Effect of periodontal treatment on circulating CD34(+) cells and peripheral vascular endothelial function: a randomized controlled trial

Effect of non-surgical periodontal therapy on risk markers of cardiovascular disease: a systematic review and meta-analysis

BACKGROUND

Cardiovascular disease (CVD) is the leading cause of mortality in the world. Patients with periodontitis have a higher risk of CVD, although a causal relationship between these conditions remains unclear. Non-surgical periodontal therapy (NSPT) is able to control inflammation at local and systemic levels. This study aimed to analyze the effect of NSPT on CVD risk markers.

METHODS

Four electronic databases were searched from their inception to April 1, 2023, to identify and select articles without any language restrictions. Eleven CVD-related markers (e.g., C-reactive protein [CRP], Interleukin-6 [IL-6]) were selected. Meta-analyses were performed using random and fixed effect models. The differences were expressed as weighted mean differences (WMD) and 95% confidence interval (95% CI).

RESULTS

From 1353 studies, twenty-one randomized controlled clinical trials were included in the meta-analysis. Results showed a significant decrease in CRP, IL-6, and systolic blood pressure (SBP) after NSPT.

CONCLUSION

Moderate certainty evidence shows that NSPT has a positive effect on the reduction of IL-6 and SBP in patients with periodontitis, while low certainty evidence shows that NSPT is effective for reduction of CRP. Moderate certainty evidence showed that NSPT did not show a positive effect on low-density lipoprotein (LDL), high-density lipoprotein (HDL), total cholesterol (TC) and triglycerides (TG), and low certainty evidence showed that NSPT did not show a positive effect on Interleukin-1β (IL-1β), tumor necrosis factor-alpha (TNF-α), diastolic blood pressure (DBP), and flow-mediated dilatation (FMD).

PROTOCOL REGISTRATION

The protocol was registered in the PROSPERO (International Prospective Register of Systematic Reviews), number CRD42022377565.

Oral health as a modifiable risk factor for cardiovascular diseases

Cardiovascular diseases (CVDs) are a leading cause of morbidity and mortality worldwide with a high socioeconomic burden. Increasing evidence supports a convincing connection with increased cardiovascular risk of periodontal diseases (PD), a group of widespread, debilitating, and costly dysbiotic relapsing-remitting inflammatory diseases of the tissues supporting the teeth. Herein, we ensembled the best available evidence on the connection between CVDs and PD to review the recently emerging concept of the latter as a non-traditional risk factor for CVDs. We focused on oral dysbiosis, inflammation-associated molecular and cellular mechanisms, and epigenetic changes as potential causative links between PD and CVDs. The available evidence on the effects of periodontal treatment on cardiovascular risk factors and diseases was also described.

Periodontal inflammation is associated with increased circulating levels of endothelial progenitor cells: a retrospective cohort study in a high vascular risk population

Background

One of the main biological mechanisms behind the link between periodontitis and atherosclerotic vascular diseases is vascular endothelial dysfunction. Particularly, circulating endothelial progenitor cells (EPCs) have been considered a biomarker of altered vascular endothelial function.

Objectives

The aim of this study was to investigate relationship between periodontal inflammation and increased number of circulating EPCs.

Design

This is retrospective cohort study.

Methods

In this study, 85 elderly patients with a previous history of hypertension were followed up to 12 months. A baseline full-mouth periodontal assessment was carried out, and the amount of periodontal tissue inflamed per subject was calculated as a proxy of periodontal inflammation [periodontal inflamed surface area (PISA)]. The number of circulating EPCs (CD34+/CD133+/KDR+) was determined by flow cytometry from peripheral blood samples collected at baseline and 12 months.

Results

Mean concentrations of CD34+/CD133+/KDR+ progenitor cells were higher in periodontitis patients than in those without periodontitis at baseline [55.4, 95% confidence interval (CI) = 20.8 to 90.0 versus 27.2, 95% CI = 13.6 to 40.8, p = 0.008] and 12 months (114.6, 95% CI = 53.5 to 175.7 versus 19.1, 95% CI = 10.8 to 27.4, p = 0.003). A significant increase over the follow-up was noticed in the group of subjects with periodontitis (p = 0.049) but not in the nonperiodontitis group (p = 0.819). PISA was independently associated with CD34+/CD133+/KDR+ EPCs at baseline (B coefficient = 0.031, 95% CI = 0.005 to 0.058; p = 0.021). The relationship between PISA and CD34+/CD133+/KDR+ EPCs at 12 months was confounded by increased baseline body mass index (B coefficient = 0.064, 95% CI = -0.005 to 0.132; p = 0.066).

Conclusion

Periodontal inflammation is associated with high number of CD34+/CD133+/KDR+ EPCs, thus supporting a potential link between periodontitis and endothelial dysfunction.

Discovering genetic linkage between periodontitis and type 1 diabetes: A bioinformatics study

Background: Relationship between periodontitis (PD) and type 1 diabetes (T1D) has been reported, but the detailed pathogenesis requires further elucidation. This study aimed to reveal the genetic linkage between PD and T1D through bioinformatics analysis, thereby providing novel insights into scientific research and clinical treatment of the two diseases.

Methods: PD-related datasets (GSE10334, GSE16134, GSE23586) and T1D-related datasets(GSE162689)were downloaded from NCBI Gene Expression Omnibus (GEO). Following batch correction and merging of PD-related datasets as one cohort, differential expression analysis was performed (adjusted p-value <0.05 and ∣log2  fold change| > 0.5), and common differentially expressed genes (DEGs) between PD and T1D were extracted. Functional enrichment analysis was conducted via Metascape website. The protein-protein interaction (PPI) network of common DEGs was generated in The Search Tool for the Retrieval of Interacting Genes/Proteins (STRING) database. Hub genes were selected by Cytoscape software and validated by receiver operating characteristic (ROC) curve analysis.

