Involvement of insulin resistance in normoglycaemic obese patients with periodontitis: A cross-sectional study

Insulin resistance and periodontitis: Mediation by blood pressure

AIM

This study investigated the association between the triglyceride-glucose (TyG) index, a surrogate marker of insulin resistance, and moderate/severe periodontitis and the role of blood pressure as a mediator in this association. A second aim was to assess the role of cardiometabolic conditions such as obesity, hypertension, and dyslipidemia as potential effect modifiers.

METHODS

Data from 5733 US adults aged 30-64 years and with complete periodontal examination were analyzed (NHANES 2011-2014). Participants were classified as having moderate/severe periodontitis or mild/no periodontitis according to the CDC/AAP criteria as the outcome. The exposure was the TyG index, while both systolic (SBP), and diastolic (DBP) blood pressure were tested as mediators using parametric g-formula. Analyses were adjusted for relevant confounders, namely, age, sex, ethnicity, poverty-income ratio, and smoking, using inverse probability treatment weighting. Obesity status (based on a body mass index ≥30 kg/m2), self-report of hypertension and dyslipidemia (calculated based on the thresholds provided by National Cholesterol Education Program-Adult Treatment Panel-III) were tested as effect modifiers.

RESULTS

The findings showed the TyG index to be associated with increased odds of moderate/severe periodontitis [odds ratio (OR), 95% confidence interval (CI) = 1.17 (1.11-1.23)], with 50% of the total effect mediated by SBP. Stratified analysis showed a stronger association in individuals with obesity, hypertension, and dyslipidemia compared to those without these conditions. However, in those taking anti-hypertensive medications, the association was partially mitigated. Sensitivity analysis using imputed data showed consistent results.

CONCLUSION

The TyG index was associated with increased odds of moderate/severe periodontitis, especially in individuals with obesity, hypertension, and dyslipidemia. SBP levels partially mediated this association.

Association between Periodontal Disease and Obesity: Umbrella Review

Objective: Determine the association between periodontal disease (PD) and obesity through an umbrella review. Materials and Methods: A search for information until March 2024 was carried out in the following electronic databases: PubMed, Cochrane library, Scopus, SciELO, Web of Science, Google Scholar, Proquest Dissertations and Theses, and OpenGrey. We included studies that were systematic reviews (SR) with or without meta-analysis, without time or language restrictions, that evaluated primary studies that associated PD with obesity. Literary or narrative reviews, rapid reviews, intervention studies, observational studies, preclinical and basic research, summaries, comments, case reports, protocols, personal opinions, letters, and posters were excluded. The AMSTAR-2 tool was used to determine the quality and overall confidence of the included studies. Results: The preliminary search yielded a total of 419 articles, discarding those that did not meet the selection criteria, leaving only 14 articles. All studies reported that PD was associated with obesity, with an OR and RR ranging from 1.1 to 1.46 and 1.64 to 2.21, respectively. Conclusions: Based on the results and conclusions of the SR with a high overall confidence level, PD is associated with obesity.

Could Periodontitis Increase the Risk of Suffering from Pancreatic Cancer?-A Systematic Review

(1) Background: The relationship between periodontitis and systemic pathologies continues to grow. Recently, the presence of periodontal pathogens has been linked to an increased risk of pancreatic cancer (PC) and its mortality. Thus, a systematic review is needed to identify whether an association between the two diseases can be established. The objective of this review is to elucidate the mechanisms responsible for this association. (2) Methods: A systematic review was carried out using three databases (PubMed, Embase and Scopus) with the following keywords "Periodontitis AND pancreatic cancer". A total of 653 articles were retrieved; before selection and screening, the inclusion and exclusion criteria were defined, resulting in a total of 13 articles being included in the review. (3) Results: The increase in low-grade systemic inflammation, pH changes, and the cytotoxicity of certain periodontopathogenic bacteria were found in the scientific literature reviewed as mechanisms linking periodontitis with the risk of PC. (4) Conclusions: Through this systematic review, we have seen how periodontitis can be related to PC and how it worsens its prognosis. Knowing the behavior of periodontopathogenic bacteria and the influence they have on our immune and inflammatory system may help to achieve an interdisciplinary approach to both pathologies.

