Serum C-reactive protein and immunoglobulin G antibodies to periodontal pathogens may be effect modifiers of periodontitis and hyperglycemia

Pathogenic Mechanisms That May Link Periodontal Disease and Type 2 Diabetes Mellitus-The Role of Oxidative Stress

Given the posited role of oxidative stress in the pathogenesis of both periodontitis and type 2 diabetes mellitus (T2DM), it may also serve as a link between these highly prevalent chronic inflammatory diseases. This view is supported by an ample body of evidence indicating that the severity and progression of periodontitis is in part driven by diabetes, while periodontal infection may hinder the attainment of adequate glycemic control in diabetic patients. Thus, this review focuses on the potential synergistic interactions along the oxidative stress-inflammation pathway characterizing both conditions. Because periodontitis and T2DM share the same risk factors and compromise patients' quality of life, to develop effective strategies for combatting both conditions, their mutual influence needs to be explored.

Association between groups of immunoglobulin G antibodies against periodontal microorganisms and diabetes related mortality

BACKGROUND

Immunoglobulin G (IgG) antibodies against periodontal microorganisms can be markers of periodontal infection because their levels rise following infection and remain elevated several years later.

METHODS

We evaluated the relation between groups of IgG antibodies against 19 periodontal microorganisms and diabetes related mortality over 27 years among participants of the National Health and Nutrition Examination Survey III (1988 to 1992) 40 years and older at the time of examination (N = 8153).

RESULTS

Individuals in the highest versus lowest antibody tertiles were at 86% higher risk of dying due to diabetes related causes in the Red-Green antibody cluster (T. forsythia, T. denticola, A. actinomycetemcomitans, E. corrodens, S. noxia, V. parvula, C. rectus) (HR = 1.86, 95% CI 1.09 to 3.20) and 55% lower in the Orange-Blue antibody cluster (E. nodatum, A. naeslundii) (HR = 0.45, 95% CI 0.32 to 0.63) in multivariable models. In these models, individuals with diabetes at the time of examination had a 16-fold higher risk of dying due to diabetes related causes (HR = 16.4, 95% CI 11.0 to 24.7).

CONCLUSION

As a subset of periodontal microorganisms are associated with adverse systemic outcomes, antibody profiles may help in prediction of diabetes related mortality and identify sub-groups of individuals among whom periodontal treatment may impact diabetes related outcomes. This article is protected by copyright. All rights reserved.

Helicobacter pylori, periodontal pathogens, and their interactive association with incident all-cause and Alzheimer's disease dementia in a large national survey

Co-infection between Helicobacter pylori (Hp) and groups of periodontal pathogens may alter the onset of Alzheimer's disease (AD) and all-cause dementia. We examined the interactive associations among Hp sero-positivity, periodontal disease (Pd), and infections with incident AD and all-cause dementia, among older adults (≥65 years at baseline). Up to 1431 participants from phase 1 of the National Health and Nutrition Survey III (1988-1991) had complete data till January 1st, 2014 on Hp sero-positivity with a mean follow-up of 10-11 years for AD and all-cause dementia incidence. Exposures consisted of 19 periodontal pathogens, constructed factors and clusters, and two Pd markers- probing depth and clinical attachment loss (CAL). Cox proportional hazards models were performed. Around 55% of the selected sample was Hp⁺. We found that Prevotella intermedia, Campylobacter Rectus, Factor 2 (Pi/Prevotella nigrescens/Prevotella melaninogenica), and the Orange-Red cluster interacted synergistically with Hp sero-positivity, particularly with respect to AD incidence. The presence of higher levels of Actinomyces Naeslundii (An) enhanced the effect of being Hp⁺ on both AD and all-cause dementia incidence. In contrast, Fusobacterim nucleatum (Fn), and Factor 1 (which included Fn), exhibited an antagonistic interaction with Hp in relation to all-cause dementia. Both probing depth and CAL had direct associations with all-cause dementia among Hp⁺ individuals, despite nonsignificant interaction. Selected periodontal pathogen titers, factors, and clusters interacted mostly synergistically, with Hp sero-positivity, to alter the risk of AD and all-cause dementia. Ultimately, a randomized controlled trial is needed, examining effects of co-eradication of Hp and select periodontal pathogens on neurodegenerative disease.