Results: 59 common DEGs of PD and T1D were identified. Among these DEGs, 23 genes were commonly upregulated, and 36 genes were commonly downregulated in both PD- and T1D-related cohorts. Functional enrichment analysis indicated that common DEGs were mainly enriched in tube morphogenesis, supramolecular fiber organization, 9 + 0 non-motile cilium, plasma membrane bounded cell projection assembly, glomerulus development, enzyme-linked receptor protein signaling pathway, endochondral bone morphogenesis, positive regulation of kinase activity, cell projection membrane and regulation of lipid metabolic process. After PPI construction and modules selection, 6 hub genes (CD34, EGR1, BBS7, FMOD, IGF2, TXN) were screened out and expected to be critical in linking PD and T1D. ROC analysis showed that the AUC values of hub genes were all greater than 70% in PD-related cohort and greater than 60% in T1D-related datasets.

Conclusion: Shared molecular mechanisms between PD and T1D were revealed in this study, and 6 hub genes were identified as potential targets in treating PD and T1D.

Identifying Common Genes and Pathways Associated with Periodontitis and Aging by Bioinformatics Analysis

BACKGROUND

This work used bioinformatic analysis to identify the relationship between periodontitis (PD) and aging, which could lead to new treatments for periodontal disease in the elderly.

METHOD

Four microarray datasets were obtained from the Gene Expression Omnibus (GEO) database and analyzed in R language to identify differentially expressed genes (DEGs). The common DEGs of PD and aging were evaluated as key genes in this investigation by a Venn diagram. These common DEGs were analyzed through additional experiments and analysis, such as pathway analysis and enrichment analysis, and a network of protein-protein interactions (PPIs) was constructed. Cytoscape was used to visualize hub genes and critical modules based on the PPI network. Interaction of TF-genes and miRNAs with hub genes is identified.

RESULT

84 common DEGs were found between PD and aging. Cytohubba was performed on the PPI network obtained from STRING tool, and the top 10 genes (MMP2, PDGFRB, CTGF, CD34, CXCL12, VIM, IL2RG, ACTA2, COL4A2, and TAGLN) were selected as hub genes. VIM may be a potential biomarker in the analysis of linked hub gene regulatory networks, and hsa-mir-21 and hsa-mir-125b are predicted to be associated in PD and aging.

CONCLUSION

This study investigated the key genes and pathways interactions between PD and aging, which may help reveal the correlation between PD and aging. The current research results are obtained by prediction, and follow-up biological experiments are required for further verification.

The impact of periodontitis on vascular endothelial dysfunction

Periodontitis, an oral inflammatory disease, originates from periodontal microbiota dysbiosis which is associated with the dysregulation of host immunoinflammatory response. This chronic infection is not only harmful to oral health but is also a risk factor for the onset and progress of various vascular diseases, such as hypertension, atherosclerosis, and coronary arterial disease. Vascular endothelial dysfunction is the initial key pathological feature of vascular diseases. Clarifying the association between periodontitis and vascular endothelial dysfunction is undoubtedly a key breakthrough for understanding the potential relationship between periodontitis and vascular diseases. However, there is currently a lack of an updated review of their relationship. Therefore, we aim to focus on the implications of periodontitis in vascular endothelial dysfunction in this review.

Porphyromonas gingivalis lipopolysaccharide affects the angiogenic function of endothelial progenitor cells via Akt/FoxO1 signaling

AIMS

Endothelial progenitor cells (EPCs) function as the angiogenic switch of many physiological and pathological conditions. We aimed to investigate the effects of Porphyromonas gingivalis lipopolysaccharide on the angiogenic capacity of EPCs and delineate the underlying mechanisms.

MATERIALS AND METHODS

EPCs were isolated from human umbilical blood. CCK-8 assay was undertaken to analyze the cell viability. The migration and tube formation capacity were assessed by wound healing and tube formation, respectively. The protein expression of Akt/p-Akt, endothelial nitric oxide synthase (eNOS)/p-eNOS, and Forkhead box O1 (FoxO1)/p-FoxO1 was determined by Western blot. The intracellular localization of FoxO1 was evaluated by immunofluorescent staining.

RESULTS

P. gingivalis LPS at 10 μg/ml significantly increased the viability (10.9 ± 2.9%), migration (16.3 ± 3.1%), and tube formation (38.6 ± 5.5%) of EPCs, along with increased phosphorylation of Akt, eNOS, and FoxO1. Mechanistically, Akt inhibition by specific inhibitor wortmannin and FoxO1 forced expression by adenovirus transfection in EPCs markedly attenuated the P. gingivalis LPS-induced eNOS activation, tube formation, and migration. Moreover, P. gingivalis LPS-induced phosphorylation and nuclear exclusion of FoxO1 were blunted by Akt inhibition.

CONCLUSIONS

The present study suggests that P. gingivalis LPS could affect the angiogenic function of EPCs through the Akt/FoxO1 signaling. The current findings may shed light on the clinical association of periodontitis with aberrant angiogenesis seen in atherosclerotic plaque rupture.

A randomized controlled trial of the effects of non-surgical periodontal therapy on cardiac function assessed by echocardiography in type 2 diabetic patients

BACKGROUND

Periodontitis significantly increases the risk of diabetic complications. This clinical trial investigated the effects of periodontal therapy on cardiac function in patients with type 2 diabetes mellitus (T2DM) and periodontitis.

MATERIALS AND METHODS

Fifty-eight subjects with T2DM and periodontitis were randomly allocated to Treatment Group (n = 29) receiving non-surgical periodontal therapy, and Control Group (n = 29) having only oral hygiene instructions with delayed periodontal treatment until completion of this 6-month study. The left ventricle (LV) diastolic function was assessed by echocardiography with the tissue Doppler imaging index (E/e' ratio); and LV hypertrophy was evaluated by LV mass index (LVMI). Blood samples were collected for biochemical analysis.

