Number of Teeth and Denture Use Are Associated with Frailty among Chinese Older Adults: A Cohort Study Based on the CLHLS from 2008 to 2018

Associations between the oral microbiome, number of teeth and frailty among American adults: A cross-sectional study from NHANES 2009-2012

BACKGROUND

The intricate interrelationship between oral health, the number of teeth, oral microbiota, and frailty remains largely unexplored in clinical research. This study aimed to investigate the interrelationship between oral microbiome, the number of teeth, and frailty.

METHODS

Data from 4518 participants in NHANES 2009-2012 were analyzed. Frailty was measured using the 48-item Frailty Index (FI). Multivariable logistic regression and restricted cubic spline (RCS) evaluated associations between alpha diversity and frailty. Mediation analysis was used to assess the role of number of teeth. The associations between oral microbiome diveristy and mortality were analyzed by Cox regression. Beta diversity was examined with PCoA and PERMANOVA.

RESULTS

The prevalence of frailty was 39.73 %. Univariate analysis showed that alpha diversity indices except for the Simpson index were significantly lower in frailty, and after adjusted for confounders, observed ASVs (adjusted OR: 0.80 [0.73, 0.87], p < 0.001), Faith's PD (adjusted OR: 0.81 [0.74, 0.88], p < 0.001) and Shannon-Weiner index (adjusted OR: 0.88 [0.81, 0.95], p = 0.002) were remained significantly associated with frailty. The reduced number of teeth partially mediated the relationship (for Faith's PD: βindirect = -0.001 [-0.003, 0.000], p = 0.036, proportion: 8.33 % [0.00 %, 37.50 %]; for Shannon-Weiner index, βindirect = -0.007 [-0.013, -0.002], p = 0.007, Proportion = 17.07 % [3.39 %, 65.00 %]). Univariable Cox proportional hazard regression showed that all alpha diversity indices were significantly associated with all-cause mortality in frail population, and in multivariable analysis, Shannon-Weiner index (HR: 0.72 [0.55, 0.94], p = 0.017) and Simpson index (HR: 0.71 [0.60, 0.83], p < 0.001) remained statistically significant. PCoA showed that beta diversity was also significantly associated with frailty.

CONCLUSION

Lower oral microbiome diversity is associated with higher frailty and mortality. The number of teeth partially mediates this link, emphasizing the importance of oral health in mitigating frailty and promoting healthy aging.

Examining the Impact of Natural Teeth Trajectory on Mortality Among CLHLS

BACKGROUND

To investigate the associations between trajectories of the number of natural teeth and all-cause mortality among Chinese middle-aged and older adults.

METHODS

Data for this study were sourced from the 2002, 2005, 2008, 2011, 2014, and 2018 waves of the Chinese Longitudinal Healthy Longevity Survey (CLHLS). The number of natural teeth was assessed through self-reports. Population-based trajectory models were utilised to explore potential heterogeneity in longitudinal changes over 16 years and to examine the associations between baseline predictors and different trajectories among cohort members. Additionally, the Cox proportional hazards model was employed to assess the risk factors associated with these trajectories.

RESULTS

Three distinct trajectories in the number of natural teeth were identified: fewer teeth (33.34%), a moderate number of teeth (47.58%), and most teeth retained (19.08%). Several factors were found to influence changes in these trajectories: older age, male gender, poor self-reported health status, impaired vision, a higher number of chronic diseases, diminished cognitive function, and reduced frequency of social activities. Compared to the group with fewer teeth, those with moderate and most teeth demonstrated a better prognosis.

CONCLUSION

The number of natural teeth is associated with mortality, and retaining more natural teeth may play a significant role in promoting healthy aging.

Association between oral health status and frailty in older adults: a systematic review and meta-analysis

Aim

This study aims to explore the association between oral health status and frailty in older adults using comprehensive and objective oral health measurement indicators.

Method

This study conducted a collection and retrieval of relevant literature in the following English databases: PubMed, Embase, Cochrane Library, and Web of Science (up to July 1, 2024). After screening the literature according to the specified inclusion and exclusion criteria, the quality of the literature was assessed using the Joanna Briggs Institute critical appraisal tool and the Newcastle-Ottawa Scale. The degree of heterogeneity was then represented by the I 2 statistic, and based on this result, a random-effects or fixed-effects model was determined for analysis. Odds ratios (OR)/standardized mean differences (SMD) and 95% confidence intervals were employed to identify the association between various oral health indicators and frailty. Sensitivity analysis was performed for all outcomes.

