Oral Infections, Metabolic Inflammation, Genetics, and Cardiometabolic Diseases

Preconception Periodontitis and Risk of Spontaneous Abortion in a Prospective Cohort Study

Few studies have evaluated the association between periodontitis and spontaneous abortion (SAB), and all had limitations. We used data from the Pregnancy Study Online (PRESTO), a prospective preconception cohort study of 3,444 pregnancy planners in the United States and Canada (2019-2022), to address this question. Participants provided self-reported data on periodontitis diagnosis, treatment, and symptoms of severity (i.e., loose teeth) via the enrollment questionnaire. SAB (pregnancy loss at <20 weeks' gestation) was assessed via bimonthly follow-up questionnaires. Participants contributed person-time from the date of a positive pregnancy test to the gestational week of SAB, loss to follow-up, or 20 weeks' gestation, whichever came first. We fitted Cox regression models with weeks of gestation as the time scale to estimate adjusted hazard ratios (HRs) and 95% confidence intervals (CIs), and we used inverse probability of treatment weighting to account for differential loss to follow-up. We used probabilistic quantitative bias analysis to estimate the magnitude and direction of the effect of exposure misclassification bias on results. In weighted multivariable models, we saw no appreciable association between preconception periodontitis diagnosis (HR = 0.97, 95% CI: 0.76, 1.23) or treatment (HR = 1.01, 95% CI: 0.79, 1.27) and SAB. A history of loose teeth was positively associated with SAB (HR = 1.38, 95% CI: 0.88, 2.14). Quantitative bias analysis indicated that our findings were biased towards the null but with considerable uncertainty in the bias-adjusted results.

Tachykinins and the potential causal factors for post-COVID-19 condition

The most prevalent symptoms of post-COVID-19 condition are pulmonary dysfunction, fatigue and muscle weakness, anxiety, anosmia, dysgeusia, headaches, difficulty in concentrating, sexual dysfunction, and digestive disturbances. Hence, neurological dysfunction and autonomic impairments predominate in post-COVID-19 condition. Tachykinins including the most studied substance P are neuropeptides expressed throughout the nervous and immune systems, and contribute to many physiopathological processes in the nervous, immune, gastrointestinal, respiratory, urogenital, and dermal systems and participate in inflammation, nociception, and cell proliferation. Substance P is a key molecule in neuroimmune crosstalk; immune cells near the peripheral nerve endings can send signals to the brain with cytokines, which highlights the important role of tachykinins in neuroimmune communication. We reviewed the evidence that relates the symptoms of post-COVID-19 condition to the functions of tachykinins and propose a putative pathogenic mechanism. The antagonism of tachykinins receptors can be a potential treatment target.

An updated review on the link between oral infections and atherosclerotic cardiovascular disease with focus on phenomics

Atherosclerotic cardiovascular diseases (ACVD) and oral infections such as periodontal disease, dental caries, and apical periodontitis are diseases that affect a great portion of the worldwide population. Both are complex in nature and several studies show that they share etiological factors but a causal relationship between them has not been yet established due to the lack of well-designed clinical trials. Many studies in the recent years show convincing evidence of different mechanisms that might be involved in this association including chronic inflammation and immune response. However, some of these mechanisms are controversial because of confounding factors. It has been suggested that maladaptive inflammatory reactivity, determined in part by single nucleotide polymorphisms (SNPs) in pathway genes, could influence the association between oral infections, and cardiovascular diseases as pleiotropic genes. That is, these conditions could be outcomes of similar inflammatory pathways. Phenomics, the study of the changes in phenotypes or traits considering environmental variables and genetics is efficient in assessing and determining pleiotropic genes. Future research should focus on analyzing a combination of oral inflammatory conditions instead of focusing on one inflammatory phenotype alone and consider pleiotropy as a mechanistic contributor for these associations. Further, prospective observational studies seeking to follow the development of oral disease and subclinical ACVD will foster the understanding of the impact of oral health on general systemic health. Lastly, to demonstrate that oral infections would increase risk for subclinical ACVD development, clinical trials proposing to treat those infections considering genetic background and all other confounders are needed.

The interplay between oral microbes and immune responses

Oral microbes play a critical role in maintaining oral homeostasis. Microbial dysbiosis promotes disease pathogenesis through several mechanisms. Recent studies have revealed that microbial imbalance and sustained inflammation are involved in disease progression. The adverse interaction triggered by a host immune response to microorganisms can lead to oral and systemic diseases. Here, we reviewed how oral microbes communicate with hosts during the development of local and distant inflammation. Elucidation of these processes may reveal future directions in this field and the potential targets of novel biological therapies for oral and systemic diseases.