RESULTS

The intention-to-treat analysis showed that periodontal treatment significantly reduced the E/e' ratio by 1.66 (95% CI: -2.64 to -0.68, p < .01), along with marked improvement of periodontal conditions (p < .05). LVMI was not altered at the 6-month follow-up. The serum levels of N-terminal pro-B type natriuretic peptide (NT-proBNP) as a cardiac stress biomarker, C-reactive protein and interleukin-6 decreased numerically without reaching statistical significance.

CONCLUSION

The present study provides the first evidence that non-surgical periodontal therapy may improve cardiac diastolic function in type 2 diabetic patients with periodontitis.

Reporting quality and spin in abstracts of randomized clinical trials of periodontal therapy and cardiovascular disease outcomes

OBJECTIVE

Poor reporting in randomized clinical trial (RCT) abstracts reduces quality and misinforms readers. Spin, a biased presentation of findings, could frequently mislead clinicians to accept a clinical intervention despite non-significant primary outcome. Therefore, good reporting practices and absence of spin enhances research quality. We aim to assess the reporting quality and spin in abstracts of RCTs evaluating the effect of periodontal therapy on cardiovascular (CVD) outcomes.

METHODS

PubMed, Scopus, the Cochrane Central Register of Controlled Trials (CENTRAL), and 17 trial registration platforms were searched. Cohort, non-randomized, non-English studies, and pediatric studies were excluded. RCT abstracts were reviewed by 2 authors using the CONSORT for abstracts and spin checklists for data extraction. Cohen's Kappa statistic was used to assess inter-rater agreement. Data on the selected RCT publication metrics were collected. Descriptive analysis was performed with non-parametric methods. Correlation analysis between quality, spin and bibliometric parameters was conducted.

RESULTS

24 RCTs were selected for CONSORT analysis and 14 fulfilled the criteria for spin analysis. Several important RCT elements per CONSORT were neglected in the abstract including description of the study population (100%), explicitly stated primary outcome (87%), methods of randomization and blinding (100%), trial registration (87%). No RCT examined true outcomes (CVD events). A significant fraction of the abstracts appeared with at least one form of spin in the results and conclusions (86%) and claimed some treatment benefit in spite of non-significant primary outcome (64%). High-quality reporting had a significant positive correlation with reporting of trial registration (p = 0.04) and funding (p = 0.009). Spinning showed marginal negative correlation with reporting quality (p = 0.059).

CONCLUSION

Poor adherence to the CONSORT guidelines and high levels of data spin were found in abstracts of RCTs exploring the effects of periodontal therapy on CVD outcomes. Our findings indicate that journal editors and reviewers should consider strict adherence to proper reporting guidelines to improve reporting quality and reduce waste.

Periodontitis and Tooth Loss Have Negative Systemic Impact on Circulating Progenitor Cell Levels: A Clinical Study

The aim of the present study was to investigate the association and impact of periodontitis and tooth loss on a subtype of endothelial progenitor cell (EPC) levels (CD133+/KDR+). Furthermore, the objective was to determine if the periodontal status influenced CD133+/KDR+ levels. In all, 88 patients with periodontitis and 79 healthy controls (HCs) were enrolled in the study. Enrolled patients were examined and characterized by clinical and blood sample analysis. Spearman's correlation test was applied in order to assess the interdependence between CD133+/KDR+ levels and all periodontal parameters. In order to estimate a statistically significant trend (p-trend) for ordered CD133++/KDR+ quartiles, the Jonckheere-Terpstra test was applied for all variables. Patients in the periodontitis group presented significantly lower CD133+/KDR+ levels (66.4 (45.5-269.6 cells/µL)) compared to the HC group (76.7 (24.3-313.2 cells/µL), p < 0.001). Lower CD133+/KDR+ levels negatively correlated with C-reactive protein (CRP), with the number of teeth, and with all periodontal parameters (p < 0.001). Moreover, there was a proportional increase in CD133+/KDR+ levels with a progressive increase in number of teeth (p-trend < 0.001), while there was a proportional decrease in CD133+/KDR+ levels with a proportional increase in clinical attachment level (CAL, p-trend = 0.003), probing depth (PD, p-trend = 0.007), and bleeding sites (bleeding on probing (BOP), p-trend < 0.001) as an extent measure of periodontitis. This study demonstrated that patients with periodontitis presented significantly lower CD133+/KDR+ levels compared to HCs. Moreover, all patients presented an increase in the CD133+/KDR+ EPC levels with an extended level of periodontitis and tooth loss.

The Association of Periodontitis and Peripheral Arterial Occlusive Disease-A Systematic Review

Background: Observational studies support an association between periodontitis (PD) and atherosclerotic vascular disease, but little is known specifically about peripheral arterial occlusive disease (PAOD).

OBJECTIVES

To systematically review the evidence for an association between PD and PAOD.

DATA SOURCES

Medline via PubMed.

REVIEW METHODS

We searched the Pubmed database for original studies, case reports, case series, meta-analyses and systematic reviews that assessed whether there is an association between PD (all degrees of severity) and PAOD (all degrees of severity). The reporting of this systematic review was in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement following the Population, Intervention, Control, and Outcome (PICO) format.

RESULTS

17 out of 755 detected studies were included in the qualitative synthesis. Nine studies demonstrated associations between PD and PAOD, and two studies reported associations between tooth loss and PAOD. Six studies addressed the pathomechanism regarding PD as a possible trigger for PAOD. No study that dismissed an association could be detected. Odds ratios or hazard ratios ranged from 1.3 to 3.9 in four large cohort studies after adjusting for established cardiovascular risk factors.

