Relationship between Blood and Standard Biochemistry Levels with Periodontitis in Parkinson's Disease Patients: Data from the NHANES 2011-2012

Association of dietary selenium intake and all-cause mortality of Parkinson's disease and its interaction with blood cadmium level: a retrospective cohort study

BACKGROUND

Parkinson's disease (PD) is a slowly progressive neurodegenerating disease that may eventually lead to disabling condition and pose a threat to the health of aging populations. This study aimed to explore the association of two potential risk factors, selenium and cadmium, with the prognosis of Parkinson's disease as well as their interaction effect.

METHODS

Data were obtained from the National Health and Nutrition Examination Survey (NHANES) 2005-2006 to 2015-2016 and National Death Index (NDI). Participants were classified as Parkinson's patients by self-reported anti-Parkinson medications usage. Cox regression models and restricted cubic spline models were applied to evaluate the association between PD mortality and selenium intake level as well as blood cadmium level. Subgroup analysis was also conducted to explore the interaction between them.

RESULTS

A total of 184 individuals were included. In full adjusted cox regression model (adjusted for age, gender, race, hypertension, pesticide exposure, smoking status and caffeine intake), compared with participants with low selenium intake, those with normal selenium intake level were significantly associated with less risk of death (95%CI: 0.18-0.76, P = 0.005) while no significant association was found between low selenium intake group and high selenium group (95%CI: 0.16-1.20, P = 0.112). Restricted cubic spline model indicated a nonlinear relationship between selenium intake and PD mortality (P for nonlinearity = 0.050). The association between PD mortality and blood cadmium level was not significant (95%CI: 0.19-5.57, P = 0.112). However, the interaction term of selenium intake and blood cadmium showed significance in the cox model (P for interaction = 0.048). Subgroup analysis showed that the significant protective effect of selenium intake existed in populations with high blood cadmium but not in populations with low blood cadmium.

CONCLUSION

Moderate increase of selenium intake had a protective effect on PD mortality especially in high blood cadmium populations.

Glucose-6-Phosphatase-Dehydrogenase activity as modulative association between Parkinson's disease and periodontitis

The association between periodontitis (PD) and Parkinson's disease (PK) is discussed due to the inflammatory component of neurodegenerative processes. PK severity and affected areas were determined using the following neuropsychological tests: Unified Parkinson's Disease Rating Score (UPDRS) and Hoehn and Yahr; non-motoric symptoms by Non-Motor Symptoms Scale (NMSS), and cognitive involvement by Mini-Mental State Examination (MMSE). Neuroinflammation and the resulting Glucose-6-Phosphatase-Dehydrogenase (G6PD) dysfunction are part of the pathophysiology of PK. This study aimed to evaluate these associations in periodontal inflammation. Clinical data and saliva-, serum-, and RNA-biobank samples of 50 well-characterized diametric patients with PK and five age- and sex-matched neurologically healthy participants were analyzed for G6PD function, periodontal pathogens (Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola, Prevotella intermedia, Campylobacter rectus, Fusobacterium nucleatum, and Filifactor alocis), monocyte chemoattractant protein (MCP) 1, and interleukin (IL) 1-beta. Regression analysis was used to identify associations between clinical and behavioral data, and t-tests were used to compare health and disease. Compared with PK, no pathogens and lower inflammatory markers (p < 0.001) were detectible in healthy saliva and serum, PK-severity/UPDRS interrelated with the occurrence of Prevotella intermedia in serum as well as IL1-beta levels in serum and saliva (p = 0.006, 0.019, 0.034), Hoehn and Yahr correlated with Porphyromonas gingivalis, Prevotella intermedia, RNA IL1-beta regulation, serum, and saliva IL1-beta levels, with p-values of 0.038, 0.011, 0.008, <0.001, and 0.010, while MMSE was associated with Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum, serum MCP 1 levels, RNA IL1-beta regulation and G6PD serum activity (p = 0.036, 0.003, 0.045, <0.001, and 0.021). Cognitive and motor skills seem to be important as representative tests are associated with periodontal pathogens and oral/general inflammation, wherein G6PD-saliva dysfunction might be involved.

