Effects of Systemic Simvastatin on the Concentrations of Visfatin, Tumor Necrosis Factor-α, and Interleukin-6 in Gingival Crevicular Fluid in Patients with Type 2 Diabetes and Chronic Periodontitis

Association between visfatin and periodontitis: a systematic review and meta-analysis

Background

Periodontitis is a chronic inflammatory disease caused by bacterial infection in the periodontal support tissue. Visfatin, a hormone secreted mainly by adipocytes and macrophages, plays an important role in immune regulation and defense. Although studies have indicated that patients with periodontitis have significantly high serum and gingival crevicular fluid levels of visfatin, the relationship between this adipocytokine and periodontal disease remains unclear.

Aim

The aim of this study was to systematically evaluate the association between visfatin levels and periodontitis.

Methods

The PubMed, Web of Science, ScienceDirect, EBSCO, and Wiley Online Library databases were searched for potential studies, using "periodontitis" and "visfatin" as the keywords in the title and abstract search fields. Standardized mean difference (SMD) values with corresponding 95% confidence intervals (CIs) were determined from the results of this meta-analysis.

Results

In total, 22 articles involving 456 patients with periodontitis and 394 healthy individuals (controls) were included in the meta-analysis. Visfatin levels were significantly higher in the patients with periodontitis than in the healthy individuals (SMD: 3.82, 95% CI [3.01-4.63]). Moreover, the visfatin levels were significantly lowered after periodontitis treatment (SMD: -2.29, 95% CI [-3.33 to -1.26]).

Conclusion

This first-ever meta-analysis comparing visfatin levels between patients with periodontitis and healthy individuals suggests that this adipocytokine can be a diagnostic and therapeutic biomarker for periodontal disease.

The Role of Interleukin 6 in Periodontitis and Its Complications

Interleukin 6 (IL-6) is a pleomorphic pro-inflammatory cytokine that is strongly associated with local as well as systemic inflammatory processes. Its role in physiological and pathogenic processes throughout the human body has been the subject of numerous studies in recent years. Measurements of the IL-6 levels in gingival crevicular fluid (GFC), as well as in serum, can be important diagnostic and prognostic factors in periodontal diseases (PD) and in assessing their impact on a range of related inflammatory diseases. This narrative review explores the significant role of IL-6 in patients with periodontitis and its association with other widespread inflammatory pathologies.

Endogenous and microbial biomarkers for periodontitis and type 2 diabetes mellitus

It has been well documented that there is a two-way relationship between diabetes mellitus and periodontitis. Diabetes mellitus represents an established risk factor for chronic periodontitis. Conversely, chronic periodontitis adversely modulates serum glucose levels in diabetic patients. Activated immune and inflammatory responses are noted during diabetes and periodontitis, under the modulation of similar biological mediators. These activated responses result in increased activity of certain immune-inflammatory mediators including adipokines and microRNAs in diabetic patients with periodontal disease. Notably, certain microbes in the oral cavity were identified to be involved in the occurrence of diabetes and periodontitis. In other words, these immune-inflammatory mediators and microbes may potentially serve as biomarkers for risk assessment and therapy selection in diabetes and periodontitis. In this review, we briefly provide an updated overview on different potential biomarkers, providing novel diagnostic and therapeutic insights on periodontal complications and diabetes mellitus.