CONCLUSIONS

The presented evidence supports a link between PD and PAOD. Further studies which address the temporality of PD and PAOD and randomized controlled intervention trials examining the causal impact of PD on PAOD are needed. Although our results cannot confirm a causal role of PD in the development of PAOD, it is likely that PD is associated with PAOD and plays a contributing role.

The impact of periodontal treatment on inflammatory markers and cellular parameters associated with atherosclerosis in patients after myocardial infarction

Introduction

The aim of this study was to analyze whether periodontal treatment affects the cardiovascular risk profile of patients after myocardial infarction (MI).

Material and methods

The study included 30 patients with chronic periodontitis (ChP). Sociodemographic and medical variables were collected. Patients were provided with scaling and root planing (SRP) 3 months after MI (1^st visit). Periodontal examination and blood tests were performed immediately before SRP, then 1 month and 6 months after treatment (2^nd and 3^rd visit, respectively).

Results

A statistically significant decrease in blood hsCRP concentration and a decrease in the number of white blood cells (WBC) and neutrophils between the first and the second visit were observed. At 6 months after SRP, the mean platelet volume (MPV) had increased with respect to the value at 1 month after treatment. Multivariate analysis showed that the associations between: 1) change in LDL-C concentration and change in approximal plaque index value (b = –0.546, p = 0.005); 2) change in the number of monocytes and change in the plaque index value (b = 0.616, p = 0.01); 3) change in MPV and change in probing pocket depth (b = 0.567, p = 0.018) are all independent of the classic cardiovascular risk factors.

Conclusions

The obtained results indicate the existence of a relationship between the state of periodontal tissues on one hand and mediators of atherosclerosis and the number of immunologically competent cells on the other hand.

Periodontal therapy and endothelial function in coronary artery disease: A randomized controlled trial

OBJECTIVE

To assess the effects of periodontal treatment on endothelial function in patients with coronary artery disease.

MATERIALS AND METHODS

A randomized controlled trial was conducted with 69 patients with stable coronary disease and severe periodontitis. The test group received nonsurgical periodontal therapy consisting of personalized oral hygiene instructions, subgingival scaling, and root planing per quadrant, whereas the control group received equal treatment after the study period. Endothelial function was assessed by measurement of brachial artery flow-mediated dilation, concentrations of sVCAM-1, sICAM-1, and P-selectin in serum before and 3 months after periodontal therapy.

RESULTS

The test group exhibited statistically better periodontal parameters-plaque, probing depth, periodontal attachment loss, and bleeding on probing. No significant improvements were observed in the control (1.37%) and test (1.39%) groups in flow-mediated dilation, with no significant between-group difference. sVCAM-1 concentration increased in the control group (997.6 ± 384.4-1201.8 ± 412.5; p = 0.03), whereas in the test group, no significant changes were observed (915.1 ± 303.8-1050.3 ± 492.3; p = 0.17), resulting in a significant difference between the two groups (p = 0.04). The same pattern was observed for concentrations of sICAM-1.

CONCLUSION

Periodontal treatment did not provide better vasodilation in patients with coronary disease in a short-term follow-up period, although it maintained blood concentrations of markers of vascular inflammation.

Association between a history of periodontitis and the risk of systemic lupus erythematosus in Taiwan: A nationwide, population-based, case-control study

Objective

To examine the association between a history of periodontitis (PD) and incident systemic lupus erythematosus (SLE)

Methods

We used 2003–2012 claims data from the Taiwanese National Health Insurance Database to identify 7,204 incident SLE patients during 2007–2012 as the study group, along with randomly selecting 72,040 non-SLE patients matched (1:10) for age, gender, and first diagnosis date (index date) as the control group. The correlation between PD and SLE risk was estimated using conditional logistic regression analysis, after making adjustments for confounders (including a history of diabetes and number of non-PD related dental visits before the index date). To evaluate the effects of PD severity and the lag time which occurred since the last PD visit on SLE development, odds ratios (ORs) with 95% confidence intervals (CIs) were calculated for subgroups of patients with PD according to their number of visits, cumulative cost and also the time gaps between their last PD-related visit and the index date.

Results

A statistically significant association between a history of PD and newly diagnosed SLE was observed (OR, 1.21; 95% CI, 1.14–1.28; p-value, <0.001). The association was both dose- and time-dependent and was found to be strongest when the interval between the last PD-related visit and the index date was less than three months (OR, 1.83; 95% CI, 1.61–2.09; p-value, <0.001). The association between PD exposure and SLE risk was consistently significant among subgroups stratified based on age, gender, or DM status.

Conclusions

The results of this nationwide, population-based, case-control study suggest that there is a significant association between a history of PD and incident SLE in Taiwan. This weak association is limited to lack of information on individual smoking status in the database.

Effect of Intensive Periodontal Therapy on Blood Pressure and Endothelial Microparticles in Patients With Prehypertension and Periodontitis: A Randomized Controlled Trial

BACKGROUND

Although some studies show a positive association between periodontitis and blood pressure (BP) elevation, research on the effect of intensive periodontal treatment on decline in BP levels and endothelial microparticles (EMPs) without any antihypertensive management is lacking. Therefore, the present clinical trial explores whether intensive periodontal therapy would lower BP levels and EMPs of patients with prehypertension with periodontitis.

METHODS

From a total 107 patients, 95 underwent randomization (47 assigned to control-treatment [CT] group and 48 assigned to intensive-treatment [IT] group) and completed the trial. Patients received intervention for 4 consecutive weeks and were followed for 6 months. Levels of BP and EMPs were evaluated at baseline and 1, 3, and 6 months after intervention.