Clinical trial registration

https://www.bfarm.de/DE/Das-BfArM/Aufgaben/Deutsches-Register-Klinischer-Studien/_node.html, identifier DRKS00005388.

Association between dietary intake and risk of Parkinson's disease: cross-sectional analysis of survey data from NHANES 2007-2016

Background

While dietary factors have shown an association with Parkinson's disease (PD), the available data remains a subject of ongoing debate and controversy.

Aim

We sought to evaluate potential relationships between dietary consumption of nutrients and micronutrients and risk of PD in a large sample.

Methods

Cross-sectional data were retrospectively analyzed for 10,651 adults aged 40-80 years that had been collected in the US between 2007 and 2016 as a component of the nationwide National Health and Nutrition Examination Survey. Aspects of dietary intake were compared between those who reported having specific PD medication regimens or not when they completed the survey, and potential associations between diet and risk of PD were explored using binomial logistic regression. We employed Propensity Score Matching (PSM) to minimize the impact of potential confounding factors, thus enhancing the reliability of the results. Additionally, subgroup analysis based on gender and age was conducted to investigate these relationships.

Results

Higher dietary intake of iron was linked to greater PD risk [odds ratio (OR) 1.065, 95% confidence interval (CI) 1.019-1.114, p = 0.006], whereas risk decreased with higher intake of vitamin K (OR 0.999, 95% CI 0.998-1.000, p = 0.024) or vitamin C (OR 0.998, 95% CI 0.996-0.999, p = 0.039). Even after applying PSM, the connection between dietary iron intake and dietary vitamin C intake with PD risk remained substantial. Subgroup analysis results revealed a significant positive association between dietary intake of iron from food and the PD risk, which was evident among individuals under 60 years of age and among males.

Conclusion

The intake of micronutrients can influence risk of PD, which should be verified and explored further in prospective samples with other dietary habits and ethnic backgrounds.

Associations between vitamin D levels and periodontal attachment loss

OBJECTIVES

Periodontitis is accompanied by attachment loss and alveolar bone resorption. Vitamin D (VD) deficiency was closely associated with bone loss or osteoporosis. The study aims to investigate the potential relationship between different VD levels and severe periodontal attachment loss in American adults.

METHODS

A cross-sectional analysis was conducted including 5749 participants in the National Health and Nutrition Examination Survey (NHANES) from 2009 to 2014. The association of periodontal attachment loss progression with total VD, vitamin D3 (VD3), and vitamin D2 (VD2) levels was assessed using multivariable linear regression models, hierarchical regression, fitted smoothing curves, and generalized additive models.

RESULTS

Based on the indicators of 5749 subjects, we found that severe attachment loss tended to occur in the elderly or males and was accompanied by less total VD levels, or VD3 levels, as well as a lower poverty-income ratio (PIR). Total VD (below the inflection point: 111 nmol/L) or VD3 were negatively associated with the progression of attachment loss in each multivariable regression model. In threshold analysis, VD3 is linearly correlated with the progression of attachment loss (β =  - 0.0183, 95% CI: - 0.0230 to - 0.0136). The relationship between VD2 and attachment loss progression was an S-shaped curve (inflection point: 5.07 nmol/L).

CONCLUSION

Increasing total VD (below 111 nmol/L) and VD3 levels may be beneficial to periodontal health. VD2 levels above 5.07 nmol/L were a risk factor for severe periodontitis.

CLINICAL RELEVANCE

The present study reports that different vitamin D levels may serve as different associations with periodontal attachment loss progression.

Chaudhuri's Dashboard of Vitals in Parkinson's syndrome: an unmet need underpinned by real life clinical tests

We have recently published the notion of the "vitals" of Parkinson's, a conglomeration of signs and symptoms, largely nonmotor, that must not be missed and yet often not considered in neurological consultations, with considerable societal and personal detrimental consequences. This "dashboard," termed the Chaudhuri's vitals of Parkinson's, are summarized as 5 key vital symptoms or signs and comprise of (a) motor, (b) nonmotor, (c) visual, gut, and oral health, (d) bone health and falls, and finally (e) comorbidities, comedication, and dopamine agonist side effects, such as impulse control disorders. Additionally, not addressing the vitals also may reflect inadequate management strategies, leading to worsening quality of life and diminished wellness, a new concept for people with Parkinson's. In this paper, we discuss possible, simple to use, and clinically relevant tests that can be used to monitor the status of these vitals, so that these can be incorporated into clinical practice. We also use the term Parkinson's syndrome to describe Parkinson's disease, as the term "disease" is now abandoned in many countries, such as the U.K., reflecting the heterogeneity of Parkinson's, which is now considered by many as a syndrome.

