Association of Tooth Loss with New-Onset Parkinson's Disease: A Nationwide Population-Based Cohort Study

Ultrastructural localization of Porphyromonas gingivalis gingipains in the substantia nigra of Parkinson's disease brains

Gingipains are protease virulence factors produced by Porphyromonas gingivalis, a Gram-negative bacterium best known for its role in chronic periodontitis. Gingipains were recently identified in the middle temporal gyrus of postmortem Alzheimer's disease (AD) brains, where gingipain load correlated with AD diagnosis and tau and ubiquitin pathology. Since AD and Parkinson's disease (PD) share some overlapping pathologic features, including nigral pathology and Lewy bodies, the current study explored whether gingipains are present in the substantia nigra pars compacta of PD brains. In immunohistochemical techniques and multi-channel fluorescence studies, gingipain antigens were abundant in dopaminergic neurons in the substantia nigra of both PD and neurologically normal control brains. 3-dimensional reconstructions of Lewy body containing neurons revealed that gingipains associated with the periphery of alpha-synuclein aggregates but were occasionally observed inside aggregates. In vitro proteomic analysis demonstrated that recombinant alpha-synuclein is cleaved by lysine-gingipain, generating multiple alpha-synuclein fragments including the non-amyloid component fragments. Immunogold electron microscopy with co-labeling of gingipains and alpha-synuclein confirmed the occasional colocalization of gingipains with phosphorylated (pSER129) alpha-synuclein. In dopaminergic neurons, gingipains localized to the perinuclear cytoplasm, neuromelanin, mitochondria, and nucleus. These data suggest that gingipains localize in dopaminergic neurons in the substantia nigra and interact with alpha-synuclein.

Oral health experiences of people living with Parkinson's disease: a scoping review

Background and aim Parkinson's disease is the fastest growing and second most common progressive neurodegenerative condition in the UK; poised to represent a major societal and health care challenge. The scoping review aims to provide an overview of the literature on the oral health (OH) experiences of people living with Parkinson's, identifying current research gaps and future priorities.Method Search strategies included three electronic databases, two grey literature databases, relevant organisations, specialist journals and hand searching of the reference lists. A data extraction tool was developed and piloted.Results A total of 121 items were included in the review. Four themes were identified: OH impact, education and training, service delivery and wider impacts of OH for people with Parkinson's (PwP). The majority of studies included were cross-sectional in design, describing the OH status of PwP.Conclusion The majority of research to date has focused on OH impact. Areas for future research include use of qualitative studies exploring the experiences, attitudes and priorities of PwP and their care partners. Inclusion of medical, dental and allied health care professionals, together with people with lived experience, is required to develop, implement and evaluate interventions to support OH.

Oral pathogens exacerbate Parkinson's disease by promoting Th1 cell infiltration in mice

BACKGROUND

Parkinson's disease (PD) is a common chronic neurological disorder with a high risk of disability and no cure. Periodontitis is an infectious bacterial disease occurring in periodontal supporting tissues. Studies have shown that periodontitis is closely related to PD. However, direct evidence of the effect of periodontitis on PD is lacking. Here, we demonstrated that ligature-induced periodontitis with application of subgingival plaque (LIP-SP) exacerbated motor dysfunction, microglial activation, and dopaminergic neuron loss in 1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced PD mice.

RESULTS

The 16S rRNA gene sequencing revealed that LIP-SP induced oral and gut dysbiosis. Particularly, Veillonella parvula (V. parvula) and Streptococcus mutans (S. mutans) from oral ligatures were increased in the fecal samples of MPTP + LIP-SP treated mice. We further demonstrated that V. parvula and S. mutans played crucial roles in LIP-SP mediated exacerbation of motor dysfunction and neurodegeneration in PD mice. V. parvula and S. mutans caused microglial activation in the brain, as well as T helper 1 (Th1) cells infiltration in the brain, cervical lymph nodes, ileum and colon in PD mice. Moreover, we observed a protective effect of IFNγ neutralization on dopaminergic neurons in V. parvula- and S. mutans-treated PD mice.

CONCLUSIONS

Our study demonstrates that oral pathogens V. parvula and S. mutans necessitate the existence of periodontitis to exacerbate motor dysfunction and neurodegeneration in MPTP-induced PD mice. The underlying mechanisms include alterations of oral and gut microbiota, along with immune activation in both brain and peripheral regions. Video Abstract.