RESULTS

Periodontal conditions were significantly improved (P <0.05) 6 months after intensive periodontal treatment. In parallel, the primary outcomes including systolic and diastolic BP and EMPs were markedly reduced in the IT group compared with the CT group (absolute difference: 12.57 and 9.65 mm Hg and 581.59/μL, respectively; 95% confidence intervals: 10.45 to 14.69, 7.06 to 12.24, and 348.12 to 815.06, respectively; P <0.05). Reduction in BP levels and EMPs was related to improvement in probing depth (r = 0.358, 0.363, and 0.676, respectively, by the Pearson product-moment correlation; P = 0.009, 0.008, and P <0.001, respectively).

CONCLUSION

To the best knowledge of the authors, the present study demonstrates for the first time that intensive periodontal intervention without any antihypertensive medication therapy may be an effective means to lower levels of BP and EMPs in patients with prehypertension with periodontitis.

Oral Health and Erectile Dysfunction

Ample evidence strongly supports the fact that periodontal disease is a major risk factor for various systemic diseases namely cardio-vascular disease, diabetes mellitus, etc. Recently, investigators focussed on exploring the link between chronic periodontitis (CP) and erectile dysfunction (ED) by contributing to the endothelial dysfunction. Both the diseases share common risk factors. Various studies conducted in different parts of the world in recent years reported the evidence linking this relationship as well as improvement in ED with periodontal treatment. Systemic exposure to the periodontal pathogen and periodontal infection-induced systemic inflammation was thought to associate with these conditions. The objective of this review was to highlight the evidence of the link between CP and ED and the importance of oral health in preventing the systemic conditions.

The microbiome of the oral mucosa in irritable bowel syndrome

Irritable bowel syndrome (IBS) is a poorly understood disorder characterized by persistent symptoms, including visceral pain. Studies have demonstrated oral microbiome differences in inflammatory bowel diseases suggesting the potential of the oral microbiome in the study of non-oral conditions. In this exploratory study we examine whether differences exist in the oral microbiome of IBS participants and healthy controls, and whether the oral microbiome relates to symptom severity. The oral buccal mucosal microbiome of 38 participants was characterized using PhyloChip microarrays. The severity of visceral pain was assessed by orally administering a gastrointestinal test solution. Participants self-reported their induced visceral pain. Pain severity was highest in IBS participants (P = 0.0002), particularly IBS-overweight participants (P = 0.02), and was robustly correlated to the abundance of 60 OTUs, 4 genera, 5 families and 4 orders of bacteria (r² > 0.4, P < 0.001). IBS-overweight participants showed decreased richness in the phylum Bacteroidetes (P = 0.007) and the genus Bacillus (P = 0.008). Analysis of β-diversity found significant separation of the IBS-overweight group (P < 0.05). Our oral microbial results are concordant with described fecal and colonic microbiome-IBS and -weight associations. Having IBS and being overweight, rather than IBS-subtypes, was the most important factor in describing the severity of visceral pain and variation in the microbiome. Pain severity was strongly correlated to the abundance of many taxa, suggesting the potential of the oral microbiome in diagnosis and patient phenotyping. The oral microbiome has potential as a source of microbial information in IBS.

Circulating endothelial progenitor cells in periodontitis

BACKGROUND

Several biologically plausible mechanisms have been proposed to mediate the association between periodontitis and atherosclerotic vascular disease (AVD), including adverse effects on vascular endothelial function. Circulating endothelial progenitor cells (cEPCs) are known to contribute to vascular repair, but limited data are available regarding the relationship between cEPC levels and periodontitis. The aims of this cross-sectional study are to investigate the levels of hemangioblastic and monocytic cEPCs in patients with periodontitis and periodontally healthy controls and to associate cEPC levels with the extent and severity of periodontitis.

METHODS

A total of 112 individuals (56 patients with periodontitis and 56 periodontally healthy controls, aged 26 to 65 years; mean age: 43 years) were enrolled. All participants underwent a full-mouth periodontal examination and provided a blood sample. Hemangioblastic cEPCs were assessed using flow cytometry, and monocytic cEPCs were identified using immunohistochemistry in cultured peripheral blood mononuclear cells. cEPC levels were analyzed in the entire sample, as well as in a subset of 50 pairs of patients with periodontitis/periodontally healthy controls, matched with respect to age, sex, and menstrual cycle.

RESULTS

Levels of hemangioblastic cEPCs were approximately 2.3-fold higher in patients with periodontitis than periodontally healthy controls, after adjustments for age, sex, physical activity, systolic blood pressure, and body mass index (P = 0.001). A non-significant trend for higher levels of monocytic cEPCs in periodontitis was also observed. The levels of hemangioblastic cEPCs were positively associated with the extent of bleeding on probing, probing depth, and clinical attachment loss. Hemangioblastic and monocytic cEPC levels were not correlated (Spearman correlation coefficient 0.03, P = 0.77), suggesting that they represent independent populations of progenitor cells.

CONCLUSION

These findings further support the notion that oral infections have extraoral effects and document that periodontitis is associated with a mobilization of EPCs from the bone marrow, apparently in response to systemic inflammation and endothelial injury.

Multiple tooth loss is associated with vascular cognitive impairment in subjects with acute ischemic stroke

BACKGROUND AND OBJECTIVE

Emerging evidence shows that tooth loss is associated with cognitive impairment and dementia. Vascular cognitive impairment (VCI) is a common consequence of ischemic stroke. This study investigated the association of tooth loss with VCI in patients with acute stroke.

MATERIAL AND METHODS

A total of 161 subjects with acute ischemic stroke were recruited. Within 1 wk after admission, fasting blood tests were undertaken and the number of teeth present was recorded. VCI was evaluated with the Montreal Cognitive Assessment (MoCA).

RESULTS

The patients with loss of ≥ 8 teeth exhibited significantly lower MoCA values as compared to those with loss of ≤ 7 teeth (13.2 ± 6.6 vs. 17.3 ± 6.0, p < 0.001). Multivariate logistic regression analysis showed that loss of ≥ 8 teeth (OR = 3.1, 95% CI: 1.2-7.9, p = 0.02) and stroke history (OR = 3.8, 95% CI: 1.1-14.1, p = 0.04) were significantly associated with VCI (MoCA score ≤ 20.0).