Results

A total of 28 articles were included. Number of teeth (SMD: -0.591), functional dentition (≥21 teeth) (OR: 0.236), no false teeth (OR: 0.733), ≤20 teeth/with denture (OR: 2.320), tooth brushing daily (OR: 0.562), tongue pressure/decreased tongue pressure (SMD: -0.582/OR: 1.618), occlusal force/occlusal force reduced (SMD: -0.526/OR: 1.846), oral diadochokinesis hypofunction (OR: 1.876), poor mixing ability (OR: 2.303) and oral health assessment tool scores ≥4 (OR: 2.501) were correlated with frailty in older adults.

Conclusion

Various types of oral health indicators are associated with frailty in older adults. Investigating the relationship between oral health and frailty in older adults is of significant importance for preventing frailty, ensuring the quality of life for older adults, and promoting healthy longevity.

Systematic review registration

PROSPERO CRD42024587687.

Association between dietary patterns and existing natural teeth in Chinese elderly: a national community-based study

Objective

To promote healthy aging, we aimed to evaluate the independent and joint effects of protein, sugar-salt, and anti-inflammatory diets on existing natural teeth among the Chinese elderly, and further explore the mediating role of body mass index (BMI).

Methods

Based on the 2017-2019 Chinese Longitudinal Healthy Longevity Survey (CLHLS), 11,608 participants aged 65 and above were recruited in this cross-sectional study. Protein, sugar-salt, and anti-inflammatory diets were measured via a simplified 13-item dietary frequency questionnaire (dietary frequency around age 60). Restricted cubic spline and multiple linear regression analyses evaluated associations between dietary patterns and existing natural teeth, and mediation analysis explored BMI's role.

Results

Protein and anti-inflammatory diets were positively and linearly associated with existing natural teeth, while sugar-salt diets were negatively and linearly associated. Compared with the low dietary patterns (Q1), high protein and anti-inflammatory diets (Q4) were associated with a higher number of teeth (β: 1.70, 95%CI: 1.14, 2.25; β: 1.98, 95%CI: 1.45, 2.51, respectively; and 28% and 38% risk decreased for fewer than 20 teeth, respectively), whereas high sugar-salt diets had the lowest number (β: -1.14, 95%CI: -1.61, -0.67; 44% risk increased for fewer than 20 teeth). We further found a joint effect of low protein, high sugar-salt, and low anti-inflammatory diets on existing natural teeth (β: -1.97, 95% CI: -2.61, -1.33). Moreover, BMI mediated 10.88%, 19.69%, and 10.74% of the effects of the protein, sugar-salt, and anti-inflammatory diets with existing teeth, respectively.

Conclusion

Promoting high protein and anti-inflammatory diets and reducing sugar-salt intake in elderly individuals may reduce tooth loss, possibly partly mediated through overweight or obesity.

Association between oral health and physio-cognitive decline syndrome of older adults in China and its sex differences: a cross-sectional study

BACKGROUND

Physio-Cognitive Decline Syndrome (PCDs) is characterized by the coexistence of MIND (mobility impairment, no disability) and CIND (cognitive impairment, no dementia), which predicts dementia risk. Deteriorating oral health can contribute to malnutrition, cognitive decline, and physical frailty, all of which may exacerbate PCDs symptoms. This study investigates the association between oral health and PCDs, exploring sex differences in this relationship.

METHOD

A cross-sectional analysis of the baseline data from the Nanjing Brain Health Cohort included 252 participants aged 60 and older, assessing physical mobility (6-meter walk test, grip strength), cognitive function (MoCA), and oral health (natural teeth count, denture use, tongue and lip motor function, masticatory and swallowing ability, Oral Frailty Index). Logistic regression models were used to examine associations between oral health and PCDs.

RESULTS

Among participants, 15.5% were classified as having PCDs. The odds of having PCDs were lower with a higher number of teeth (OR = 0.939, 95% CI: 0.890-0.991, p = 0.021), while impaired tongue and lip motor function increased the odds of PCDs (OR = 3.811, 95% CI: 1.059-13.717, p = 0.041). In females, the odds of MIND and CIND were lower with a greater number of teeth and denture use. For males, the odds of PCDs were higher with oral frailty (OR = 5.202, 95% CI: 1.429-18.940, p = 0.012).

CONCLUSIONS

Findings underscore the significant association between oral health and the odds of PCDs among older adults, with sex-specific effects. For women, maintaining natural teeth and proper denture use are associated with lower odds of MIND and CIND, while for men, oral frailty is linked to higher odds of PCDs. Healthcare providers should consider oral health and incorporate sex-specific strategies.

Tooth loss trajectories and their association with all-cause mortality among older Chinese adults

Background

The association between tooth loss trajectories and all-cause mortality has not been sufficiently explored. This study aims to examine the relationship between tooth loss trajectories and all-cause mortality in Chinese adults aged 65 years and older.

