Adherence to the food-based Japanese dietary guidelines and prevalence of poor oral health-related quality of life among older Japanese adults in the Kyoto-Kameoka study

Oral frailty is associated with mortality independently of physical and psychological frailty among older adults

BACKGROUND

Although oral frailty is independently associated with an increased risk of mortality, evidence for the usefulness of screening tools for oral frailty is less than that for physical frailty screening tools. We aimed to investigate the relationship between oral frailty and mortality in older adults.

METHODS

This prospective cohort study included 11,374 adults aged ≥65 years, who provided valid responses to a baseline mail survey questionnaire from the Kyoto-Kameoka study. Oral frailty status was evaluated using the Oral Frailty Index-8 (range, 0 [best] to 10 [worst]). Participants were classified into four categories according to the Oral Frailty Index-8: robust (score, 0-2), oral pre-frailty (score, 3), oral frailty (score, 4-6), and oral severe frailty (score ≥ 7). Physical and psychological frailty were evaluated using the validated frailty-screening index and defined as a score of ≥3 out of a possible 5 points. Mortality data were collected from 30 July 2011 to 30 November 2016. Hazard ratios (HR) for all-cause mortality were calculated using a multivariable Cox proportional hazards model.

RESULTS

During the 5.3-year median follow-up period (57,157 person-years), 1184 deaths were recorded. After adjusting for confounders, including physical and psychological frailty, medical history, and lifestyle, in comparison with a robust oral status, oral pre-frailty (HR, 1.29; 95 % confidence interval [CI], 1.02-1.63), oral frailty (HR, 1.22; 95 % CI, 1.01-1.48), and oral severe frailty (HR, 1.43; 95 % CI, 1.16-1.76) were associated with higher HRs of mortality (p for trend = 0.002).

CONCLUSION

Oral frailty is associated with mortality independent of physical and psychological frailty in older adults. The Oral Frailty Index-8 may be useful for identifying individuals at high risk of mortality.

Curcumin effects on age-related changes in oral immunity: an in vivo study

The current study aimed to investigate the effects of ageing on oral immunity using β-defensin (DEFB) 1/2 as a marker and evaluate the effects of curcumin (CUR) on these processes. The study sample included thirty male C57BL/6J mice divided into three groups based on the treatment method used. The young control (YC) and old control (OC) groups received 0·5 % methylcellulose-400 (CUR vehicle) orally for 5 days, whereas the CUR group of older mice received a CUR solution suspended in 0·5 % methylcellulose-400 (dose: 3·0 mg/kg body). DEFB1/2 and immune indicator levels were measured in the saliva and salivary glands post-treatment. The saliva volume and protein content were significantly reduced in the OC group compared with the YC group. CUR administration restored these parameters, decreased DEFB1 expression in the salivary gland and increased DEFB1/2 secretion and DEFB2 expression. These findings were supported by epigenetic gene regulation and partial cytokine activation from changes in WD40 repeat protein 5, TNF alpha and IL-1beta. CUR can partially restore age-related changes in oral immune responses and promote oral health, thereby preventing frailty in the older population through a nutritional therapeutic pathway.

Dose-Response Relationships between Diet Quality and Mortality among Frail and Non-Frail Older Adults: A Population-Based Kyoto-Kameoka Prospective Cohort Study

OBJECTIVES

Although better diet quality is inversely associated with mortality risk, the association between diet quality and mortality remains unclear in frail and non-frail older adults. Thus, we aimed to examine this association in older Japanese adults.

DESIGN

A prospective cohort study.

SETTING AND PARTICIPANTS

We used the data of 8,051 Japanese older adults aged ≥65 years in the Kyoto-Kameoka study.

MESUREMENTS

Dietary intake was estimated using a validated food frequency questionnaire. Diet quality was evaluated by calculating the adherence scores to the Japanese Food Guide Spinning Top (range, 0 [worst] to 80 [best]), which were stratified into quartiles. Frailty status was assessed using the validated self-administered Kihon Checklist (KCL) and the Fried phenotype (FP) model. Survival data were collected between February 15, 2012 and November 30, 2016. Statistical analysis was performed using the multivariate Cox proportional hazard analysis and the spline model.

RESULTS

During the median 4.75-year follow-up (36,552 person-years), we recorded 661 deaths. After adjusting for confounders, compared with the bottom adherence score quartile, the top quartile was associated with lower hazard ratio (HR) of mortality in frailty (HR, 0.73; 95% confidence interval [CI], 0.54-1.00) and non-frailty, as defined by the KCL (HR, 0.72; 95% CI, 0.52-1.01). In the spline model, regardless of frailty status defined by the KCL and FP model, adherence score showed a strongly dose-dependent inverse association with mortality up to approximately 55 points; however, no significant differences were observed thereafter. This association was similar to the results obtained in individuals with physical, cognitive, and depression as domains of KCL in the spline model.

CONCLUSIONS

Our findings demonstrate an L-shaped association between diet quality and mortality in both frail and non-frail individuals. This study may provide important knowledge for improving poor diet quality in older individuals with frailty or domains of frailty.

Diet quality and physical or comprehensive frailty among older adults

Purpose

While the association between diet quality and mortality has been previously demonstrated, the association between frailty and diet quality has not been evaluated well. This study aimed to investigate the association between diet quality and prevalence of both physical and comprehensive frailty, using two validated tools, in a community-based cohort of older adults.

Methods

We conducted cross-sectional analyses using baseline data of 7022 participants aged ≥ 65 years in the Kyoto-Kameoka study. Diet quality was assessed by calculating the adherence scores to the Japanese Food Guide Spinning Top using a validated questionnaire; the participants were stratified into quartile groups based on these scores. Physical and comprehensive frailty was assessed using the Fried phenotype model-based Frailty Screening Index and the Kihon Checklist, respectively. Multivariable logistic regression and the restricted cubic spline model were used to calculate odds ratios (ORs) and their 95% confidence intervals (CIs) for associations between adherence scores and frailty prevalence.

Results

Higher adherence scores signified a higher intake of vitamin C, vegetables, dairy products, and fruits. Physical and comprehensive frailty prevalence was 14.2 and 35.8%, respectively. In a multivariable adjusted model, compared with the bottom adherence score quartile, the top quartile was associated with lower ORs of physical (OR 0.64; 95% CI 0.52–0.80) and comprehensive frailty (OR 0.60; 95% CI 0.51–0.71). These relationships were similar to results in the spline model.

Conclusions

This study shows an inverse dose–response relationship between diet quality and prevalence of both physical and comprehensive frailty in older adults.