Parkinson's disease and oral health: A systematic review

OBJECTIVE

in patients with Parkinson's Disease (PD), oral health can be affected by motor and non-motor symptoms and/or medication use. Therefore, the aim was to systematically review the literature on oral health and associated factors of oral health in PD patients.

DESIGN

a literature search was performed from inception up to April 5th, 2023. Original studies that assessed oral health-related factors in PD patients and were written in English or Dutch, were included.

RESULTS

11276 articles were identified, of which 43 met the inclusion criteria (quality range poor-good). A higher prevalence of dental biofilm, bleeding/gingivitis, pocket depth (≥4 mm), tooth mobility, caries, and number of decayed missing filled teeth/surfaces was found in PD patients than in controls. However, no difference between both groups was found when analysing edentulism and wearing dentures. Poor oral health of PD patients was associated with a longer disease duration, higher disease severity, and more prescribed medications.

CONCLUSIONS

oral health of PD patients is worse than that of healthy individuals. It is associated with the duration and severity of PD and medication use. Therefore, we advise regular appointments with oral health care professionals, with an important focus on prevention.

Revisiting Alpha-Synuclein Pathways to Inflammation

Alpha-synuclein (α-Syn) is a short presynaptic protein with an active role on synaptic vesicle traffic and the neurotransmitter release and reuptake cycle. The α-Syn pathology intertwines with the formation of Lewy Bodies (multiprotein intraneuronal aggregations), which, combined with inflammatory events, define various α-synucleinopathies, such as Parkinson's Disease (PD). In this review, we summarize the current knowledge on α-Syn mechanistic pathways to inflammation, as well as the eventual role of microbial dysbiosis on α-Syn. Furthermore, we explore the possible influence of inflammatory mitigation on α-Syn. In conclusion, and given the rising burden of neurodegenerative disorders, it is pressing to clarify the pathophysiological processes underlying α-synucleinopathies, in order to consider the mitigation of existing low-grade chronic inflammatory states as a potential pathway toward the management and prevention of such conditions, with the aim of starting to search for concrete clinical recommendations in this particular population.

Is There an Association Between Parkinson's Disease and Periodontitis? A Systematic Review and Meta-Analysis

BACKGROUND

Multiple observational studies have yielded controversial results regarding the association between Parkinson's disease (PD) and periodontitis.

OBJECTIVE

This systematic review and meta-analysis was conducted to ascertain their bidirectional relationship.

METHODS

A literature search for relevant studies was performed in PubMed, EMBASE, the Cochrane Library, and Web of Science databases from inception to December 19, 2022. Effect sizes (ES) with 95% confidence intervals were pooled under the random-effects model. Then, leave-one-out sensitivity analysis and contour-enhanced funnel plot were applied to assess the stability of the results.

RESULTS

A total of 34 studies and 24 studies were included for systematic review and quantitative meta-analysis, respectively. Pooled ES indicated that periodontitis was not significantly associated with PD risk (HR = 1.13, 95% CI 0.88-1.45, n = 3; OR = 1.94, 95% CI 0.55-6.90, n = 7), while the Mendelian randomization study revealed no association between PD and periodontitis risk (coefficient [B] = -0.0001, standard error = 0.0001, p = 0.19). Furthermore, PD patients exhibited higher levels of periodontal pocket depth (SMD = 1.10, 95% CI 0.53-1.67), clinical attachment level (SMD = 1.40, 95% CI 0.55-2.26), plaque index (SMD = 0.81, 95% CI 0.22-1.39), and Oral Health Impact Profile-14 score (SMD = 0.91, 95% CI 0.33-1.49) compared to healthy controls.

