Association of periodontitis with leukocyte telomere length in US adults: A cross-sectional analysis of NHANES 1999 to 2002

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.

Association of Tooth Loss and Diet Quality with Acceleration of Aging: Evidence from NHANES

BACKGROUND

Although tooth loss is widely recognized as a typical sign of aging, whether it is associated with accelerated aging, and to what extent diet quality mediates this association are unknown.

METHODS

Data were collected from the National Health and Nutrition Examination Survey. The missing tooth counts were recorded as the number of edentulous sites. Phenotypic accelerated aging was calculated using 9 routine clinical chemistry biomarkers and chronological age. Healthy Eating Index 2015 (HEI-2015) score was used to evaluate diet quality. Multivariate logistic regression and linear regression were used to analyze the association between tooth loss and accelerated aging. Mediation analyses were used to examine the mediation role of diet quality in the association.

RESULTS

The association between tooth loss and accelerated aging was confirmed. The highest quartile of tooth loss showed a positive association with accelerated aging (β=1.090; 95% confidence interval, 0.555 to 1.625; P < .001). Diet quality decreased with increase number of missing teeth and showed a negative association with accelerated aging. Mediation analysis suggested that the HEI-2015 score partially mediated the association between tooth loss and accelerated aging (proportion of mediation: 5.302%; 95% confidence interval, 3.422% to 7.182%; P < .001). Plant foods such as fruits and vegetables were considered the key mediating food.

CONCLUSIONS

The association between tooth loss and accelerated aging, as well as the partially mediating role of dietary quality in this association was confirmed. These findings suggested that more attention should be paid to the population with severe tooth loss and the changes of their dietary quality.

An Overview of Systemic Health Factors Related to Rapid Oral Health Deterioration among Older People

The oral health of older individuals can be negatively impacted by various systemic health factors, leading to rapid oral health deterioration. This paper aims to present an overview of the published evidence on systemic health factors that contribute to rapid oral health deterioration in older individuals, and to explore the implications of these factors for both general healthcare and oral healthcare provision. Older people are at risk of experiencing adverse reactions to medications due to multimorbidity, polypharmacy, and changes in pharmacokinetics and pharmacodynamics. Hyposalivation, a significant side effect of some medications, can be induced by both the type and number of medications used. Frailty, disability, sarcopenia, care dependency, and limited access to professional oral healthcare can also compromise the oral health of older people. To prevent rapid oral health deterioration, a comprehensive approach is required that involves effective communication between oral healthcare providers, other healthcare providers, and informal caregivers. Oral healthcare providers have a responsibility to advocate for the importance of maintaining adequate oral health and to raise awareness of the serious consequences of weakened oral health. By doing so, we can prevent weakened oral health from becoming a geriatric syndrome.

Reverse causal relationship between periodontitis and shortened telomere length: Bidirectional two-sample Mendelian random analysis

Background

Observational studies have demonstrated a link between shortened telomere lengths(TL) and chronic periodontitis. However, whether the shortened TL is the cause or the result of periodontitis is unknown.Therefore, our objective was to investigate a bidirectional causal relationship between periodontitis and TL using a two-sample Mendel randomized (MR) study.

Methods

A two-sample bidirectional MR analysis using publicly available genome-wide association study (GWAS) data was used. As the primary analysis, inverse variance weighting (IVW) was employed. To identify pleiotropy, we used leave-one-out analysis, MR-Egger, Weighted median, Simple mode, Weighted mode, and MR pleiotropy residual sum and outlier (MR-PRESSO).

Results

In reverse MR results, a genetic prediction of short TL was causally associated with a higher risk of periodontitis (IVW: odds ratio [OR]: 1.0601, 95% confidence interval [CI]: 1.0213 to 1.1002; P =0.0021) and other complementary MR methods. In the forward MR analysis, periodontitis was shown to have no significant effect on TL (IVW: p = 0.7242), with consistent results for the remaining complementary MR. No pleiotropy was detected in sensitivity analysis (all P>0.05).

Conclusion

Our MR studies showed a reverse causal relationship, with shorten TL being linked to a higher risk of periodontitis, rather than periodontitis shorten that TL. Future research is needed to investigate the relationship between cell senescence and the disease.

Senescent CD4+CD28- T Lymphocytes as a Potential Driver of Th17/Treg Imbalance and Alveolar Bone Resorption during Periodontitis

Senescent cells express a senescence-associated secretory phenotype (SASP) with a pro-inflammatory bias, which contributes to the chronicity of inflammation. During chronic inflammatory diseases, infiltrating CD4⁺ T lymphocytes can undergo cellular senescence and arrest the surface expression of CD28, have a response biased towards T-helper type-17 (Th17) of immunity, and show a remarkable ability to induce osteoclastogenesis. As a cellular counterpart, T regulatory lymphocytes (Tregs) can also undergo cellular senescence, and CD28⁻ Tregs are able to express an SASP secretome, thus severely altering their immunosuppressive capacities. During periodontitis, the persistent microbial challenge and chronic inflammation favor the induction of cellular senescence. Therefore, senescence of Th17 and Treg lymphocytes could contribute to Th17/Treg imbalance and favor the tooth-supporting alveolar bone loss characteristic of the disease. In the present review, we describe the concept of cellular senescence; particularly, the one produced during chronic inflammation and persistent microbial antigen challenge. In addition, we detail the different markers used to identify senescent cells, proposing those specific to senescent T lymphocytes that can be used for periodontal research purposes. Finally, we discuss the existing literature that allows us to suggest the potential pathogenic role of senescent CD4⁺CD28⁻ T lymphocytes in periodontitis.

Periodontitis and Accelerated Biological Aging: A Geroscience Approach

As the whole world is epidemically aging, the burden of periodontitis and tooth loss is becoming a major health concern. Growing meta-epidemiological data implicate chronic systemic inflammation/infection due to periodontitis as an independent risk factor for aging-related diseases and mortality. However, because people age differently, chronological age is not a reliable marker of an individual's functional status. Recent advances in geroscience have shown that various biomarker signatures of biological aging are longitudinally associated with declined physical function, morbidity, and mortality due to major age-related diseases, including periodontitis. Here, we emphasize novel research developments bidirectionally linking periodontitis to accelerated biological aging. Using a composite biomarker age estimator, a striking increase in periodontitis and tooth loss was observed in subjects whose biological age at baseline was higher than their chronological age. Moreover, significantly shortened telomeres were encountered in populations affected by severe periodontitis. Second, we elucidate the cellular and molecular pillars of the aging process at the periodontal level. Accumulating evidence suggests that cellular senescence, stem cell exhaustion, and immunoaging are hallmarks of biological aging implicated in the impairment of periodontal homeostasis and the pathophysiology of periodontitis. Indeed, persistent bacteria-derived lipopolysaccharide stimulation influences cellular senescence in osteocytes, driving alveolar bone resorption. Moreover, inflammaging status induced by chronic hyperglycemia elevates the burden of senescent cells in gingival tissues, impairing their barrier function. Lastly, we reviewed a recent breakthrough in senotherapy to directly target the mechanisms of aging at the periodontal level. Physical exercise and intermittent fasting, together with natural compounds, senolytic drugs, and cell therapy, are increasingly being evaluated to rejuvenate the oral cavity. Following these innovations in geroscience, further advancements could provide oral clinicians the chance to intercept biological aging when still "subclinical" and set interventions for halting or delaying the trajectory toward aging-related diseases while patients are still chronologically young.