (-) group, the living alone (-)/cognitive impairment (+) group, and the living alone (+)/cognitive impairment (+) group were 54.8%, 37.3%, 5.6%, and 2.3%, respectively. Compared to the living alone (-)/cognitive impairment (-) group, the living alone (+)/cognitive impairment (+) group was more likely to have a low serum albumin level (adjusted odds ratio = 3.10, 95% confidence interval = 1.31 to 7.33) and low FFMI (adjusted odds ratio = 2.79, 95% confidence interval = 1.10 to 7.06) after adjusting for potential confounders.

CONCLUSION

Cognitively impaired older adults living alone had poorer nutrition than cognitively normal and cohabitating persons in this study. Our results highlight the importance of paying extra attention to nutritional status for this group of community-dwelling older adults.

[Development of a risk prediction model and a sample risk chart for long-term care certification based on the functional health of older adults]

Objectives　The first aim of this study was to develop risk prediction models based on age, sex, and functional health to estimate the absolute risk of the 3-year incidence of long-term care certification and to evaluate its performance. The second aim was to produce risk charts showing the probability of the incident long-term care certification as a tool for prompting older adults to engage in healthy behaviors.Methods　This study's data was obtained from older adults, aged ≥65 years, without any disability (i.e., they did not certify≥care level 1) and residing in Yabu, Hyogo Prefecture, Japan (n=5,964). A risk prediction model was developed using a logistic regression model that incorporated age and the Kihon Checklist (KCL) score or the Kaigo-Yobo Checklist (KYCL) score for each sex. The 3-year absolute risk of incidence of the long-term care certification (here defined as≥care level 1) was then calculated. We evaluated the model's discrimination and calibration abilities using the area under the receiver operating characteristic curves (AUC) and the Hosmer-Lemeshow goodness-of-fit test, respectively. For internal validity, the mean AUC was calculated using a 5-fold cross-validation method.Results　After excluding participants with missing KCL (n=4) or KYCL (n=1,516) data, we included 5,960 for the KCL analysis and 4,448 for the KYCL analysis. We identified incident long-term care certification for men and women during the follow-up period: 207 (8.2%) and 390 (11.3%) for KCL analysis and 128 (6.6%) and 256 (10.2%) for KYCL analysis, respectively. For calibration, the χ² statistic for the risk prediction model using KCL and KYCL was: P=0.26 and P=0.44 in men and P=0.75 and P=0.20 in women, respectively. The AUC (mean AUC) in the KCL model was 0.86 (0.86) in men and 0.83 (0.83) in women. In the KYCL model, the AUC was 0.86 (0.85) in men and 0.85 (0.85) in women. The risk charts had six different colors, suggesting the predicted probability of incident long-term care certification.Conclusions　The risk prediction model demonstrated good discrimination, calibration, and internal validity. The risk charts proposed in our study are easy to use and may help older adults in recognizing their disability risk. These charts may also support health promotion activities by facilitating the assessment and modification of the daily behaviors of older adults in community settings. Further studies with larger sample size and external validity verification are needed to promote the widespread use of risk charts.

Interrelationships among whole-body skeletal muscle mass, masseter muscle mass, oral function, and dentition status in older Japanese adults

Background

Generalized loss of skeletal muscle mass (SMM) may modulate or otherwise affect the loss of masseter muscle mass and be responsible for low masseter muscle performance and strength (i.e., low oral function). Moreover, dentition status can affect oral function independent of the muscle state. This cross-sectional study aimed to simultaneously investigate the relationships among whole-body SMM, masseter muscle mass, oral function (masseter muscle performance and strength), and dentition status in 1349 Japanese adults (mean age = 73.6 years).

Methods

We determined the estimated masseter muscle mass (e-MMM) based on morphological measurements of the masseter muscle. Masseter muscle performance was assessed via masticatory performance evaluation scores using gum, and strength was assessed as the maximal occlusal force. Dentition status was assessed as the number of functional teeth. SMM was measured by bioelectrical impedance analysis. Structural equation modeling stratified by sex was employed to investigate associations among SMM, e-MMM, gum score, occlusal force, and number of functional teeth.