CONCLUSION

Within the limitations of this study, the current findings provide the first evidence that multiple tooth loss is independently associated with VCI in patients with acute ischemic stroke.

The implication of periodontitis in vascular endothelial dysfunction

BACKGROUND

Periodontitis is the most common oral infection seen in humans worldwide. It is characterized by gradual destruction of tooth supporting tissues, eventually leading to loss of tooth. The periodontal biofilm associated with periodontitis comprises of gram-positive and gram-negative bacteria, instrumental for the initiation and progression of periodontitis. Evidence-based literature has identified the nature of periodontal infection as a possible causative condition in the inducement of 'low-grade systemic inflammation and infection'. The periodontal pathogens exert systemic effects via the haematogenous route.

AIM

The present review provides an insight into the pathophysiology of the endothelial dysfunction with reference to periodontal infection and highlights the association between periodontitis and endothelial dysfunction. Various studies addressing the implication of periodontitis on endothelial dysfunction will be described, with a focus of periodontal treatment on improvement of endothelial function.

MATERIALS AND METHODS

Studies examining the effects of periodontitis on vascular endothelial function were segregated. Studies conducted on both animal and human models were identified using MEDLINE database search with key search terms such as 'Periodontitis', 'vascular endothelium', 'endothelial dysfunction', 'periodontal bacteria' and 'periodontal therapy'. Systematic reviews and meta-analysis were also screened. Only studies published in English language were considered. The review has been prepared by screening MEDLINE database from 1989 to 2012.

RESULTS AND CONCLUSIONS

Chronic periodontitis results in altered vascular response, increased expression of pro-inflammatory cytokines and adhesion molecules inducing vascular endothelial dysfunction. Periodontal therapy may ameliorate the perturbed vascular endothelial function.

Periodontal disease, atherosclerosis, adverse pregnancy outcomes, and head-and-neck cancer

Interrelationships between periodontal infection and systemic conditions such as cardiovascular disease, adverse pregnancy outcomes, and head-and-neck cancer have become increasingly appreciated in recent years. Periodontitis is associated with cardiovascular disease (CVD) and, experimentally, with measures of atherosclerosis and endothelial dysfunction. Periodontal therapy may reduce atherosclerotic changes and improve endothelial function. Preliminary findings suggest a role for the genetic locus ANRIL in the pathobiology of both CVD and periodontitis. Periodontal pathogens induce anticardiolipin in periodontitis patients by molecular mimicry of the serum protein β-2 glycoprotein I. These antibodies have biological and pathological activities consistent with those reported for other infection-induced antiphospholipid antibodies. Anticardiolipin may explain some of the observed associations between periodontitis and systemic conditions such as CVD and adverse pregnancy outcomes. The oral commensal Fusobacterium nucleatum (Fn) becomes pathogenic on migration to extra-oral sites. Fn infection of the fetal-placental unit has been linked to pregnancy complications, including preterm birth, stillbirth, and early-onset neonatal sepsis. Reagents aimed at inhibiting or resolving inflammatory responses may be used to treat or prevent pregnancy complications due to bacterial infection. Chronic periodontitis may be independently associated with head-and-neck squamous cell carcinoma (HNSCC) through direct toxic effects of bacteria and their products, and/or through indirect effects of inflammation. Additionally, chronic periodontitis may facilitate the acquisition and persistence of oral HPV infection, a recently emerged risk factor for HNSCC.

Periodontitis treatment improves systemic lupus erythematosus response to immunosuppressive therapy

Periodontal disease (POD) may affect rheumatic diseases severity, but there are no data regarding the effect of its treatment on disease activity in SLE patients under immunosuppressive therapy. Forty-nine consecutive SLE patients (SLEDAI ≥ 2) with POD and under corticosteroid and cyclophosphamide pulse therapy (IVCYC) were selected. Periodontal assessment included bleeding gingival index (BGI), probing depth (PD), and probing attachment level (PAL). At entry, POD was defined as BGI > 1 and patients were assigned to groups according to the availability of odontological intervention in TREATED (n = 32) and NOT TREATED (n = 17). SLEDAI and POD parameters were determined at entry and after 3 months. Age, female gender, and race were alike among TREATED and NOT TREATED (p > 0.05). Both groups had also comparable disease duration (10.7 ± 6.8 vs. 11.0 ± 6.6, p = 0.83), IVCYC number (5.8 ± 4.8 vs. 4.5 ± 4.8, p = 0.17), and SLEDAI (5.9 ± 4.2 vs. 6.3 ± 4.3, p = 0.73) as well as POD parameters [BGI (40.8 ± 31.0 vs. 40.7 ± 36.2 %, p = 0.89), PD (1.7 ± 1.8 vs. 1.5 ± 0.60 mm, p = 0.80), and PAL (2.5 ± 1.9 vs. 1.9 ± 1.1 mm, p = 0.18)]. At the end of the study, TREATED group had a significant improvement in SLEDAI (5.9 ± 4.2 vs. 3.4 ± 3.3, p = 0.04) with a paralleled reduction in BGI (40.8 ± 31.0 vs. 15.2 ± 17.2 %, p < 0.01), PD (1.7 ± 1.8 vs. 1.1 ± 0.3 mm, p < 0.01), and PAL (2.5 ± 1.9 vs. 1.7 ± 0.9 mm, p < 0.01). In contrast, SLEDAI (6.3 ± 4.3 vs. 6.0 ± 5.5, p = 0.40) and POD parameters [BGI (p = 0.33), PD (p = 0.91), and PAL (p = 0.39)] remained largely unchanged in NOT TREATED group. Periodontal disease treatment seems to have a beneficial effect in controlling disease activity in SLE patients under immunosuppressive therapy. Therefore, management of this modifiable risk factor is recommended.