CONCLUSIONS

Our meta-analysis identified no bidirectional association between PD risk and periodontitis risk, though the prevalence of periodontitis and poorer oral status was higher in PD patients.

Bioinformatics analysis of gene expression profile and functional analysis in periodontitis and Parkinson’s disease

Periodontitis is a chronic inflammatory disease inextricably linked to both the innate and acquired immune systems of the body. Parkinson’s disease (PD) is a neurodegenerative disease caused by immune system dysfunction. Although recent studies suggest that a clinical relationship exists between PD and periodontitis, the pathogenesis of this relationship is unclear. Therefore, in the present study, we obtained datasets of periodontitis and PD from the Gene Expression Omnibus (GEO) database and extracted 785 differentially expressed genes (DEGs), including 15 common upregulated genes and four common downregulated genes. We performed enrichment analyses of these DEGs using Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes analyses. We found that the genes were mainly enriched in keratinocyte differentiation, neuronal cell bodies, and structural constituents of epidermis terms, and pathways such as immune response and synaptic pathways. In addition, we screened matching hub genes by constructing a protein–protein interaction (PPI) network map and a Molecular Complex Detection (MCODE) map using the Cytoscape software. The hub genes were then subjected to GO enrichment analysis, which revealed that the dopamine biosynthetic process, dopaminergic synapse and dopamine-binding terms, and dopaminergic synapse and serotonergic synapse pathways were primarily where they were expressed. Finally, we selected four of these genes for validation in the periodontitis and PD datasets, and we confirmed that these hub genes were highly sensitive and specific for diagnosing and monitoring PD and periodontitis. In conclusion, the above experimental results indicate that periodontitis is a high-risk factor for PD, and the association between these two conditions is mainly manifested in immune and dopamine-related pathways. Hub genes, such as the CDSN, TH, DDC, and SLC6A3 genes, may serve as potential biomarkers for diagnosing or detecting PD.

Association between trichlorophenols and neurodegenerative diseases: A cross-sectional study from NHANES 2003-2010

PURPOSE OF THE RESEARCH

To evaluate the association of the exposure of trichlorophenols (TCPs) on the morbidity and mortality of patients with Parkinson's disease (PD) and Alzheimer's disease (AD) using the data from the National Health and Nutrition Examination Survey (NHANES) 2003-2010. Multivariable logistic regression models and COX regression were used to evaluate the association between TCP exposure and the AD and PD risk. Least Absolute Shrinkage and Selection Operator (LASSO) methods were used to screen latent covariates.

PRINCIPAL RESULTS

A total of 6333 participants over the age of 18 years were included in the analysis. After the adjustments for major confounders, participants with higher concentrations of urinary 2,4,6-TCP had higher risk of AD (odds ratios (ORs), 3.19; 95% CI: 1.07, 9.45) than the group below the limit of detection (LOD). Compared to group of below the LOD, higher urinary concentrations of 2,4,5-TCP was associated with higher risk of all-cause mortality in PD patients (log-rank P = 0.022) and all participants (log-rank P < 0.001) without adjustments for confounders. In addition, a higher risk of all-cause mortality in all participants with high urinary concentrations of 2,4,6-TCP (log-rank P = 0.001) was found without adjustments for confounders. With the adjustments for major confounders, participants with higher concentrations of urinary 2,4,5-TCP had a higher risk of death in patients with PD (hazard ratios (HRs), 53.19; 95% CI: 2.82, 1004.13) than in the group below the LOD.

MAJOR CONCLUSIONS

Exposure to high concentration of 2,4,6-TCP may increase the risk of AD, and the level of 2,4,5-TCP may be associated with the risk of death in patients with PD. Our findings reveal the potential toxicity of TCPs, highlight the potential impact of TCPs on neurodegenerative diseases, and express concerns regarding the use of organochlorine pesticides.