Transcriptomic analysis reveals shared gene signatures and molecular mechanisms between obesity and periodontitis

Background

Both obesity (OB) and periodontitis (PD) are chronic non-communicable diseases, and numerous epidemiological studies have demonstrated the association between these two diseases. However, the molecular mechanisms that could explain the association between OB and PD are largely unclear. This study aims to investigate the common gene signatures and biological pathways in OB and PD through bioinformatics analysis of publicly available transcriptome datasets.

Methods

The RNA expression profile datasets of OB (GSE104815) and PD (GSE106090) were used as training data, and GSE152991 and GSE16134 as validation data. After screening for differentially expressed genes (DEGs) shared by OB and PD, gene enrichment analysis, protein-protein interaction (PPI) network construction, GeneMANIA analysis, immune infiltration analysis and gene set enrichment analysis (GSEA) were performed. In addition, receiver operating characteristic (ROC) curves were used to assess the predictive accuracy of the hub gene. Finally, we constructed the hub gene-associated TF-miRNA-mRNA regulatory network.

Results

We identified a total of 147 DEGs shared by OB and PD (38 down-regulated and 109 up-regulated). Functional analysis showed that these genes were mainly enriched in immune-related pathways such as B cell receptor signalling, leukocyte migration and cellular defence responses. 14 hub genes (FGR, MNDA, NCF2, FYB1, EVI2B, LY86, IGSF6, CTSS, CXCR4, LCK, FCN1, CXCL2, P2RY13, MMP7) showed high sensitivity and specificity in the ROC curve analysis. The results of immune infiltration analysis showed that immune cells such as macrophages, activated CD4 T cells and immune B cells were present at high infiltration levels in both OB and PD samples.The results of GeneMANIA analysis and GSEA analysis suggested that five key genes (FGR, LCK, FYB1, LY86 and P2RY13) may be strongly associated with macrophages. Finally, we constructed a TF-miRNA-mRNA regulatory network consisting of 233 transcription factors (TFs), 8 miRNAs and 14 mRNAs based on the validated information obtained from the database.

Conclusions

Five key genes (FGR, LCK, FYB1, LY86, P2RY13) may be important biomarkers of OB and PD. These genes may play an important role in the pathogenesis of OB and PD by affecting macrophage activity and participating in immune regulation and inflammatory responses.

Association of Adiposity with Periodontitis and Metabolic Syndrome: From the Third National Health and Nutrition Examination Survey of United States

This study explored the epidemiological role of central adiposity and body mass index (BMI) in terms of clinical attachment loss (CAL)/pocket depth (PD) and metabolic syndrome components. This study included data from the National Health and Nutrition Examination Survey III of America on 12,254 adults aged 20 years of age or older with a blood sample, anthropometric measurements, and a periodontal examination. Clinical periodontitis measurements, including CAL and PD, were classified into quintiles or quartiles and compared. CAL was positively associated with central adiposity, hypertension, and hyperglycemia; the relationship between CAL and diabetes was stronger when central adiposity was absent (odds ratio [OR] and 95% confidence interval: 6.33, 2.14-18.72 vs. 3.14, 1.78-5.56). The relationship between CAL and impaired fasting glucose (IFG) differed slightly with BMI. The IFG ORs for normal, overweight, and obese patients were 1.63 (1.08-2.45), 1.76 (1.05-2.97), and 1.43 (0.88-2.30), respectively. CAL was positively correlated with all metabolic syndrome components except hypertriglyceridemia. Associations between CAL, diabetes, and IFG significantly varied with BMI. Periodontitis in individuals without central obesity or with normal bodyweight may independently indicate diabetes and IFG. Therefore, preventive measures against periodontitis without obesity are necessary to improve general and oral health.

Obesity and periodontitis: A systematic review and updated meta-analysis

Background

A previous 2014 meta-analysis reported a positive association between obesity and periodontitis. It was considered necessary to update the recently published papers and to analyse subgroups on important clinical variables that could affect the association between obesity and periodontitis. Therefore, we updated the latest studies and attempted to derive more refined results.

Methods

All observational studies were eligible for inclusion. The Newcastle-Ottawa scale was used to qualitatively evaluate the risk of bias. Subgroup analyses were conducted for patients aged 18-34, 35-54, and 55+ years and the countries (European countries, USA, Brazil, Japan, Korea, and other Asian countries).