Dental and Periodontal Health in Acute Intermittent Porphyria

In the inherited metabolic disorder acute intermittent porphyria (AIP), high sugar intake prevents porphyric attacks due to the glucose effect and the following high insulin levels that may lower AIP disease activity. Insulin resistance is a known risk factor for periodontitis and sugar changes diabetogenic hormones and affects dental health. We hypothesized differences in homeostasis model assessment (HOMA) scores for insulin resistance in AIP cases vs. controls and in those with periodontitis. Our aim was to systematically study dental health in AIP as poor dental health was previously only described in case reports. Further, we aimed to examine if poor dental health and kidney failure might worsen AIP as chronic inflammation and kidney failure might increase disease activity. In 47 AIP cases and 47 matched controls, X-rays and physical examination of clinical attachment loss (CAL), probing pocket depth (PPD), and decayed missing filled teeth (DMFT) were performed. Dietary intake was evaluated through a diet logbook. Plasma cytokines and diabetogenic hormones were measured using multiplex technology and urine porphobilinogen and kidney and liver function by routine methods. An excel spreadsheet from the University of Oxford was used to estimate HOMA scores; beta cell function, HOMA%B (%B), insulin sensitivity, HOMA%S (%S), and insulin resistance HOMA-IR (IR), based on glucose and plasma (P) C-peptide. The Wilcoxon matched-pairs signed rank test, the Mann−Whitney U-test, and Spearman’s non-parametric correlation were used. Insulin (p = 0.007) and C-peptide (p = 0.006) were higher in the AIP cases with periodontitis versus those without. In AIP patients, the liver fibrosis index 4 correlated with DMFT (p < 0.001) and CAL ≥4 mm (p = 0.006); the estimated glomerular filtration rate correlated with DMFT (p < 0.001) and CAL ≥4 mm (p = 0.02). CAL ≥4 mm was correlated with chemokine ligand 11 and interleukin (IL)-13 (p = 0.04 for both), and PPD >5 mm was correlated with plasminogen activator inhibitor-1 (p = 0.003) and complement component 3 (p = 0.02). In conclusion, dental health in AIP cases was correlated with insulin resistance, inflammatory markers, and biomarkers of kidney and liver function, demonstrating that organ damage in the kidney and liver are associated with poorer dental health.

Association between Frequency of Toothbrushing and Metabolic Syndrome among Adolescents: A 5-Year Follow-Up Study

This study longitudinally examines the relationship between the frequency of toothbrushing and the development of selected components of metabolic syndrome (MetS), along with the potential role of salivary biomarkers in this relationship. In 2014, 6317 12-year-old children underwent health examinations (T1), of which, 348 children participated in the second stage of data collection in 2019 (T2). The association between the change in the metabolic status during the 5-year follow-up examination (between T1 and T2) and frequency of toothbrushing was assessed using multinomial logistic regression analyses. At T2, healthy adolescents had significantly higher odds of toothbrushing twice or more daily compared with adolescents with components of MetS (OR = 1.99, 95% CI 1.15-3.45). Adolescents who were healthy at T1 but developed components of MetS at T2, had significantly higher frequencies of dining-out compared with adolescents with components of MetS at both T1 and T2 (OR = 0.09, 95% CI 0.02 to 0.49). Adolescents who were 'healthy' at both T1 and T2 had significantly (p < 0.05) lower levels of C-reactive protein (T2), insulin (T1 and T2), interleukin-6 (T1) and adiponectin (T1) compared with adolescents who had components of MetS. Toothbrushing and frequency of dining-out were associated with the presence of MetS components.

Polyphenols: Potential anti-inflammatory agents for treatment of metabolic disorders

Ample evidence highlights the potential benefits of polyphenols in health status especially in obesity-related metabolic disorders such as insulin resistance, type 2 diabetes, and cardiovascular diseases. Mechanistically, due to the key role of "Metainflammation" in the pathomechanism of metabolic disorders, recently much focus has been placed on the properties of polyphenols in obesity-related morbidities. This narrative review summarizes the current knowledge on the role of polyphenols, including genistein, chlorogenic acid, ellagic acid, caffeic acid, and silymarin in inflammatory responses pertinent to metabolic disorders and discusses the implications of this evidence for future directions. This review provides evidence that the aforementioned polyphenols benefit health status in metabolic disorders via direct and indirect regulation of a variety of target proteins involved in inflammatory signaling pathways. However, due to limitations of the in vitro and in vivo studies and also the lack of long-term human clinical trials studies, further high-quality investigations are required to firmly establish the clinical efficacy of the polyphenols for the prevention and management of metabolic disorders.

