COX-2 rs689466, rs5275, and rs20417 polymorphisms and risk of head and neck squamous cell carcinoma: a meta-analysis of adjusted and unadjusted data.

BACKGROUND: Numerous case-control studies have been performed to investigate the association between three cyclooxygenase-2 (COX-2) polymorphisms (rs20417 (-765G > C), rs689466 (-1195G > A), and rs5275 (8473 T > C)) and the risk of head and neck squamous cell carcinoma (HNSCC). However, the results were inconsistent. Therefore, we conducted this meta-analysis to investigate the association. METHODS: We searched in PubMed, Embase, and Web of Science up to January 20, 2015 (last updated on May 12, 2016). Two independent reviewers extracted the data. Odds ratios (ORs) with their 95 % confidence intervals (CIs) were used to assess the association. All statistical analyses were performed using the Review Manager (RevMan) 5.2 software. RESULTS: Finally 8 case-control studies were included in this meta-analysis. For unadjusted data, an association with increased risk was observed in three genetic models in COX-2 rs689466 polymorphism; however, COX-2 rs5275 and rs20417 polymorphisms were not related to HNSCC risk in this study. The pooled results from adjusted data all revealed non-significant association between these three polymorphisms and risk of HNSCC. We also found a similar result in the subgroup analyses, based on both unadjusted data and adjusted data. CONCLUSION: Current results suggest that COX-2 rs689466, rs5275, and rs20417 polymorphisms are not associated with HNSCC. Further large and well-designed studies are necessary to validate this association.

Association between the TP53 codon 72 polymorphism and risk of oral squamous cell carcinoma in Asians: a meta-analysis.

BACKGROUND: Several epidemiological studies have previously investigated the association between the TP53 codon 72 polymorphism and oral squamous cell carcinoma (OSCC) susceptibility; however, current results are inconsistent. We therefore performed this meta-analysis to thoroughly investigate any association among Asian patients. METHODS: A comprehensive search of PubMed and Embase databases was performed up to December 2013. We only considered studies consisting of patients diagnosed with OSCC by pathological methods. Statistical analyses were performed using Review Manager (RevMan) 5.2 software and odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the association. RESULTS: A total of 11 case-control studies involving 2,298 OSCC patients and 2,111 controls were included. We found no association between the TP53 codon 72 polymorphism and OSCC susceptibility [(OR = 0.77, 95% CI = 0.48-1.22) for Arg vs. Pro; (OR = 0.67, 95% CI = 0.31-1.43) ArgArg vs. ProPro; (OR = 1.14, 95% CI = 0.97-1.35) ArgPro vs. ProPro; (OR = 0.85, 95% CI = 0.53-1.34) (ArgPro + ArgArg) vs. ProPro; or (OR = 0.34, 95% CI = 0.34-1.23) for ArgArg vs. (ProPro + ArgPro)]. However, subgroup analysis demonstrated an association between the TP53 codon 72 polymorphism and human papillomavirus (HPV)-related OSCC patients. Although statistical heterogeneity was detected, there was no evidence of publication bias. CONCLUSIONS: Current results suggest that the TP53 codon 72 polymorphism is not associated with OSCC in Asians without the presence of HPV infection. Further research is necessary to determine if such a relationship exists in HPV-related OSCC patients.

Cancer burden and risk in the Chinese population aged 55 years and above: A systematic analysis and comparison with the USA and Western Europe.

Background: We analysed the cancer burden among elderly Chinese people over the age of 55 years and compared them to USA and Western Europe to explore the cancer model in China. Methods: We retrieved data on 29 cancers with 34 risk factors from the 2019 Global Burden of Disease database to evaluate the cancer burden in Chinese elderly individuals aged 55 years and older. We then used the age-standardised incidence rate (ASIR), age-standardised death rate (ASDR), age-standardised disability-adjusted life year (DALY) rate, and average annual percentage change (AAPC) to compare the characteristics and change trend of cancers among China, USA, and Western Europe. Results: In 2019, the number of incident cases of 29 cancers among people aged 55 years and above in China increased more than 3-fold compared to 1990, while the number of deaths and DALYs approximately doubled. We also found that the cancer population in China was ageing; meanwhile, the cancer burden became significantly higher for men than for women, and the gap between men and women had widened. Cancers with the highest cancer DALYs were lung cancer (13 444 500; 95% uncertainty interval (UI) = 11 307 100, 15 853 700), stomach cancer (7 303 900; 95% UI = 6 094 600, 8 586 500), oesophageal cancer (4 633 500; 95% UI = 3 642 500, 5 601 200), colon and rectum cancer (4 386 500; 95% UI = 3 769 500, 5 067 200), liver cancer (2 915 100, 95% UI = 2 456 300, 3 463 900), and pancreatic cancer (2 028 400; 95% UI = 1 725 000, 2 354 900). Compared with 1990, the DALY rate and incidence rate of stomach cancer, oesophageal cancer, and liver cancer had markedly decreased. The DALY rate and incidence rate of lung, colon, rectum, and pancreatic cancer had increased significantly, as did the incidence rate of breast cancer in women. Smoking and diet were the top two cancer risk factors, and the impact of ambient particulate matter pollution on cancer increased each year. The overall 29 cancers age-standardised DALY rate and ASDR in China, USA, and Western Europe were similar, and all showed downward trend in the past 30 years. Compared with the USA and Western Europe, the age-standardised DALY rate of liver, nasopharyngeal, oesophageal, stomach, and cervical cancers in China was more prominent. The age-standardised DALY rate of lung cancer and colon and rectum cancer decreased annually in Western Europe and the USA, but increased in China. Conclusions: Over the past 30 years, China had made progress in controlling stomach, oesophageal, and liver cancer. However, lung, colon, rectum, pancreatic, and breast cancers had become more prevalent, having risen alongside economic development. The risks of smoking and dietary were major issues that need to be addressed urgently. The cancer situation in China remains serious; future cancer prevention efforts need to balance economic development with people's physical health, identify key groups, improve the health environment of residents and guide them to live a healthy life, and expand the scope of cancer screening.