Periodontitis is associated with endothelial dysfunction in a general population: a cross-sectional study

A large body of evidence underlines an association between periodontal disease and cardiovascular disease. In contrast, data on its relation with endothelial dysfunction as a marker of early subclinical atherosclerosis is inconclusive and limited to patient-cohort studies. We therefore investigated the association between periodontal disease and flow-mediated dilation of the brachial artery (FMD) as a measure of endothelial dysfunction in a general population, and also addressed a possible mediation via inflammation. The study population comprised 1,234 subjects (50.5% men) aged 25–85 years from the 5-year follow-up of the Study of Health in Pomerania, a population-based cohort study. Clinical attachment loss (CAL) and pocket probing depth (PPD) as measures of periodontal disease were assessed half-mouth at four sites per tooth. Subjects were classified according to the periodontitis case definition proposed by Tonetti and Claffey (2005). Measurements of FMD and nitroglycerin-mediated dilation (NMD) were performed using standardized ultrasound techniques. High-sensitive C-reactive protein, fibrinogen and leukocyte count were measured. Fully adjusted multivariate linear regression analyses revealed significant associations of the percentage of sites with PPD ≥6 mm with FMD (p_trend=0.048), with subjects within the highest category having a 0.74% higher FMD compared to subjects within the lowest category (p<0.05). Consistently, FMD values increased significantly across categories of the percentage of sites with CAL ≥6 mm (p_trend=0.01) and the periodontitis case definition (p_trend=0.006). Restrictions to subjects without antihypertensive or statin medication or current non-smokers confirmed previous results. Systemic inflammation did not seem to mediate the relation. Both PPD and CAL were not consistently associated with NMD. In contrast to previous studies, high levels of periodontal disease were significantly associated with high FMD values. This association was not mediated via systemic inflammation. This study revives the discussion on whether and how periodontitis contributes to endothelial dysfunction.

Treatment of periodontitis improves the atherosclerotic profile: a systematic review and meta-analysis

AIM

Systematic review and meta-analyses to study the robustness of observations that treatment of periodontitis improves the atherosclerotic profile.

MATERIAL AND METHODS

Literature was searched in Medline-PubMed, Cochrane CENTRAL and EMBASE, based on controlled periodontal intervention trials, including also a non-intervention group. Data were extracted and meta-analyses were performed.

RESULTS

From 3928 screened studies, 25 trials met the eligibility criteria. These trials enrolled 1748 periodontitis patients. Seven trials enrolled periodontitis patients that were otherwise healthy, 18 trials recruited periodontal patients with various co-morbidities, such as CVD or diabetes. None of the trials used hard clinical endpoints of CVD. However, improvement of endothelial function has been consistently reported. Meta-analyses demonstrated significant weighted mean difference (WMD) for hsCRP (-0.50 mg/l, 95% CI:-0.78; -0.22), IL-6 (-0.48 ng/l, 95% CI: -0.90; -0.06), TNF-α (-0.75 pg/ml, 95% CI: -1.34; -0.17), fibrinogen (-0.47 g/l, 95% CI: -0.76; -0.17), total cholesterol (-0.11 mmol/l, 95% CI: -0.21; -0.01) and HDL-C (0.04 mmol/l, 95% CI: 0.03; 0.06) favouring periodontal intervention. Importantly, periodontitis patients with co-morbidity benefitted most from periodontal therapy; significant WMD were observed for levels of hsCRP (-0.71 mg/l, 95% CI: -1.05; -0.36), IL-6 (-0.87 ng/l, 95% CI: -0.97; -0.78), triglycerides (-0.24 mmol/l, 95% CI: -0.26; -0.22), total cholesterol (-0.15 mmol/l, 95% CI: -0.29; -0.01), HDL-C (0.05 mmol/l, 95% CI: 0.03; 0.06) and HbA1c (-0.43%, 95% CI: -0.60; -0.25).

CONCLUSIONS

This systematic review and meta-analyses demonstrate that periodontal treatment improves endothelial function and reduces biomarkers of atherosclerotic disease, especially in those already suffering from CVD and/or diabetes.

The influence of anti-infective periodontal treatment on C-reactive protein: a systematic review and meta-analysis of randomized controlled trials

Background

Periodontal infections are hypothesized to increase the risk of adverse systemic outcomes through inflammatory mechanisms. The magnitude of effect, if any, of anti-infective periodontal treatment on systemic inflammation is unknown, as are the patient populations most likely to benefit. We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) to test the hypothesis that anti-infective periodontal treatment reduces systemic c-reactive protein (CRP).

Methods and Findings

MEDLINE, EMBASE, CENTRAL and CINAHL databases were searched using sensitivity-enhancing search terms. Eligible RCTs enrolled patients with periodontal infection, compared a clearly defined anti-infective periodontal intervention (experimental group) to an “inactive control” (no periodontal intervention) or to an “active control” (lower treatment intensity than the experimental group). Mean differences in final CRP values at the earliest post-treatment time point (typically 1-3 months) between experimental and control groups were analyzed using random-effects regression. Among 2,753 possible studies 20 were selected, which included 2,561 randomized patients(median=57). Baseline CRP values were >3.0 mg/L in 40% of trials. Among studies with a control group receiving no treatment, the mean difference in CRP final values among experimental treatment vs. control groups was -0.37 mg/L [95%CI=-0.64, -0.11], (P=0.005), favoring experimental treatment. Trials for which the experimental group received antibiotics had stronger effects (P for interaction=0.03) and the mean difference in CRP final values among experimental treatment vs. control was -0.75 mg/L [95%CI=-1.17,-0.33]. No treatment effect was observed among studies using an active treatment comparator. Treatment effects were stronger for studies that included patients with co-morbidities vs. studies that included “systemically healthy” patients, although the interaction was not significant (P=0.48).

