Inflammatory cytokines, adiponectin, insulin resistance and metabolic control after periodontal intervention in patients with type 2 diabetes and chronic periodontitis

The effect of dental bleaching on pulpal tissue response in a diabetic animal model: a study of immunoregulatory cytokines

AIM

To evaluate the influence of tooth bleaching on immunoregulatory cytokines production (IL-6, Tumour necrosis factor (TNF)-α and IL-17) in the pulp tissue of normoglycaemic and diabetic rats.

METHODOLOGY

Twenty-eight rats were divided into normoglycaemic and diabetic rats (n = 14). Diabetes mellitus (DM) was induced with a single dose of alloxan diluted in citrate buffer via intramuscular injection. After DM confirmation, all rats were sedated and tooth bleaching was performed using 35% hydrogen peroxide on the right maxillary molars for 30 min. Left molars were used as controls. Bleaching resulted in four hemimaxillae groups: normoglycaemic (N), N-bleached (NBle), diabetic (D) and D-bleached (DBle). After 2 and 30 days, rats were euthanized and hemimaxillae processed for analysis by haematoxylin and eosin and immunohistochemistry. Results within and between animals were submitted to Wilcoxon signed-rank and Mann-Whitney tests (P < 0.05).

RESULTS

At 2 days, the NBle group had mild, and the DBle had severe inflammatory infiltration in the pulpal tissue (P < 0.05). TNF-α and IL-6 cytokines were associated with increased immunolabelling in the bleached groups compared to nonbleached (P < 0.05). However, IL-17 had increased immunolabelling in the NBle compared to the N and DBle group (P < 0.05). At 30 days, reactionary dentine was observed in the coronal pulp of all bleached teeth and no inflammation was present (P > 0.05). TNF-α cytokines had increased immunolabelling in the DBle group compared to the D group (P < 0.05). However, for IL-6 and IL-17, no difference was observed in this period (P > 0.05).

CONCLUSIONS

Tooth bleaching increased IL-6 and TNF-α in the pulp tissue regardless of diabetes mellitus; however, diabetic rats had higher TNF-α levels for longer periods. Tooth bleaching influenced the increase in IL-17 in the early periods in normoglycaemic rats.

Metformin in combination with rosiglitazone contribute to the increased serum adiponectin levels in people with type 2 diabetes mellitus

To evaluate how metformin plus rosiglitazone affect serum adiponectin levels in people suffering from type 2 diabetes mellitus (T2DM), 240 patients having T2DM were selected in this cohort study. Included subjects were randomly and equally separated into three subsets: i) Group A (rosiglitazone group); ii) group B (metformin group); and iii) group C (rosiglitazone + metformin group). Furthermore, meta-analysis of previous studies was performed by searching the general search engines and bibliographic databases. Compared with before treatment, the serum amount of adiponectin grew considerably in the three groups after treatment, and the levels in the group C was much greater than those of groups A and B (all P<0.05). Corresponding meta-analysis results suggested post-treatment serum adiponectin level to be greater than pretreatment level in T2DM patients (P<0.001). Further subgroup analyses indicated that combination therapy of metformin and rosiglitazone may increase the amount of serum adiponectin in T2DM sufferers among the majority subgroups (all P<0.05). The combination of metformin and rosiglitazone treatment increased serum adiponectin levels, suggesting that metformin plus rosiglitazone therapy is a suitable choice to treat T2DM.

Effects of nonsurgical periodontal therapy in patients with moderately controlled type 2 diabetes mellitus and chronic periodontitis in Nepalese population

Objectives

Despite several investigations, evidence is still controversial regarding the effect of periodontal treatment on diabetes. This study evaluates and compares the effect on glycemic control and periodontal status with or without nonsurgical periodontal therapy in patients with type 2 diabetes mellitus and chronic periodontitis in a Nepalese population.

Materials and methods

A total of 82 patients attending the diabetes clinic and fulfilling enrollment criteria with moderate to severe periodontitis were selected. They were assigned in an alternative sequence, into test and control group. Both groups were instructed to continue with their medical treatment without modifications. Scaling and root surface debridement were performed in the test group whereas the control group received oral hygiene instructions with no treatment during the 3-month study period.

Results

There were 41 participants in each group with the mean age of 50.66±7.70 and 53.80±9.16 years, average diabetes duration of 6.32±4.21 and 6.24±4.00 years, mean body mass index of 24.78±1.85 and 24.6±1.79 kg/m², and glycated hemoglobin (HbA1c) level of 6.71±0.50% and 6.80±0.45%, in the test and control group, respectively. After 3 months, there was significant reduction in HbA1c levels in the test group compared to the control group (p=0.029). Clinical periodontal parameters of gingival index, probing depth (PD), and clinical attachment level (CAL) significantly improved in the test group (p<0.001) with PD reduction by 0.9 mm and gain in CAL by 0.3 mm compared to the control group (p>0.001) who showed an increase by 0.05 mm.

Conclusion

This study showed that nonsurgical periodontal therapy may have a beneficial effect on HbA1c level in moderately controlled type 2 diabetic patients.

Association of circulating leptin and adiponectin with periodontitis: a systematic review and meta-analysis

BACKGROUND

This study aimed to assess the difference in serum levels of leptin and adiponectin in patients with periodontitis and in periodontally healthy individuals and evaluate the changes in circulating leptin and adiponectin after periodontal therapy. Leptin and adiponectin are the most generally studied adipokines that function as inflammatory cytokines. Although the association between periodontitis and serum levels of leptin and adiponectin has been studied extensively, the results were not consistent.

METHODS

A systematic search of the Pubmed, Embase, Web of Science, and Cochrane Library up to September 2016 was conducted. The studies were screened and selected by two writers according to the specific eligibility criteria. The quality of included cross-sectional studies was assessed using the quality assessment form recommended by the Agency for Healthcare Research and Quality and Methodological Index for Nonrandomized Studies. The meta-analyses were conducted using the STATA 12.0 software.

RESULTS

A total of 399 manuscripts were yielded and 25 studies were included in the present meta-analysis. Significantly elevated serum levels of leptin and decreased serum levels of adiponectin in patients with periodontitis were observed in the subgroup analysis of body mass index (BMI) <30. The overall and subgroup analyses showed no significant change in the serum levels of leptin in patients with periodontitis after periodontal treatment. The subgroup analysis of systemically healthy patients showed no significant change in serum levels of adiponectin in patients with periodontitis after periodontal treatment.

CONCLUSIONS

The present meta-analysis supported elevated serum levels of leptin and decreased serum levels of adiponectin in patients with periodontitis compared with controls in the BMI <30 population. In systemically healthy patients with periodontitis, serum levels of leptin and adiponectin do not significantly change after periodontal treatment.

Effect of Non-Surgical Periodontal Therapy Along With Myo-Inositol on High-Sensitivity C-Reactive Protein and Insulin Resistance in Women With Polycystic Ovary Syndrome and Chronic Periodontitis: A Randomized Controlled Trial

BACKGROUND

The purpose of this study is to evaluate the effect of non-surgical periodontal therapy and medical treatment on the level of a serologic marker of inflammation (high-sensitivity C-reactive protein [hsCRP]) and insulin resistance (homeostatic model assessment [HOMA]) in women with polycystic ovary syndrome (PCOS) and chronic periodontitis (CP).

METHODS

Women with PCOS and CP (n = 60) were randomly divided into two groups. The test group was treated with scaling and root planing (SRP) and myo-inositol (MI). The control group was treated with MI and given oral hygiene instructions. Anthropometric, metabolic, and periodontal parameters were assessed at baseline and re-evaluated at 3 and 6 months. All parameters of both groups at 6 months were compared with 25 systemically and periodontally healthy females (group A).

RESULTS

Periodontal parameters were significantly improved in the test group compared with the control group at 3- and 6-month follow-up (P <0.001). A statistically significant reduction was observed in hsCRP and HOMA in both groups at 3- and 6-month follow-up (P <0.05). However, significantly more improvement in hsCRP (P <0.05) and a statistically comparable reduction in HOMA (P >0.05) was observed in the test group compared with the control group at 3 and 6 months. Both the test and control group showed significant consistent improvement in metabolic parameters at 3- and 6-month follow-up, which was further comparable to group A.

CONCLUSION

SRP together with medical treatment results in a greater reduction of systemic inflammatory burden compared with medical treatment alone in management of women with PCOS and CP.