Plasmid encoding microRNA-200c ameliorates periodontitis and systemic inflammation in obese mice

The present study was conducted to characterize microRNA-200c (miR-200c) and its regulators in adipogenic differentiation, obesity, and periodontitis in obese subjects (PiOSs), and to determine the therapeutic efficacy of plasmid DNA encoding miR-200c as a treatment for PiOSs. We report that highly expressed miR-200c in gingival tissues was downregulated in diet-induced obese (DIO) mice and during adipogenic differentiation of human bone marrow mesenchymal stromal cells (hBMSCs). Local injection of Porphyromonas gingivalis lipopolysaccharide (Pg-LPS) in the maxilla interdental gingiva of DIO mice reduced miR-200c in gingival and adipose tissues and induced periodontal inflammation associated with systemic elevation of interleukin-6 (IL-6) and impaired glucose tolerance. The inhibitory functions of Pg-LPS and IL-6 on miR-200c and their effectiveness on Zeb1 were confirmed in vitro. Injection of naked plasmid DNA encoding miR-200c into the gingiva effectively rescued miR-200c downregulation, prevented periodontal and systemic inflammation, and alleviated the impaired glucose metabolism in obese mice with LPS-induced periodontitis. Increased circulating exosomal miR-200c and its function on suppressing proinflammatory cytokines and adipogenesis explained the mechanism(s) of gingival application of miR-200c in attenuating systemic inflammation in PiOSs. These results demonstrated that miR-200c reduced by Pg-LPS and IL-6 in periodontitis and obesity might lead to the pathogenesis of PiOSs, and upregulation of miR-200c in the gingiva presents a therapeutic approach for PiOSs.

Clinical and Bacterial Markers of Periodontitis and Their Association with Incident All-Cause and Alzheimer's Disease Dementia in a Large National Survey

Microbial agents including periodontal pathogens have recently appeared as important actors in Alzheimer's disease (AD) pathology. We examined associations of clinical periodontal and bacterial parameters with incident all-cause and AD dementia as well as AD mortality among US middle-aged and older adults. Clinical [Attachment Loss (AL); probing pocket depth (PPD)] and bacterial [pathogen immunoglobulin G (IgG)] periodontal markers were investigated in relation to AD and all-cause dementia incidence and to AD mortality, using data from the third National Health and Nutrition Examination Surveys (NHANES III, 1988-1994) linked longitudinally with National Death Index and Medicare data through January 1, 2014, with up to 26 years of follow-up. Sex- and age-specific multivariable-adjusted Cox proportional hazards models were conducted. Among those ≥65 years, AD incidence and mortality were consistently associated with PPD, two factors and one cluster comprised of IgG titers against Porphyromonas gingivalis (P. gingivalis), Prevotella melaninogenica (P. melaninogenica) and Campylobacter rectus (C. rectus) among others. Specifically, AD incidence was linked to a composite of C. rectus and P. gingivalis titers (per SD, aHR = 1.22; 95% CI, 1.04-1.43, p = 0.012), while AD mortality risk was increased with another composite (per SD, aHR = 1.46; 95% CI, 1.09-1.96, p = 0.017) loading highly on IgG for P. gingivalis, Prevotella intermedia, Prevotella nigrescens, Fusobacterium nucleatum, C. rectus, Streptococcus intermedius, Capnocylophaga Ochracea, and P. melaninogenica. This study provides evidence for an association between periodontal pathogens and AD, which was stronger for older adults. Effectiveness of periodontal pathogen treatment on reducing sequelae of neurodegeneration should be tested in randomized controlled trials.