Association Between High Serum Tetrahydrofolate and Low Cognitive Functions in the United States: A Cross-Sectional Study

Background: The relationship between serum folate status and cognitive functions is still controversial. Objective: To evaluate the association between serum tetrahydrofolate and cognitive functions. Methods: A total of 3,132 participants (60–80 years old) from the 2011–2014 NHANES were included in this cross-sectional study. The primary outcome measure was cognitive function assessment, determined by the Consortium to Establish a Registry for Alzheimer’s Disease Word Learning Test (CERAD-WL), CERAD-Delayed Recall Test (CERAD-DR), Animal Fluency Test (AF), Digit Symbol Substitution Test (DSST), and global cognitive score. Generalized linear model (GLM), multivariate logistic regression models, weighted generalized additive models (GAM), and subgroup analyses were performed to evaluate the association between serum tetrahydrofolate and low cognitive functions. Results: In GLM, and the crude model, model 1, model 2 of multivariate logistic regression models, increased serum tetrahydrofolate was associated with reduced cognitive functions via AF, DSST, CERAD-WL, CERAD-DR, and global cognitive score (p <  0.05). In GAM, the inflection points were 1.1, 2.8, and 2.8 nmol/L tetrahydrofolate, determined by a two-piece wise linear regression model of AF, DSST, and global cognitive score, respectively. Also, in GAM, there were no non-linear relationship between serum tetrahydrofolate and low cognitive functions, as determined by CERAD-WL or CERAD-DR. The results of subgroup analyses found that serum tetrahydrofolate levels and reduced cognitive functions as determined by AF had significant interactions for age and body mass index. The association between high serum tetrahydrofolate level and reduced cognitive functions as determined using DSST, CERAD-WL, CERAD-DR, or global cognitive score had no interaction with the associations between cognition and gender, or age, or so on. Conclusion: High serum tetrahydrofolate level is associated with significantly reduced cognitive function.

Self-reported periodontitis and C-reactive protein in Parkinson's disease: a cross-sectional study of two American cohorts

Periodontitis triggers systemic repercussions, such as elevated levels of high-sensitive C-reactive protein (hs-CRP). This has never been studied within Parkinson's Disease (PD). The aim of this study is to compare hs-CRP levels of self-reported periodontitis cases versus cases without periodontitis in PD patients. Data from the National Health and Nutrition Examination Survey (2015-2016 and 2017-2018 waves) were analyzed. PD cases were identified through medication regimens and periodontitis cases through a validated self-report questionnaire. 51 participants were included (24 females, 27 males, with mean age of 62.96 (14.71)). While the self-reported periodontitis group presented elevated levels of circulating hs-CRP (5.36 vs. 1.99 mg/L, p = 0.031), the self-reported without periodontitis group presented higher lymphocyte levels (29.35 vs. 28.03%, p = 0.007). Blood levels of hs-CRP were significantly higher in PD cases with self-reported periodontitis. Apart from the lymphocyte levels, there were no other significant differences according to the self-reported periodontal status. Future studies shall explore this association using clinical measures.

Alterations in Proteostasis System Components in Peripheral Blood Mononuclear Cells in Parkinson Disease: Focusing on the HSP70 and p62 Levels

Parkinson disease (PD) is attributed to a proteostasis disorder mediated by α-synuclein accumulating in a specific brain region. PD manifestation is often related to extraneuronal alterations, some of which could be used as diagnostic or prognostic PD biomarkers. In this work, we studied the shifts in the expression of proteostasis-associated chaperones of the HSP70 family and autophagy-dependent p62 protein values in the peripheral blood mononuclear cells (PBMC) of mild to moderate PD patients. Although we did not detect any changes in the intracellular HSP70 protein pool in PD patients compared to non-PD controls, an increase in the transcriptional activity of the stress-associated HSPA1A/B and HSPA6 genes was observed in these cells. Basal p62 content was found to be increased in PD patients’ PBMC, similarly to the p62 level in substantia nigra neural cells in PD. Moreover, the spontaneous apoptosis level was increased among PBMC and positively correlated with the p62 intracellular level in the PD group. A combined HSPA6- and p62-based analysis among 26 PD patients and 36 age-matched non-PD controls pointed out the diagnostic significance of these markers, with intermediate sensitivity and high specificity of this combination when observing patients diagnosed with PD.