Periodontal and glycemic effects of nonsurgical periodontal therapy in patients with type 2 diabetes stratified by baseline HbA1c

We evaluated the effects of nonsurgical periodontal therapy in 100 patients with type 2 diabetes and chronic periodontitis. The participants were classified as having good (n = 48) or poor (n = 52) glycemic control and were further randomly allocated to receive either scaling and root planning treatment group or no treatment (n = 50 each). The effect of nonsurgical periodontal therapy was compared among diabetic patients with good glycemic control, those with poor glycemic control, and 25 nondiabetic individuals. Periodontal and metabolic status was recorded at baseline, 3 months, and 6 months. In patients receiving treatment, periodontal parameters significantly improved and HbA1c decreased by 10.8%. Improvements in gingival index and bleeding on probing were greater in the nondiabetic participants and the treated patients with good glycemic control than in the treated patients with poor glycemic control (P < 0.05). Regression analysis showed that improvement in periodontal status was independently associated with glycemic improvement. Nonsurgical periodontal therapy improved glycemic control and periodontal health in patients with type 2 diabetes. However, patients with poor baseline glycemic control had less clinical improvement than did those without diabetes and those with good glycemic control.

Nonsurgical periodontal-therapy improves glycosylated hemoglobin levels in pre-diabetic patients with chronic periodontitis

AIM

To evaluate the effect of nonsurgical periodontal therapy on glycosylated haemoglobin levels in pre-diabetic patients with chronic periodontitis (CHP).

METHODS

Sixty pre-diabetic patients with CHP were selected and equally allocated to case and control group. All subjects were evaluated at base line for periodontal parameters (plaque index, oral hygiene index, modified gingival index, probing pocket depth, clinical attachment level) and systemic parameters [glycosylated hemoglobin (HbA1c), fasting lipid profile, and fasting blood glucose]. The case group received non-surgical periodontal therapy. Subjects were re-evaluated for periodontal and systemic parameters after three months.

RESULTS

Both groups were comparable at baseline. Three months after non surgical periodontal therapy (NSPT), there was significant improvement in periodontal parameters in case group. The mean difference in systemic parameters like HbA1c and fasting plasma glucose from baseline to fourth month for case group was 0.22 ± 0.11 and 3.90 ± 8.48 respectively and control group was -0.056 ± 0.10 and -1.66 ± 6.04 respectively, which was significant between case and control group (P < 0.05). In the case group there was a significant decrease in HbA1c from baseline to three months following NSPT (P < 0.05).

CONCLUSION

This study showed that periodontal inflammation could affect the glycemic control in otherwise systemically healthy individuals. Periodontal therapy improved periodontal health status and decreased glycosylated haemoglobin levels, thus reducing the probability of occurrence of inflammation induced prediabetes in patients with CHP.

Effects of periodontal treatment on the medical status of patients with type 2 diabetes mellitus: a pilot study

Background

Studies have demonstrated that periodontal disease is associated with the development of systemic complications in patients with type 2 diabetes mellitus (T2DM). The purpose of this pilot study was to investigate which markers among various systemic disease parameters are affected by periodontal treatment in patients with T2DM.

Methods

Twelve patients with T2DM were given oral hygiene instructions and subsequent subgingival scaling and root planing. The periodontal status was recorded, and blood and urine samples were taken to measure various parameters of glucose control and systemic status at baseline and 1 month following the periodontal treatment. Serum concentrations of tumor necrosis factor-α and high-sensitivity C-reactive protein were measured by enzyme-linked immunosorbent assay.

Results

After the periodontal treatment, the glycated hemoglobin value was significantly improved. The levels of urinary N-acetyl-β-D-glucosaminidase and albumin, which are markers of renal dysfunction, also decreased significantly after treatment. Among the parameters measured in serum, the γ-glutamyl transpeptidase level, which is usually interpreted as a marker of liver dysfunction, was significantly reduced. The serum concentrations of tumor necrosis factor-α and high-sensitivity C-reactive protein were also significantly reduced by periodontal treatment.

Conclusion

Within the limitations of this pilot study, periodontal treatment may be effective not only in improving metabolic control, but also in reducing the risk of diabetic kidney and liver disease in patients with T2DM.

Periodontitis and type 2 diabetes among women with previous gestational diabetes: epidemiological and immunological aspects in a follow-up of three years

OBJECTIVE

The aim of this study was to verify the incidence on the development of type 2 diabetes in women with previous gestational diabetes with and without periodontitis after a three-year time interval.

MATERIAL AND METHODS

Initial sample of this follow-up study consisted of 90 women diagnosed with gestational diabetes who underwent periodontal examination. After three years, 49 women were subjected to new periodontal examination and biological, behavioral, and social data of interest were collected. Additionally, the quantification of the C-reactive protein in blood samples was performed. Fasting glucose and glycated hemoglobin levels were requested. Saliva samples were collected for quantification of interleukin 6 and 10, tumor necrosis factor α, matrix metalloproteinase 2 and 9.

RESULTS

The incidence of type 2 diabetes mellitus was 18.4% and of periodontitis was 10.2%. There was no significant difference in the incidence of type 2 diabetes mellitus among women with and without periodontitis. It was observed impact of C-reactive protein in the development of type 2 diabetes mellitus. However, it was not observed impact of periodontitis on the development of type 2 diabetes mellitus among women with previous gestational diabetes.

CONCLUSIONS

It was not observed impact of periodontitis on the development of type 2 diabetes among women with previous gestational diabetes. The impact of C-reactive protein in the development of type 2 diabetes mellitus highlights the importance of an inflammatory process in the diabetes pathogenesis.

Systematic review and assessment of systematic reviews examining the effect of periodontal treatment on glycemic control in patients with diabetes

OBJECTIVES

There have been several systematic reviews(SRs) on whether periodontal treatment for an individual with both periodontal disease and diabetes can improve diabetes outcomes. The purpose of this investigation was to conduct a systematic review (SR) of previous meta-analyses, and to assess the methodological quality of the SRs examining the effects of periodontal treatment and diabetes. (PROSPERO Registration # CRD 42015023470).

STUDY DESIGN

We searched five electronic databases and identified previous meta-analyses of randomized controlled trials published through July 2015. In cases where the meta-analysis did not meet our criteria, the meta-analyses were recalculated. General characteristics of each included trial were abstracted, analyzed, and compared. The mean difference, 95% confidence intervals (CIs) and the I2 statistic were abstracted or recalculated. The Assessment of Multiple Systematic Reviews Instrument (AMSTAR) was used to assess methodological quality.

RESULTS

Of the 475 citations screened, nine systematic reviews were included. In total, 13 meta-analyses included in nine SRs were examined. In comparability analyses, meta-analyses in four SRs did not meet our criteria, and were recalcuated. Of these 13 meta-analyses, 10 suggested significant effects of periodontal treatment on HbA1c improvement. Mean differences found in the 13 meta-analyses ranged from -0.93 to 0.13. AMSTAR assessment revealed six SRs with moderate and three with high overall quality.

CONCLUSIONS

We can conclude that there is a significant effect of periodontal treatment on improvement of HbA1c in diabetes patients, although the effect size is extremely small. In addition to the small effect size, not all SRs could be considered of high quality.

Reduced platelet hyper-reactivity and platelet-leukocyte aggregation after periodontal therapy

Background

Platelets from untreated periodontitis patients are hyper-reactive and form more platelet-leukocyte complexes compared to cells from individuals without periodontitis. It is not known whether the improvement of the periodontal condition achievable by therapy has beneficial effects on the platelet function. We aimed to assess the effects of periodontal therapy on platelet reactivity.

Methods

Patients with periodontitis (n = 25) but unaffected by any other medical condition or medication were included and donated blood before and after periodontal therapy. Reactivity to ADP or oral bacteria was assessed by flow cytometric analysis of membrane markers (binding of PAC-1, P-selectin, CD63) and platelet-leukocyte complex formation. Reactivity values were expressed as ratio between the stimulated and unstimulated sample. Plasma levels of soluble (s) P-selectin were determined by enzyme-linked immunosorbent assay (ELISA).

Results

Binding of PAC-1, the expression of P-selectin and CD63 in response to the oral bacterium P. gingivalis were lower at recall (1.4 ± 1.1, 1.5 ± 1.2, and 1.0 ± 0.1) than at baseline (2.7 ± 4.1, P = 0.026, 6.0 ± 12.5, P = 0.045, and 2.7 ± 6.7, P = 0.042, respectively). Formation of platelet-leukocyte complexes in response to P. gingivalis was also reduced at recall compared to baseline (1.2 ± 0.7 vs. 11.4 ± 50.5, P = 0.045). sP-selectin levels were significantly increased post-therapy.

