Correlation between diabetes mellitus and periodontitis in Taiwan: A nationwide cohort study

Risk of periodontitis in adolescents with bipolar disorder: a cohort study of 21,255 subjects

Although a growing number of studies have investigated the relationship between psychosocial factors and periodontitis, studies investigating the association between bipolar disorder (BD) and periodontitis are lacking. Using the Taiwan National Health Insurance Research Database, 4251 adolescents with BD and 17,004 age- and sex-matched controls were included. They were followed up from enrollment to the end of 2011 or death. Periodontitis was diagnosed during the follow-up. Cox regression analysis indicated that adolescents with BD had a higher risk of periodontitis (hazard ratio [HR]: 2.96, 95% confidence interval [CI] 2.77-3.17) than did controls. Subanalyses stratified by sex revealed a higher risk of periodontitis in male (HR: 2.83, 95% CI 2.56-3.14) and female (HR: 3.01, 95% CI 2.74-3.30) adolescents with BD than their respective controls. The long-term use of mood stabilizers was associated with a higher risk of periodontitis (HR: 1.19, 95% CI 1.06-1.35) in the BD cohort. Our study highlighted an increased risk of periodontitis in adolescents with BD compared with controls during the follow-up. We recommend that more attention should be paid to the prevention of periodontitis in adolescents with BD, especially those who are female or receiving mood stabilizers.

Type 2 Diabetes Mellitus and Periodontitis: Bidirectional Association in Population-based 15-year Retrospective Cohorts

OBJECTIVE

A two-way relationship between periodontitis and diabetes has been proposed. However, bidirectional epidemiological observation is limited and inconsistent.

OBJECTIVE

Using the National Health Insurance Research Database of Taiwan (covering over 99% of the entire population), we aimed to estimate the development of diabetes in periodontitis patients or that of periodontitis in patients with type 2 diabetes mellitus (T2DM), respectively.

METHODS

A total of 11 011 patients with severe periodontitis were recruited from 2000 to 2015. After matching by age, sex, and index date, 11 011 patients with mild periodontitis and 11 011 non-periodontitis controls were registered. Additionally, 157 798 patients with T2DM and 157 798 non-T2DM controls were enrolled, in whom the development of periodontitis was traced. Cox proportional hazards model was performed.

RESULTS

Periodontitis patients tended to have a statistically high risk for T2DM. The adjusted hazard ratio was 1.94 (95% CI, 1.49-2.63, P < .01) and 1.72 (95% CI, 1.24-2.52, P < .01) for severe and mild periodontitis groups, respectively. The patients with severe periodontitis had a higher risk of having T2DM relative to those with mild periodontitis (1.17 [95% CI, 1.04-1.26, P < .001]). Conversely, the risk of periodontitis increased significantly in patients with T2DM (1.99 [95% CI, 1.42-2.48, P < .01]). However, high risk was observed for the outcome of severe periodontitis (2.08 [95% CI, 1.50-2.66, P < .001]), but not for mild periodontitis (0.97 [95% CI, 0.38-1.57, P = .462]).

CONCLUSION

We suggest that the bidirectional association is between T2DM and severe but not mild periodontitis.

Bidirectional associations between periodontal disease and systemic diseases: a nationwide population-based study in Korea

To evaluate the associations of periodontal disease (PD) with systemic diseases, including diabetes mellitus (DM) and cardiovascular disease (CVD), as well as the reciprocal association. The CVD included the cases of coronary heart disease and heart failure. A prospective study was conducted from 2007 to 2019 using linked data from three databases in Korea. Three separate study groups were formed to individually determine the risks of PD (n = 10,533), DM (n = 14,523) and CVD (n = 14,315). All diseases were confirmed based on physicians' diagnoses using medical records and self-reports. Cox proportional hazard regression was applied with 95% confidence intervals (CIs) to obtain hazard ratios (HRs). PD was significantly associated with an elevated risk of DM (HR [95% CI]: 1.22 [1.07-1.39]) after full adjustment for age, sex, lifestyle factors, body mass index, dental behaviour and CVD. PD was also found to increase the risk of CVD (1.27 [1.03-1.57]), whereas CVD increased the risk of PD (1.20 [1.09-1.32]) after full adjustment for other covariates including DM. This study found a bidirectional association between PD and CVD, as well as a positive association of PD with DM.