Periodontal disease and visfatin level: A systematic review and meta-analysis

Visfatin is considered an inflammatory biomarker in periodontal disease (PD). In this meta-analysis, we aimed to evaluate the relationship between Visfatin biomarker level with PD. In this study, Medline, Scopus, Web of Science, and Google Scholar were searched. We included studies that examined visfatin levels in samples from healthy people and periodontal disease until March 2023. The quality of the selected articles was evaluated using the Newcastle-Ottawa assessment scale. Depending on heterogeneity of studies, random-effects or fixed-effect models were used to pool results and report the standardized mean difference (SMD). After screening the retrieved papers, the related data were extracted. A total of 159 studies were identified, and 16 studies were included in the meta-analysis. In 9 studies, the SMD of visfatin level of gingival crevicular fluid (GCF) in patients with chronic periodontitis (CP) and healthy individuals was 4.32 (p<0.001). In 6 studies, the SMD of salivary visfatin level in patients with CP and healthy individuals was 2.95 (p = 0.004). In addition, in five studies, the SMD of serum visfatin level in patients with CP and healthy individuals was 7.87 (p<0.001). Therefore, Visfatin levels in serum, saliva, and GCF of patients with CP were increased in comparison to healthy individuals. Comparison of visfatin levels in saliva of gingivitis patients and healthy individuals showed a significant increase of visfatin in gingivitis patients (SMD:0.57, P = 0.018), but no significant difference was observed in the mean GCF visfatin level of gingivitis patients and healthy individuals (SMD:2.60, P = 0.090). In addition, the results suggested that there is no difference between gingivitis cases compared to CP patients (SMD:3.59, P = 0.217). Visfatin levels in GCF, serum, and saliva have the potential to be used as a diagnostic biomarker of periodontitis.

Periodontitis is associated with the increased levels of visfatin: a meta-analysis

OBJECTIVE

Periodontitis is a common inflammatory disease associated with systemic factors. Visfatin is a pleiotropic adipokine that exerts metabolic and immune functions. Studies have shown visfatin played roles in the development of periodontitis. The present study aims to compare the levels of visfatin in body fluids including serum, saliva, and gingival crevicular fluid (GCF) between periodontitis patients and healthy individuals, and to elucidate the alteration of visfatin levels after periodontal treatments.

MATERIALS AND METHODS

The database searched included Pubmed, Embase, Web of Science, and Cochrane Library. According to the Eligibility criteria, the records were screened and the eligible studies were included. The methodological qualities of the included case-controlled studies were assessed according to the Newcastle-Ottawa scale (NOS). The Methodological Index for Nonrandomized Studies (MINORS) was applied for assessing the qualities of the included clinical trials. The statistical analyses were processed using STATA 15.0.

RESULTS

Twenty-three studies were included in the statistical analyses. The meta-analysis showed significantly elevated visfatin levels of GCF, serum, and saliva in the periodontitis population compared with the controls (GCF: SMD = 5.201, 95% CI: 3.886-6.516, Z = 7.75, P < 0.05; Serum: SMD = 7.417, 95% CI: 3.068-11.767, Z = 3.34, P = P < 0.05; Saliva: SMD = 2.683, 95% CI: 1.202-4.163, Z = 3.34, P < 0.05). Visfatin levels of saliva serum and GCF were significantly decreased after periodontal treatment. (Saliva: SMD = -1.338, 95% CI: -2.289-0.487, Z = 39.77, P < 0.05; Serum: SMD = -2.890, 95% CI: -5.300-0.480, Z = 2.35, P < 0.05; GCF: SMD = -6.075, 95% CI: -11.032-1.117, Z = 2.40, P = 0.016; I 2 = 95.9%, P < 0.05).

CONCLUSIONS

Periodontitis elevated the visfatin levels in GCF, serum, and saliva. Additionally, GCF, serum, and saliva visfatin levels could be reduced after periodontal treatment.

[Advances in Research on the Mechanism of Association Between Periodontitis and Diabetes Mellitus]

Periodontitis and diabetes mellitus are both chronic diseases with a rather high prevalence and they are closely associated with each other. On one hand, diabetes mellitus poses as a risk factor for periodontitis. On the other hand, periodontitis has a negative impact on glucose control in diabetic patients. The two-way relationship has aroused a lot of research interest in recent years. Herein, approaching the issue by looking at the effect of periodontitis on diabetes, we summarized the mechanism of the traditional periodontal pocket-blood circulation pathway and reviewed the role of the oral-gut axis in the mechanism, which has been proposed in recent years. In addition, regarding the impact of diabetes on periodontitis, we summarized new findings concerning changes in oral microbiota, abnormal levels of cytokines and adipokines, oxidative stress, unbalanced osteogenic and osteoclastic activities, and the accumulation of advanced glycation end-products. We hope this paper will be helpful for further studies on the mechanism of association between periodontitis and diabetes.