Results

Thirty-seven full-text articles were included. Obesity conferred increased odds of periodontal disease with an odds ratio (1.35, 95% CI: 1.05-1.75). In the subgroup analysis by age, the odds ratio was the highest in the 18-34 years group (2.21, 95% CI: 1.26-3.89). In the subgroup analysis by country, European countries had the highest odds ratio (2.46, 95% CI: 1.11-5.46).

Conclusion

Despite the differences in degree, a positive association between obesity and periodontitis was found regardless of country or age. Therefore, medical professionals should try to prevent periodontitis by controlling patient weights, and more studies should be conducted to determine the association between obesity and oral health.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42022301343.

The bidirectional biological interplay between microbiome and viruses in periodontitis and type-2 diabetes mellitus

Periodontitis was an inflammatory disease associated with a dysbiosis of the oral flora characterized by a chronic sustained inflammation inducing the resorption of alveolar bone and leading to tooth loss. Type 2 diabetes mellitus (T2D) was a metabolic disease caused by impaired insulin action. The oral microbiome played a crucial role in modulating both the innate and adaptive immune system during the trigger and exacerbation of periodontitis and T2D. The bidirectional relationship of T2D and periodontitis had been the focus of intensive research, but those were not well explored. In this commentary, an in-depth analysis of the changes of microbiome and bacterial metabolites in periodontitis with or without diabetes was described. The promotion of periodontitis to T2D might involve inflammatory factors/receptors, oxidative stress, microRNA and so on. The effect of diabetes on periodontitis might involve adipose factor pathway, AGE/RAGE and RANK/RANKL pathway etc. Generally, periodontitis and diabetes are closely related to the microecological-epithelial interaction, soft tissue degradation, bone coupling disorder, immune regulation and gene transcription. The viruses, including HBV, HCV, HSV-1, Coronavirus, HCMV, EBV, HIV, phageome and so on, played an important role in the development of T2D and periodontitis. An in-depth understanding of the relationship between microbiome and host was of great significance to clarify the bidirectional mechanisms, suggesting that the periodontitis or T2D remission will have a positive impact on the other.

Untargeted and targeted gingival metabolome in rodents reveal metabolic links between high-fat diet-induced obesity and periodontitis

AIM

To characterize gingival metabolome in high-fat diet (HFD)-induced obesity in mice with/without periodontitis.

METHODS

HFD-induced obesity mouse model was established by 16-week feeding, and a lean control group was fed with low-fat diet (n = 21/group). Both models were induced for periodontitis on the left sides by molar ligation for 10 days, whereas the right sides were used as controls. Gingival metabolome and arginine metabolism were analysed by non-targeted/targeted liquid chromatography-mass spectrometry.

RESULTS

Of 2247 reference features, presence of periodontitis altered 165 in lean versus 885 in HFD mice; and HFD altered 525 in absence versus 1435 in presence of periodontitis. Compared with healthy condition, periodontitis and HFD had distinct effects on gingival metabolome. Metabolomic impacts of periodontitis were generally greater in HFD mice versus lean controls. K-medoids clustering showed that HFD amplified the impacts of periodontitis on gingival metabolome in both intensity and extensity. Ten metabolic pathways were enriched, including 2 specific to periodontitis, 5 specific to HFD and 3 shared ones. Targeted validation on arginine metabolism confirmed the additive effects between HFD and periodontitis.

CONCLUSION

The obese population consuming excessive HFD display amplified metabolic response to periodontitis, presenting a metabolic susceptibility to exacerbated periodontal destruction.

Association between clinical measures of gingival inflammation and obesity in adults: systematic review and meta-analyses

OBJECTIVE

This study aimed to systematically review the literature about the association between clinical measures of gingival inflammation and obesity in adults.

MATERIAL AND METHODS

Searches for studies were performed in five databases (Medline-PubMed, Scopus, Web of Science, Cochrane Library, and Embase) to compile studies of any design that evaluated the association between clinical measures of gingival inflammation and obesity in adults. Selection of studies, data extraction and risk of bias analysis were performed independently by two reviewers, and a third researcher was involved to resolve disagreements. Meta-analyses were performed for measures of gingival inflammation as compared to body mass index (BMI). Independent analyses were performed for studies involving periodontitis, gingivitis, and population-based/studies that did not provide a periodontal diagnosis. Standard mean deviation (SMD) and its 95% confidence interval (95%CI) were estimated.