Conclusions

In periodontitis patients, the improvement of the periodontal condition is paralleled by a reduction in platelet hyper-reactivity. We suggest that periodontal therapy, as an intervention for improved oral health, can facilitate the management of thrombotic risk, and on the long term can contribute to the prevention of cardiovascular events in patients at risk.

Trial registration

Current Controlled Trials identifier ISRCTN36043780. Retrospectively registered 25 September 2013.

Electronic supplementary material

The online version of this article (doi:10.1186/s12959-016-0125-x) contains supplementary material, which is available to authorized users.

The Impact of Resveratrol Supplementation on Blood Glucose, Insulin, Insulin Resistance, Triglyceride, and Periodontal Markers in Type 2 Diabetic Patients with Chronic Periodontitis

The aim of this study was to investigate the impact of resveratrol supplementation along with non-surgical periodontal treatment on blood glucose, insulin, insulin resistance, triglyceride (TG), and periodontal markers in patients with type 2 diabetes with periodontal disease. In this double-blind clinical trial study, 43 patients with diabetes with chronic periodontitis were participated. Subjects were randomly allocated to intervention and control groups. The intervention and control groups received either 480 mg/day of resveratrol or placebo capsules (two pills) for 4 weeks. Fasting blood glucose, insulin, insulin resistance (homeostasis model assessment of insulin resistance), TGs, and pocket depth were measured in all subjects' pre-intervention and post-intervention. The mean serum levels of fasting insulin and insulin resistance (homeostasis model assessment of insulin resistance) were significantly lower in the intervention group compared with control group (10.42 ± 0.28 and 10.92 ± 0.9; 3.66 ± 0.97 and 4.49 ± 1.56, respectively). There was a significant difference in the mean pocket depth between intervention and control groups (2.35 ± 0.6 and 3.38 ± 0.5, respectively) following intervention. No significant differences were observed in the mean levels of fasting blood glucose and TGs between two groups' post-intervention. It is recommended that resveratrol supplementation may be beneficial as adjuvant therapy along with non-surgical periodontal treatment in insulin resistance and improving periodontal status among patients with diabetes with periodontal disease. Copyright © 2016 John Wiley & Sons, Ltd.

Effect of non-surgical periodontal therapy on insulin resistance in patients with type II diabetes mellitus and chronic periodontitis, as assessed by C-peptide and the Homeostasis Assessment Index

AIM

A bidirectional relationship exists between diabetes and periodontitis. In the present clinical trial, we evaluated the effects of non-surgical periodontal therapy (NSPT) on insulin resistance in patients with type II diabetes mellitus (DM) and chronic periodontitis.

METHODS

Forty chronic periodontitis patients with type II DM were selected and equally allocated to case and control groups. All patients were assessed for periodontal parameters and systemic parameters. The case group received NSPT, and both groups were re-evaluated after 3 months.

RESULTS

All periodontal parameters were found to be significantly improved in the case group compared to the control group 3 months after NSPT. The mean differences in systemic parameters, such as fasting serum C-peptide, Homeostasis Assessment (HOMA) Index-insulin resistance, and HOMA-insulin sensitivity, from baseline to 3 months for the case group were 0.544 ± 0.73, 0.54 ± 0.63, and -25.44 ± 36.81, respectively; for the control group, they were significant at -1.66 ± 1.89, -1.48 ± 1.86, and 31.42 ± 38.82 respectively (P < 0.05). There was a significant decrease in fasting blood glucose and glycosylated hemoglobin A1c from baseline to 3 months in the case group (P < 0.05).

CONCLUSION

The present study showed that periodontal inflammation could affect glycemic control and insulin resistance. Effective periodontal therapy reduced insulin resistance and improved periodontal health status and insulin sensitivity in patients with type II DM and chronic periodontitis.

Periodontal treatment and glycaemic control in patients with diabetes and periodontitis: an umbrella review

BACKGROUND

Studies suggest that non-surgical periodontal treatment improves glycaemic control in patients with diabetes and periodontitis. The aim of this umbrella review is to summarize the effects of periodontal treatment on glycaemic control in patients with periodontitis and diabetes.

METHODS

A systematic review of systematic reviews with or without meta-analysis published between 1995 and 2015 was performed. Three independent reviewers assessed for article selection, quality and data extraction.

RESULTS

Thirteen (13) systematic reviews/meta-analysis were included for qualitative synthesis. A reduction (0.23 to 1.03 percentage points) in the levels of HbA1c at 3 months after periodontal intervention was found. This reduction was statistically significant in 10/12 meta-analysis. One review with sufficiently large samples found a non-significant reduction (-0.014 percentage points; 95% CI -0.18 to 0.16; p = 0.87). Only three studies separated the use of adjunctive antibiotics and found a reduction of 0.36 percentage points but the difference was not statistically significant.

CONCLUSIONS

Highly heterogeneous short-term studies with small sample size suggest that periodontal treatment could help improve glycaemic control at 3 months in patients with type 2 diabetes and periodontitis. However, longer term studies having sufficient sample size do not provide evidence that periodontal therapy improves glycaemic control in these patients.

Systemic Inflammatory Biomarkers and Their Association With Periodontal and Diabetes-Related Factors in the Diabetes and Periodontal Therapy Trial, A Randomized Controlled Trial

BACKGROUND

The present study evaluates effects of non-surgical periodontal treatment on serum biomarkers in patients with type 2 diabetes mellitus (t2DM) and chronic periodontitis who participated in the Diabetes and Periodontal Therapy Trial (DPTT); and associations among diabetes markers, serum biomarkers, and periodontal measures in these patients.

METHODS

DPTT participants randomized to receive immediate or delayed non-surgical periodontal therapy were evaluated at baseline and 6 months. Serum samples from 475 participants with 6-month data were analyzed for the following biomarkers: 1) high sensitivity C-reactive protein; 2) E-selectin; 3) tumor necrosis factor (TNF)-α; 4) vascular cell adhesion molecule (VCAM); 5) interleukin (IL)-6; 6) IL-8; 7) intercellular adhesion molecule; and 8) IL-10. Changes in biomarker levels from baseline and correlations among biomarker levels and clinical findings were analyzed.

RESULTS

No differences between treatment and control groups were observed for any biomarkers at baseline or 6 months (P >0.05 for all variables). VCAM levels increased by an average (standard deviation) of 17.9 (99.5); ng/mL (P = 0.006) and E-selectin decreased by 2.33 (16.08) ng/mL (P = 0.03) in the treatment group after 6 months. E-selectin levels were significantly correlated with DM-related variables (hemoglobin A1c [HbA1c] and fasting glucose) at baseline and with 6-month change in both groups; no significant correlations were found among periodontal clinical parameters and serum biomarkers or DM-related variables. Neither HbA1c or body mass index varied during the study period in either study group.

CONCLUSIONS

Non-surgical periodontal therapy and periodontal disease severity were not associated with significant changes in serum biomarkers in DPTT participants during the 6-month follow-up. Correlations among changes in E-selectin, IL-6, and DM-related variables suggest that t2DM may be the primary driver of systemic inflammation in these patients.

A review of the evidence for pathogenic mechanisms that may link periodontitis and diabetes

AIMS

To review the evidence for the molecular and cellular processes that may potentially link periodontal disease and diabetes. The pathogenic roles of cytokines and metabolic molecules (e.g. glucose, lipids) are explored and the role of periodontal bacteria is also addressed. Paradigms for bidirectional relationships between periodontitis and diabetes are discussed and opportunities for elaborating these models are considered.

METHODS

Database searches were performed using MeSH terms, keywords, and title words. Studies were evaluated and summarized in a narrative review.

RESULTS

Periodontal microbiota appears unaltered by diabetes and there is little evidence that it may influence glycaemic control. Small-scale clinical studies and experiments in animal models suggest that IL-1β, TNF-α, IL-6, OPG and RANKL may mediate periodontitis in diabetes. The AGE-RAGE axis is likely an important pathway of tissue destruction and impaired repair in diabetes-associated periodontitis. A role for locally activated pro-inflammatory factors in the periodontium, which subsequently impact on diabetes, remains speculative.

CONCLUSION

There is substantial information on potential mechanistic pathways which support a close association between diabetes and periodontitis, but there is a real need for longitudinal clinical studies using larger patient groups, integrated with studies of animal models and cells/tissues in vitro.

Evidence that periodontal treatment improves diabetes outcomes: a systematic review and meta-analysis

CONTEXT

The effect of periodontal therapy on diabetes outcomes has not been established.

OBJECTIVE

This update examines the effect of periodontal treatment on diabetes outcomes.

DATA SOURCES

Literature since October 2009 using MEDLINE.