Better oral hygiene is associated with a reduced risk of osteoporotic fracture: a nationwide cohort study

Background

The aim of this study was to examine the longitudinal association between oral health parameters and osteoporotic fracture.

Methods

The study included participants who received oral health screening by dentists from the National Health Screening cohort database of Korea between 2003 and 2006. The primary outcome was osteoporotic fracture occurrence, which was defined using specific international classification of diseases-10 codes; vertebral fracture (S22.0, S22.1, S32.0, S32.7, T08, M48.4, M48.5, and M49.5), hip fracture (S72.0 and S72.1), distal radius fracture (S52.5 and S52.6), and humerus fracture (S42.2 and S42.3). The presence of periodontitis and various oral health examination findings, such as missing teeth, caries, frequency of tooth brushing, and dental scaling, were analyzed using a Cox proportional hazard model to assess their association with osteoporotic fracture occurrence.

Results

The analysis included a total of 194,192 participants, among whom 16,683 (8.59%) developed osteoporotic fracture during a median follow-up of 10.3 years. Poor oral health status, including periodontitis (adjusted hazard ratio [aHR]: 1.09, 95% confidence interval [CI]: 1.01-1.18, p = 0.039), a higher number of missing teeth (≥15; aHR: 1.59, 95% CI: 1.45-1.75, p < 0.001), and dental caries (≥6; aHR: 1.17, 95% CI: 1.02-1.35, p = 0.030), was associated with an increased risk of osteoporotic fracture. On the other hand, better oral hygiene behaviors such as brushing teeth frequently (≥3 times per day; aHR: 0.82, 95% CI: 0.78-0.86, p < 0.001) and having dental scaling within 1 year (aHR: 0.87, 95% CI: 0.84-0.90, p < 0.001) were negatively associated with the occurrence of osteoporotic fracture.

Conclusion

The study found that poor oral health, such as periodontitis, missing teeth, and dental caries, was associated with an increased risk of osteoporotic fracture. Conversely, good oral hygiene behaviors like frequent teeth brushing and dental scaling within 1 year were associated with a reduced risk. Further research is needed to confirm this association.

Association of high estimated glomerular filtration rate with risk of atrial fibrillation: a nationwide cohort study

Aim

While the relationship between impaired kidney function and atrial fibrillation (AF) is well established, there is limited research exploring the association between elevated estimated glomerular filtration rate (eGFR) and AF development. This study aimed to examine the association between higher-than-normal eGFR and AF risk using a nationwide longitudinal study of the general population in Korea.

Materials and methods

This study utilized the National Health Insurance Service cohort database of Korea, analyzing data from 2,645,042 participants aged 20-79 years who underwent health examinations between 2010 and 2011. Participants with a history of end-stage renal disease, renal transplantation, and AF prior to the index date were excluded. Renal function was assessed using eGFR levels, calculated with the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation. Baseline characteristics were gathered through questionnaires, while comorbidities and AF occurrence outcomes were identified and validated using diagnostic codes and medication histories. The study employed Kaplan-Meier survival curves and Cox proportional hazard models to evaluate the association between eGFR and AF occurrence.

Results

The mean age of subjects was 48.82 ± 10.08 years. Over a median follow-up of 9.58 years, 27,469 (1.04%) AF cases were identified. The risk for AF increased in the higher-than-normal decile, as demonstrated by Kaplan-Meier survival curves (p < 0.001). The eGFR <30 mL/min/1.73 m2 group was associated with an increased risk of AF [hazard ratio (HR): 1.22, 95% confidence interval (CI) (1.01, 1.46), p = 0.039], while the eGFR >120 mL/min/1.73 m2 group was associated with a decreased risk of AF [HR: 0.88, 95% CI (0.78, 0.98), p = 0.045]. Compared to the 5th decile, the 1st [HR: 1.08, 95% CI (1.03, 1.13), p = 0.010] eGFR decile was significantly associated with an increased risk of AF, while the 10th [HR: 0.77, 95% CI (0.70, 0.85), p < 0.001] eGFR decile was significantly associated with a reduced risk of AF.

Conclusion

The study revealed that individuals with eGFR>120 mL/min/1.73 m2 or those falling within eGFR 10th decile (>113.41 mL/min/1.73 m2) demonstrated an inverse association linked to a reduced risk of AF. Our study suggests that general population with higher-than-normal eGFR levels may have a lower risk of developing AF.