Evaluation of Salivary Mucin, Amylase, Protein Profile, and Periodontal Parameters among Hypertensive and Diabetic Patients

Systemic and localized oral disease instigates alterations in salivary composition and content. The objective of the study was to evaluate the levels of salivary amylase, mucin, total protein levels, and periodontal inflammatory parameters in Type 2 Diabetes mellitus (T2DM), hypertensive (HTN) patients, and healthy controls. The study sample was divided into three groups: healthy, T2DM, and HTN. Salivary samples were collected from the included participants and salivary flow rate (SFR) and pH were measured. The salivary levels of amylase, mucin, and total protein concentration were analyzed using an enzyme-linked immunosorbent assay. The effect of anti-hypertensive and hypoglycemic drugs on the salivary flow rate, salivary pH, mucin, amylase, and total protein concentrations was evaluated. The results were analyzed with Chi-squared and analysis of variance to compare the means and standard deviations of variables among the study groups. SFR was significantly (p < 0.01) lower among diabetics (0.78 ± 0.45 mL/min) in comparison to healthy (1.52 ± 0.62 mL/min) and hypertensive (1.07 ± 0.7 mL/min) subjects. PISA values were significantly higher in T2DM (1029 ± 234.6 mm2) and HTN (799.4 ± 155.05 mm2) subjects when compared to controls, indicating a high inflammatory burden of oral cavity caused by these conditions, and showed statistically significant difference between the groups (p-value < 0.001). Mucin levels were significantly higher (p-value < 0.05) in hypertensive patients (4.6 ± 1.17 units) compared to diabetics (3.59 ± 1.03 unit/mL) and healthy (2.26 ± 1.09 units/mL) subjects. Amylase levels were significantly higher among healthy subjects (1.76 ± 0.75 mg/mL) compared to both hypertensive (1.33 ± 1.0 mg/mL) and diabetic (0.88 ± 0.57 mg/mL) patients. Total protein concentration was significantly raised (p-value < 0.001) in diabetics (37.67 ± 3.12 mg/mL) compared to healthy (29.3 ± 3.22 mg/mL) subjects. Significant differences in BOP, CAL, and PPD was observed (p-value < 0.001). Use of antihypertensive and hypoglycemic drugs showed a significant influence on salivary flow rate, protein, mucin, and amylase levels. T2DM and HTN induced irregularities in salivary flow rate, pH, amylase, and mucin levels and showed an increased incidence of moderate to severe periodontitis in patients. UWS levels of SFR, mucin, amylase, and total protein can be used as diagnostic and therapeutic biomarkers in patients with T2DM and HTN with oral disease.

Bidirectional Association Between Psoriasis and Nonalcoholic Fatty Liver Disease: Real-World Evidence From Two Longitudinal Cohort Studies

Background

Association between nonalcoholic fatty liver disease (NAFLD) and future psoriasis has not yet been confirmed, although the two diseases partially share a common pathogenesis pathway. Studies have revealed an association between psoriasis and subsequent NAFLD; however, these studies were limited to small sample sizes and a cross-sectional study design. Hence, the main objective of this population-based longitudinal cohort study was to evaluate the bidirectional association between psoriasis and NAFLD.

Methods

Data were retrieved from Taiwan’s National Health Insurance Research Database. Patients with new-onset NAFLD and psoriasis were respectively enrolled in two cohorts. For each comparison cohort, propensity-score-matched controls with no record of NAFLD or psoriasis were selected. An adjusted hazard ratio (aHR) was applied to evaluate subsequent risks.

Results

The risk of patients with new-onset NAFLD developing psoriasis was statistically significant, with an HR of 1.07 (95% CI, 1.01–1.14). For younger patients with NAFLD, the risk of developing psoriasis was 1.3-fold higher. The risk of patients with new-onset psoriasis developing NAFLD in the future was 1.28-fold higher than that of patients without psoriasis (95% CI, 1.21–1.35), and patients in younger psoriasis subgroups below the age of 40 years were at a higher risk than those in older subgroups, with an aHR of 1.55 (95% CI, 1.40–1.71).