STUDY ELIGIBILITY CRITERIA

Published RCTs including periodontal therapy for diabetic subjects, a metabolic outcome, an untreated control group, and follow-up of 3 months.

DATA EXTRACTION

Pre-defined data fields, including study quality indicators were used.

DATA SYNTHESIS

A search revealed 56 publications of which 9 met inclusion criteria. Mean change of HbA1c from baseline was compared across treatment groups. Pooled analysis was based on random effects models.

RESULTS

A meta-analysis indicated a mean treatment effect of -0.36% HbA1c (CI -0.54, -0.19) compared to no treatment after periodontal therapy (p < 0.0001). Heterogeneity tests revealed only minimal evidence of publication bias (I(2 ) = 9%).

LIMITATIONS

Small sample size and high risk of bias remain problematic for studies of this type. Periodontal therapy varied considerably.

CONCLUSION

The modest reduction in HbA1c observed as a result of periodontal therapy in subjects with type 2 diabetes is consistent with previous systematic reviews. Despite this finding, there is limited confidence in the conclusion due to a lack of multi-centre trials of sufficient sample size are lacking.

Evidence that periodontal treatment improves biomarkers and CVD outcomes

AIM

The aim of this review was to critically appraise the evidence on the impact of periodontal treatment of cardiovascular diseases (CVDs) biomarkers and outcomes.

METHODS

A systematic search was performed in Cinhal, Cochrane, Embase and Medline for relevant articles up to July 2012. Duplicate screening and reference hand searching were performed. Data were then summarized and evidence graded in tables.

RESULTS

The search resulted in: (a) no evidence on the effects of periodontal therapy on subclinical atherosclerosis, serum levels of CD40 ligand, serum amyloid A and monocyte chemoattractant protein-1, (b) limited evidence on the effects of periodontal therapy on arterial blood pressure, leucocyte counts, fibrinogen, tissue necrosis factor-α, sE-selectin, von Willebrand factors, d-dimers, matrix metalloproteinases, oxidative stress and CVD events, and (c) moderate evidence suggesting a negligible effect of periodontal therapy in reducing interleukin-6 and lipids levels, whilst a positive effect in reducing serum C-reactive protein levels and improving endothelial function.

CONCLUSIONS

Periodontal therapy triggers a short-term inflammatory response followed by (a) a progressive and consistent reduction of systemic inflammation and (b) an improvement in endothelial function. There is however limited evidence that these acute and chronic changes will either increase or reduce CVD burden of individuals suffering from periodontitis in the long term.

Evidence that periodontal treatment improves biomarkers and CVD outcomes

AIM

The aim of this review was to critically appraise the evidence on the impact of periodontal treatment of cardiovascular diseases (CVDs) biomarkers and outcomes.

METHODS

A systematic search was performed in Cinhal, Cochrane, Embase and Medline for relevant articles up to July 2012. Duplicate screening and reference hand searching were performed. Data were then summarized and evidence graded in tables.

RESULTS

The search resulted in: (a) no evidence on the effects of periodontal therapy on subclinical atherosclerosis, serum levels of CD40 ligand, serum amyloid A and monocyte chemoattractant protein-1, (b) limited evidence on the effects of periodontal therapy on arterial blood pressure, leucocyte counts, fibrinogen, tissue necrosis factor-a, sE-selectin, von Willebrand factors, d-dimers, matrix metalloproteinases, oxidative stress and CVD events, and (c) moderate evidence suggesting a negligible effect of periodontal therapy in reducing interleukin-6 and lipids levels, whilst a positive effect in reducing serum C-reactive protein levels and improving endothelial function.

CONCLUSIONS

Periodontal therapy triggers a short-term inflammatory response followed by (a) a progressive and consistent reduction of systemic inflammation and (b) an improvement in endothelial function. There is however limited evidence that these acute and chronic changes will either increase or reduce CVD burden of individuals suffering from periodontitis in the long term.

Evidence that periodontal treatment improves diabetes outcomes: a systematic review and meta-analysis

CONTEXT

The effect of periodontal therapy on diabetes outcomes has not been established.

OBJECTIVE

This update examines the effect of periodontal treatment on diabetes outcomes.

DATA SOURCES

Literature since October 2009 using MEDLINE.

STUDY ELIGIBILITY CRITERIA

Published RCTs including periodontal therapy for diabetic subjects, a metabolic outcome, an untreated control group, and follow-up of 3 months.

DATA EXTRACTION

Pre-defined data fields, including study quality indicators were used.

DATA SYNTHESIS

A search revealed 56 publications of which 9 met inclusion criteria. Mean change of HbA1c from baseline was compared across treatment groups. Pooled analysis was based on random effects models.

RESULTS

A meta-analysis indicated a mean treatment effect of _0.36% HbA1c (CI _0.54, _0.19) compared to no treatment after periodontal therapy (p < 0.0001). Heterogeneity tests revealed only minimal evidence of publication bias (I2 = 9%).

LIMITATIONS

Small sample size and high risk of bias remain problematic for studies of this type. Periodontal therapy varied considerably.

CONCLUSION

The modest reduction in HbA1c observed as a result of periodontal therapy in subjects with type 2 diabetes is consistent with previous systematic reviews. Despite this finding, there is limited confidence in the conclusion due to a lack of multi-centre trials of sufficient sample size are lacking.

Comparison of Experimental Diabetic Periodontitis Induced by Porphyromonas gingivalis in Mice

Periodontitis is one of the severe complications in diabetic patients and gingival epithelium plays an initial role on the onset and progression of this disease. However the potential mechanism is yet sufficiently understood. Meanwhile, the research on the correlational experimental animal models was also insufficient. Here, we established periodontitis with type 2 diabetes in db/db and Tallyho/JngJ (TH) mice and periodontitis with type 1 diabetes in streptozotocin induced diabetes C57BL/6J (STZ-C57) mice by oral infection of periodontal pathogen Porphyromonas gingivalis W50. We demonstrated that periodontal infected mice with high blood glucose levels showed dramatically more alveolar bone loss than their counterparts, in which infected db/db mice exhibited the most bone defects. No contrary impact could be observed between this periodontal infection and onset and severity of diabetes. The expressions of PTPN2 were inhibited whereas the expression of JAK1, STAT1, and STAT3 increased dramatically in gingival epithelia and the serum TNF-α also significantly increased in the mice with diabetic periodontitis. Our results indicated that the variations of inflammation-related protein expressions in gingival epithelia might lead to the phenotype differences in the mice with diabetic periodontitis.

Glycemic control and the production of cytokines in diabetic patients with chronic periodontal disease

Objective: To evaluate the association of glycemic control and cytokine production in type 2 diabetic subjects with chronic periodontitis. Methods: Gingival biopsies were performed in 40 patients, divided into four groups: systemically healthy subjects without periodontal disease (S); systemically healthy patients with chronic periodontitis (P); patients with well-controlled type 2 diabetes mellitus (DM) with chronic periodontitis (C); poorly controlled type 2 diabetes mellitus with chronic periodontitis (D). The production of interleukin (IL) -4, -6, -10, -17 and interferon (IFN) -g was quantified by ELISA. Results: The production of IL-4, IL-10, IL-17 and INF-g was higher on group D when compared to other groups (p <0.05), which in turn were similar (p ³0.05). In addition, there was no difference in the production of IL-6 in any of the evaluated groups (p³0.05). Conclusion: Were observed significantly elevated levels of pro-inflammatory and anti-inflammatory cytokines in patients with poorly controlled type 2 diabetes and chronic periodontitis, demonstrating that glycemic control may be associated to the immune inflammatory response of sites with chronic periodontitis.

Treatment of periodontal disease for glycaemic control in people with diabetes mellitus

BACKGROUND

Glycaemic control is a key issue in the care of people with diabetes mellitus (DM). Periodontal disease is the inflammation and destruction of the underlying supporting tissues of the teeth. Some studies have suggested a bidirectional relationship between glycaemic control and periodontal disease. This review updates the previous version published in 2010.

OBJECTIVES

The objective is to investigate the effect of periodontal therapy on glycaemic control in people with diabetes mellitus.