Results

The direct path from SMM to e-MMM was statistically significant, as was the direct path from e-MMM to oral function (gum score and maximum occlusal force) for both sexes. We additionally confirmed that SMM indirectly affected gum score and maximum occlusal force via e-MMM (men; standardized coefficient [95% CI] = 3.64 [1.31 to 5.96] for maximum occlusal force and 0.01 [0.01 to 0.02] for gum score, women; 2.01 [0.38 to 3.81] for maximum occlusal force and 0.01 [0.002 to 0.01] for gum score). The number of functional teeth had direct effects on e-MMM, gum score, and maximum occlusal force.

Conclusions

Low SMM was significantly indirectly associated with poor oral function through a low masseter muscle mass, and dentition status was independently associated with oral function.

Short-, Medium-, and Long-term Weight Changes and All-Cause Mortality in Old Age: Findings From the National Survey of the Japanese Elderly

BACKGROUND

Recent studies, predominantly in Western populations, suggest that both weight loss and weight gain are associated with an increased mortality risk in old age. However, evidence of this association in older Asian populations remains sparse. This study aimed to examine the association between weight change and all-cause mortality in a nationally representative sample of community-dwelling older Japanese people.

METHODS

Data were obtained from the National Survey of the Japanese Elderly, which included 4869 adults aged ≥60 years. Participants were followed for up to 30 years. We considered 3 indicators of weight change according to the follow-up interval: short-term (3 years), medium-term (6-7 years), and long-term (12-13 years). Weight change was classified as loss ≥ 5%, loss 2.5%-4.9%, stable (±2.4%), gain 2.5%-4.9%, and gain ≥ 5%. Cox proportional hazards models were used to calculate the relative mortality risk of each weight change category.

RESULTS

Weight loss ≥ 5% for all intervals was associated with higher mortality than stable weight and the effects were largely similar across all 3 intervals (hazard ratio [95% confidence interval]: 1.36 [1.22-1.51] for short-term, 1.36 [1.22-1.51] for medium-term, and 1.31 [1.11-1.54] for long-term). A similar pattern of results was observed among the young-old and old-old, and among men and women. The effect of weight loss on higher mortality was greater among those with a lower body mass index at baseline.

CONCLUSIONS

These findings could inform clinical and public health approaches to body-weight management aimed at improving the health and survival of older adults, particularly in Asian populations.

1184Combined association of living alone and dietary variety with mental health in older Japanese adults

Background

We examined whether dietary variety (DV) might alleviate poor mental health (MH) of living-alone (LA) older adults.

Methods

Cross-sensational data from 15073 (7566 men; 7507 women) residents aged 65-84 years were assessed using the WHO-Five Well-being Index to determine poor MH (defined by a score ≤ 12) and DV (low and high DV defined by a score ≤ 3 and ≥ 4, respectively). Participants were divided into living together with high DV (G1), living together with low DV (G2), LA with high DV (G3), and LA with low DV (G4). Logistic regression analyses stratified by gender were performed to examine the association of poor MH with LA and DV.

Results

Prevalence of LA, low DV, and poor MH were 13.6%, 63.3%, and 26.1%, respectively, in men, and 21.2%, 54.6%, and 24.8%, respectively, in women. Compared with the G1, the multivariate-adjusted odds ratios (ORs) (95% confidence intervals) for worse MH were 1.69 (1.49-1.93) for G2, 2.04 (1.50-2.78) for G3, and 3.34 (2.70-4.11) for G4 in men. Corresponding ORs were 1.73 (1.52-1.96), 1.02 (0.83-1.26), and 1.66 (1.36-2.01) in women.

Conclusions

The association of poor MH with LA was more apparent in older adults with low DV than in those with high DV; however, this association differed with gender.