Conclusion

Evidence supports a bidirectional association between NAFLD and psoriasis, especially in patients below the age of 40 years. The correlation between the two diseases and the subsequent risk of disease development should be considered when caring for patients.

Links between Insulin Resistance and Periodontal Bacteria: Insights on Molecular Players and Therapeutic Potential of Polyphenols

Type 2 diabetes is a metabolic disease mainly associated with insulin resistance during obesity and constitutes a major public health problem worldwide. A strong link has been established between type 2 diabetes and periodontitis, an infectious dental disease characterized by chronic inflammation and destruction of the tooth-supporting tissue or periodontium. However, the molecular mechanisms linking periodontal bacteria and insulin resistance remain poorly elucidated. This study aims to summarize the mechanisms possibly involved based on in vivo and in vitro studies and targets them for innovative therapies. Indeed, during periodontitis, inflammatory lesions of the periodontal tissue may allow periodontal bacteria to disseminate into the bloodstream and reach tissues, including adipose tissue and skeletal muscles that store glucose in response to insulin. Locally, periodontal bacteria and their components, such as lipopolysaccharides and gingipains, may deregulate inflammatory pathways, altering the production of pro-inflammatory cytokines/chemokines. Moreover, periodontal bacteria may promote ROS overproduction via downregulation of the enzymatic antioxidant defense system, leading to oxidative stress. Crosstalk between players of inflammation and oxidative stress contributes to disruption of the insulin signaling pathway and promotes insulin resistance. In parallel, periodontal bacteria alter glucose and lipid metabolism in the liver and deregulate insulin production by pancreatic β-cells, contributing to hyperglycemia. Interestingly, therapeutic management of periodontitis reduces systemic inflammation markers and ameliorates insulin sensitivity in type 2 diabetic patients. Of note, plant polyphenols exert anti-inflammatory and antioxidant activities as well as insulin-sensitizing and anti-bacterial actions. Thus, polyphenol-based therapies are of high interest for helping to counteract the deleterious effects of periodontal bacteria and improve insulin resistance.

Association between metabolic syndrome and periodontitis: The role of lipids, inflammatory cytokines, altered host response, and the microbiome

Periodontitis has been associated with many systemic diseases and conditions, including metabolic syndrome. Metabolic syndrome is a cluster of conditions that occur concomitantly and together they increase the risk of cardiovascular disease and double the risk of type 2 diabetes. In this review, we focus on the association between metabolic syndrome and periodontitis; however, we also include information on diabetes mellitus and cardiovascular disease, since these two conditions are significantly intertwined with metabolic syndrome. With regard to periodontitis and metabolic syndrome, to date, the vast majority of studies point to an association between these two conditions and also demonstrate that periodontitis can contribute to the development of, or can worsen, metabolic syndrome. Evaluating the effect of metabolic syndrome on the salivary microbiome, data presented herein support the hypothesis that the salivary bacterial profile is altered in metabolic syndrome patients compared with healthy patients. Considering periodontitis and these three conditions, the vast majority of human and animal studies point to an association between periodontitis and metabolic syndrome, diabetes, and cardiovascular disease. Moreover, there is evidence to suggest that metabolic syndrome and diabetes can alter the oral microbiome. However, more studies are needed to fully understand the influence these conditions have on each other.

Smoking and Periodontitis Can Play a Synergistic Role in the Development of Psoriasis: A Nationwide Cohort Study

BACKGROUND

Periodontitis is a chronic inflammatory disorder involving the periodontium. The precise nature of the association between periodontitis and psoriasis has not been determined.

OBJECTIVE

This nationwide population-based study investigated the relationship between periodontitis and the risk of psoriasis.

METHODS

A health screening database, which is a sub-dataset of the Korean National Health Insurance System database, was used in this study. Subjects with (n = 1,063,004) and without (n = 8,655,587) periodontitis who underwent health examinations from January to December 2009 were followed for 9 years.

