Association of Psychosocial Conditions, Oral Health, and Dietary Variety with Intellectual Activity in Older Community-Dwelling Japanese Adults

Association between social isolation and diversity in food intake by gender in community-dwelling older adults: A cross-sectional study

AIM

Few studies have investigated the relationship between low dietary variety and clearly defined social isolation by gender. This study explored the association between dietary variety and social isolation, classified by operational definition, separately by gender in community-dwelling older adults.

METHODS

This cross-sectional study recruited respondents via mail. A total of 4798 participants aged ≥65 years participated in the on-site assessment. Social isolation was assessed by "lack of conversation," "lack of passive support," "lack of offering support," and "lack of social participation." Dietary variety was evaluated using the Dietary Variety Score (DVS).

RESULTS

The participants' median age was 73 (interquartile range 25-75: 69-77) years, and 2147 (44.7%) were male. After adjusting for covariates, with regard to male participants, a lack of offering support (β = -0.051, P = 0.019) and a lack of social participation (β = -0.089, P < 0.001) were associated with a low DVS. For female participants, only a lack of social participation was related to a low DVS (β = -0.067, P < 0.001). A lack of conversation and passive support were not associated with a low DVS for both genders (P >0.05).

CONCLUSION

The results indicate that encouraging social participation, regardless of gender, as well as preventing a lack of offering support for others among men, may contribute to improving individuals' DVS. Geriatr Gerontol Int 2024; ••: ••-••.

Relationships between locomotive and non-locomotive MVPA and 'ikigai' in older Japanese adults

Objective

This study aimed to investigate the relationship between physical activity (PA) of moderate to vigorous intensity (MVPA) and ikigai in older Japanese adults. We evaluated the amount of PA using an activity meter equipped with a three-axis accelerometer. The measured activities were classified into locomotive PA and non-locomotive PA to clarify not only the relationship between MVPA and ikigai, but the types of activities that lead to increased ikigai as well.

Methods

Participants were 86 community-dwelling older adult Japanese men and women. Measurement items included basic information (age, sex, BMI, and the number of underlying diseases), PA, Self-completed Occupational Performance Index (SOPI), and ikigai (the K-1 Scale). Confounding factors presumed to be related to ikigai were also elicited from previous studies. Associations of ikigai into three groups (high, middle, and low) with PA were analyzed by group comparisons and multivariate analyses.

Results

The comparison of PA indices among the high, middle, and low ikigai groups revealed that non-locomotive MVPA is significantly associated with ikigai (p < 0.05). In multiple comparisons, the low ikigai group was significantly and negatively affected by non-locomotive MVPA (p < 0.05) compared to the middle and high ikigai groups. Furthermore, in a multivariate analysis with ikigai as the dependent variable and sex, age, locomotive MVPA, and non-locomotive MVPA as independent variables, only non-locomotive MVPA (p < 0.05) was associated.

Discussion

These results suggest that non-locomotive MVPA is effective in enhancing ikigai.

Positive Association between High Protein Food Intake Frequency and Physical Performance and Higher-Level Functional Capacity in Daily Life

Nutritional factors, including low protein intake and poor dietary variety, affect age-associated impairment in physical performance resulting in physical frailty. This cross-sectional study investigated the association between intake frequency of major high protein foods and both physical performance and higher-level functional capacity using the food frequency score (FFS) and high protein food frequency score (PFFS) among community-dwelling older adults. The data of 1185 older adults categorized into quartiles based on FFS and PFFS were analyzed. After adjusting for covariates, FFS and PFFS were significantly associated with physical performance [FFS, usual gait speed (p for trend = 0.007); PFFS, usual gait speed (p for trend < 0.001), maximum gait speed (p for trend = 0.002), timed up and go (p for trend = 0.025)], and higher-level functional capacity [FFS (p for trend < 0.001); PFFS (p for trend < 0.001)]. After excluding PFFS data, the participants’ scores were associated with only higher-level functional capacity. Multi-regression analysis with higher-level functional capacity as the covariate showed that FFS and PFFS were significantly correlated with physical performance. Hence, improving food intake frequency, particularly that of high protein foods, and dietary variety may help maintain higher-level functional capacity and physical performance in community-dwelling older adults.

Gender differences in the relationship between personality, cognitive function and regular dental visits in Japanese community-dwelling older adults

OBJECTIVES

Studies have examined the association between personality and health behaviour, but research focusing exclusively on regular dental visits has yet to be conducted. This study examined the association between personality traits and regular dental visits among Japanese community-dwelling older adults.

METHODS

The participants in this cross-sectional study included 1,057 community-dwelling older adults aged 65-74 years from Ranzan and Yoshimi towns; data were collected from October to November 2015 and October to November 2016, respectively. Interviews were conducted to obtain sociodemographic, income, occupation and medical data. The Tokyo Metropolitan Institute of Gerontology Index of Competence was used to assess higher-level competence; general intelligence was also evaluated. The 'Big Five' personality traits-openness to experience, consciousness, neuroticism, extraversion and agreeableness-were also examined. A multivariable logistic regression analysis was performed to examine the relationship between regular dental visits and personality traits.