Key message

Eating a variety of food may help alleviate the negative effects of living alone on mental health in older adults.

The relationship between blood pressure and cognitive function

Background

Although an elevated systolic blood pressure (SBP) is associated with cognitive dysfunction, BP may decrease with advanced cognitive dysfunction; therefore, we attempted to identify the turning point in the relationship between cognitive function and SBP in elderly subjects.

Methods

In pooled datasets of general populations and outpatient clinics (age>65 years), in which the risk of frailty or cognitive dysfunction was assessed (N = 4076), the relationship between SBP and the Mini Mental State Examination (MMSE) score was examined.

Results

Mean age was 72.5 ± 6.2 years (male 45.1%), and SBP was 133.0 ± 19.5 mmHg. In an analysis of locally weighted scatter plot smoothing, the relationship between SBP and MMSE scores changed at an MMSE score of 24 points. In subjects with preserved cognitive function (MMSE ≥24 points), MMSE scores decreased with increases in SBP (B = −0.047 per 10 mmHg increase, P = 0.002) after adjustments for age, sex, body mass index, alcohol habit, smoking status, diabetes, a history of stroke, and the geriatric nutritional index; however, in subjects with reduced cognitive function (MMSE<24 points), decreases in the MMSE score were associated with reductions in SBP (B = 1.178 per 1 point decrease in the MMSE score, P = 0.002).

Conclusion

The relationship between SBP and cognitive function changed at a MMSE score of approximately 24 points (mild to moderate cognitive dysfunction). In patients with preserved MMSE, higher BP values were associated with a reduction of cognitive function, but this was not a case for those with impaired MMSE.

Standardized gait speed ratio in elderly patients with heart failure

Aims

Although aging is strongly associated with both heart failure and a decline in gait speed, a definition of slowness incorporating an age‐related decline has yet to be developed. We aimed to define an event‐driven cut‐off for the relative decline in gait speed against age‐adjusted reference values derived from the general population and evaluate its prognostic implications.

Methods and results

Standardized gait speed (SGS) was defined as the median gait speed stratified by age, sex, and height in 3777 elderly (age ≥ 65 years) individuals without a history of cardiovascular diseases (Tokyo Metropolitan Institute of Gerontology‐Longitudinal Interdisciplinary Study on Aging: general population cohort). The mortality event‐driven optimal cut‐off of the SGS ratio (actual gait speed divided by the respective SGS) was defined using FRAGILE‐HF cohort data and externally validated using Kitasato cohort data, comprising 1301 and 1247 hospitalized elderly patients with heart failure, respectively. Using FRAGILE‐HF data, the optimal SGS ratio cut‐off was determined as 0.527. In the Kitasato cohort, SGS ratio < 0.527 was associated with a higher 1 year [hazard ratio (HR): 1.70, 95% confidence interval (CI): 1.07–2.72, P = 0.024] and long‐term (HR: 1.46, 95% CI: 1.05–2.02, P = 0.024) mortality rate, independent of pre‐existing covariates.

Conclusions

Gait speed was significantly declined in patients with heart failure, even after taking age and sex‐related decline into account. A SGS ratio of 0.527 is a validated cut‐off for slowness independently associated with mortality in patients with heart failure age ≥65.

[The effects of the "Tabepo Check Sheet," which lists 10 food groups, on the dietary variety of older adults in a metropolitan area]