RESULTS

In multivariable analysis, compared to the non-periodontitis group, periodontitis patients had a significantly higher risk of developing psoriasis (hazard ratio 1.116, 95% confidence interval 1.101-1.13). Non-smokers with periodontitis had an 11% increase in risk of psoriasis and smokers with periodontitis had a 26.5% increase in risk of psoriasis compared to non-smokers without periodontitis.

CONCLUSION

Our study highlights periodontitis as a potential independent risk factor for psoriasis, increasing awareness of the synergistic role of smoking and periodontitis in the pathogenesis of psoriasis.

Periodontal disease and the risk of Alzheimer's disease and mild cognitive impairment: a systematic review and meta-analysis

BACKGROUND

Results of studies on the association between periodontal disease (PD) and Alzheimer's disease (AD) or mild cognitive impairment (MCI) are inconsistent, and a previous meta-analysis published in 2017 included inadequate studies and is thus outmoded. This study aims to systematically evaluate the correlation between PD and the risk of AD or MCI.

METHODS

The following electronic databases were screened by two investigators independently, without restriction of language: CENTRAL (Cochrane library), PubMed (MEDLINE), EMBASE, China National Knowledge Interne, China Science and Technology Journal Database, Wanfang Data, www.ClinicalTrials.gov, and WHO International Clinical Trials Registry Platform. Meta-analysis was conducted using random-effects model or fixed-effects model according to the heterogeneity of included studies.

RESULTS

Thirteen eligible studies, of which eight reported AD (291 114 participants) and eight reported MCI (4805 participants), were included in this meta-analysis. The pooled results showed that compared with the non-PD population, the risk of AD and MCI in PD patients was significantly higher (for AD: odds ratio (OR) = 1.78, 95% CI 1.15-2.76; for MCI: OR = 1.60, 95% CI 1.24-2.06), and especially in those with severe PD (for AD: OR = 4.89, 95% CI 1.60-14.97; for MCI, OR = 2.32, 95% CI 1.24-4.36).

CONCLUSIONS

This meta-analysis indicated that PD was related to an elevated risk of AD and cognitive impairment, and that it should receive early intervention.

Bidirectional association between periodontal disease and diabetes mellitus: a systematic review and meta-analysis of cohort studies

Periodontal disease has been reported to be associated with diabetes mellitus. However, the direction of the association and the influence of bias are not clear. Thus, the aim of this systematic review and meta-analysis was to summarize the existing evidence on the bidirectional prospective association between periodontal disease and diabetes mellitus by accounting for the risk of bias of the original studies. The literature search was conducted on the electronic data sources PubMed and Web of Science up to February 9th, 2021. We included observational studies, which investigated the prospective association between diabetes mellitus and periodontal disease or vice versa. The risk of bias of the primary studies was evaluated by applying the Quality in Prognosis Studies (QUIPS) tool. Random effects models were used to calculate summary relative risk (SRR) with 95% CI. Subgroup analyses were applied to investigate heterogeneity and the robustness of the finding. In total, 15 studies were included . The SRR for incident diabetes mellitus was 1.26 (95% CI 1.12, 1.41; I²: 71%, n = 10; participants = 427,620; identified cases = 114,361), when comparing individuals with periodontitis to individuals without periodontitis. The SRR for incident periodontitis was 1.24 (95% CI 1.13, 1.37; I²: 92%, n = 7; participants = 295,804; identified cases: > 22,500), comparing individuals with diabetes to individuals without diabetes. There were no significant differences between subgroups after stratification for risk of bias. The findings show a positive bidirectional association between periodontal disease and diabetes mellitus, and thus, underline the need for screening of patients with periodontitis regarding diabetes mellitus and vice versa. The main limitation of the study is the high unexplained heterogeneity between the studies including the different assessment methods of the disease diagnosis.