Non-linear association between Mediterranean diet and depressive symptom in U.S. adults: A cross-sectional study

The Mediterranean diet (MED), a dietary pattern rich in fruits and vegetables, whole grains, legumes, nuts, fish, and olive oil, has anti-oxidative and anti-inflammatory effects. Although some data suggest that MED adherence is associated with decreased manifestation of depressive symptoms, it remains necessary to further analyze this apparent non-linear association as well as the influence of different factors on the relationship between MED and depression. Here, we investigated associations between the alternate MED (aMED) score and depressive symptom via multivariate logistic regression, weighted generalized additive (GAM) and two-step linear regression models, analyzing data from the 2005-2018 National Health and Nutrition Examination Survey (NHANES). The most important factor relevant to aMED score that contributed to the prevalence of depressive symptom was assessed using random forest. Furthermore, we examined whether the relationship between aMED score and depressive symptom differs by age, race, sex, socioeconomic variables, lifestyle- and health-related variables, and chronic medical conditions, via subgroup analyses. A total of 19,477 participants (20-80 years of age) were included in this cross-sectional study. In crude and adjusted (1-5) multivariate logistic regression models, increased aMED score was noted to associate with non-depressive status, as defined using the Patient Health Questionnaire-9 (P < 0.05). Data analyses via GAM and two-piecewise linear regression revealed a non-linear association between aMED and depressive symptom, which had an inflection point of 3. Random forest results revealed that vegetable score contributes greatest to the relationship between aMED and depressive symptom. Subgroup analyses revealed that aMED score is significantly negatively related with depressive symptom in most different populations (P < 0.05) with the exception of high annual income, diabetes, borderline blood glucose level and Parkinson's disease (PD) (P > 0.05). In conclusion, we observed a non-linear association between aMED score and depressive symptom. Further studies are needed to validate our results.

Reduced Immunosenescence of Peripheral Blood T Cells in Parkinson's Disease with CMV Infection Background

Immunosenescence is a process of remodeling the immune system under the influence of chronic inflammation during aging. Parkinson’s disease (PD) is a common age-associated neurodegenerative disorder and is frequently accompanied by neuroinflammation. On the other hand, cytomegalovirus (CMV), one of the most spread infections in humans, may induce chronic inflammation which contributes to immunosenescence, differentiation and the inflation of T cells and NK cells. Currently, there is no clear understanding of immunosenescence severity in PD patients infected with CMV. In this study, we analyzed differentiation stages and immunosenescence characteristics of T cells and NK cells in 31 patients with mild and moderate PD severity, 33 age-matched and 30 young healthy donors. The PD patients were 100% CMV-seropositive compared to 76% age-matched and 73% young CMV-infected healthy donors. The proportion of effector memory T cells re-expressing CD45RA, CD57⁺CD56⁻ T cells and CD57⁺CD56⁺ T cells was significantly reduced in PD patients compared with CMV-seropositive age-matched healthy individuals. The CD57⁺CD56⁻ T cell proportion in PD patients was similar to that of CMV-seropositive young healthy donors. Thus, PD is characterized by reduced peripheral blood T cell immunosenescence, even against the background of CMV infection.

Causal Association between Periodontitis and Parkinson's Disease: A Bidirectional Mendelian Randomization Study

The latest evidence revealed a possible association between periodontitis and Parkinson’s disease (PD). We explored the causal relationship of this bidirectional association through two-sample Mendelian randomization (MR) in European ancestry populations. To this end, we used openly accessible data of genome-wide association studies (GWAS) on periodontitis and PD. As instrumental variables for periodontitis, seventeen single-nucleotide polymorphisms (SNPs) from a GWAS of periodontitis (1817 periodontitis cases vs. 2215 controls) and eight non-overlapping SNPs of periodontitis from an additional GWAS for validation purposes. Instrumental variables to explore for the reverse causation included forty-five SNPs from a GWAS of PD (20,184 cases and 397,324 controls). Multiple approaches of MR were carried-out. There was no evidence of genetic liability of periodontitis being associated with a higher risk of PD (B = −0.0003, Standard Error [SE] 0.0003, p = 0.26). The eight independent SNPs (B = −0.0000, SE 0.0001, p = 0.99) validated this outcome. We also found no association of genetically primed PD towards periodontitis (B = −0.0001, SE 0.0001, p = 0.19). These MR study findings do not support a bidirectional causal genetic liability between periodontitis and PD. Further GWAS studies are needed to confirm the consistency of these results.