Association between periodontal disease status and risk of atrial fibrillation: a nationwide population-based cohort study

BACKGROUND

Periodontal disease can activate an immune process linked to systemic diseases, including atrial fibrillation. However, the relationship between periodontal disease and atrial fibrillation remains unclear.

AIM

This study aimed to investigate whether changes in periodontal disease status are associated with the risk of atrial fibrillation.

METHODS

Using the National Health Insurance Database Korea, participants who underwent the first oral health examination in 2003 and a second examination in 2005-2006 without a history of atrial fibrillation were included. Participants were grouped according to changes in periodontal disease status during two oral examinations: periodontal disease-free, periodontal disease-recovered, periodontal disease-developed, and periodontal disease-chronic. The outcome was the incidence of atrial fibrillation.

RESULTS

The study included 1,254,515 participants, with a median follow-up of 14.3 years and 25,402 (2.02%) cases of atrial fibrillation occurred. During follow-up, the risk of atrial fibrillation was highest in the periodontal disease-chronic group, followed by the periodontal disease-developed, periodontal disease-recovered, and periodontal disease-free groups (p for trend < 0.001). Moreover, recovery from periodontal disease was associated with a reduced risk of atrial fibrillation compared to a chronic periodontal disease status (Hazard ratio: 0.97, 95% Confidence interval: 0.94-0.99, p = 0.045). The development of periodontal disease was associated with an increased risk of atrial fibrillation compared to being periodontal disease-free (Hazard ratio: 1.04, 95% Confidence interval: 1.01-1.08, p = 0.035).

CONCLUSION

Our findings suggest that changes in periodontal disease status impact the risk of atrial fibrillation. Management of periodontal disease may help prevent atrial fibrillation.

Better oral hygiene is associated with a reduced risk of cataract: A nationwide cohort study

Objective

To investigate the association of oral health status and oral hygiene behaviors with cataract occurrence longitudinally.

Materials and methods

Based on the National Health Screening cohort database of Korea, participants who underwent oral health screening by dentists in 2003 were included. Cataract was defined as two or more claims of disease classification for the International Classification of Diseases-10 (E10.34, E11.34, E12.34, E13.34, E14.34, H25, and H26) with cataract specific treatment or surgery procedure claim codes. The occurrence of cataract was analyzed with Cox proportional hazard model according to the presence of periodontitis and oral health examination findings, including missing teeth, caries, tooth brushing, and dental scaling.

Results

Overall, 103,619 subjects were included. During a median follow-up of 12.2 years, cataract developed in 12,114 (11.7%) participants. Poor oral health status such as the presence of periodontitis (adjusted hazard ratio [HR] 1.08, 95% CI [confidence interval] 0.99-1.17, p = 0.088) and increased number of missing teeth (adjusted HR = 1.74, 95% CI = 1.55-1.96, p < 0.001) was associated with the increased cataract risk. Better oral hygiene behaviors such as increased frequency of tooth brushing (adjusted HR = 0.84, 95% CI = 0.79-0.88, p < 0.001) and performed dental scaling within 1 year (adjusted HR = 0.90, 95% CI = 0.86-0.94, p < 0.001) were negatively associated with cataract occurrence.

Conclusion

Periodontitis and increased number of missing teeth may increase the risk of cataract. However, maintaining good oral hygiene through tooth brushing and dental scaling may reduce the risk of future cataract occurrence. Further studies should be performed to confirm the association between chronic oral inflammation and cataract.

Periodontal health in a population with Parkinson's disease in Spain: a cross-sectional study

BACKGROUND

The aim of this research is to evaluate the periodontal health of patients with Parkinson Disease (PD) in a Spanish cohort.

MATERIAL AND METHODS

A cross-sectional study was performed on 104 patients with PD (mean age: 66.19+9.3 years) and 106 controls (mean age: 59.26+14.11 years). A pre-designed clinical protocol was implemented, which included a standardized epidemiological index for periodontal disease (CPITN), clinical attachment loss (CAL), tooth-loss, full mouth plaque index (FMPI), and oral hygienic habits. Univariate descriptions and comparative analysis were performed.

RESULTS

The majority of PD patients presented good oral hygienic habits. There were no significant differences in relation to CPITN, periodontitis, gingival recessions and tooth loss. However, moderate/severe CAL (p=0.027) and FMPI (p=0.003) was higher in the PD group.