SEARCH METHODS

We searched the following electronic databases: the Cochrane Oral Health Group Trials Register (to 31 December 2014), the Cochrane Central Register of Controlled Trials (CENTRAL) (Cochrane Library 2014, Issue 11), MEDLINE via OVID (1946 to 31 December 2014), EMBASE via OVID (1980 to 31 December 2014), LILACS via BIREME (1982 to 31 December 2014), and CINAHL via EBSCO (1937 to 31 December 2014). ZETOC (1993 to 31 December 2014) and Web of Knowledge (1990 to 31 December 2014) were searched for conference proceedings. Additionally, two periodontology journals were handsearched for completeness, Annals of Periodontology (1996 to 2003) and Periodontology 2000 (1993 to 2003). We searched the US National Institutes of Health Trials Registry (http://clinicaltrials.gov) and the WHO Clinical Trials Registry Platform for ongoing trials. No restrictions were placed on the language or date of publication when searching the electronic databases.

SELECTION CRITERIA

We searched for randomised controlled trials (RCTs) of people with type 1 or type 2 DM (T1DM/T2DM) with a diagnosis of periodontitis. Interventions included periodontal treatments such as mechanical debridement, surgical treatment and antimicrobial therapy. Two broad comparisons were proposed:1. periodontal therapy versus no active intervention/usual care;2. periodontal therapy versus alternative periodontal therapy.

DATA COLLECTION AND ANALYSIS

For this review update, at least two review authors independently examined the titles and abstracts retrieved by the search, selected the included trials, extracted data from included trials and assessed included trials for risk of bias.Our primary outcome was blood glucose levels measured as glycated (glycosylated) haemoglobin assay (HbA1c).Our secondary outcomes included adverse effects, periodontal indices (bleeding on probing (BOP), clinical attachment level (CAL), gingival index (GI), plaque index (PI) and probing pocket depth (PPD)), cost implications and diabetic complications.

MAIN RESULTS

We included 35 studies (including seven from the previous version of the review), which included 2565 participants in total. All studies used a parallel RCT design, and 33 studies (94%) only targeted T2DM patients. There was variation between studies with regards to included age groups (ages 18 to 80), duration of follow-up (3 to 12 months), use of antidiabetic therapy, and included participants' baseline HbA1c levels (from 5.5% to 13.1%).We assessed 29 studies (83%) as being at high risk of bias, two studies (6%) as being at low risk of bias, and four studies (11%) as unclear. Thirty-four of the studies provided data suitable for analysis under one or both of the two comparisons.Comparison 1: low quality evidence from 14 studies (1499 participants) comparing periodontal therapy with no active intervention/usual care demonstrated that mean HbA1c was 0.29% lower (95% confidence interval (CI) 0.48% to 0.10% lower) 3 to 4 months post-treatment, and 0.02% lower after 6 months (five studies, 826 participants; 95% CI 0.20% lower to 0.16% higher).Comparison 2: 21 studies (920 participants) compared different periodontal therapies with each other. There was only very low quality evidence for the multiple head-to-head comparisons, the majority of which were unsuitable to be pooled, and provided no clear evidence of a benefit for one periodontal intervention over another. We were able to pool the specific comparison between scaling and root planing (SRP) plus antimicrobial versus SRP and there was no consistent evidence that the addition of antimicrobials to SRP was of any benefit to delivering SRP alone (mean HbA1c 0.00% lower: 12 studies, 450 participants; 95% CI 0.22% lower to 0.22% higher) at 3-4 months post-treatment, or after 6 months (mean HbA1c 0.04% lower: five studies, 206 patients; 95% CI 0.41% lower to 0.32% higher).Less than half of the studies measured adverse effects. The evidence was insufficient to conclude whether any of the treatments were associated with harm. No other patient-reported outcomes (e.g. quality of life) were measured by the included studies, and neither were cost implications or diabetic complications.Studies showed varying degrees of success with regards to achieving periodontal health, with some showing high levels of residual inflammation following treatment. Statistically significant improvements were shown for all periodontal indices (BOP, CAL, GI, PI and PPD) at 3-4 and 6 months in comparison 1; however, this was less clear for individual comparisons within the broad category of comparison 2.

AUTHORS' CONCLUSIONS

There is low quality evidence that the treatment of periodontal disease by SRP does improve glycaemic control in people with diabetes, with a mean percentage reduction in HbA1c of 0.29% at 3-4 months; however, there is insufficient evidence to demonstrate that this is maintained after 4 months.There was no evidence to support that one periodontal therapy was more effective than another in improving glycaemic control in people with diabetes mellitus.In clinical practice, ongoing professional periodontal treatment will be required to maintain clinical improvements beyond 6 months. Further research is required to determine whether adjunctive drug therapies should be used with periodontal treatment. Future RCTs should evaluate this, provide longer follow-up periods, and consider the inclusion of a third 'no treatment' control arm.Larger, well conducted and clearly reported studies are needed in order to understand the potential of periodontal treatment to improve glycaemic control among people with diabetes mellitus. In addition, it will be important in future studies that the intervention is effective in reducing periodontal inflammation and maintaining it at lowered levels throughout the period of observation.

Supragingival biofilm control and systemic inflammation in patients with type 2 diabetes mellitus

The objective of this study was to evaluate the effect of strict supragingival biofilm control on serum inflammatory markers and on periodontal clinical parameters in type 2 diabetes mellitus (T2DM) patients with chronic severe periodontitis. Twenty-four individuals with T2DM and periodontitis were randomly allocated to two treatment groups. The supragingival therapy group (ST, n = 12) received supragingival scaling, whereas the intensive therapy group (IT, n = 12) underwent supra- and subgingival scaling, as well as root planing. Patients from both groups received professional oral hygiene instructions every month. Data regarding visible plaque index (VPI), gingival bleeding index (GBI), bleeding on probing (BOP), probing pocket depth (PPD), clinical attachment level (CAL), serum levels of interleukin (IL)-6, IL-17A, IL-8, tumor necrosis factor α (TNF-α), monocyte chemoattractant protein (MCP)-1 enzyme-linked immunosorbent assay (ELISA), and glycated hemoglobin (HbA1c) levels were obtained at baseline and at 6 months post-therapy. Both therapies resulted in the improvement of almost all clinical periodontal parameters (p < 0.05). There were no differences in TNF-α, IL-8, IL-17A and HbA1c levels in either group (p > 0.05), between the two periods. However, MCP-1 levels were significantly reduced in both the ST (p = 0.034) and the IT (p = 0.016) groups, whereas the serum IL-6 levels were significantly reduced only in the IT group (p = 0.001). Strict control of supragingival biofilm has a limited effect on systemic inflammatory markers, and a moderate effect on periodontal clinical parameters.

The Influence of Glycated Hemoglobin on the Cross Susceptibility Between Type 1 Diabetes Mellitus and Periodontal Disease

BACKGROUND

Periodontal disease is a major complication of type 1 diabetes mellitus (T1DM). The aim of the present study is to investigate the relationship between glycated hemoglobin and circulating levels of interleukin (IL)-6, IL-8, and C-X-C motif chemokine ligand 5 (CXCL5) in non-smoking patients suffering from T1DM, with and without periodontitis. In addition, to determine the effect of advanced glycation end products (AGE) in the presence and absence of Porphyromonas gingivalis lipopolysaccharide (LPS) on IL-6, IL-8, and CXCL5 expression by THP-1 monocytes and OKF6/TERT-2 cells.

METHODS

There were 104 participants in the study: 19 healthy volunteers, 23 patients with periodontitis, 28 patients with T1DM, and 34 patients with T1DM and periodontitis. Levels of blood glucose/glycated hemoglobin (International Federation of Clinical Chemistry [IFCC]) were determined by high-performance liquid chromatography. Levels of IL-6, IL-8, and CXCL5 in plasma were determined by enzyme-linked immunosorbent assay (ELISA). In vitro stimulation of OKF6/TERT-2 cells and THP-1 monocytes was performed with combinations of AGE and P. gingivalis LPS. Changes in expression of IL-6, IL-8, and CXCL5 were monitored by ELISA and real-time polymerase chain reaction.

RESULTS

Patients with diabetes and periodontitis had higher plasma levels of IL-8 than patients with periodontitis alone. Plasma levels of IL-8 correlated significantly with IFCC units, clinical probing depth, and attachment loss. AGE and LPS, alone or in combination, stimulated IL-6, IL-8, and CXCL5 expression in both OKF6/TERT-2 cells and THP-1 monocytes.

CONCLUSIONS

Elevated plasma levels of IL-8 potentially contribute to the cross-susceptibility between periodontitis and T1DM. P. gingivalis LPS and AGE in combination caused significantly greater expression of IL-6, IL-8, and CXCL5 from THP-1 monocytes and OKF6/TERT-2 cells than LPS alone.