Expression of inflammatory mediators in periodontitis and T2D patients: a systematic review and meta-analysis

The high concentration of glucose in the blood in Type 2 diabetes (T2D) may be related to either insulin resistance or insulin deficiency. Moreover, the literature points to periodontitis as the main oral disease caused by glycemia imbalance. The quantification of inflammatory markers in blood or saliva samples of T2D patients may represent a valuable tool in revealing how well an individual's immune system can respond to injuries and periodontal treatment. In addition, an evaluation of the cytokine expression is extremely relevant to help understand the connection between periodontitis and T2D. This systematic review and meta-analysis aimed to evaluate the expression of inflammatory markers in T2D patients with periodontitis, compared with non-diabetic patients with periodontitis. A total of 3,894 studies were retrieved after a systematic literature search, 15 of which were included in the systematic review, and 4 of these 15, in the meta-analysis. The results did not indicate any statistical difference between the groups regarding TNF-α and IL-6 markers. T2D patients with periodontitis had increased levels of IL-10, compared with non-diabetic individuals with periodontitis (p = 0.003). On the other hand, the IL-4 concentration in non-diabetic individuals with periodontitis was high, compared with the T2D group (p< 0.001). Several studies did not include quantitative results and were excluded from the meta-analysis. The high IL-10 expression and low IL-4 expression in the T2D group suggest an association between the level of these markers and the impairment of the immune response in T2D patients with periodontitis.

Increased expression of advanced glycation endproducts in the gingival crevicular fluid compromises periodontal status in cigarette-smokers and waterpipe users

Background

The aim was to assess the association between levels of advanced glycation endproducts (AGEs) in the gingival crevicular fluid (GCF) and periodontal parameters among cigarette-smokers and waterpipe-users.

Methods

Self-reported cigarette-smokers; waterpipe-users and never-smokers were included. Demographic data was recorded using a questionnaire. Periodontal parameters (plaque index [PI], gingival index [GI], clinical attachment loss [AL], probing depth [PD], and marginal bone loss [MBL]) were assessed in all groups. The GCF samples were collected using standard techniques and assessed for AGEs levels using enzyme-linked immunosorbent assay. Sample-size estimation was done and group-comparisons were done. Correlation between levels of GCF AGEs levels and periodontal parameters was assessed using a logistic regression model. Level of significance was set at P < 0.01.

Results

Eighty-two individuals (28 cigarette-smokers, 28 waterpipe-users and 26 never-smokers) were included. There was no difference in mean ages of all patients. Cigarette-smokers had a smoking history of 5.1 ± 0.2 pack years and waterpipe-users were using waterpipe for 4.4 ± 0.6 years. There was no statistically significant difference in PI, GI, clinical AL, PD and MBL in all groups. Levels of AGEs were significantly higher among cigarette-smokers (P < 0.001) and waterpipe-users (P < 0.001) than never-smokers. There was no significant correlation between levels of GCF AGEs levels and periodontal parameters in all groups.

Conclusion

Clinical periodontal status of individuals with a short history of cigarette-smoking and waterpipe-usage may appear similar to never-smokers. On a molecular level, cigarette-smoking and waterpipe-users express raised levels of AGEs than never-smokers that sirens about the ongoing yet latent periodontal inflammatory process.

Targeting Small GTPases and Their Prenylation in Diabetes Mellitus

A fundamental role of pancreatic β-cells to maintain proper blood glucose level is controlled by the Ras superfamily of small GTPases that undergo post-translational modifications, including prenylation. This covalent attachment with either a farnesyl or a geranylgeranyl group controls their localization, activity, and protein–protein interactions. Small GTPases are critical in maintaining glucose homeostasis acting in the pancreas and metabolically active tissues such as skeletal muscles, liver, or adipocytes. Hyperglycemia-induced upregulation of small GTPases suggests that inhibition of these pathways deserves to be considered as a potential therapeutic approach in treating T2D. This Perspective presents how inhibition of various points in the mevalonate pathway might affect protein prenylation and functioning of diabetes-affected tissues and contribute to chronic inflammation involved in diabetes mellitus (T2D) development. We also demonstrate the currently available molecular tools to decipher the mechanisms linking the mevalonate pathway’s enzymes and GTPases with diabetes.