Objectives　This study examined the effects of checking the "Tabepo Check Sheet," which has 10 food groups, on changes in dietary variety among older adults living in Japanese metropolitan areas.Methods　We used baseline and two-year follow-up data from a community-wide intervention to prevent frailty in Ota City, Tokyo. A total of 8,635 non-disabled residents (4,145 men and 4,490 women) aged 65-84 years who responded to the self-administered questionnaire surveys in 2016 and 2018, were included in the two analyses. In 2018, we asked about their experience with the "Tabepo Check Sheet," which had been distributed among participating communities from three districts in Ota City since July 2017. The "checked group" consists of those who answered "habitually check" or "have checked." Dietary variety was assessed using the Dietary Variety Score (DVS). We performed propensity score matching with a 1:1 ratio (checked group vs. non-checked group) for the following variables: demographic, socioeconomic, physical, medical, and lifestyle variables, and DVS. After propensity score matching, 876 participants from the checked and non-checked groups were selected. We used a two-way ANOVA to examine the changes in DVS over two years. We also compared the rates of DVS ≤3 and ≥7 points in 2018 using multivariate adjusted logistic regression analysis.Results　In 2018, 11.9% of the respondents had checked the "Tabepo Check Sheet." The DVS mean±standard deviation in the checked and non-checked groups were 3.9±2.2 points and 3.9±2.3 points in 2016, respectively, and 4.5±2.4 points and 4.1±2.4 points in 2018, respectively. The DVS showed a significant interaction between checking experience and time (p<0.001). The rates of DVS ≤3 points in 2018 were 35.2% and 43.8% among the checked and non-checked groups, respectively. The multivariate adjusted odds ratio (OR) of DVS ≤3 points was 0.68 (95% confidence interval [95% CI] 0.56-0.83) in the checked group versus the non-checked group. The rates of DVS ≥7 points in 2018 were 21.7% and 16.8% among the checked and non-checked groups, respectively. The multivariate adjusted OR (95% CI) of DVS ≥7 points was 1.40 (1.10-1.78) in the checked versus the non-checked group.Conclusions　These results suggest that checking the "Tabepo Check Sheet" may improve dietary variety. However, the effects of dietary variety improvement may be weakened by the incidence of skipped meals, social isolation, frailty, and lack of social participation.

[Trajectories of Dietary Variety Score among community-dwelling older Japanese and their related factors]

AIM

To categorize the age-related trajectories of dietary variety score (DVS) in the community-dwelling elderly and to examine the associated factors.

METHODS

The study population included 1,195 people who underwent a medical checkup for the elderly in Kusatsu-town, Gunma Prefecture in 2012 to 2017. A multinomial logistic regression analysis was performed to examine the factors associated with the age-related trajectories of DVS. The dependent variables were sex, age, family structure, years of education, BMI, subjective chewing ability, TMIG-IC, GDS-15, MMSE, smoking, alcohol consumption, and history of hypertension, dyslipidemia, diabetes mellitus, and stroke.

RESULTS

The adjusted odds ratio (95% confidence intervals) of the low trajectory group in comparison to the medium trajectory group were 2.69 (1.02-7.08) for subjective chewing ability (no chewing), 1.11 (1.06-1.17) for GDS-15, 1.76 (1.14-2.73) for current smoking, and 1.70 (1.19-2.43) for past smoking. In contrast, the adjusted odds ratio of the high trajectory group in comparison to the medium trajectory group were 0.61 (0.37-1.00) for men, 1.04 (1.01-1.07) for age, 0.58 (0.38-0.89) for subjective masticatory ability (difficult to chew), 0.88 (0.82-0.96) for GDS-15, and 0.55 (0.37-0.83) for a history of hypertension.

CONCLUSIONS

The age-related trajectory patterns of DVS in the community-dwelling elderly can be categorized into three types. In order to maintain a high quality of food intake, it was shown that, in addition to subjective masticatory ability and mental health factors, such as depression, we should pay attention to the control of hypertension, which is a risk factor for lifestyle diseases, and lifestyle habits such as smoking.

Oral frailty and gait performance in community-dwelling older adults: findings from the Takashimadaira study

PURPOSE

This cross-sectional study compared gait performance between community-dwelling older adults with and without accumulated deficits in oral health, defined as oral frailty.