Myeloid-derived suppressor cells in obesity-associated periodontal disease: A conceptual model

Periodontitis is a common chronic inflammatory disease characterized by destruction of the supporting structures of the teeth. Severe periodontitis is highly prevalent-affecting 10%-15% of adults-and carries several negative comorbidities, thus reducing quality of life. Although a clear relationship exists between severity of obesity and incidence of periodontal disease, the biologic mechanisms that support this link are incompletely understood. In this conceptual appraisal, a new "two-hit" model is presented to explain obesity-exacerbated periodontal bone loss. This proposed model recognizes a previously unappreciated aspect of myeloid-derived suppressor cell population expansion, differentiation, and activity that can participate directly in periodontal bone loss, providing new mechanistic and translational perspectives.

Emerging Role of Epigenetics in Explaining Relationship of Periodontitis and Cardiovascular Diseases

Cardiovascular diseases such as ischemic heart diseases or stroke are among the leading cause of deaths globally, and evidence suggests that these diseases are modulated by a multifactorial and complex interplay of genetic, environmental, and lifestyle factors. Genetic predisposition and chronic exposure to modifiable risk factors have been explored to be involved in the pathophysiology of CVD. Environmental factors contribute to an individual's propensity to develop major cardiovascular risk factors through epigenetic modifications of DNA and histones via miRNA regulation of protein translation that are types of epigenetic mechanisms and participate in disease development. Periodontal disease (PD) is one of the most common oral diseases in humans that is characterized by low-grade inflammation and has been shown to increase the risk of CVDs. Risk factors involved in PD and CVD are determined both genetically and behaviorally. Periodontal diseases such as chronic inflammation promote DNA methylation. Epigenetic modifications involved in the initiation and progression of atherosclerosis play an essential role in plaque development and vulnerability. Epigenetics has opened a new world to understand and manage human diseases, including CVDs and periodontal diseases. Genetic medicine has started a new era of epigenetics to overcome human diseases with various new methodology. Epigenetic profiling may aid in better diagnosis and stratification of patients showing potential predisposed states for disease. A better understanding of the exact regulatory mechanisms of epigenetic pathways driving inflammation is slowly emerging and will aid in developing novel tools for the treatment of disease.

Comparison of periodontal parameters between patients with ischemic and dilative cardiomyopathy

Background

This cross-sectional study aimed in the comparison of periodontal parameters, number of remaining teeth and oral behaviour between patients with ischemic- (ICM) and non-ischemic dilative cardiomyopathy (DCM).

Methods

Patients with HF from the Department for Cardiac Surgery at the Heart Center Leipzig were included. The two groups (ICM and DCM) were composed by matching according to age, gender and smoking habits. All participants received a comprehensive periodontal examination, including a periodontal probing on six measurement points of each tooth.

Results

A total of 226 patients (n = 113 each group) was included. Patients in DCM group used interdental cleaning significantly more often than ICM (23.9% vs. 12.5%, p = 0.04). The majority of patients in both groups (ICM: 83.6%, DCM: 84.6%, p = 0.23) were diagnosed with stage III–IV periodontitis. Periodontal parameters were comparable between groups (p > 0.05). Variance analysis revealed no influence of the group (ICM vs. DCM) on the number of remaining teeth (p = 0.16), periodontitis stage (p = 0.27) or the periodontal inflamed surface area (p = 0.62).

Conclusions

Patients with severe HF show high periodontal burden, without any differences between ICM and DCM group. Therefore, increased attention should be payed to periodontal health of patients with severe heart disease, irrespective of their underlying disease.

Periodontal microorganisms and diagnosis of malignancy: A cross-sectional study

BACKGROUND

Oral infections associate statistically with cancer.

OBJECTIVE

We hypothesized that certain periodontal microorganisms might specifically link to malignancies in general and set out to investigate this in our ongoing cohort study.

METHODS

A sample of 99 clinically examined patients from our cohort of 1676 subjects was used to statistically investigate the associations between harboring periodontal microorganisms Aggregatibacter actinomycetemcomitans (A.a), Porphyromonas gingivalis (P.g), Prevotella intermedia (P.i), Tannerella forsythia (T.f) and Treponema denticola (T.d). We used oral infection indexes and the incidence figures of malignancies as registered in 2008-2016 in the Swedish National Cancer Register.

RESULTS

The pathogen A.a showed strong association with malignancy in 32 out of the 99 patients while P.g and P.i were more prevalent among patients without malignancy. In principal component analyses, A.a appeared in the strongest component while the second strongest component consisted of a combination of T.f and T.d. The third component consisted of a combination of P.g and P.i, respectively. Of basic and oral health variables, gingival index appeared to be the strongest expression of inflammation (Eigen value 4.11 and Explained Variance 68.44 percent).

CONCLUSIONS

The results partly confirmed our hypothesis by showing that harboring certain periodontal bacteria might link to malignancy. However, the associations are statistical and no conclusions can be drawn about causality.