Oral health and longitudinal changes in fasting glucose levels: A nationwide cohort study

We investigated the association between oral hygiene indicators of periodontitis, tooth loss, and tooth brushing on the longitudinal fasting glucose level in non-diabetic subjects. Using a nationwide health screening database in Korea, we included non-diabetic individuals who received a health screening program with oral health check in 2009-2010. We constructed a linear mixed model for the longitudinal data of fasting glucose from the baseline to 2015. During the 4.84-year of median follow-up, 91,963 individuals (mean age 56.2 at baseline) underwent 392,780 health examinations with fasting glucose level (mmol/L). The presence of periodontitis was 39.3%. In the multivariate linear mixed analysis, periodontitis was related with increased fasting glucose levels (β = 0.0084, standard error = 0.0035, p = 0.018). Similarly, tooth loss was associated with increased level of fasting glucose (β = 0.0246, standard error = 0.0038, p < 0.001). Compared with tooth brushing ≤2 times/day, tooth brushing ≥3 times/day was associated with decreased fasting glucose levels (β = -0.0207, standard error = 0.0033, p < 0.001). Our data showed that periodontitis and tooth loss were associated with increased fasting glucose levels in non-diabetic individuals. The study findings imply that frequent tooth brushing may reduce fasting glucose levels. Further research is needed to determine the effect of periodontal intervention on glycemic control.

Association between Diabetes Mellitus and Oral Health Status in Patients with Cardiovascular Diseases: A Nationwide Population-Based Study

Diabetes mellitus (DM) can lead to poor oral health. However, oral health among diabetic patients with cardiovascular diseases (CVDs) is scarcely studied. This study aimed to elucidate the prevalence of oral health complications and the relationship between DM and oral health status in diabetic patients with CVDs. This retrospective nationwide cross-sectional study evaluated 3495 patients aged ≥40 years with CVD, with DM (n = 847) and without DM (n = 2648). The participant's characteristics between the two groups were compared using the Chi-square test and t-test. Logistic regression analyses were performed to identify associations between DM and oral health status. The prevalence of periodontitis (54.3% vs. 43.2%) and <20 number of remaining teeth (30.9% vs. 22.8%) was significantly higher in the DM than in the non-DM group. In the multivariate regression analysis, the incidence of periodontitis was 1.4 times higher in the DM group than in the non-DM after adjusting for confounders; however, the number of remaining teeth and active caries were not associated with DM. In conclusion, the oral health status of patients with coexisting CVD and DM should be assessed closely and actively. Healthcare professionals should provide accessible dental care services and develop strategies to improve patients' oral health.

Nec-1 attenuates inflammation and cytotoxicity induced by high glucose on THP-1 derived macrophages through RIP1

OBJECTIVES

This research aimed to study whether necrostain-1 (Nec-1) could alleviate inflammatory injury induced by high glucose upon THP-1 derived macrophages through RIP1.

DESIGN

Firstly, THP-1 derived macrophages were incubated with 5.5 mM glucose (normal glucose, NG), 25 mM glucose (high glucose, HG), and mannitol as the high osmotic pressure group (5.5 mM glucose+19.5 mM mannitol) for 24, 48, and 72 h respectively. TNF-α, IL-1β, IL-6, and IL-8 levels were measured by ELISA. Secondly, macrophages were exposed to NG, HG, or HG plus 5 μM necrostatin-1 (Nec-1) for 72 h. mRNA expression of inflammatory cytokine was measured by RT-PCR, and protein levels of inflammatory cytokines and LDH leakage were determined by ELISA. RIP1 expression was determined by RT-PCR and WB. Thirdly, macrophages were transfected with si-RIP1 or negative control (si-NC). Wild type and RIP1-silenced macrophages were incubated with NG or HG, and TNF-α, IL-1β, IL-6, IL-8, and LDH levels were measured again by ELISA.

RESULTS

1) TNF-α, IL-1β, IL-6, and IL-8 levels were elevated in the HG group, as compared with that the NG group. Inflammation remained unchanged in the mannitol group. 2) Inflammatory response and LDH levels in the HG plus Nec-1 group were remarkably lower than in the HG group. 3) Inflammatory injury in the si-NC group was more severe than in the si-RIP1 group.

CONCLUSIONS

Current results indicated that Nec-1 could alleviate HG-caused inflammatory injury on THP-1 derived macrophages by regulating RIP1. These findings could help cast light on the relationships between diabetes and periodontitis.