Contemporary approaches for identifying individual risk for periodontitis

Key breakthroughs in our understanding of the etiology and principles of predictable treatment of patients with chronic periodontitis first emerged in the late 1960s and carried on into the mid-1980s. Unfortunately, some generalizations of the evidence led many to believe that periodontitis was a predictable result of exposure to bacterial plaque accumulations over time. For a brief period, the initial plaque concept was translated by some to implicate specific bacterial infections, with both concepts (plaque exposure and specific infection) being false assumptions that led to clinical outcomes which were frustrating to both the clinician and the patient. The primary misconceptions were that every individual was equally susceptible to periodontitis, that disease severity was a simple function of magnitude of bacterial exposure over time, and that all patients would respond predictably if treated based on the key principles of bacterial reduction and regular maintenance care. We now know that although bacteria are an essential initiating factor, the clinical severity of periodontitis is a complex multifactorial host response to the microbial challenge. The complexity comes from the permutations of different factors that may interact to alter a single individual's host response to challenge, inflammation resolution and repair, and overall outcome to therapy. Fortunately, although there are many permutations that may influence host response and repair, the pathophysiology of chronic periodontitis is generally limited to mild periodontitis with isolated moderate disease in most individuals. However, approximately 20%-25% of individuals will develop generalized severe periodontitis and probably require more intensive bacterial reduction and different approaches to host modulation of the inflammatory outcomes. This latter group may also have serious systemic implications of their periodontitis. The time appears to be appropriate to use what we know and currently understand to change our approach to clinical care. Our goal would be to increase our likelihood of identifying those patients who have a more biologically disruptive response combined with a more impactful microbial dysbiosis. Current evidence, albeit limited, indicates that for those individuals we should prevent and treat more intensively. This paper discusses what we know and how we might use that information to start individualizing risk and treat some of our patients in a more targeted manner. In my opinion, we are further along than many realize, but we have a great lack of prospective clinical evidence that must be accumulated while we continue to unravel the contributions of specific mechanisms.

Increased Oral Porphyromonas gingivalis Prevalence in Cardiovascular Patients with Uncontrolled Diabetes Mellitus

The aim of this study was to determine the correlation between periodontopathic bacteria and diabetes mellitus (DM) status in cardiovascular disease (CVD) subjects.DM is associated with the progression of periodontitis. Several epidemiological studies have suggested that periodontitis may be a risk factor for CVD. However, no study has compared the periodontal condition between well-controlled and poorly-controlled DM patients with CVD.The subjects were well-controlled (n = 73) or poorly-controlled (n = 39) DM patients with CVD. Blood examinations and dental clinical measurements, including number of teeth, probing pocket depth, bleeding on probing (BOP), and clinical attachment level (CAL) were performed. Periodontopathic bacterial existence was evaluated.Worsened CAL and BOP rate were detected in the uncontrolled DM group compared to the controlled group. We found increased salivary Porphyromonas gingivalis counts in the uncontrolled DM group compared to well-controlled DM subjects.Specific periodontopathic bacterial infection may affect DM condition in CVD patients.

Mediation analysis of systemic inflammation on the association between periodontitis and glycaemic status

AIM

This cross-sectional study investigated the associations between periodontitis, systemic inflammation and glycaemic status.

MATERIALS AND METHODS

The participants were divided into three groups: normoglycaemia, impaired fasting glucose (IFG) and diabetes. Multinomial logistic regression was used to examine the associations between periodontitis severity and glycaemic status, adjusting for potential confounders. Mediation analysis of four systemic inflammatory biomarkers, C-reactive protein (CRP), white blood cell count (WBC), neutrophil-lymphocyte ratio (NLR) and platelet-lymphocyte ratio (PLR), was performed.

RESULTS

This study comprised 2,036 participants, aged 39-66 years. Severe periodontitis was associated with IFG and diabetes with odds ratios of 1.6 (95% confidence interval [CI]: 1.1-2.4, p = .023) and 2.4 (95% CI: 1.3-4.5, p = .006), respectively. The CRP, WBC and PLR were associated with both periodontitis severity and glycaemic status (p < .05). In contrast, the NLR was associated with periodontitis severity (p < .05) but not glycaemic status (p > .05). The CRP, WBC and PLR mediated 8%, 13% and 6%, respectively, of the association between severe periodontitis and diabetes. Similar proportions mediated were observed for the periodontitis-IFG association.

CONCLUSIONS

Our findings support the role of systemic inflammation as mediators of the associations between periodontitis and IFG or diabetes.

An update on the evidence for pathogenic mechanisms that may link periodontitis and diabetes

AIM

To provide an update of the review by Taylor (Journal of Clinical Periodontology, 2013, 40, S113) regarding the scientific evidence of the biological association between periodontitis and diabetes.

METHODS

Literature searches were performed using MeSH terms, keywords and title words and were published between 2012 and November 2016. All publications were screened for their relevance. The data from the articles were extracted and summarized in tables and a narrative review.

RESULTS

Small-scale molecular periodontal microbiome studies indicate a possible association between altered glucose metabolism in pre-diabetes and diabetes and changes in the periodontal microbiome, with no evidence for casual relationships. Clinical and animal studies found elevated gingival levels of IL1-β, TNF-α, IL-6, RANKL/OPG and oxygen metabolites in poorly controlled diabetes. In addition, individuals with diabetes and periodontitis exhibit high levels of circulating TNF-α, CRP and mediators of oxidative stress, and successful periodontal treatment reduces their levels.