NLRP3 Inflammasome Biomarker-Could Be the New Tool for Improved Cardiometabolic Syndrome Outcome

Metabolomics, the research area studying chemical processes involving metabolites, finds its utility in inflammasome biomarker discovery, thus representing a novel approach for cardiometabolic syndrome pathogeny acknowledgements. Metabolite biomarkers discovery is expected to improve the disease evolution and outcome. The activation of abundantly expressed NLRP3 inflammasome represents the background process of the diabetes mellitus disturbances like hyperglycemia and insulin resistance, as well as for myocardial cell death and fibrosis, all of them being features characteristic for cardiometabolic syndrome. Many molecules like troponins, brain natriuretic protein (BNP), ST2/IL-33, C-reactive protein (CRP), TNF, IL-1β, and IL-18 cytokines have been already examined as molecular markers for diagnosing or predicting different cardiac disturbances like myocardial infarction, heart failure, or myocarditis. In addition, metabolomics research comes with new findings arguing that NLRP3 inflammasome becomes a promising molecular tool to use for clinical and therapeutical management providing new targets for therapies in cardiometabolic syndrome. Inflammasome markers analyses, along with other molecular or genetic biomarkers, will result in a better understanding of cardiometabolic syndrome pathogenesis and therapeutic targets. Screening, diagnostic, and prognostic biomarkers resulted from inflammasome biomarker research will become standard of care in cardiometabolic syndrome management, their utility becoming the first magnitude.

The association of periodontal diseases with metabolic syndrome and obesity

Periodontitis is a multifactorial chronic inflammatory disease associated with dysbiotic plaque biofilms and characterized by progressive destruction of the tooth-supporting apparatus. Globally, it is estimated that 740 million people are affected by its severe form. Periodontitis has been suggested to be linked to obesity and metabolic syndrome. Obesity, defined as excessive fat accumulation, is a complex multifactorial chronic inflammatory disease, with a high and increasing prevalence. Metabolic syndrome is defined as a cluster of obesity, dyslipidemia, hypertension, and dysglycemia. Obesity, metabolic syndrome and periodontitis are among the most common non-communicable diseases and a large body of evidence from epidemiologic studies supports the association between these conditions. Extensive research has established plausible mechanisms to explain how these conditions can negatively impact each other, pointing to a bidirectional adverse relationship. At present there is only limited evidence available from a few intervention studies. Nevertheless, the global burden of periodontitis combined with the obesity epidemic has important clinical and public health implications for the dental team. In accordance with the common risk factor approach for tackling non-communicable diseases, it has been proposed that oral healthcare professionals have an important role in the promotion of periodontal health and general well-being through facilitation of healthy lifestyle behaviours.

Vitamin D status affects the relationship between lipid profile and high-sensitivity C-reactive protein

Background

The biological pathways through which vitamin D is involved in the regulation of systemic inflammation remain largely unknown.

Objective

The objective of this study was to evaluate the role of vitamin D status on the relationship between lipid profile and high-sensitivity C-reactive protein (hs-CRP) in pregnant women.

Design

Serum 25-hydroxyvitamin D (25(OH)D), hs-CRP, and indicators of lipid profiles (total cholesterol, TC; triglyceride, TG; high-density lipoprotein cholesterol, HDL-C; low-density lipoprotein cholesterol, LDL-C), were measured in 2479 pregnant women during the second trimester. Potential confounding including maternal sociodemographic characteristics, perinatal health status, diet, and lifestyle was prospectively collected. Multiple regression models and cubic models were used to evaluate the associations.

Results

There was a significant non-linear relationship between lipid profile (TC, TG, HDL-C, LDL-C) and hs-CRP (P < 0.05). Increased serum 25(OH)D was significantly associated with decreasing TC, TG, HDL-C, LDL-C, and hs-CRP levels. Compared with medium levels of lipids group, pregnant women with higher levels of TC or TG have higher levels of hs-CRP, and pregnant women with lower levels of TC, HDL-C or LDL-C also have higher levels of hs-CRP in the vitamin D deficient group, and there was a significant correlation between low levels of TG and decreased hs-CRP (adjusted β for TG: -0.063, 95%CI: − 0.120,-0.007) in the non-vitamin D deficient group. Mediators that had appreciable shares of the associations between 25(OH)D and hs-CRP was TG (10.2% of the association; β = − 0.011; total indirect effect: 95% CI: − 0.019, − 0.002). The cubic model suggested that a steep increase in the adjusted regression coefficient of lipid with hs-CRP up to 50 nmol/L of 25(OH)D, and the highest adjusted regression coefficients were observed in pregnant women with 25(OH)D above 50 nmol/L.