Study on caspase-1 and partial cognitive impairment in the comorbidity of type 2 diabetes and MDD

BACKGROUND

Major depressive disorder (MDD) is a major mood disorder characterized by chronic low mood with cognitive impairment. Diabetes mellitus is a group of chronic metabolic diseases, Type 2 diabetes (T2DM) will obviously increase the risk of dementia. People with the the comorbidity of T2DM and MDD have a higher risk of dementia. In this study, we aim to investigate partial cognitive impairment in the comorbidity of T2DM and MDD, and to determine the relationship between changes in caspase-1 expression and cognitive impairment. To further explore the role of caspase-1 in the partial cognitive impairment in the comorbidity of T2DM and MDD.

METHODS

A total of 162 people were enrolled, there were 49 patients in the comorbidity of T2DM and MDD group, 54 patients in the MDD group, and 45 patients in the T2DM group. Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) was used to assess the cognitive function of these three groups. Serum level of caspase-1 was determined by ELISA, and the level of caspase-1, as well as partial cognitive function, was compared in the three groups.

RESULTS

The cognitive impairment of patients of the comorbidity of T2DM and MDD group was worse than the MDD group and the T2DM group, and the immediate memory, attention, and delayed memory in the comorbidity of T2DM and MDD group were lower than those in the other two groups, and the caspase-1 of the comorbidity of T2DM and MDD is higher than the caspase-1 of the MDD group, all the difference was statistically significant (P < 0.05). Caspase-1 protein was negatively correlated with immediate memory, attention, and delayed memory (r=-0.332, r=-0.182, r=-0.313, P<0.05).

CONCLUSION

The cognitive impairment of patients of the comorbidity of T2DM and MDD group was worse than the MDD group and the T2DM group, and the immediate memory, attention, and delayed memory in the comorbidity of T2DM and MDD group were lower than those in the other two groups. The differences of the caspase-1 in the comorbidity of T2DM and MDD group, the MDD group and the T2DM group were significant, the level of the caspase-1 is higher than the other two groups, the cognitive impairment of three groups is associated with caspase-1, suggesting caspase-1 protein may be involved in the cognitive impairment aggravation mechanism of the comorbidity of T2DM and MDD group.

Visfatin regulates Pg LPS-induced proinflammatory/prodegradative effects in healthy and inflammatory periodontal cells partially via NF-κB pathway

Periodontitis is a widespread chronic infectious-inflammatory disease associated with multiple systemic diseases. Visfatin is an adipokine-enzyme that can be locally produced by human periodontal ligament cells (hPDLCs) and human gingival fibroblasts (hGFs). It can upregulate proinflammatory cytokines and matrix metalloproteinases (MMPs) in various types of cells. However, the effects of visfatin on healthy and inflammatory human periodontal cells as well as the underlying molecular mechanisms remain unclear. This study firstly demonstrated visfatin expression was highly elevated in inflamed human gingiva and Pg LPS-treated hPDLCs. Moreover, recombinant visfatin significantly upregulated the expression of proinflammatory cytokines (TNF-α, IL-1β and IL-6) and prodegradative factors (EMPPRIN, MMP1, MMP3 and MMP13) in hPDLCs. Next, we found the levels of proinflammatory and prodegradative cytokines were significantly increased in visfatin-overexpressing hPDLCs, and decreased in visfatin-silencing inflammatory hGFs (iGFs) when treated with Pg LPS. In the absence of Pg LPS, visfatin silencing failed to affect the expression of these factors in iGFs, and overexpression of visfatin upregulated MMPs but no other factors in hPDLCs. Furthermore, marked NF-κB pathway activation with increased phosphorylation of p65 was observed in visfatin-overexpressing hPDLCs. BAY11-7082, a specific inhibitor of NF-κB, partially reversed the upregulation proinflammatory and prodegradative factors induced by visfatin overexpression. Taken together, this study showed that visfatin critically regulates Pg LPS-induced proinflammatory/prodegradative effects in healthy and inflammatory periodontal cells partially via NF-κB pathway. The findings suggest that visfatin is closely involved in the development of periodontitis, and may serve as a promising novel biomarker and therapeutic target for periodontitis management.