RESULTS

Ninety studies were included (cross-sectional/clinical trials [n=82], case-control [n=3], cohorts [n=5]). Most of the studies demonstrated no significant difference in the measures of gingival inflammation regardless of the comparison performed. However, meta-analysis showed that among individuals with periodontitis, significantly higher levels of gingival inflammation are observed in those with obesity (n of individuals=240) when compared to those who were not obese (n of individuals=574) (SMD:0.26; 95%CI:0.07-0.44). When considering population-based/those studies that did not provide periodontal diagnosis, significantly higher measures of gingival inflammation were observed in the groups with higher BMI.

CONCLUSIONS

Within the limitations of the present study, it was concluded that higher measures of gingival inflammation may be expected for those with higher BMI.

CLINICAL RELEVANCE

Clinicians must be aware that higher measures of gingival inflammation may be expected for individuals with higher BMI. However, there is a necessity for further longitudinal studies regarding the association between obesity and gingival inflammation.

Influence of body mass index and obesity upon the association between periodontitis and sleep apnea-hypopnea syndrome

OBJECTIVES

We aimed to explore the association between periodontitis and sleep apnea-hypopnea syndrome (SAHS) and the possible influence of body mass index (BMI) and obesity upon this association.

MATERIALS AND METHODS

A case-control study was made involving 114 subjects (60 patients with SAHS and 54 controls). A thorough periodontal evaluation was carried out, and demographic and clinical data were collected.

RESULTS

Periodontitis was more prevalent in SAHS (80%) than in the controls (48.1%). The recorded statistically significant association (OR = 4.31; p = 0.001) was seen to weaken in the multivariate model (OR = 2.03; p = 0.204), with BMI adopting a more influential role. The apnea-hypopnea index (AHI) was correlated to probing depth (PD) (r = 0.40; p = 0.002) and clinical attachment level (CAL) (r = 0.41; p = 0.001). The periodontal parameters were seen to be higher in obese SAHS patients (BMI ≥ 30 kg/m²) than in non-obese SAHS patients (BMI < 30 kg/m²).

CONCLUSIONS

The greater prevalence and severity of periodontitis in patients with SAHS were fundamentally influenced by BMI. On the other hand, periodontitis was more severe in patients with severe SAHS.

CLINICAL RELEVANCE

Patients with SAHS have a greater prevalence of periodontitis, fundamentally related to increased obesity. Therefore, obese subjects with SAHS should be screened for periodontal disease.

Association between Periodontal Diseases and Polycystic Ovary Syndrome: A Systematic Review

Background: A convergent association between polycystic ovary syndrome (PCOS) and periodontal disease, in particular chronic periodontitis (CP), has recently been proposed. The underlying molecular mechanisms of this association are not fully understood, though it is thought that chronic inflammation is responsible. Therefore, the aim of this study was to evaluate the association between periodontal disease—gingivitis and CP—and PCOS. Materials and Methods: The PICO (Participants, Intervention, Control, and Outcomes) question was as follows: “Is there an association between PCOS and CP?” A systematic review of three databases—PubMed, Embase and Scopus—was performed following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Original studies in human cohorts carried out in the last 10 years and including a control group were eligible for inclusion. Letters to the editor, case reports, and reviews were not considered. Results: Ten articles met all the selection criteria and provided a positive answer to the PICO question. Our review of these articles revealed an association between CP and PCOS, since periodontal parameters were altered more frequently in patients with these conditions than in healthy young women. This altered periodontal response in PCOS was associated with a proinflammatory status that seemed to increase susceptibility to periodontal disease. Conclusion: Patients with PCOS appear to be more susceptible to developing periodontal diseases than women without the pathology.