Conclusion

Our findings suggest that high levels of vitamin D during pregnancy may improve lipid profile levels and inhibit elevated hs-CRP induced by high lipid metabolism.

On the Road to Accurate Biomarkers for Cardiometabolic Diseases by Integrating Precision and Gender Medicine Approaches

The need to facilitate the complex management of cardiometabolic diseases (CMD) has led to the detection of many biomarkers, however, there are no clear explanations of their role in the prevention, diagnosis or prognosis of these diseases. Molecules associated with disease pathways represent valid disease surrogates and well-fitted CMD biomarkers. To address this challenge, data from multi-omics types (genomics, epigenomics, transcriptomics, proteomics, metabolomics, microbiomics, and nutrigenomics), from human and animal models, have become available. However, individual omics types only provide data on a small part of molecules involved in the complex CMD mechanisms, whereas, here, we propose that their integration leads to multidimensional data. Such data provide a better understanding of molecules related to CMD mechanisms and, consequently, increase the possibility of identifying well-fitted biomarkers. In addition, the application of gender medicine also helps to identify accurate biomarkers according to gender, facilitating a differential CMD management. Accordingly, the impact of gender differences in CMD pathophysiology has been widely demonstrated, where gender is referred to the complex interrelation and integration of sex (as a biological and functional marker of the human body) and psychological and cultural behavior (due to ethnical, social, and religious background). In this review, all these aspects are described and discussed, as well as potential limitations and future directions in this incipient field.

Association of the salivary triggering receptor expressed on myeloid cells/its ligand peptidoglycan recognition protein 1 axis with oral inflammation in kidney disease

BACKGROUND

Triggering receptor expressed on myeloid cells (TREM-1) is a cell-surface receptor involved in amplification of inflammatory response to bacterial infections, along with its ligand peptidoglycan recognition protein 1 (PGLYRP1). TREM-1 is shed by matrix metalloproteinases (MMPs) to its soluble (s) form. The aim of the study is to investigate association of sTREM-1 and PGLYRP1 with oral inflammatory burden among patients with chronic kidney disease (CKD) at predialysis and posttransplantation stages.

METHODS

One hundred forty-four patients with CKD were examined at predialysis, and oral infection foci were treated prior to kidney transplantation. Fifty-three patients were available for follow-up after transplantation. Oral inflammatory burden was assessed by the Periodontal Inflammatory Burden Index (PIBI) and Total Dental Index. sTREM-1, PGLYRP1, and interleukin (IL)-1β were measured in saliva by enzyme-linked immunosorbent assay, and MMP-8 was measured by immunofluorometric assay.

RESULTS

In the predialysis stage, sTREM-1 and PGLYRP1 were positively associated with IL-1β, MMP-8, and PIBI. More specifically, patients with deeper probing depth (PD) (at least two sites with ≥6 mm) had higher concentrations of salivary sTREM-1 and PGLYRP1 compared with those with shallower PD. Higher concentrations of PGLYRP1 and IL-1β were associated with a higher number of teeth (> 25). On follow-up, higher PGLYRP1 and sTREM-1 were associated with one or more sites with ≥4 mm PD.

CONCLUSIONS

sTREM-1 and PGLYRP1 are elevated in patients with CKD with poor oral health and positively correlate with number of active periodontal pockets after oral infection therapy. Moreover, they positively correlate with MMP-8 and IL-1β. Hence, the salivary sTREM-1/PGLYRP1 axis could be useful as a diagnostic marker for oral infection within patients with CKD.

Gut microbiotas and immune checkpoint inhibitor therapy response: a causal or coincidental relationship?

As the largest immune organ, human gut microbiome could influence the efficacy of immune checkpoint inhibitor therapy (ICI). However, identifying contributory microbes from over 35,000 species is virtually impossible and the identified microbes are not consistent among studies. The reason for the disparity may be that the microbes found in feces are markers of other factors that link immune response and microbiotas. Notably, gut microbiome is influenced by stool consistency, diet and other lifestyle factors. Therefore, the ICI and microbiotas relationship must be adjusted for potential confounders and analyzed longitudinally. Moreover, a recent study where 11 low-abundance commensal bacteria induced interferon-γ-producing CD8 T cells, challenges the validity of the abundance-oriented microbiotas investigations. This study also confirmed the hierarchy in immunogenic roles among microbiotas. Fecal transplantation trials in germ-free mice provided “the proof of principle” that germ-free mice reproduce the donor’s microbiome and corresponding ICI efficacy. However, species-specific biological differences prevent direct extrapolation between the results in murine and human models. Fecal transplantation or supplementation with microbes found in ICI responders requires caution due to potential adverse events.