Rheumatoid arthritis risk in periodontitis patients: A systematic review and meta-analysis

OBJECTIVE

Many clinical studies have been carried out to investigate the relationship between periodontitis and rheumatoid arthritis (RA). Owing to limited evidence and inconsistent findings among these studies, it is unclear whether periodontitis would increase the risk for RA. This meta-analysis was performed to evaluate whether periodontitis represents a risk factor for RA.

METHODS

PubMed, Cochrane Library, Embase, Web of Science, and Wanfang were searched for eligible studies that compared periodontitis patients with controls. A pooled odds ratio (OR) and 95% confidence interval (CI) were calculated to assess the association between periodontitis and RA.

RESULTS

Thirteen studies including a total of 706611 periodontitis patients and 349983 control subjects were included. The pooled OR of RA risk between periodontitis and controls was (OR: 1.69; 95% CI: 1.31-2.17; P<0.0001), indicating that the patients in periodontitis group had a 69% greater risk for RA than people in control group. When stratified by disease type, the pooled results showed periodontitis represents a risk factor for incident RA (OR=1.70, 95%CI: 0.75-3.85, P<0.001) and mixed RA (OR=1.61, 95%CI: 1.26-2.06; P<0.001). When stratified by disease duration, the pooled results showed periodontitis represents a risk factor for RA disease duration>5 years (OR=2.88, 95%CI: 0.66-12.62, P=0.018), disease duration<5 years (OR=2.59, 95%CI: 0.83-8.11, P<0.001), mixed disease duration (OR=1.53; 95%CI: 1.05-2.22, P<0.001).

CONCLUSION

Our meta-analysis revealed an increased risk of RA in patients with periodontitis compared to healthy controls. Moreover, when stratified by disease type, there was a higher risk between incident RA and periodontitis. When stratified by disease duration, the patients with periodontitis might be more closely associated with the RA patients with disease duration >5 years.

Improved oral hygiene is associated with decreased risk of new-onset diabetes: a nationwide population-based cohort study

AIMS/HYPOTHESIS

Inflammation plays an important role in the development of diabetes, a major global health problem. Periodontal disease is also common in the general population. Because periodontal disease and poor oral hygiene can provoke transient bacteraemia and systemic inflammation, we hypothesised that periodontal disease and oral hygiene indicators would be associated with the occurrence of new-onset diabetes.

METHODS

In this study we analysed data collected between 2003 and 2006 on 188,013 subjects from the National Health Insurance System-Health Screening Cohort (NHIS-HEALS) in Korea who had no missing data for demographics, past medical history, oral hygiene indicators or laboratory findings. The presence of periodontal disease was defined on the basis of a modified version of ICD-10 codes (Korean Classification of Disease, sixth edition), if claims for treatment for acute periodontitis (K052), chronic periodontitis (K053) and periodontosis (K054) were made more than two times by a dentist, or if, according to medical records, subjects received treatment by a dentist for periodontal disease with ICD-10 codes K052, K053 or K054. Oral hygiene behaviours (number of tooth brushings, a dental visit for any reason and professional dental cleaning) were collected as self-reported data of dental health check-ups. Number of missing teeth was ascertained by dentists during oral health examination. The incidence of new-onset diabetes was defined according to ICD-10 codes E10-E14. The criterial included at least one claim per year for both visiting an outpatient clinic and admission accompanying prescription records for any glucose-lowering agent, or was based on a fasting plasma glucose ≥7 mmol/l from NHIS-HEALS.

RESULTS

Of the included subjects, 17.5% had periodontal disease. After a median follow-up of 10.0 years, diabetes developed in 31,545 (event rate: 16.1%, 95% CI 15.9%, 16.3%) subjects. In multivariable models, after adjusting for demographics, regular exercise, alcohol consumption, smoking status, vascular risk factors, history of malignancy and laboratory findings, the presence of periodontal disease (HR 1.09, 95% CI 1.07, 1.12, p < 0.001) and number of missing teeth (≥15 teeth) remained positively associated with occurrence of new-onset diabetes (HR 1.21, 95% CI 1.09, 1.33, p < 0.001, p for trend <0.001). Frequent tooth brushing (≥3 times/day) was negatively associated with occurrence of new-onset diabetes (HR 0.92, 95% CI 0.89, 0.95, p < 0.001, p for trend <0.001).