Conclusions

Anti-infective periodontal treatment results in short-term modest reductions in systemic CRP.

Mobilization of endothelial progenitors by recurrent bacteremias with a periodontal pathogen

Background

Periodontal infections are independent risk factors for atherosclerosis. However, the exact mechanisms underlying this link are yet unclear. Here, we evaluate the in vivo effects of bacteremia with a periodontal pathogen on endothelial progenitors, bone marrow-derived cells capable of endothelial regeneration, and delineate the critical pathways for these effects.

Methods

12-week old C57bl6 wildtype or toll-like receptor (TLR)-2 deficient mice were repeatedly intravenously challenged with 10⁹ live P. gingivalis 381 or vehicle. Numbers of Sca1+/flk1+ progenitors, circulating angiogenic cells, CFU-Hill, and late-outgrowth EPC were measured by FACS/culture. Endothelial function was assessed using isolated organ baths, reendothelization was measured in a carotid injury model. RANKL/osteoprotegerin levels were assessed by ELISA/qPCR.

Results

In wildtype mice challenged with intravenous P.gingivalis, numbers of Sca1+/flk1+ progenitors, CAC, CFU-Hill, and late-outgrowth EPC were strongly increased in peripheral circulation and spleen, whereas Sca1+/flk1+ progenitor numbers in bone marrow decreased. Circulating EPCs were functional, as indicated by improved endothelial function and improved reendothelization in infected mice. The osteoprotegerin/RANKL ratio was increased after P. gingivalis challenge in the bone marrow niche of wildtype mice and late-outgrowth EPC in vitro. Conversely, in mice deficient in TLR2, no increase in progenitor mobilization or osteoprotegerin/RANKL ratio was detected.

Conclusion

Recurrent transient bacteremias, a feature of periodontitis, increase peripheral EPC counts and decrease EPC pools in the bone marrow, thereby possibly reducing overall endothelial regeneration capacity, conceivably explaining pro-atherogenic properties of periodontal infections. These effects are seemingly mediated by toll-like receptor (TLR)-2.

Periodontal therapy decreases serum levels of adipocyte fatty acid-binding protein in systemically healthy subjects: a pilot clinical trial

BACKGROUND AND OBJECTIVE

Adipocyte fatty acid-binding protein (A-FABP) is expressed in adipocytes, macrophages and microvascular endothelial cells, and it plays a central role in inflammation, atherosclerosis and metabolic responses. This pilot study investigated the effect of nonsurgical periodontal therapy on the serum levels of A-FABP in subjects with chronic periodontitis.

MATERIAL AND METHODS

A pilot clinical trial was conducted in 24 otherwise healthy Chinese subjects with moderate to severe chronic periodontitis. The treatment group (n = 12) received nonsurgical periodontal therapy immediately, whereas in the control group (n = 12) the treatment was delayed for 3 months. The serum levels of A-FABP were measured by ELISAs. Other inflammatory and endothelial biomarkers and periodontal conditions were evaluated at baseline and at the 3-month follow-up appointment.

RESULTS

A-FABP levels decreased significantly in the treatment group compared with the control group (treatment effect: -1.7 ng/mL; 95% confidence interval: -2.8 to -0.6; p = 0.003). The treatment also significantly improved periodontal conditions but had no significant effect on other biomarkers. In the multivariable regression model, the change in the percentage of sites with detectable plaque was significantly associated with the change in the level of A-FABP (beta: 0.04, 95% confidence interval: 0.01-0.06, p = 0.004).

CONCLUSION

Within the limitations of this pilot study, the current findings suggest that treatment of periodontitis may significantly decrease the serum levels of A-FABP. Further longitudinal study with a large sample size is warranted to confirm this finding and elaborate the relevant clinical implications.

Oral microbiome and oral and gastrointestinal cancer risk

A growing body of evidence implicates human oral bacteria in the etiology of oral and gastrointestinal cancers. Epidemiological studies consistently report increased risks of these cancers in men and women with periodontal disease or tooth loss, conditions caused by oral bacteria. More than 700 bacterial species inhabit the oral cavity, including at least 11 bacterial phyla and 70 genera. Oral bacteria may activate alcohol and smoking-related carcinogens locally or act systemically, through chronic inflammation. High-throughput genetic-based assays now make it possible to comprehensively survey the human oral microbiome, the totality of bacteria in the oral cavity. Establishing the association of the oral microbiome with cancer risk may lead to significant advances in understanding of cancer etiology, potentially opening a new research paradigm for cancer prevention.

Novel Endothelial Biomarkers: Implications for Periodontal Disease and CVD

Endothelial cells are actively involved in various aspects of vascular biology and different stages of atherosclerosis. Endothelial function is increasingly used as an important outcome measure in cardiovascular research. Endothelial progenitor cells (EPCs) are closely linked to endothelial function, and their biomarkers have received much attention. EPCs may not only serve as a pool of progenitor cells and possess the capacity to repair the damaged vasculature, but also act as potent effectors in systemic inflammation, suggesting that EPCs may play a critical role in maintaining endothelial function and the progression of cardiovascular disease (CVD). Emerging evidence shows an association of periodontal infections (gingivitis and periodontitis) with endothelial dysfunction, while the relevant mechanisms remain unknown. Our recent finding of the association of periodontitis with EPCs warrants their utilization as additional biomarkers in future studies on periodontal medicine. This review starts with a brief account on the current understanding of the nature of periodontal infections and their link with systemic inflammation and endothelial dysfunction. The paper also provides an update on endothelial biology and function as well as the novel biomarkers of EPCs and concludes with clinical studies on periodontal diseases and CVD.