METHODS

A total of 1,082 individuals (439 men and 643 women; mean age, 77.1 years) from the Takashimadaira study were included in the current analysis. Based on a multifaceted oral health assessment, oral frailty was defined as having three or more of the following six components: (i) fewer teeth, (ii) low masticatory performance, (iii) low articulatory oral motor skills, (iv) low tongue pressure, (v) difficulties in eating, and (vi) swallowing. Eight gait parameters were assessed using an electronic walkway. Gait characteristics comparison between groups with and without oral frailty was performed using multiple linear regression models. Models were adjusted for age, sex, educational status, income, smoking, drinking, physical activity level, height, body mass index, comorbidities, and the presence of chronic pain.

RESULTS

Oral frailty was observed in 227 (21.0%) participants. After adjusting for potential confounders, the participants with oral frailty had slower gait speed, shorter stride and step length, wider step width, and longer double support duration as well as higher variability of stride length and step length.

CONCLUSIONS

Oral frailty was associated with poor gait performance among community-dwelling older adults.

Sarcopenia: prevalence, associated factors, and the risk of mortality and disability in Japanese older adults

BACKGROUND

There is limited evidence on sarcopenia in Asian populations. This study aimed to clarify the prevalence, associated factors, and the magnitude of association with mortality and incident disability for sarcopenia and combinations of its components among Japanese community-dwelling older adults.

METHODS

We conducted a 5.8 year prospective study of 1851 Japanese residents aged 65 years or older (50.5% women; mean age 72.0 ± 5.9) who participated in health check-ups. Sarcopenia was defined according to the Asian Working Group for Sarcopenia 2019 algorithm. Appendicular lean mass index (ALMI) was measured using direct segmental multi-frequency bioelectrical impedance analysis. A Cox proportional hazards regression model was used to identify associations of sarcopenia and the combinations of its components with all-cause mortality and incident disability.

RESULTS

The prevalence of sarcopenia was 11.5% (105/917) in men and 16.7% (156/934) in women. Significant sarcopenia-related factors other than ageing were hypoalbuminaemia, cognitive impairment, low activity, and recent hospitalization (all P-values <0.05) among men and cognitive impairment (P = 0.004) and depressed mood (P < 0.001) among women. Individuals with sarcopenia had higher risks of mortality [hazard ratios (95% confidence interval): 2.0 (1.2-3.5) in men and 2.3 (1.1-4.9) in women] and incident disability [1.6 (1.0-2.7) in men and 1.7 (1.1-2.7) in women]. Compared with the individuals without any sarcopenia components, those having low grip strength and/or slow gait speed without low ALMI tended to have an increased risk of disability [1.4 (1.0-2.0), P = 0.087], but not mortality [1.3 (0.8-2.2)]. We did not find increased risks of these outcomes in participants having low ALMI in the absence of low grip strength and slow gait speed [1.2 (0.8-1.9) for mortality and 0.9 (0.6-1.3) for incident disability].

CONCLUSIONS

Japanese older men and women meeting Asian criteria of sarcopenia had increased risks of all-cause mortality and disability. There were no significant increased risks of death or incident disability for both participants with muscle weakness and/or low performance without low muscle mass and those with low muscle mass with neither muscle weakness nor low performance. Further studies are needed to examine the interaction between muscle loss, muscle weakness, and low performance for adverse health-related outcomes.

Differences in the association between white matter hyperintensities and gait performance among older adults with and without cognitive impairment

AIM

Gait impairment implies subtle cognitive impairment (CI) and is associated with severity of white matter hyperintensities (WMHs). However, cognitive differences in such an association are not yet fully understood. This study examined the association between WMHs and gait performance among three cognitively different older groups.

METHODS

Gait performance and WMHs were assessed in 150 community-dwelling older adults, comprising 53 with CI (Mini-Mental State Examination [MMSE] score <24), 63 with mild CI (MMSE score ≥24 and Montreal Cognitive Assessment [MoCA] score <25), and 34 who were cognitively normal or preserved (MMSE ≥24 and MoCA score ≥25). Gait velocity and variability were assessed on a 5-m electronic walkway. Furthermore, WMH volume was derived by automated segmentation using 1.5 T magnetic resonance imaging.

