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.

Factors associated with inability to attend a follow-up assessment, mortality, and institutionalization among community-dwelling older people with cognitive impairment during a 5-year period: evidence from community-based participatory research.

BACKGROUND: The aim of the present study was to explore factors associated with (i) the inability to attend a follow-up assessment in the community-based participatory research (CBPR) framework; (ii) mortality; and (iii) institutionalization, across a 5-year period among older people with cognitive impairment identified via an epidemiological survey. METHODS: The participants were 198 older people whose score on the Mini-Mental State Examination was below 24, and who were living in our CBPR region in the Tokyo metropolitan area. Baseline data included sociodemographic factors, health-related factors, social factors, and assessments by healthcare professionals. Over the following 5 years we observed what happened to the subjects within the CBPR framework. Bivariate and stepwise multiple logistic regression analyses were performed to explore the factors associated with the inability to attend a follow-up assessment, 5-year mortality, and institutionalization. RESULTS: Participants who did not attend a follow-up assessment tended to live alone. Being older (>80), living with others, frailty, and the need for rights protection and daily living support were associated with increased mortality. Long-term care insurance certification was strongly associated with institutionalization as a natural consequence of the health-care system. Having dementia and low access to doctors were also positively associated with institutionalization. CONCLUSIONS: Older people with cognitive impairment who are living alone are at higher risk of being overlooked by society. To move toward more inclusive communities, the following are recommended: (i) more interventions focusing on older people living alone; (ii) social interventions to detect daily life collapse or rights violations; and (iii) more support to help people with dementia continue living in the community.

A comparison of colorimetric and visual methods for the assessment of masticatory performance with color-changeable chewing gum in older persons.

BACKGROUND/PURPOSE: Color-changeable chewing gum is used for the evaluation of masticatory performance. However, it is currently unclear whether colorimetric and visual assessment methods yield consistent results. This study aimed to clarify the consistency between colorimetric and visual methods used for the evaluation of color changes in color-changeable chewing gum. MATERIALS AND METHODS: The sample comprised 644 older persons (mean age, 75.4 ± 6.4 years). The chewing gum was masticated 60 times at the participant's own chewing rate and then expectorated. The color of the chewing gum was evaluated with the ΔE values and a∗ values, measured using a colorimeter, and the 10 Color Shades (10CSh) and 5 Color Scales (5CSc), using visual evaluation. Spearman's correlation analysis was performed to examine the correlation between the results obtained by the four methods. The significance level was set at α = 0.05. RESULTS: The ΔE values, a∗ values, 10CSh scores, and 5CSc scores were all significantly correlated. The highest correlation coefficient (0.979) was between the ΔE values and a∗ values. The lowest correlation coefficient (0.847) was between the a∗ values and 5CSc scores. Decreased masticatory performance was observed with increased age. CONCLUSION: Significant correlations were found for all four methods used in the assessment of masticatory performance with color-changeable chewing gum. While visually based assessments are valid, colorimetric methods are more sensitive to smaller changes in masticatory performance.

The Mini Nutritional Assessment-Short Form as a predictor of nursing home mortality in Japan: A 30-month longitudinal study.

OBJECTIVES: We examined whether the Mini Nutritional Assessment-Short Form (MNA®-SF) predicted mortality in 367 nursing home residents (82% women; mean age = 84.4 ± 8.5 years) in Japan. MEASUREMENTS: We examined participants' basic characteristics (sex, age, height, weight, and medical history), the Barthel index (BI), clinical dementia rating (CDR), and six items of the MNA®-SF. The association between the MNA®-SF and 30-month mortality was assessed using a Cox proportional regression analysis. RESULTS: During the study, 157 (42.8%) participants died. MNA®-SF scores in the Survival group were significantly higher than in the Death group (9.4 ± 2.1 vs. 8.4 ± 2.3, respectively; p < .001). After adjusting for age, sex, history of aspiration pneumonia, BI, and CDR, MNA®-SF scores were significantly associated with 30-month mortality (hazard ratio: 0.89, 95% confidence interval: 0.82-0.97, p = .005). CONCLUSION: The MNA®-SF was an effective predictor of mortality among nursing home residents in Japan, even after adjusting for potential confounders. These results indicate that periodically evaluating nutritional status using the MNA®-SF, and nutritional interventions according to status, may result in maintenance and improvement of nutritional status, as well as lead to reduced mortality.

Childhood socioeconomic disadvantage as a determinant of late-life physical function in older Japanese people.

BACKGROUND: In this study, we examined the relationship between childhood socioeconomic status and physical function among older Japanese people, and investigated whether there is a sex variation in this association. METHODS: We administered a cross-sectional questionnaire survey to all independent community-dwelling individuals ≥65 years old, living in Adachi Ward, Tokyo (N = 132,005). Participants self-reported their physical function using the Motor Fitness Scale, and we divided the scores into quartiles for analysis. Childhood socioeconomic status was retrospectively assessed according to a single item. RESULTS: We analyzed 75,358 questionnaires. The average age of participants was 73.8 ± 6.0 years, and 55.0% were women. An ordered logistic regression analysis showed that lower childhood socioeconomic status was associated with lower physical function, independent of adult sociodemographic factors, health behaviors, and health conditions. This association was stronger in women than in men. CONCLUSIONS: Our findings indicate that low childhood socioeconomic status might have a long-term influence on physical function in late life and that this influence varies by sex. Assessment of socioeconomic disadvantage in childhood is important for developing strategies to help older people maintain their physical function longer.