Methods

This study included 3,726 participants from the Chinese Longitudinal Healthy Longevity Study (CLHLS). The inclusion criteria required participants to be aged 65 years or older, with complete data on tooth count at baseline and at least one follow-up survey. Participants were excluded if they had missing data on death, time to death, or if their they reported tooth count showed an abnormally high increase. The mean age of participants was 85.16 ± 10.7 years. To identify distinct trajectories of tooth loss, growth mixture models (GMM) were employed. Cox regression analysis was utilized to assess the association between tooth loss trajectories and all-cause mortality. Sensitivity analyses were conducted to test the robustness of the findings, while subgroup analyses were performed to explored potential variations in association across different demographic groups.

Results

The prevalence of edentulism at baseline was 37.13%, with a cumulative incidence of 15.8% over 10-year period. Three distinct tooth loss trajectories were identified during follow-up of 9.41 years: (1) progressively mild loss: comprising 312 participants (8.37%); (2) progressively severe loss, comprising 505 participants (13.55%); and (3) edentulism group, comprising 2,909 participants (78.07%). The median follow-up times for each group were 5.91 years, 3.44 years, and 1.84 years, respectively. During the follow-up period, the number of deaths were 114 (36.54%) in the progressively mild loss group, 274 (54.26%) in the progressively severe loss group, and 2,284 (78.51%) in the edentulism group. Compared to the progressively mild loss group, the hazard ratio (HR) for all-cause mortality was 1.29 (95% CI, 1.01-1.64) in the progressively severe loss group, and 1.60 (95% CI, 1.28-1.99) in the edentulism group.

Conclusions

This study identified three distinct tooth loss trajectories among older Chinese adults, with the edentulism group exhibiting the strongest association with all-cause mortality. These findings highlight the crucial importance of maintaining oral health and preserving natural teeth to promote longevity and improve overall health outcomes in older adults.

Does low body weight mediate the relationship between tooth loss and cognitive impairment? A longitudinal cohort study of an older Chinese population

OBJECTIVE

Our study aimed to investigate the relationship between the number of teeth remaining and cognitive impairment among Chinese older adults, and to explore the role of low body weight in this association.

METHODS

Data were drawn from 2011 to 2014 surveys of the Chinese Longitudinal Healthy Longevity Survey (CLHLS), involving 4056 respondents who had no cognitive decline and aged ≥ 65 years at baseline. Cognitive function was measured by the Mini-Mental Status Examination (MMSE), and the cognitive impairment was classified according to the length of education. Number of natural teeth was self-reported (classified as ≥ 20, 10-19, 1-9, and 0). Low body weight was defined as having a body mass index (BMI) of less than 18.5 kg/m2. Cox proportional hazards regression and mediation effect analyses were applied in the study.

RESULTS

Comparing with participants with ≥ 20 teeth, 10-19 teeth and 1-9 teeth, those with 0 teeth (HR:2.14, 95% CI: 1.51, 3.03) were significantly associated with higher cognitive impairment risk in the fully adjusted model. Compared with denture users, the fully adjusted HR (95% CI) for non-denture users was 1.33 (1.04, 1.70). no teeth with non-denture users had the highest cognitive impairment risk (HR:1.63, 95% CI: 1.10, 2.41). Low body weight mediated 6.74% (ranging from 3.49 to 11%) of the association between the number of teeth remaining and cognitive impairment.

CONCLUSION

Tooth loss increases the risk of cognitive decline, and low body weight partially mediates this association.

CLINICAL TRIAL NUMBER

This is a retrospective cohort study targeting a population survey, which does not involve clinical trials and does not have clinical trial numbers.

Linear and non-linear associations of depressive symptoms with oral health knowledge, attitudes, and practices among rural older adults in China: a cross-sectional study

BACKGROUND

Depression affects the oral health of older adults; however, little is known about its impact on oral health among rural older adults in developing countries, which warrants further research. Taking China as an example, there is a large population base of rural older adults suffering from depression, and many rural older people also have long-term oral health problems, which have seriously affected their quality of life in later life. Therefore, this study aimed to explore linear and non-linear associations of depressive symptoms with oral health knowledge, attitudes, and practices among rural older adults in China.

METHODS

From November 2020 to December 2020, 1,902 rural community-dwelling older people aged 60 years and older were investigated, via a cross-sectional survey. The general information, depressive status, oral health knowledge, attitudes, and practices of the participants were obtained through face-to-face structured questionnaires. Among them, the Zung Depression Self-Rating Scale was used to investigate the depressive symptoms of the participants in this survey. The generalized linear model and classification and regression tree model were used, separately.