The Two-Way Association of Periodontal Infection with Systemic Disorders: An Overview

Oral cavity that harbors diverse bacterial populations could also act as a site of origin for spread of pathogenic microorganisms to different body sites, particularly in immunocompromised hosts, patients, the elderly, or the underprivileged. A number of recent publications have advocated that patients with periodontal diseases are more susceptible to metabolic endotoxemia, inflammation, obesity, type 2 diabetes, and other related systemic complications, concluding that periodontal diseases could be a potential contributing risk factor for a wide array of clinically important systemic diseases. However, despite a significant increase in the prevalence of periodontal infections and systemic diseases in the past few decades, the fundamental biological mechanisms of connection between these ailments are still not fully explicated. Consequently, the mechanisms by which this bidirectional damage occurs are being explored with a concentric vision to develop strategies that could prevent or control the complications of these ailments. This paper attempts to summarize and hypothesize the diverse mechanisms that hint to a certain connection between the two prevalent chronic situations.

Antimicrobial photodynamic therapy combined with periodontal treatment for metabolic control in patients with type 2 diabetes mellitus: study protocol for a randomized controlled trial

Background

The relationship between diabetes mellitus (DM) and periodontal disease is bidirectional. DM is a predisposing and modifying factor of periodontitis, which, in turn, worsens glycemic control and increases proteins found in the acute phase of inflammation, such as C-reactive protein. The gold standard for the treatment of periodontal disease is oral hygiene orientation, scaling and planing. Moreover, systemic antibiotic therapy may be employed in some cases. In an effort to minimize the prescription of antibiotics, photodynamic therapy (PDT) has been studied as an antimicrobial technique and has demonstrated promising results. The aim of the proposed study is to determine whether PDT as a complement to periodontal therapy (PT) is helpful in the metabolic control of individuals with type 2 diabetes and the reduction of acute-phase inflammatory markers.

Methods/Design

The patients will be randomized using a proper software program into two groups: 1) PT + placebo PDT or 2) PT + active PDT. All patients will first be examined by a specialist, followed by PT performed by two other healthcare professionals. At the end of each session, PDT (active or placebo) will be administered by a fourth healthcare professional. The following will be the PDT parameters: diode laser (660 nm); power output = 110 mW; exposure time = 90 s per point (9 J/point); and energy density = 22 J/cm². The photosensitizer will be methylene blue (50 μg/mL). The patients will be re-evaluated 15, 30, 90 and 180 days after treatment. Serological examinations with complete blood count, fasting glucose, glycated hemoglobin and salivary examinations to screen for tumor necrosis factor alpha, interleukin 1, interleukin 6, ostelocalcin, and osteoprotegerin/RANKL will be performed at each evaluation. The data will be statistically evaluated using the most appropriate tests.

Discussion

The results of this study will determine the efficacy of photodynamic therapy as an adjuvant to periodontal treatment in diabetic patients.

Trial registration

The protocol for this trial was registered with Clinical Trials registration number NCT01964833 on 14 October 2013.

Periodontal therapy and systemic inflammation in type 2 diabetes mellitus: a meta-analysis

AIM

The aim of this systematic review was to assess the effect of periodontal therapy (PT) on serum levels of inflammatory markers in people with type 2 diabetes mellitus (T2DM).

METHODS OF STUDY SELECTION

A literature search was carried out using MEDLINE via Pubmed, EMBASE, LILACS and Cochrane Central Register of Controlled Trials (CENTRAL) databases. Randomized-controlled trials (RCTs) and controlled clinical trials (CCTs) evaluating the effect of PT on systemic inflammatory markers were deemed eligible. Case series (CS), reports and pilot trials were excluded. Study quality was assessed using the Cochrane Collaboration's risk assessment tool. Meta-analysis was carried out using random effect methods.

RESULTS

The search strategy identified 3,164 potential studies of which 61 were assessed for eligibility and 9 (6 RCTs and 3 CCTs) were included in this systematic review. Three RCTs were classified by the authors as being at low risk of bias and three were "unclear" and classified as uncertain risk of bias. All CCTs were considered to be at a high risk of bias. The meta-analysis showed a statistically significant mean difference (MD) for TNF- α (-1.33 pg/ml, 95% CI: -2.10; -0.56, p<0.001) and CRP (-1.28 mg/l, 95% CI: -2.07; - 0.48, p<0.001) favoring periodontal intervention versus control.

CONCLUSION

The results of this meta-analysis support the hypothesis that PT reduces serum levels of TNF- α and CRP in T2DM individuals. The decrease of inflammatory burden has important implications for metabolic control and can, in part, explain the mechanisms linking periodontitis and increased risk for complications in people with T2DM.

Short term effects of periodontal therapy on inflammatory markers in patients with type-2 diabetes

OBJECTIVES

To evaluate the influence of periodontal therapy on glycosylated hemoglobin and fasting blood glucose and serum levels of interleukin (IL)-4, IL-6, IL-8, IL-10, and tumor necrosis factor-alpha (TNF-α) in chronic periodontitis (CP) patients with type-2 diabetes mellitus (T2DM) and in controls.

METHODS

A total of 30 periodontal patients, 15 of which were systemically healthy (control group), and 15 were T2DM patients (test group) were included in this study. This prospective study was carried out at Istanbul University, Istanbul, Turkey between February 2011 and December 2013. Plaque index, gingival index, bleeding on probing, periodontal probing depth, and clinical attachment level were assessed and recorded at baseline, one, and 3 months after therapy. Serum samples were collected at the same time-points and analyzed using Luminex assay for the levels of IL-4, IL-6, IL-8, IL-10, and TNF-α. The change in the metabolic control was also monitored.

RESULTS

All clinical parameters were significantly improved after the periodontal therapy in both groups (p less than l0.001). Glycosylated hemoglobin levels were decreased; however, the difference was not significant (p more than 0.05). Fasting blood glucose levels were decreased one month after therapy, and increased at 3 months. Patients with T2DM had significantly higher levels of circulating IL-8 at each time point, and TNF-α (p less than 0.05) at baseline. The IL-4 and IL-10 levels were decreased at one month after therapy (p more than 0.05).

CONCLUSION

Periodontal therapy has limited impact on the serum levels of IL-4, IL-6, IL-8, IL-10, and TNF-α. Metabolic control levels were not influenced by periodontal therapy.

Expression of Leptin and Visfatin in Gingival Tissues of Chronic Periodontitis With and Without Type 2 Diabetes Mellitus: A Study Using Enzyme-Linked Immunosorbent Assay and Real-Time Polymerase Chain Reaction

BACKGROUND

The aim of this study is to investigate the protein and gene expression of leptin and visfatin in gingival tissue from patients with chronic periodontitis (CP), patients with CP and type 2 diabetes mellitus (T2DM), and healthy individuals.

METHODS

The study includes 50 individuals: 10 healthy individuals, 20 patients with CP, and 20 patients with CP and T2DM. Plaque index, gingival index, probing depth, and clinical attachment loss were measured, and gingival biopsies were obtained. Leptin and visfatin protein expression in gingival tissues was determined using enzyme-linked immunosorbent assay, and messenger RNA (mRNA) expression was measured via real-time polymerase chain reaction.

RESULTS

The highest leptin mRNA and protein expression was observed in the control group and was significantly (P ≤0.05) different from the CP and CP+T2DM groups. Gingival tissues from patients with CP and T2DM had a significant increase in visfatin and a decrease in leptin gene and protein expression (P <0.05) compared with both controls and patients with CP.

CONCLUSION

Expression of leptin and visfatin in the gingival tissues suggests a possible role for these adipokines in the pathogenesis of CP and T2DM.

Resveratrol ameliorates experimental periodontitis in diabetic mice through negative regulation of TLR4 signaling

AIM

To investigate the therapeutic effects of resveratrol (RSV) on periodontitis in diabetic mice and to explore the underlying mechanisms in vitro.

METHODS

Experimental periodontitis was induced in db/db mice by ligature application of porphyromonas gingivalis. The mice were treated with RSV (20 mg/kg, p.o.) daily for 4 weeks. Alveolar bone loss, proinflammatory cytokines and TLR4 expression in the gingival tissue were measured. Cultured gingival epithelial cells (GECs) were used for in vitro studies. The transcriptional activity of TLR4 downstream signaling was analyzed using Western blotting.

RESULTS

RSV administration significantly decreased the blood glucose levels, and ameliorated alveolar bone loss in db/db mice with experimental periodontitis. RSV administration also suppressed the high levels of IL-1β, IL-6, IL-8, TNF-α, and TLR4 in gingival tissue of the mice. In the GECs incubated in high glucose medium, TLR4 expression was substantially upregulated, which was partly blocked in the presence of RSV. Lipopolysaccharides markedly increased the expression and secretion of IL-1β, IL-6, IL-8, and TNF-α in the GECs cultured in high glucose medium, which was also partly blocked in the presence of RSV. Furthermore, RSV significantly suppressed the phosphorylation of TLR4 downstream factors NF-κB p65, p38MAPK, and STAT3.