Periodontal complications with obesity

The purpose of this paper was to identify and summarize current evidence describing periodontal complications associated with obesity. Electronic searches supplemented with manual searches were carried out to identify relevant systematic reviews. Identification, screening, eligibility, and inclusion of studies were performed independently by two reviewers. A MeaSurement Tool to Assess systematic Reviews (AMSTAR) was used to assess the quality and risk of bias of the included reviews. From 430 titles and abstracts screened, 14 systematic reviews were considered as eligible for inclusion in this meta-review. Eight reviews reported on cross-sectional studies investigating the association of obesity and periodontal diseases, 4 included longitudinal studies, 5 addressed response to periodontal therapy, 5 reported on studies investigating biomarkers, and only 2 were related to pediatric population samples. Systematic review summaries in the various study design domains (cross-sectional, longitudinal and experimental) report that obese individuals are more likely to have periodontal diseases, with more severe periodontal conditions, than nonobese individuals, with cross-sectional evidence congruent with longitudinal studies showing that obesity or weight gain increases the risk of periodontitis onset and progression. Published research on the effect of obesity on responses to periodontal therapy, or systemic or local biomarkers of inflammation, is variable and therefore inconclusive based on the evidence currently available, which suggests that overweight/obesity contributes to periodontal complications independently of other risk factors, such as age, gender, smoking, or ethnicity. This evidence supports the need for risk assessments for individual patients to facilitate personalized approaches in order to prevent and treat periodontal diseases.

Comparison of clinical and radiographic peri-implant parameters among obese and non-obese patients: A 5-year study

BACKGROUND

It is postulated that peri-implant parameters are worse in obese individuals as compared to nonobese.

OBJECTIVE

The aim of the present 5-year longitudinal study was to analyze and compare the changes in clinical and radiographic peri-implant parameters among obese and non-obese patients.

MATERIALS AND METHODS

Twenty patients with body mass index ≥ 27.5 kg/m² and 18 non-obese controls were included. All patients were indicated for single tooth maxillary or mandibular molar replacement with the adjacent teeth intact. Peri-implant clinical (plaque index [PI], bleeding on probing [BOP], probing depth [PD]) and radiographic (marginal bone loss [MBL]) parameters were measured at 12, 24, and 60 months of follow-up.

RESULTS

All peri-implant parameters showed statistically significant difference between obese and non-obese individuals. Obese group recorded significant higher BOP, PD, and MBL at different observation times. Probing depth and MBL increased significantly with advance of time in both groups. After 60 months of follow-up period, greater PI and BOP was observed in obese patients (P < 0.01). At 60 months follow-up period, obese patients showed significant increased PD (3.69 mm) as compared to non-obese individuals (2.46 mm). Marginal bone loss in non-obese individuals varied from 0.30 mm after 12 months, reaching 0.55 mm after 60 months of follow-up period, while in obese patients MBL values went from 0.36 mm after 12 months to 0.91 mm at 60 months follow-up (P < 0.01).

CONCLUSIONS

Patients with obesity are at risk of increased localized peri-implant soft and hard tissue inflammation. It is recommended that clinicians should educate obese patients about risk of increased peri-implant tissue inflammation and susceptibility to bone loss and stipulate stringent oral hygiene care for ideal peri-implant health.

Improved General and Oral Health in Diabetic Patients by an Okinawan-Based Nordic Diet: A Pilot Study

Periodontal disease, periodontitis as well as the preceding gingivitis, has been associated with both obesity and diabetes. Studies have shown that diet changes can lead to a lower incidence of such inflammation. The aim of the present case series over four weeks was to study the effects on medical and dental conditions in patients with type 2 diabetes of the consumption of the Okinawan-based Nordic Diet (OBND^®). Medical and dental examinations were performed to estimate the general health and gingivitis/periodontitis. Serum cytokine levels were assessed using Luminex technology. Eight of ten study participants completed the study. All participants lost weight (p = 0.012). Six out of seven that were treated with insulin could reduce their insulin intake after two weeks with OBND^®. The reduction was about 16 units which corresponds to a 34% relative reduction compared to the starting point (range 15–63%). Fasting blood glucose values fell (p = 0.035). Hemoglobin A1c (HbA1c) (p = 0.01), triglycerides (p = 0.05), and low-density lipoprotein (LDL) (p = 0.05) were also reduced. Bleeding on probing changed from ~28% before any dietary changes to ~13% after two weeks with OBND^® (p = 0.01). The reduction in gingival bleeding was as substantial as might be expected from one session of professional tooth cleaning. Markers of inflammation were also reduced. The OBND^® thus showed significant promise in alleviating the impact of diabetes on dental as well as general health.