RESULTS

Based on linear analysis results, we found that minimal to mild depressive symptoms [regression coefficient (β) = -0.345; 95% confidence interval (CI): -0.582 to -0.109, P = 0.004] and depressive symptoms (β = -1.064; 95% CI: -1.982 to -0.146, P = 0.023) were significantly correlated with oral health knowledge. A negative correlation was observed between minimal to mild depressive symptoms (β = -0.385; 95% CI: -0.600 to -0.170, P < 0.001) and oral health attitudes. In addition, while both minimal to mild depressive symptoms (β = 0.018; 95% CI: -0.312 to 0.347, P = 0.916) and depressive symptoms (β = 0.604; 95% CI: -0.675 to 1.883, P = 0.355) were associated with oral health practices. Furthermore, the non-linear analysis showed a combined effect of depressive symptoms on oral health attitudes, indicating that older people of a younger age, not living alone, and not suffering from depressive symptoms are more likely to report better oral health attitudes.

CONCLUSION

Both the linear and non-linear analyses in our study showed that depressive symptoms are significantly correlated with the poor oral health attitudes of older adults in rural communities. Furthermore, depressive symptoms were associated with oral health knowledge in the linear analysis. However, no statistically significant difference was found between depressive symptoms and oral health practices in either analysis. This research deepens our knowledge and understanding of relevant evidence in the mental and oral health of people in later life. In addition, analyzing the factors that affect the oral health of older people from the perspective of their depressive status provides new thinking directions and scientific references for improving the oral health of older adults in practical life.

Causal effects of denture wearing on epigenetic age acceleration and the mediating pathways: a mendelian randomization study

BACKGROUND

The epigenetic-age acceleration (EAA) represents the difference between chronological age and epigenetic age, reflecting accelerated biological aging. Observational studies suggested that oral disorders may impact DNA methylation patterns and aging, but their causal relationship remains largely unexplored. This study aimed to investigate potential causal associations between dental traits and EAA, as well as to identify possible mediators.

METHODS

Using summary statistics of genome-wide association studies of predominantly European ancestry, we conducted univariable and multivariable Mendelian randomization (MR) to estimate the overall and independent effects of ten dental traits (dentures, bleeding gums, painful gums, loose teeth, toothache, ulcers, periodontitis, number of teeth, and two measures of caries) on four EAA subtypes (GrimAge acceleration [GrimAA], PhenoAge acceleration [PhenoAA], HannumAge acceleration [HannumAA] and intrinsic EAA [IEAA]), and used two-step Mendelian randomization to evaluate twelve potential mediators of the associations. Comprehensive sensitivity analyses were used to verity the robustness, heterogeneity, and pleiotropy.

RESULTS

Univariable inverse variance weighted MR analyses revealed a causal effect of dentures on greater GrimAA (β: 2.47, 95% CI: 0.93-4.01, p = 0.002), PhenoAA (β: 3.00, 95% CI: 1.15-4.85, p = 0.001), and HannumAA (β: 1.96, 95% CI: 0.58-3.33, p = 0.005). In multivariable MR, the associations remained significant after adjusting for periodontitis, caries, number of teeth and bleeding gums. Three out of 12 aging risk factors were identified as mediators of the association between dentures and EAA, including body mass index, body fat percentage, and waist circumference. No evidence for reverse causality and pleiotropy were detected (p > 0.05).

CONCLUSIONS

Our findings supported the causal effects of genetic liability for denture wearing on epigenetic aging, with partial mediation by obesity. More attention should be paid to the obesity-monitoring and management for slowing EAA among denture wearers.

The relationship between healthy lifestyles and cognitive function in Chinese older adults: the mediating effect of depressive symptoms

BACKGROUND

Previous studies have proven the positive relationship between healthy lifestyles and cognitive function in older adults. However, the specific impacts and mechanisms require further investigation. Therefore, this study aimed to investigate whether healthy lifestyles and cognitive function were associated with Chinese older adults and whether depressive symptoms mediated their association.

METHODS

8272 valid samples were included using the latest data from the Chinese Longitudinal Healthy Longevity Survey (CLHLS). Pearson's test was applied to investigate the relationship between the key variables. Regression models were employed to examine the mediating effects of healthy lifestyles, using Sobel's test and the bootstrap method to confirm path effects.

RESULTS

There was a significant correlation between healthy lifestyles, depressive symptoms, and cognitive function (p < 0.01). Healthy lifestyles directly impact cognitive function (β = 0.162, p < 0.01). Healthy lifestyles had a significant effect on depressive symptoms (β=-0.301, p < 0.01), while depressive symptoms have a significant impact on cognitive function (β=-0.108, p < 0.01). Depressive symptoms partially mediated the effect of healthy lifestyles on cognitive function (β = 0.032, p < 0.01). The Sobel and bootstrap tests confirmed the robustness of the regression analysis results.

CONCLUSION

Depressive symptoms mediate the relationship between healthy lifestyles and cognitive function. Our findings suggest that prevention strategies for cognitive impairment in older adults should focus on healthy lifestyles and mental health.