Oral and Systemic Effects of Xylitol Consumption

Recent results of randomized trials testing the efficacy of xylitol in caries prevention have been conflicting. This narrative review reveals the sources of discrepancy. The following databases were searched for the terms "xylitol" or "artificial sweeteners" restricted to the English language: PubMed, Web of Science, Evidenced-Based Medicine, Scopus, and the Cochrane database. In a separate search, the terms "dental caries" or "cariogenicity" or "glucosyltransferase" or "low glycemic" or "low insulinemic" or "dysbiosis" or "gut microbiome" were used and then combined. In section I, findings regarding the role of xylitol in dental caries prevention, the appropriateness of research methods, and the causes for potential biases are summarized. In section II, the systemic effects of xylitol on gut microbiota as well as low-glycemic/insulinogenic systemic effects are evaluated and summarized. The substitution of a carbonyl group with an alcohol radical in xylitol hinders its absorption and slowly releases sugar into the bloodstream. This quality of xylitol is beneficial for diabetic patients to maintain a constant glucose level. Although this quality of xylitol has been proven in in vitro and animal studies, it has yet to be proven in humans. Paradoxically, recent animal studies reported hyperglycemia and intestinal dysbiosis with artificial sweetener consumption. Upon careful inspection of evidence, it was revealed that these reports may be due to misinterpretation of original references or flaws in study methodology. Any systemic benefits of xylitol intake must be weighed in consideration with the well-established adverse gastrointestinal consequences. The contribution of xylitol to gut dysbiosis that may affect systemic immunity warrants further research.

Salivary IgA to MAA-LDL and Oral Pathogens Are Linked to Coronary Disease

A large body of literature has established the link between periodontal disease and cardiovascular disease. Oxidized low-density lipoproteins (OxLDLs) have a crucial role in atherosclerosis progression through initiation of immunological response. Monoclonal IgM antibodies to malondialdehyde-modified low-density lipoprotein (MDA-LDL) and to malondialdehyde acetaldehyde-modified low-density lipoprotein (MAA-LDL) have been shown to cross-react with the key virulence factors of periodontal pathogens Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans. We have previously shown that salivary IgA antibodies to MAA-LDL cross-react with P. gingivalis in healthy humans. In this study, we aim to assess whether oral mucosal immune response represented by salivary IgA to MAA-LDL and oral pathogens is associated with coronary artery disease (CAD). Also, the molecular mimicry through antibody cross-reaction between salivary IgA to MAA-LDL and oral pathogens was evaluated. The study subjects consisted of 451 patients who underwent a coronary angiography with no CAD ( n = 133), stable CAD ( n = 169), and acute coronary syndrome (ACS, n = 149). Elevated salivary IgA antibody levels to MAA-LDL, Rgp44 (gingipain A hemagglutinin domain of P. gingivalis), and Aa-HSP60 (heat shock protein 60 of A. actinomycetemcomitans) were discovered in stable-CAD and ACS patients when compared to no-CAD patients. In a multinomial regression model adjusted for known cardiovascular risk factors, stable CAD and ACS were associated with IgA to MAA-LDL ( P = 0.016, P = 0.043), Rgp44 ( P = 0.012, P = 0.004), Aa-HSP60 ( P = 0.032, P = 0.030), Tannerella forsythia ( P = 0.002, P = 0.004), Porphyromonas endodontalis ( P = 0.016, P = 0.020), Prevotella intermedia ( P = 0.038, P = 0.005), and with total IgA antibody concentration ( P = 0.002, P = 0.016). Salivary IgA to MAA-LDL showed cross-reactivity with the oral pathogens tested in the study patients. The study highlights an association between salivary IgA to MAA-LDL and atherosclerosis. However, whether salivary IgA to MAA-LDL and the related oral humoral responses play a causal role in the development in the CAD should be elucidated in the future.

Salivary fingerprint of simple obesity

BACKGROUND

The nature of a link between poor oral health and obesity is not fully understood. It is also unclear if saliva contributes to it and whether the properties of saliva change as a result of an increase in body mass or rather as a consequence of obesity-associated comorbidities. This pilot study was undertaken in an attempt to determine if salivary biomarkers can identify obesity per se.

METHODS

Whole mixed saliva was analysed for 16 soluble parameters covering 4 categories (inflammation, oxidative stress, endothelial dysfunction, adipokines). In the discovery group, 19 obese and 25 non-obese women matched for age, with similar hygiene habits, with no comorbidities and not taking any medication known to affect saliva secretion were analysed. In the validation group, a cohort of no-preselected 81 individuals (34 obese) were analysed.

RESULTS

Individuals with obesity had significantly higher salivary concentrations of several cytokines and adipokines, of which TNF-R1, serpin A12 and PAI-1 were identified as parameters discriminating between obese and non-obese subjects with the highest sensitivity and specificity.