The Differential Effects of Age on the Association Between Childhood Socioeconomic Disadvantage and Subjective Symptoms of Dementia Among Older Japanese People.

BACKGROUND: Despite increasing evidence of an association between childhood socioeconomic disadvantage and cognitive outcomes, such as dementia and cognitive decline, in Western countries, there are no studies on this association from non-Western societies. We investigated the relationship between childhood socioeconomic status (SES) and subjective symptoms of dementia among community-dwelling older Japanese people and examined age and sex variations in this association. METHODS: Data were derived from a cross-sectional survey for all community-dwelling individuals aged 65 years and over in Adachi, Tokyo (n = 132,005). We assessed subjective dementia symptoms using a self-administered dementia checklist, which was validated by comparison with the Clinical Dementia Rating scale. RESULTS: Data from 75,358 questionnaires were analyzed. After adjusting for potential covariates, lower childhood SES was associated with greater likelihood of subjective dementia symptoms. We found a significant interaction between childhood SES and age on subjective dementia symptoms but no interaction between childhood SES and sex. Age-stratified analysis indicated that the association between lower childhood SES and subjective dementia symptoms was stronger in the ≥75 years subgroup than in the 65-74 years subgroup, indicating an effect modification of age on this association. CONCLUSIONS: Our findings suggested that low SES in childhood might have a long-term influence on dementia symptoms in late life and that this influence varied by age. This differential association might be explained by the social and historical context in Japan (ie, World War II, postwar chaos, and high economic growth) that has shaped participants' early experiences.

A 2-year longitudinal study of the relationship between masticatory function and progression to frailty or pre-frailty among community-dwelling Japanese aged 65 and older.

BACKGROUND: An association has recently been reported between frailty and reduced masticatory function; however, the causal relationship remains unclear. OBJECTIVE: The aim of this study was to clarify the relationship between masticatory function and frailty progression. METHODS: Among 6699 individuals aged 65 and older (mean age 72.8 ± 5.2 years) who were invited to participate in comprehensive medical check-ups, 418 who underwent examinations at the Tokyo Metropolitan Institute of Gerontology in both 2013 and 2015 and who met inclusion criteria were included in this study. Frailty was determined with the Kihon Checklist developed by the Japanese Ministry of Health, Labour and Welfare. The following three masticatory functions were evaluated: occlusal force, mixing ability and subjective chewing ability. The following confounding factors were investigated: age, sex, grip strength, comfortable walking speed, Mini-Mental State Examination (MMSE) score, Self-Rating Depression Scale (SDS) score, skeletal mass index (SMI), number of medications taken and number of remaining teeth. Statistical analysis was performed with binomial logistic regression analysis. RESULTS: Logistic regression analysis revealed that comfortable walking speed, SDS score, MMSE score and masticatory function were significantly related to progression to frailty or pre-frailty. Of the three masticatory function items evaluated, mixing ability and subjective chewing ability were related to frailty progression. CONCLUSION: Our results confirm that masticatory function was associated with the progression to pre-frailty or frailty among community-dwelling individuals 65 years and older over the 2-year period of this longitudinal study. Of the masticatory function items evaluated, mixing ability and subjective chewing ability were associated with frailty progression.

Factors affecting masticatory function of community-dwelling older people: Investigation of the differences in the relevant factors for subjective and objective assessment.

OBJECTIVE: This study aimed to examine relevant factors for subjective and objective assessment of masticatory functions and elucidate any differences between the two methods. BACKGROUND: Previous studies have reported that the results of subjective and objective assessment of masticatory function in older people do not necessarily agree. MATERIALS AND METHODS: This study included 487 community-dwelling Japanese older people (205 male and 282 female; mean age 74.1±6.3 years) who participated in a comprehensive geriatric health examination. Basic information (gender and age), higher level of competence in daily living, depression, subjective masticatory function (SMF) and objective masticatory function (OMF) assessments, cognitive function, skeletal muscle mass, handgrip strength, gait speed and oral status (number of remaining and functional teeth, mouth dryness and occlusal force) were recorded. RESULTS: Multiple logistic regression analysis showed that depression (odds ratio [OR]: 1.181, 95% confidence interval [CI]: 1.094-1.275), mouth dryness (OR: 2.037, CI: 1.212-3.423) and occlusal force (OR: 0.997, CI: 0.996-0.999) were significantly associated with SMF, whereas higher level of competence in daily living (OR: 0.730 CI: 0.586-0.910), skeletal muscle mass (OR: 0.521 CI: 0.283-0.960), number of functional teeth (OR: 0.862 CI: 0.775-0.959), number of remaining teeth (OR: 0.868 CI: 0.810-0.930) and occlusal force (OR: 0.994, CI: 0.991-0.998) were associated with OMF. CONCLUSION: Subjective masticatory functionSMF and OMF were associated with different factors, suggesting that both mental and physical factors should be taken into consideration when treating decreased masticatory function.