RESULTS

Among men, the number of natural teeth, current employment status and conscientiousness were associated with dental care utilization. Among women, the number of natural teeth, current annual income, the intellectual activity domain of the Tokyo Metropolitan Institute of Gerontology Index of Competence and openness were significant.

CONCLUSIONS

The factors associated with regular dental visits differed by gender. Overall, work was associated with men's visits, whereas intellectual activity and economic factors were relevant to women. Factors such as personality traits should be considered when addressing barriers to oral health. Understanding personality traits will help practitioners more effectively encourage older adults to make dental visits.

Regular dental visits may prevent severe functional disability: A community-based prospective study

BACKGROUND

Previous studies have shown that regular dental visits can affect the relationship of tooth loss with mortality and functional disability. However, the independent association between regular dental visits and incident functional disability is unclear.

METHODS

Our study participants were community-dwelling individuals aged ≥65 years, without disability at baseline. The outcome was the level of incident functional disability, as defined in a new certification of the public long-term care insurance. We defined no disability as no certification at follow-up, mild disability as support levels 1-2 and care level 1 (i.e., independent in basic ADL, but requiring some help in daily activities), and severe disability as care levels 2-5 (i.e., dependent in basic ADL). The exposure variable, based on the questionnaire, was regular dental visits at baseline. Covariates included gender, age, socio-economic status, health status, lifestyle habits, physical and mental functioning, and oral health variables. Using multinomial logistic regression, we calculated adjusted odds ratio (aOR) and 95 % confidence interval (CI) for mild disability and severe disability, with no disability as a reference category.

RESULTS

Among 8,877 participants, the 33-month cumulative incidence of mild and severe disability was 6.0 % and 1.8 %, respectively. After controlling for all covariates, regular dental visits at baseline were significantly associated with a lower risk of incident severe disability (aOR 0.65; 95 % CI, 0.46-0.91) but not the incidence of mild disability (aOR 0.96; 95 % CI, 0.79-1.17).

CONCLUSIONS

Encouraging dental visits may contribute to prevention of severe functional disability and extension of healthy life expectancy among community-dwelling older adults.

Does reduced mastication influence cognitive and systemic health during aging?

There is a growing body of literature which suggests that oral health and mastication can influence cognitive and systemic health during aging. However, it is currently unclear whether oral health, masticatory efficiency, cognitive health and systemic health merely deteriorate independently with age, or whether mechanisms exist linking mastication to cognitive and systemic health directly. The aim of this paper is to review the extent to which reduced mastication influences cognitive and systemic health during aging because this knowledge may underpin future interventions that improve quality of life. Current evidence suggests that a deterioration in mastication and oral health during aging can have: 1) direct effects on systemic health through mechanisms such as the migration of the oral microbiota into the systemic environment, and 2) indirect effects on systemic health through changes nutrient intake. A loss of teeth and reduction in masticatory efficiency during aging can have: 1) direct effects on cognitive performance and potentially impact cognitive health through mechanisms such as enhanced adult hippocampal neurogenesis, and 2) indirect effects on cognitive health through changes in nutrient intake. It is concluded that oral health and masticatory efficiency are modifiable factors which influence the risk poor cognitive and systemic health during aging, although it is currently premature to propose chewing-based interventions to slow the rate of cognitive decline and improve cognitive health during aging. Future research should include large-scale longitudinal studies which control for the types of confounding factors which concurrently influence the association between mastication and cognitive and systemic health.

Behavioral protective factors of increased depressive symptoms in community-dwelling older adults: A prospective cohort study

BACKGROUND

It remains unclear what kinds of behavior prevent the development of geriatric depression. This study aimed to elucidate behavioral predictors of increased depressive symptoms in older adults focusing on gender differences.

METHODS

A total of 3106 community-dwelling older people aged older than or equal to 65 years without depressive symptoms at baseline participated. The 15-item Geriatric Depression Scale was used to assess depressive symptoms with a score of 6 or more at baseline and 15 month follow-up. Behavioral status was investigated by using dichotomous questions about the aspects of physical, cognitive, and social activities. Each category included 3 specific items. Demographic data and other potential confounding factors were also assessed.

RESULTS

In the 15 month follow-up survey, 239 participants (7.7%) reported increased depressive symptoms. Multiple logistic regression analysis indicated that engagement in light physical exercise (odds ratio = 0.74, 95%, CI = 0.56-0.98), taking enrichment lessons (0.62, 0.46-0.85), using a personal computer (0.68, 0.48-0.97), participation in events at the community center (0.54, 0.40-0.72), and attending a community meeting (0.69, 0.52-0.92) were independently associated with lower risk of increased depressive symptoms. In a separate analysis for each gender, significant odds ratios of using a personal computer were observed in men, whereas significant odds ratios of light physical exercise, participation in events at the community center, and attending a community meeting were observed in women.

CONCLUSIONS

Light physical exercise, taking lessons, usage of a computer, and participation in community events showed protective effects against depressive symptoms. However, the significance of each behavioral factor may vary according to gender.