CONCLUSIONS

Obesity per se leads to distinct changes in the concentration of several parameters in saliva. These findings may have diagnostic implications for distinguishing the effects of obesity and obesity-linked comorbidities on oral health.

NLRP3 Inflammasome as a Molecular Marker in Diabetic Cardiomyopathy

Diabetic cardiomyopathy (DCM), a common consequence of longstanding diabetes mellitus, is initiated by death of cardiomyocyte. Hyperglycemia-induced reactive oxygen species (ROS) overproduction is a major contributor of the chronic low-grade inflammation that characterizes as the DCM. ROS may promote the activation of nucleotide-binding oligomerization domain like receptor (NLR) pyrin domain containing 3 (NLRP3) inflammasome, a novel regulator of inflammation and cell death, by nuclear factor-kB (NF-κB) and thioredoxin interacting/inhibiting protein (TXNIP). NLRP3 inflammasome regulates the death of cardiomyocyte and activation of fibroblast in DCM, which is involved in the structural and functional disorder of DCM. However, comprehensive understanding of molecular mechanisms linking NLRP3 inflammasome and disorder of cardiomyocyte and fibroblast in DCM is lacking. Here, we review the molecular mechanism(s) of NLRP3 inflammasome activation in response to hyperglycemia in DCM.

Impact of Periodontitis Case Criteria: A Cross-Sectional Study of Lifestyle

BACKGROUND

Associations of risk factors/indicators with periodontitis may depend on the included case criterion. The objective of the current study is to evaluate differences in outcome by applying five periodontitis case definitions for cross-sectional associations with lifestyle factors among participants of the Danish Health Examination Survey (DANHES).

METHODS

A total of 4,402 adults aged 18 to 96 years from the general health examination of DANHES had a periodontal examination consisting of half-mouth registration at six sites per tooth including probing depth (PD) and clinical attachment level (CAL). Periodontitis was defined according to severe periodontitis, European Workshop of Periodontology (EWP)-specific, meanCAL ≥2.55 mm, CAL-tertile, and PD-CAL definitions. Multivariable logistic regression models fitted the association of age, sex, smoking status, diabetes mellitus, educational level, alcohol consumption, body mass index, physical activity, body fat percentage, waist circumference, triglycerides, total cholesterol, and C-reactive protein with periodontitis.

RESULTS

Number of cases captured by the five periodontitis case definitions ranged from 337 (9.2%) to 1,136 (31.0%). A total of 224 participants were defined as periodontitis cases by all five criteria. Analyses on 3,665 participants with complete data revealed statistically significant associations of age and smoking with all periodontitis case definitions and of male sex with severe periodontitis and EWP-specific definitions. Educational level (two lowest groups) was related to three periodontitis criteria. Among obesity and hyperlipidemia measures no factors were related to periodontitis.

CONCLUSION

Regression analyses showed little difference in odds ratio across the five periodontitis case definitions; however, the level of significance did show some variation.

Salivary pellets induce a pro-inflammatory response involving the TLR4-NF-kB pathway in gingival fibroblasts

Background

Whole saliva provokes a substantial pro-inflammatory response in gingival fibroblasts. This raises the question whether the salivary pellet, which is used for diagnostic purposes, also has a pro-inflammatory capacity and, if yes, what the underlying mechanisms at the molecular level are.

Methods

We examined the ability of extensively washed salivary pellets to provoke the expression of chemokines in gingival fibroblasts by real-time polymerase chain reaction and immunoassays. Protein composition was determined with proteomic analysis. Endotoxins were analyzed by a Limulus assay and removed by affinity chromatography. The inhibitors TAK-242 and BAY11-7082 were used to determine the involvement of the TLR4 and NF-kB signaling, respectively. Western blot was performed to detect phosphorylated p65.

Results

The experiments show that salivary pellets and the corresponding washing solution contain pro-inflammatory activity without impairing cell viability. Proteomic analysis revealed proteins with a binding capacity for lipopolysaccharides, and the Limulus assay indicated the presence of endotoxin in the salivary pellets. Blocking TLR4 with TAK-242 and depletion of endotoxins both lowered the capacity of salivary pellets to increase chemokine expression and phosphorylation of p65. BAY11-7082 suppressed chemokine expression in response to the salivary pellets. Autoclaving salivary pellets also reduced their pro-inflammatory activity.

Conclusions

The data support the molecular mechanism of a TLR4-NF-kB-dependent pro-inflammatory response of the gingival fibroblasts exposed to preparations of washed salivary pellets. Together, the data indicate that the salivary pellet is rich in endotoxin but it is mainly a heat labile fraction that accounts for the chemokine expression in the bioassay.