CONCLUSION

RSV exerts protective effects against experimental periodontitis in db/db mice via negative regulation of TLR4 signaling.

Effectiveness of lifestyle change plus dental care program in improving glycemic and periodontal status in aging patients with diabetes: a cluster, randomized, controlled trial

BACKGROUND

Currently, there is an increased prevalence of diabetes mellitus among the aging adult population. To minimize adverse effects on glycemic control, prevention and management of general and oral complications in patients with diabetes are essential. The objective of this study is to assess the effectiveness of the lifestyle change plus dental care (LCDC) program to improve glycemic and periodontal status in aging patients with diabetes.

METHODS

A cluster, randomized, controlled trial was conducted in Health Centers 54 (intervention) and 59 (control) from October 2013 to April 2014. Sixty-six patients with diabetes per health center were included. At baseline, the intervention group attended 20-minute lifestyle and oral health education, individual lifestyle counseling, application of a self-regulation manual, and individual oral hygiene instruction. At month 3, the intervention group received individual lifestyle counseling and oral hygiene instruction. The intervention group received booster education every visit by viewing a 15-minute educational video. The control group received a routine program. Participants were assessed at baseline and 3- and 6-month follow-up for glycemic and periodontal status. Data were analyzed by using descriptive statistic, χ(2) test, Fisher exact test, t test, and repeated-measures analysis of variance.

RESULTS

After the 6-month follow-up, participants in the intervention group had significantly lower glycated hemoglobin, fasting plasma glucose, plaque index, gingival index, probing depth, and attachment loss when compared with the control group.

CONCLUSION

The combination of lifestyle change and dental care in one program improved both glycemic and periodontal status in older patients with diabetes.

Effects of periodontal therapy on metabolic control in patients with type 2 diabetes mellitus and periodontal disease: a meta-analysis

Epidemiologic studies have reported increased incidence, prevalence and acuity of periodontitis in adults with diabetes and some have also suggested that treating periodontal disease may improve glycemic control in diabetic patients. This meta-analysis was conducted to evaluate the effects of different periodontal therapies on metabolic control in patients with type 2 diabetes mellitus (T2DM) and periodontal disease. We searched the Medline, EMBASE and Cochrane Library (Central) databases up to January 2014 for relevant studies pertaining to periodontal treatments and glycemic control in adults with T2DM. The search terms were periodontal treatment/periodontal therapy, diabetes/diabetes mellitus, periodontitis/periodontal and glycemic control. The primary outcome measure taken from the included studies was glycated hemoglobin (HbA1c). We compared differences in patients' pre- and post-intervention HbA1c results between a treatment group receiving scaling and root planing (SRP) combined with administration of oral doxycycline (n=71) and controls receiving SRP alone or SRP plus placebo (n=72). Meta-analysis was performed using Comprehensive Meta Analysis software. Nineteen randomized controlled trials (RCTs) were identified. Four trials involving a total of 143 patients with T2DM and periodontal disease were determined to be eligible for analysis. Data of 1 study were not retained for meta-analysis because HbA1c results were recorded as median with IQR. Meta-analysis of the included 3 studies revealed no significant differences in HbA1c results between the periodontal treatment group (n=71) and control group (n=72) (HbA1c SMD=-0.238, 95% CI=-0.616 to 0.140; P=0.217). Systemic doxycycline added to SRP does not significantly improve metabolic control in patients with T2DM and chronic periodontitis. Current evidence is insufficient to support a significant association between periodontal therapy and metabolic control in this patient population. However, evidence suggests that periodontal therapy itself improves metabolic control and reinforces that T2DM is a risk factor for periodontitis.

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.

Serum levels of inflammatory markers in type 2 diabetes patients with chronic periodontitis

Diabetes has been associated with periodontitis, but the mechanisms through which periodontal diseases affect the metabolic control remain unclear.

Impact of scaling and root planing on C-reactive protein levels in gingival crevicular fluid and serum in chronic periodontitis patients with or without diabetes mellitus

Purpose

The present study was conducted to evaluate the impact of scaling and root planing (SRP) on the C-reactive protein (CRP) levels of gingival crevicular fluid (GCF) and serum in chronic periodontitis patients with type 2 diabetes mellitus (T2DM-CP) or without type 2 diabetes mellitus (NDM-CP).

Methods

Forty-eight human participants were divided into two groups: an experimental (T2DM-CP) group (group I, n=24) comprising chronic periodontitis patients with random blood sugar ≥200 mg/dL and type 2 diabetes mellitus, and control (NDM-CP) group (group II, n=24) of those with chronic periodontitis and random blood sugar <200 without T2DM for the study. All subjects underwent nonsurgical periodontal therapy (NSPT) including complete SRP and subgingival debridement. Periodontal health parameters, plaque index (PI), gingival index (GI), probing pocket depth (PPD), clinical attachment level (CAL), GCF volume (GCF vol), GCF-CRP, random blood glucose (RBS), glycated hemoglobin, and systemic inflammatory markers, serum CRP, total leukocyte count (TLC), neutrophil count (Neutr) and lymphocyte count (Lymph), were evaluated at baseline, 1 month, and 3 months after SRP.

Results

NSPT resulted in statistically significant improvement in periodontal health parameters (PI, GI, PPD, CAL, GCF vol), CRP levels in serum as well as GCF of both groups I and II. The mean improvement in periodontal health parameters (PI, GI, PPD, CAL, GCF vol), CRP levels in serum and GCF was greater in group I than group II after NSPT. There was nonsignificant increase in GCF-CRP, TLC, Lymph, and RBS, and a significant increase in Neutr and Serum CRP in group II at 1 month. The Serum CRP level of 20 out of 24 group II patients had also increased at 1 month.

Conclusions

The CRP levels in both GCF and serum were higher in T2DM-CP patients than in NDM-CP patients. Although there was a significant improvement in both the groups, greater improvement was observed in both GCF and serum samples of T2DM-CP patients.

Graphical Abstract

Effect of nonsurgical periodontal treatment on glycosylated hemoglobin in diabetic patients: a systematic review

This review was designed to determine whether non-surgical periodontal treatment is able to reduce serum glycosylated hemoglobin (HbA1c) levels in patients with diabetes mellitus (DM). Several previous reports showed that scaling and root planning (SRP) improve periodontal status in patients with DM, but whether it also improves metabolic control of the disease is unclear. A systematic review was conducted according to the recommendations of the Cochrane Collaboration and PRISMA. A literature search was conducted in October 2012 using three libraries (Cochrane, Web of Knowledge, and Scopus) and the keywords "periodontal disease" and "diabetes mellitus." Only 21 of the articles met the inclusion criteria for this review. A total of 1,454 patients were thus included in this study to evaluate whether periodontal treatment improved serum HbA1c levels. Both the methodological quality and the risk of bias of each study were taken into account using the Jadad scale. Only ten of the included studies had an acceptable-good score of 3-5. Fourteen of the studies reported a significant decrease in serum HbA1c levels (p < 0.05) after periodontal treatment. The remaining seven studies failed to find a significant decrease in serum HbA1c. The findings of this review suggest that the published literature is insufficient and inconclusive to clearly support periodontal treatment as a means to improve serum HbA1c levels in patients with type 1 DM. It also demonstrates the need for homogeneous studies, with larger samples and longer follow-up periods, to properly address this question.

Beneficial effects of adiponectin on periodontal ligament cells under normal and regenerative conditions

Type 2 diabetes and obesity are increasing worldwide and linked to periodontitis, a chronic disease which is characterized by the irreversible destruction of the tooth-supporting tissues, that is, periodontium. The mechanisms underlying the association of diabetes mellitus and obesity with periodontal destruction and compromised periodontal healing are not well understood, but decreased plasma levels of adiponectin, as found in diabetic and obese individuals, might be a critical mechanistic link. The aim of this in vitro study was to examine the effects of adiponectin on periodontal ligament (PDL) cells under normal and regenerative conditions, and to study the regulation of adiponectin and its receptors in these cells. Adiponectin stimulated significantly the expression of growth factors and extracellular matrix, proliferation, and in vitro wound healing, reduced significantly the constitutive tumor necrosis factor-α expression, and caused a significant upregulation of its own expression. The beneficial actions of enamel matrix derivative on a number of PDL cell functions critical for periodontal regeneration were partially enhanced by adiponectin. The periodontopathogen Porphyromonas gingivalis inhibited the adiponectin expression and stimulated the expression of its receptors. In conclusion, reduced levels of adiponectin, as found in type 2 diabetes and obesity, may compromise periodontal health and healing.