Tooth Loss and Blood Pressure in Parkinson's Disease Patients: An Exploratory Study on NHANES Data

Objectives: To evaluate tooth loss severity in PD patients and the impact of missing teeth on blood pressure (BP) and glycated hemoglobin (Hba1c) levels. Methods: All adults reporting specific PD medication regimens with complete dental examinations were included from the NHANES 2001 to 2018 databases. Sociodemographic, systolic BP (SBP), diastolic BP (DBP) and Hba1c data were compared according to tooth loss severity, and linear regression analyses on the impact of tooth loss on SBP, DBP and Hba1c levels were conducted. Results: The 214 included participants presented 9.7 missing teeth, 23.8% severe tooth loss and 18.2% total edentulousness. Severe tooth loss cases were significantly older (p < 0.001), had higher smoking prevalence (p = 0.008), chronic medical conditions (p = 0.012) and higher Hba1c (p = 0.001), SBP (p = 0.015) and DBP (p < 0.001) levels. Crude and adjusted linear models revealed a relationship between SBP, DBP and missing teeth; however, age confounded these links (SBP: B = 0.10, SE = 0.16, p < 0.05; DBP: B = 0.16, SE = 0.10, p < 0.05). Tooth loss presented no significant relationship with Hba1c levels. Conclusions: Severe tooth loss is prevalent among PD patients. Blood pressure levels showed a positive linear relationship with the number of missing teeth, although age was a confounding factor. Furthermore, tooth loss and Hba1c levels revealed no significant linear relationship.

The Role of Inflammatory Diet and Vitamin D on the Link between Periodontitis and Cognitive Function: A Mediation Analysis in Older Adults

Patients suffering from periodontitis are at a higher risk of developing cognitive dysfunction. However, the mediation effect of an inflammatory diet and serum vitamin D levels in this link is unclear. In total, 2062 participants aged 60 years or older with complete periodontal diagnosis and cognitive tests from the National Health and Nutrition Examination Survey (NHANES) 2011-2012 and 2013-2014 were enrolled. The Consortium to Establish a Registry for Alzheimer's disease (CERAD) word learning subtest (WLT) and CERAD delayed recall test (DRT), the animal fluency test (AFT) and the digit symbol substitution test (DSST) was used. Dietary inflammatory index (DII) was computed via nutrition datasets. Mediation analysis tested the effects of DII and vitamin D levels in the association of mean probing depth (PD) and attachment loss (AL) in all four cognitive tests. Periodontitis patients obtained worse cognitive test scores than periodontally healthy individuals. DII was negatively associated with CERAD-WLT, CERAD-DRT, AFT and DSST, and was estimated to mediate between 9.2% and 36.4% of the total association between periodontitis with cognitive dysfunction (p < 0.05). Vitamin D showed a weak association between CERAD-DRT, AFT and DSST and was estimated to between 8.1% and 73.2% of the association between periodontitis and cognitive dysfunction (p < 0.05). The association between periodontitis and impaired cognitive function seems to be mediated both by a proinflammatory dietary load and vitamin D deficiency. Future studies should further explore these mediators in the periodontitis-cognitive decline link.

Network Protein Interaction in Parkinson's Disease and Periodontitis Interplay: A Preliminary Bioinformatic Analysis

Recent studies supported a clinical association between Parkinson's disease (PD) and periodontitis. Hence, investigating possible interactions between proteins associated to these two conditions is of interest. In this study, we conducted a protein-protein network interaction analysis with recognized genes encoding proteins with variants strongly associated with PD and periodontitis. Genes of interest were collected via the Genome-Wide Association Studies (GWAS) database. Then, we conducted a protein interaction analysis, using the Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) database, with a highest confidence cutoff of 0.9 and sensitivity analysis with confidence cutoff of 0.7. Our protein network casts a comprehensive analysis of potential protein-protein interactions between PD and periodontitis. This analysis may underpin valuable information for new candidate molecular mechanisms between PD and periodontitis and may serve new potential targets for research purposes. These results should be carefully interpreted, giving the limitations of this approach.