Effects of statins on cytokines levels in gingival crevicular fluid and saliva and on clinical periodontal parameters of middle-aged and elderly patients with type 2 diabetes mellitus

Objective

To analyze the effect of statins on cytokines levels in gingival crevicular fluid (GCF) and saliva and on clinical periodontal parameters of middle-aged and elderly patients with type 2 diabetes mellitus (T2DM).

Methods

Systemically healthy controls (C group, n = 62), T2DM patients not taking statins (D group, n = 57) and T2DM patients taking statins (S group, n = 24) were recruited. In each group, subjects (40–85 years) were subclassified into the h (periodontal health)group, the g (gingivitis)group or the p (periodontitis) group according to different periodontal conditions. 17 cytokines in gingival crevicular fluid (GCF) and saliva samples of each subject were measured utilizing the Luminex technology kit. Further, HbA1c (glycated hemoglobin), FPG (fasting plasma glucose), PD (probing depth), CAL (clinical attachment level), BOP (bleeding on probing), GI (gingival index) and PI (periodontal index) were recorded. Data distribution was tested through the Shapiro-Wilk test, upon which the Kruskal-Wallis test was applied followed by Mann-Whitney U test and Bonferroni’s correction.

Results

Levels of IFN-γ, IL-5, IL-10 and IL-13 in the saliva of the Dh group were significantly lower than those in the Ch group, while factor IL-4 was higher (p<0.05). Levels of MIP-3α, IL-7 and IL-2 in GCF of the Dh group were considerably higher than those in the Ch group (p<0.05), while that of IL-23 was considerably lower. Compared with the Cg group, levels of IFN-γ, IL-4, IL-5, IL-6, IL-10 and IL-13 were significantly lower in the saliva of the Dg group (p<0.05). Lower levels of IFN-γ, IL-5 and IL-10 were detected in the Sg group than those in the Cg group (p<0.05). At the same time, levels of IL-1β, IL-6, IL-7, IL-13, IL-17, IL-21 and MIP-3α in the gingival crevicular fluid of the Sg group were lower in comparison with the Dg group. In addition, lower levels of IL-4 and higher levels of IL-7 in GCF were identified in the Dg group than those in the Cg group, while in the Sg group, lower levels of IL-4, MIP-1αand MIP-3αwere observed than those in the Cg group (p<0.05). Lower levels of IFN-γ, IL-6, IL-10, IL-13 and I-TAC were found in the Sp group compared with those in the Cp group. The IFN-γ, IL-6 and IL-10 levels were lower in the Dp group than those in the Cp group (p<0.05). Meanwhile, in the Sp group, lower levels of pro-inflammatory factors IFN-γ, IL-1β, IL-2, IL-6, IL-7, IL-21 and TNF-α, in addition to higher levels of anti-inflammatory factors IL-4 and IL-5 in gingival crevicular fluid, were identified than those in the Dp group. Higher levels of IFN-γ,IL-1β,IL-2,IL-7,IL-21 and TNF-α and a lower level of IL-5 in the Dp group were identified than those in the Cp group (p<0.05). Moreover, statins were able to substantially reduce PD in T2DM patients with periodontitis, indicating an obvious influence on the levels of cytokines secreted by Th1 cells, Th2 cells and Th17 cells, as revealed by PCA (principal component analysis).

Conclusion

Statins are associated with reduced PD and cytokines levels in the GCF and saliva of T2DM patients with periodontitis.

Regulation of Osteoclast Differentiation and Activity by Lipid Metabolism

Bone is a dynamic tissue and is constantly being remodeled by bone cells. Metabolic reprogramming plays a critical role in the activation of these bone cells and skeletal metabolism, which fulfills the energy demand for bone remodeling. Among various metabolic pathways, the importance of lipid metabolism in bone cells has long been appreciated. More recent studies also establish the link between bone loss and lipid-altering conditions—such as atherosclerotic vascular disease, hyperlipidemia, and obesity—and uncover the detrimental effect of fat accumulation on skeletal homeostasis and increased risk of fracture. Targeting lipid metabolism with statin, a lipid-lowering drug, has been shown to improve bone density and quality in metabolic bone diseases. However, the molecular mechanisms of lipid-mediated regulation in osteoclasts are not completely understood. Thus, a better understanding of lipid metabolism in osteoclasts can be used to harness bone cell activity to treat pathological bone disorders. This review summarizes the recent developments of the contribution of lipid metabolism to the function and phenotype of osteoclasts.