CONCLUSIONS

There were no differences on periodontitis and tooth loss between both groups. The higher number of advanced CAL and presence of biofilm in the PD group could be related to the difficulties to perform an effective tooth brushing due to this neurological disorder.

Research progress on the relationship between chronic periodontitis and Parkinson's disease

Chronic periodontitis is an infectious disease, which has a reciprocal relationship with a variety of systemic disorders. Parkinson's disease is a prevalent neurodegenerative disease in which inflammation plays an important role for its progression. A vast number of studies suggest that there is a potential connection between chronic periodontitis and neurodegenerative diseases such as Parkinson's disease. Individuals with Parkinson's disease usually have poor periodontal health, and their oral flora composition differs from that of healthy people; at the same time, patients with chronic periodontitis have a higher risk of Parkinson's disease, which can be reduced with regular periodontal treatment. In fact, the mechanism of interaction between chronic periodontitis and Parkinson's disease is not clear. According to several studies, the clinical symptoms of Parkinson's disease prevent patients to maintain oral hygiene effectively, increasing the risk of periodontitis. Neuroinflammation mediated by microglia may be the key to the influence of chronic periodontitis on Parkinson's disease. Periodontal pathogens and inflammatory mediators may enter the brain and activate microglia in various ways, and ultimately leading to occurrence and development of Parkinson's disease. This article reviews the recent research progress on the association between chronic periodontitis and Parkinson's disease, and its potential mechanism to provide information for further research.

Association between Findings in Oral Health Screening and Body Mass Index: A Nation-Wide Longitudinal Study

Oral diseases, such as periodontitis and dental caries, can cause systemic inflammation as well as local effects, which is an important contributing factor for obesity. We aimed to investigate the change in body mass index (BMI) according to the presence of periodontitis and oral hygiene indicators. This study enrolled 110,068 participants from the national health screening cohort in Korea from 2009–2010 who underwent an oral health checkup. As oral hygiene indicators, the presence of periodontitis, dental caries, tooth loss, and tooth brushing were assessed. We constructed a linear mixed model for BMI. BMI was repeatedly measured in the health examination until 2015. In the multivariate linear mixed model for BMI, the presence of periodontitis (β = 0.0687, standard error (SE) = 0.0225, p = 0.002), dental caries (β = 0.0735, SE = 0.0152, p < 0.001), and tooth loss (β = 0.1328, SE = 0.0175, p < 0.001) were positively associated with BMI. In contrast, frequent tooth brushing (≥3 times/day) was negatively associated with BMI (β = −0.2610, SE = 0.0306, p < 0.001). The presence of periodontitis, dental caries, and tooth loss may be associated with higher BMI, whereas frequent tooth brushing may be related to lower BMI. Better oral hygiene might be associated with lower BMI. Further study is needed to determine the effect of oral health behavior and dental disease on obesity.

Evaluation of the association between periodontitis and risk of Parkinson's disease: a nationwide retrospective cohort study

The objective of this study was to examine the association between periodontitis and risk of incident Parkinson’s disease using large-scale cohort data on the entire population of South Korea. Health checkup data from 6,856,180 participants aged 40 and older were provided by the National Health Insurance Service of South Korea between January 1, 2009, and December 31, 2009, and the data were followed until December 31, 2017. The hazard ratio (HR) of Parkinson’s disease and 95% confidence interval (CI) were estimated using a Cox proportional hazards model adjusted for potential confounders. The incidence probability of Parkinson’s disease was positively correlated with the presence of periodontitis. The HR of Parkinson’s disease for the participants without the need of further dentist visits was 0.96 (95% CI 0.921–1.002); the HR of Parkinson’s disease increased to 1.142 (95% CI 1.094–1.193) for the individuals who needed further dentist visits. Compared to individuals without periodontitis and without metabolic syndrome, the HR of incident Parkinson’s disease gradually increased for individuals with periodontitis, with metabolic syndrome, and with both periodontitis and metabolic syndrome. People with periodontitis and metabolic syndrome had the highest HR of incident Parkinson’s disease, at 1.167 (95% CI 1.118–1.219). In conclusion, a weak association between periodontitis and Parkinson’s disease was suggested after adjusting for confounding factors from the population-based large-scale cohort of the entire South Korean population.