CONCLUSIONS/INTERPRETATION

Frequent tooth brushing may be an attenuating factor and the presence of periodontal disease and an increased number of missing teeth may be augmenting factors for the occurrence of new-onset diabetes. Improving oral hygiene may be associated with a decreased risk of occurrence of new-onset diabetes.

The expression of inducible nitric oxide synthase in the gingiva of rats with periodontitis and diabetes mellitus

OBJECTIVE

To ascertain the role of inducible nitric oxide synthase (iNOS) in the periodontitis response during diabetes.

METHODS

Twenty-four male SD rats were randomly divided into four groups: control group (Control), diabetes mellitus group (D), diabetes mellitus plus periodontitis group (DP), and periodontitis group (P). Periodontitis and diabetes were established separately. Then the gingival tissue and alveolar bone were collected. A stereomicroscope was used to evaluate bone loss. The expression of iNOS, TNF-α, and NF-κB in the gingiva was detected by immunohistochemical staining, real-time PCR, and western blot analysis.

RESULTS

Significant bone loss was observed in the DP and P groups and more extensive bone resorption was discovered in the DP group than in the P group (P < 0.05). The immunohistochemical staining analysis revealed enhanced expression of iNOS located in the gingiva of the three disease groups compared with the control group (P < 0.05). In particular, the level of iNOS was significantly higher in the DP group than in the P group (P < 0.05). This elevated trend of iNOS was further demonstrated by quantitative PCR and western blot analysis. Similarly, the mRNA and protein expression levels of NF-κB in the D, DP, and P groups were significantly higher than those of the control group, as was the level of TNF-α protein (P < 0.05).

CONCLUSIONS

Our results proved diabetes exacerbated alveolar bone resorption in a periodontitis rat model. iNOS may be the inflammatory mediator in the course of periodontal injury promoted by diabetes.

Association between IL-1A (-889C/T) polymorphism and susceptibility of chronic periodontitis: A meta-analysis

OBJECTIVE

The purpose of this study was to investigate the association between IL-1A (-889C/T, rs1800587) polymorphism and susceptibility of chronic periodontitis.

METHODS

A systematic literature search was carried out in the databases updated on July 1, 2019, including PubMed, Embase, Cochrane Library and Web of Science. Through STATA 14.0 software, the association between IL-1A (-889C/T) polymorphism and susceptibility of chronic periodontitis was calculated by pooled odds rations (ORs) and 95% confidence intervals (CIs). Harbord test was used for the publication bias.

RESULTS

The results of overall meta-analysis revealed that IL-1A (-889C/T) polymorphism was associated with the susceptibility of chronic periodontitis among all the genetic models, including allele contrast [T vs. C, OR (95% CI): 1.297 (1.038-1.622), P = 0.022], dominant model [TT + CT vs. CC, OR (95% CI): 1.337 (1.015-1.761), P = 0.039], recessive model [TT vs. CC + CT, OR (95% CI): 1.453 (1.138-1.856), P = 0.003], and codominant model [TT vs. CC, OR (95% CI): 1.555 (1.187-2.038), P = 0.001; CT vs. CC, OR (95% CI): 2.559 (1.245-5.260), P = 0.011]. The results of subgroup analyses indicated that IL-1A (-889C/T) polymorphism was closely related to the susceptibility of chronic periodontitis in African population [T vs. C, OR (95% CI): 1.277 (1.039-1.571), P = 0.020; TT + CT vs. CC, OR (95% CI): 1.357 (1.061-1.735), P = 0.015; TT vs. CC, OR (95% CI): 1.599 (1.115-2.292), P = 0.011], in European population [TT vs. CC + CT, OR (95% CI): 1.645 (1.112-2.435), P = 0.013; TT vs. CC, OR (95% CI): 1.639 (1.044-2.574), P = 0.032] and in American population [CT vs. CC, OR (95% CI): 6.404 (3.000-13.669), P < 0.001].

CONCLUSIONS

IL-1A (-889C/T) polymorphism is associated with the susceptibility of chronic periodontitis in African, European and American populations according to the currently available evidence.