Association between TNF-α G-308A (rs1800629) polymorphism and susceptibility to chronic periodontitis and type 2 diabetes mellitus: A meta-analysis

BACKGROUND AND OBJECTIVE

Although the association between tumor necrosis factor-α (TNF-α) G-308A (rs1800629) polymorphism and chronic periodontitis (CP), chronic periodontitis with type 2 diabetes mellitus (DP) is assumed, results of this association have been contradictory. The aim of this study was to assess the relationship between rs1800629 polymorphism and CP/DP susceptibility.

METHODS

We searched for studies on PubMed, Web of Science, MEDLINE, Chinese National Infrastructure, and WanFang databases. Study selection was performed using specific inclusion and exclusion criteria and fulfilled the PECO (participant, exposure, comparison, and outcome) format. The relationship between rs1800629 polymorphism and CP/DP susceptibility was evaluated by the effect summary odds ratio (OR) and 95% confidence intervals (CIs). Allele, dominant, and recessive genetic models were computed to assess the strength of the association.

RESULTS

A total of 25 case-control studies were included in the analysis. In the Asian population, TNF-α rs1800629 polymorphism was found to be significantly associated with CP in the overall analyses and for all genetic contrasts, while no significant risks were found among Caucasian populations for all genetic contrasts. The TNF-α rs1800629 polymorphism was also associated with increased DP risk in Asians under the fixed-effects model, but not in the recessive comparison.

CONCLUSION

The meta-analysis suggested that TNF-α rs1800629 polymorphism might affect the risk of CP and DP, particularly in individuals of Asian descent.

Inflammatory biomarkers and growth factors in saliva and gingival crevicular fluid of e-cigarette users, cigarette smokers, and dual smokers: A pilot study

BACKGROUND

Cigarette smoking remains one of the leading public health threats worldwide. Electronic cigarettes (e-cigs) provide an alternative to conventional cigarette smoking; however, the evidence base of risks and benefits of e-cig use is new and growing. In this cross-sectional pilot study, the effect of e-cig use on biological profiles in saliva and gingival crevicular fluid (GCF) was assessed and compared with the profiles of cigarette smokers (CS), dual users, and non-users. The systemic inflammatory mediators between e-cig users (EC) and these other groups were also assessed.

METHODS

This pilot cross-sectional study recruited volunteer participants consisting of four groups, non-smokers (NS), CS, EC, and dual EC and cigarette smokers (DS). Saliva and GCF samples were collected and analyzed for biomarkers of inflammation, oxidative stress, anti-inflammatory lipid mediators, tissue injury and repair, and growth factors with immunoassay (enzyme-linked immunosorbent assay and Luminex).

RESULTS

Smoking status was confirmed via salivary cotinine. Prostaglandin E2 level was significantly increased in CS compared with EC and DS, but not significantly different in EC and DS groups compared with non-smokers (NS). Statistically significant differences were observed between groups of EC and NS (myeloperoxidase [MPO], matrix metalloproteinase-9) as well as between DS and EC for biomarkers of inflammatory mediators (receptor for advanced glycation end products [RAGE], MPO, uteroglobin/CC-10); between groups of DS and NS for extracellular newly identified RAGE binding protein and between CS and NS for MPO. No statistically significant differences in biomarkers of immunity (S100A8, S100A9, galectin-3), tissue injury and repair (Serpine1/PAI-1) and growth factors (brain-derived neurotrophic factor, fibroblast growth factors, platelet-derived growth factor-AA, vascular endothelial growth factor, and others) were found between any of groups.

CONCLUSION

Statistically significant differences in measurable health outcomes were found between different smoking status groups, suggesting that smoking/vaping produces differential effects on oral health.