Effectiveness of lifestyle change plus dental care (LCDC) program on improving glycemic and periodontal status in the elderly with type 2 diabetes

Background

Currently, there is an increased prevalence of diabetes mellitus among the elderly. To minimize adverse effects on glycemic control, prevention and management of general and oral complications in diabetic patients is essential. The purpose of the present study is to assess the effectiveness of a Lifestyle Change plus Dental Care (LCDC) program to improve glycemic and periodontal status in the elderly with type 2 diabetes.

Methods

A quasi-experimental study was conducted in Health Centers 54 (intervention) and 59 (control) from October 2013 to January 2014. 66 diabetic patients per health center were included. At baseline, the intervention group attended a 20 minute lifestyle and oral health education program, individual lifestyle counseling using motivational interviewing (MI), application of self regulation manual, and individual oral hygiene instruction. The intervention group received booster education every visit by viewing a 15 minute educational video. The control group received a routine program. Participants were assessed at baseline and 3 month follow up for glycosylated hemoglobin (HbA1c), fasting plasma glucose (FPG), body mass index (BMI), periodontal status, knowledge, attitude and practice of oral health and diabetes mellitus. Data were analyzed by using descriptive statistic, Chi-square test, Fisher’s exact test, t-test, and multiple linear regression.

Results

After the 3 month follow up, a multiple linear regression analysis showed that the intervention group was significantly negatively correlated in both glycemic and periodontal status. Participants in the intervention group had significantly lower glycosylated hemoglobin (HbA1c), fasting plasma glucose (FPG), plaque index score, gingival index score, pocket depth, clinical attachment level (CAL), and percentage of bleeding on probing (BOP) when compared to the control group.

Conclusions

The combination of lifestyle change and dental care in one program improved both glycemic and periodontal status in the elderly with type 2 diabetes.

Trial registration

ClinicalTrials.in.th: TCTR20140602001.

Adiponectin ameliorates experimental periodontitis in diet-induced obesity mice

Adiponectin is an adipokine that sensitizes the body to insulin. Low levels of adiponectin have been reported in obesity, diabetes and periodontitis. In this study we established experimental periodontitis in male adiponectin knockout and diet-induced obesity mice, a model of obesity and type 2 diabetes, and aimed at evaluating the therapeutic potential of adiponectin. We found that systemic adiponectin infusion reduced alveolar bone loss, osteoclast activity and infiltration of inflammatory cells in both periodontitis mouse models. Furthermore, adiponectin treatment decreased the levels of pro-inflammatory cytokines in white adipose tissue of diet-induced obesity mice with experimental periodontitis. Our in vitro studies also revealed that forkhead box O1, a key transcriptional regulator of energy metabolism, played an important role in the direct signaling of adiponectin in osteoclasts. Thus, adiponectin increased forkhead box O1 mRNA expression and its nuclear protein level in osteoclast-precursor cells undergoing differentiation. Inhibition of c-Jun N-terminal kinase signaling decreased nuclear protein levels of forkhead box O1. Furthermore, over-expression of forkhead box O1 inhibited osteoclastogenesis and led to decreased nuclear levels of nuclear factor of activated T cells c1. Taken together, this study suggests that systemic adiponectin application may constitute a potential intervention therapy to ameliorate type 2 diabetes-associated periodontitis. It also proposes that adiponectin inhibition of osteoclastogenesis involves forkhead box O1.

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.

Insulinization: A promising strategy for the treatment of type 2 diabetes mellitus

The aim of the present study was to assess the efficiency of the long-term use of continuous subcutaneous insulin infusion (CSII), a novel regimen known as insulinization, for the treatment of type 2 diabetes mellitus. A total of 150 subjects who fulfilled the diagnostic criteria for type 2 diabetes were included in the study. The patients were divided into eight groups according to the treatment regimens they received and were monitored for 3 months. Insulin doses were adjusted to optimize glycemic control with the simplest possible insulin regimen. The outcomes studied included the time required for glycemic control and insulin dose reduction, the total daily insulin dose, the ratio of patients not requiring the administration of oral antidiabetic drugs (OADs), the rate of hypoglycemia, and hemoglobin A1c (HbA1c) and fasting plasma insulin (FinS) levels. Patients receiving insulinization required less time to achieve optimal glycemic control and insulin decrement compared with patients receiving other treatments. The total daily insulin dose for patients receiving insulinization therapy was 0.23±0.07 U/kg/day, which was lower than that in any other group. In patients receiving insulinization, the ratio of patients that did not require OADs (43.3%) and the concentration of FinS A were higher than those in the other groups. Furthermore, insulinization resulted in a greater reduction in HbA1c levels, as well as a reduced incidence of severe hypoglycemia. Insulinization may mimic physiological insulin secretion more effectively than other therapies. This regimen is more efficient and reduces the incidence of hypoglycemia in patients with type 2 diabetes, indicating that it is likely to be a promising treatment strategy for the disease.

Effect of periodontal treatment on glycemic control of patients with diabetes: A systematic review and meta-analysis

AIMS/INTRODUCTION

The aim of the present study was to investigate whether non-surgical periodontal treatment reduces glycated hemoglobin (HbA1c) and fasting plasma glucose (FPG) levels in diabetic patients.

MATERIALS AND METHODS

An electronic search was carried out on MEDLINE (through PubMed interface), EMBASE and the Cochrane Central Register of Controlled Trials. Randomized controlled trials with a minimum of 3 months follow up were included. The risk of bias was assessed for each study. A meta-analysis was carried out to evaluate the effect of non-surgical periodontal treatment on HbA1c and FPG levels. The effect of the adjunctive use of antimicrobials was also assessed.

RESULTS

A total of 15 studies were included. A reduction of -0.38% (95% confidence interval [CI] -0.23 to -0.53) after 3-4 months (P < 0.001) and of -0.31% (95% CI 0.11 to -0.74) after 6 months (P = 0.15) of follow-up was found for HbA1c, favoring the treatment group. Similarly, in treated patients, a significantly greater decrease in FPG was observed in respect to control participants. Such difference amounted to -9.01 mg/dL (95% CI -2.24 to -15.78) after 3-4 months (P = 0.009) and -13.62 mg/dL (95% CI 0.45 to -27.69) after 6 months (P = 0.06) from treatment, respectively. In participants treated with adjunctive antimicrobials, a non-significant increase of HbA1c was observed 3 months after treatment, whereas FPG decreased by 0.27 mg/dL (95% CI 39.56 to -40.11; P = 0.99).

CONCLUSIONS

The meta-analysis showed that non-surgical periodontal treatment improves metabolic control in patients with both periodontitis and diabetes.

Secreted caveolin-1 enhances periodontal inflammation by targeting gingival fibroblasts

Caveolin-1 (Cav-1) is a membrane protein. Recently, it has been reported that secreted Cav-1 induces angiogenesis in inflammatory microenvironment. However, it is unclear that Cav-1 regulates gingival inflammation. Therefore, we investigated the Cav-1 function to periodontal cells. Expression of Cav-1 in human periodontitis tissues was examined pathologically. Secretion of Cav-1 from human gingival fibroblasts (HGFs) or human periodontal ligament cells (HPLFs) treated with IL-1β and TNF-α was examined using Western blotting. Likewise, intracellular signals induced by Cav-1 were examined. Finally, we examined whether the secreted Cav-1 induces production of inflammatory mediators in HGFs using ELISA or qRT-PCR. Pathologically, high expression of Cav-1 was observed in human periodontitis tissues. Cav-1 secretion increased in both cultured HGFs and HPLFs treated with IL-1β and TNF-α. Cav-1 induced phosphorylation of JNK and ERK, but not Stat3 in HGFs. Furthermore, Cav-1 increased proMMP-1 and VEGF secretion in HGFs, and the VEGF secretion was statistically suppressed by JNK inhibitor SP600125, but not ERK inhibitor PD98059. ProMMP-1 secretion was suppressed statistically by both SP600125 and PD98059. In addition, Cav-1 increased significantly MMP-1, -10 and -14 mRNA expressions, whereas no increase of TIMPs mRNA was observed in HGFs treated with Cav-1. These data suggest that secreted Cav-1 derived from periodontal fibroblastic cells enhances inflammation-related several proteases and VEGF secretion in HGFs via MAPKs pathway, resulting in progression of periodontitis through induction of tissue degradation or angiogenesis.