RESULTS

Adjusted multiple regression analyses showed that greater WMHs were associated with slower gait velocity and greater temporal (stride time) and spatial (stride and step lengths) variabilities among older adults with CI. In contrast, WMH was only associated with spatial variability in older adults with mild CI and in cognitively normal or preserved older adults.

CONCLUSIONS

Our findings suggest that gait variability measures are more sensitive to subtle underlying neurological pathologies including WMHs in older adults. The cognitive-dependent differences found in the association between WMHs and gait performance suggests that the level of cognitive function interferes with the association between WMH and gait performance. Geriatr Gerontol Int 2021; ••: ••-••.

Association of nutrient-derived dietary patterns with sarcopenia and its components in community-dwelling older Japanese: a cross-sectional study

Background

Diet is a modifiable factor affecting sarcopenia, and accumulating evidence links dietary factors to muscle mass, strength, and function in older adults. However, few studies have examined the association of dietary patterns with sarcopenia. This study examined the association of dietary patterns derived by reduced-rank regression (RRR) with sarcopenia and its components in community-dwelling older Japanese.

Methods

We conducted a cross-sectional study of 1606 community-dwelling adults aged 65 years or older. Dietary intake was assessed by a validated, self-administered diet history questionnaire. Nutrient-derived dietary patterns were identified by using RRR, with sarcopenia-related nutrients (protein, vitamin D, vitamin C, vitamin E, folate, vitamin K, magnesium, iron, and calcium intakes) as response variables. Sarcopenia was defined by using the algorithm of the Asian Working Group for Sarcopenia 2019. Multivariate regression and logistic regression were used to examine the association of dietary patterns with sarcopenia and its components.

Results

The first RRR dietary pattern was characterized by high intakes of fish, soybean products, potatoes, most vegetables, mushrooms, seaweeds, and fruit and a low intake of rice and was associated with decreased prevalence of sarcopenia: the multivariable-adjusted odds ratio of sarcopenia was 0.57 (95% confidence interval, 0.34–0.94; p for trend=0.022) in the highest versus the lowest tertile of dietary pattern. This dietary pattern was also significantly positively associated with usual gait speed (β: 0.02, p=0.024).

Conclusions

A dietary pattern characterized by high intakes of fish, soybean products, potatoes, most vegetables, mushrooms, seaweeds, and fruits and low rice intake was inversely associated with sarcopenia in community-dwelling older Japanese.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12937-021-00665-w.

Association between Oral Frailty and Dietary Variety among Community-Dwelling Older Persons: A Cross-Sectional Study

OBJECTIVE

To examine the association between the severity of oral frailty (OF), which is one of the comprehensive oral functions evaluated, and dietary variety in community-dwelling older persons.

DESIGN

Cross-sectional study.

SETTING

Community-based.

PARTICIPANTS

A total of 769 community-dwelling older persons aged 65 and over.

INTERVENTIONS

We examined basic demographic information, functional status, cognitive status, depressive symptoms, medical history, and oral functions of the participants.

MEASUREMENTS

OF was defined by 1-2 and 3 or more of 6 items of oral function evaluation in the pre-oral frailty and oral frailty groups, respectively. Dietary variety was assessed using the dietary variety score (DVS). The participants were categorized into 3 groups for evaluation: those with a low score (0-2), medium score (3-5), and high score (≥6). Ordinal logistic regression analysis was performed to examine the association between OF and DVS.

RESULTS

The rate of OF in the participants was 21.6%, and its severity was significantly associated with DVS after adjusting for potential confounders (Pre-OF; adjusted odds ratio [OR] = 1.687, 95% confidence interval [CI] = 1.219-2.335, OF; adjusted OR = 2.857, 95% CI = 1.489-5.484).

CONCLUSION

The severity of OF was significantly associated with DVS in community-dwelling older persons. This suggests that DVS may be useful in understanding the effects of OF on the nutritional status. Further longitudinal studies are needed to elucidate the association between OF and DVS.