Electronic supplementary material

The online version of this article (doi:10.1186/s12903-016-0229-5) contains supplementary material, which is available to authorized users.

Systemic inflammatory impact of periodontitis on acute coronary syndrome

AIM

A causative relationship between acute coronary syndrome (ACS) and periodontitis has yet to be defined. The aim of this study was to assess differences in levels of serum cytokines between individuals with or without ACS or periodontal comorbidity.

MATERIAL AND METHODS

In a case-control study, individuals with ACS (78 individuals, 10.3% females) and matching healthy controls (78 individuals, 28.2% females) were included. Medical and dental examinations were performed to diagnose ACS and periodontitis. Serum levels of cytokines were assessed, using Luminex technology.

RESULTS

A diagnosis of periodontitis in the ACS and control group was diagnosed in 52.6% and 12.8% of the individuals, respectively. The unadjusted odds-ratio that individuals with ACS also had periodontitis was 7.5 (95% CI: 3.4, 16.8, p < 0.001). Independent of periodontal conditions, individuals with ACS had significantly higher serum levels of IL8 (mean: 44.3 and 40.0 pg/ml) and vascular endothelial growth factor (VEGF) (mean: 82.3 and 55.3 pg/ml) than control individuals. A diagnosis of periodontitis made no difference in serum cytokine expressions.

CONCLUSION

Elevated serum levels of VEGF were associated with ACS. Serum cytokine expression in individuals with ACS is unrelated to periodontal conditions.

Polymicrobial Biofilm Studies: From Basic Science to Biofilm Control

Microbes rarely exist as single species planktonic forms as they have been commonly studied in the laboratory. Instead, the vast majority exists as part of complex polymicrobial biofilm communities attached to host and environmental surfaces. The oral cavity represents one of the most diverse and well-studied polymicrobial consortia. Despite a burgeoning field of mechanistic biofilm research within the past decades, our understanding of interactions that occur between microbial members within oral biofilms is still limited. Thus, the primary objective of this review is to focus on polymicrobial biofilm formation, microbial interactions and signaling events that mediate oral biofilm development, consequences of oral hygiene on both local and systemic disease, and potential therapeutic strategies to limit oral dysbiosis.

Does Treatment of Periodontal Disease Influence Systemic Disease?

Periodontal diseases are the most common human diseases globally, with gingivitis affecting up to 90% and periodontitis affecting 50% of adults. Tooth enamel is the only nonshedding tissue in the human body. In the absence of proper oral hygiene measures, microbial biofilm (dental plaque) develops on the teeth to include more than 700 different bacterial species, along with viruses, fungi, archea, and parasites. With time, ecological imbalances promote the growth of selected commensal species that induce host inflammatory pathways resulting in tissue destruction, including ulceration of the periodontal epithelium.

Apical periodontitis and incident cardiovascular events in the Baltimore Longitudinal Study of Ageing

AIM

To evaluate whether the presence of apical periodontitis (AP), root canal treatment (RCT) and endodontic burden (EB) - as the sum of AP and RCT sites - were associated with long-term risk of incident cardiovascular events (CVE), including cardiovascular-related mortality, using data on participants in the Baltimore Longitudinal Study of Ageing (BLSA).

METHODOLOGY

This retrospective cohort included 278 dentate participants in the BLSA with complete medical and dental examinations. Periodontal disease (PD) and missing teeth were recorded. The total number of AP and RCT sites was determined from panoramic radiographs. EB was calculated as the sum of AP and RCT sites. Oral inflammatory burden (OIB) was calculated combining PD and EB. The main outcome was incident CVE including angina, myocardial infarction and cardiovascular-related death. Participants were monitored for up to 44 years (mean = 17.4± 11.1 years) following dental examination. Relative risks (RRs) were calculated through Poisson regression models, estimating the relationship between AP, RCT, EB, PD, OIB and incident CVE.

RESULTS

Mean age at baseline was 55.0 ±16.8 years and 51.4% were men. Sixty-two participants (22.3%) developed CVE. Bivariate analysis showed that PD, EB, number of teeth and OIB were associated with incident CVE. Multivariate models, adjusted for socio-demographic and medical variables, showed that age ≥60 years (RR = 3.07, 95% CI =1.68-5.62), hypertension (RR = 2.0, 95% CI = 1.16-3.46) and EB ≥3 (RR = 1.77, 95% CI = 1.04-3.02) were independently associated with incident CVE. The association between OIB and incident CVE was reduced to nonsignificance after adjustments (RR = 1.97, 95% CI = 0.83-4.70).

CONCLUSIONS

EB in midlife was an independent predictor of CVE amongst community-dwelling participants in the BLSA. Prospective studies are required to evaluate cardiovascular risk reduction with the treatment of AP.