CONCLUSIONS

The elevated pro-inflammatory factors in the gingiva of patients with poorly controlled diabetes suggest a biological pathway that may aggravate periodontitis. Some evidence suggests that the systemic inflammatory burden in periodontitis has the potential to affect diabetes control, but no studies addressed the impact of successful periodontal therapy on the pathophysiological mechanisms involved in systemic complications of diabetes.

Cross-Sectional Analysis of Alcohol Intake and Serum Antibodies to Oral Microorganisms

The objective of this study was to evaluate the relation between alcohol intake and groups of periodontal antibody titers among individuals with normal glucose tolerance (NGT), prediabetes and diabetes. This was a cross-sectional analysis of the National Health and Nutrition Examination Survey III (NHANES III) 1988–1994 data, among individuals 40 y and older with information on alcohol intake and serum immunoglobulin G (IgG) antibody data against 19 oral microorganisms. Participants were excluded if they did not have teeth, reported that they were taking insulin, or having gestational diabetes. The sample size for this analysis was 3,219. Periodontal antibodies were grouped into four clusters using cluster analysis: Orange-Red, Red-Green, Yellow- Orange, and Orange-Blue. Cluster scores were computed for each individual by summing z-scores of standardized log-transformed IgG titers of antibodies against periodontal microorganisms making up each respective cluster. Each cluster score was modeled as an outcome. Alcohol consumption was assessed in g/day using self-reported number of days of drinking in the past 12 mo and the average number of drinks consumed per day on days when they drank. Overall, alcohol intake was positively associated with periodontal antibodies of the Orange-Red cluster (P. melaninogenica, P. intermedia, P. nigrescens, and P. gingivalis), and inversely associated with the Yellow-Orange cluster (S. intermedius, S. oralis, S. mutans, F. nucleatum, P. micra, C. ochracea) after multivariable adjustment. The association between alcohol intake and the Orange-Red cluster was strongest among individuals with diabetes; this relation was seen among individuals with and without periodontal damage. The Orange-Red cluster was positively associated with periodontal damage among individuals with diabetes. Alcohol intake was not associated with any antibody cluster among individuals with NGT or prediabetes. The effect of alcohol intake on periodontal disease may be greater among individuals with diabetes but this finding needs to be confirmed in prospective studies.

Knowledge Transfer Statement: The results of this study can be used by clinicians when treating patients with periodontal disease and diabetes.

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.

The effect of periodontal treatment on hemoglobin a1c levels of diabetic patients: a systematic review and meta-analysis

Background

There is growing evidence that periodontal treatment may affect glycemic control in diabetic patients. And several systematic reviews have been conducted to assess the effect of periodontal treatment on diabetes outcomes. Researches of this aspect are widely concerned, and several new controlled trials have been published. The aim of this study was to update the account for recent findings.

Methods

A literature search (until the end of January 2014) was carried out using various databases with language restriction to English. A randomized controlled trial (RCT) was selected if it investigated periodontal therapy for diabetic subjects compared with a control group received no periodontal treatment for at least 3 months of the follow-up period. The primary outcome was hemoglobin A1c (HbA1c), and secondary outcomes were periodontal parameters included probing pocket depth (PPD) and clinical attachment level (CAL).

Results

Ten trials of 1135 patients were included in the analysis. After the follow-up of 3 months, treatment substantially lowered HbA1c compared with no treatment after periodontal therapy (–0.36%, 95%CI, −0.52% to −0.19%, P<0.0001). Clinically substantial and statistically significant reduction of PPD and CAL were found between subjects with and without treatment after periodontal therapy (PPD −0.42 mm, 95%CI: −0.60 to −0.23, P<0.00001; CAL −0.34 mm, 95%CI: −0.52 to −0.16, P = 0.0002). And there is no significant change of the level of HbA1c at the 6-month comparing with no treatment (–0.30%, 95%CI, −0.69% to 0.09%, P = 0.13).

Conclusions

Periodontal treatment leads to the modest reduction in HbA1c along with the improvement of periodontal status in diabetic patients for 3 months, and this result is consistent with previous systematic reviews. And the effect of periodontal treatment on HbA1c cannot be observed at 6-month after treatment.