Vascular endothelial growth factor (VEGF) gene polymorphisms and risk of head and neck cancer: a meta-analysis involving 2,444 individuals.

The association between vascular endothelial growth factor (VEGF) gene polymorphisms and risk of head and neck cancer (HNC) were investigated in many published studies; however, the currently available results are inconclusive. Therefore, we conducted this meta-analysis for deriving a more precise estimation of association between VEGF polymorphisms and the risk of HNC. Finally, we yield eight case-control studies involving six polymorphisms contain 2,444 individuals from PubMed, Embase, and CNKI up to January 30, 2013 (last updated on May 4, 2013). The results of meta-analysis showed that all the six polymorphisms of VEGF were not associated with risk of HNC [OR 1.25, 95 % CI (0.60-1.58) for TT vs. CC for 936 C/T; OR 1.41, 95 % CI (0.79-2.52) for GG vs. AA for -1,154 A/G; OR 0.97, 95 % CI (0.38-2.50) for CC vs. GG for 405 G/C; OR 1.44, 95 % CI (0.80-2.61) for AA vs. CC for 2,578 C/A; OR 1.27, 95 % CI (0.77-3.72) for TT vs. CC for -460 C/T; and OR 0.87, 95 % CI (0.37-2.06) for GG vs. CC for -634 G/C]. When performed subgroup analysis according to ethnicity for VEGF 936 C/T, the results suggested that it was not associated with the risk of HNC for either Asians [OR 0.84, 95 % CI (0.27-2.56) for TT vs. CC] or Caucasians [OR 2.10, 95 % CI (0.82-5.37) for TT vs. CC]. However, due to the limitations of this meta-analysis, more well designed, larger sample size, and adjusted risk factors studies are suggested to further assess the findings.

Periodontitis Is Associated With Heart Failure: A Population-Based Study (NHANES III).

Objectives: The aim of this study was to investigate the relationship between periodontitis and heart failure using the Third National Health and Nutrition Examination Survey (NHANES III). Methods: Participants who had received a periodontal examination were included and investigated for the occurrence of heart failure. The included participants were divided into no/mild periodontitis and moderate/severe periodontitis groups according to their periodontal status. Weighted prevalence of heart failure was calculated, and weighted logistic regressions models were used to explore the association between periodontitis and heart failure. Possible influencing factors were then explored through subgroup analysis. Results: Compared with that of the no/mild periodontitis group, the incidence of heart failure in participants with moderate/severe periodontitis was 5.72 times higher (95% CI: 3.76-8.72, p < 0.001). After adjusting for gender, age, race, body mass index, poverty income ratio, education, marital status, smoking status, drinking status, hypertension, diabetes, stroke, and asthma, the results showed that the incidence of heart failure in the moderate/severe group was 3.03 times higher (95% CI: 1.29-7.13, p = 0.012). Subgroup analysis showed that criteria, namely, male, 40-60 years old, non-Hispanic white, body mass index >30, poverty income ratio ≥1, not more than 12 years of education, currently drinking, stroke but no diabetes, or asthma supported moderate/severe periodontitis as a risk factor for heart failure (p < 0.05). Conclusion: According to data from this nationally representative sample from the United States, periodontitis is associated with an increased risk of heart failure.

The spatial and temporal trends of severe periodontitis burden in Asia, 1990-2019: A population-based epidemiological study.

BACKGROUND: To investigate the long-term and spatial patterns of incidence, prevalence, and disability-adjusted life year (DALY) rates of severe periodontitis in Asia from 1990 to 2019, and to estimate the associations between disease burden and socioeconomic development using the Socio-Demographic Index (SDI). METHODS: Data were obtained from the global burden of disease study 2019. The average annual percent change (AAPC) was calculated to reflect temporal trends, spatial autocorrelation analysis was conducted to estimate the spatial characteristics, and spatial panel models were used to investigate the association between SDI and severe periodontitis burden. RESULTS: For Asia as a whole, the crude rates increased by 1.10% per year for incidence, 1.42% per year for prevalence, and 1.41% per year for DALY from 1990 to 2019. The age-standardized incidence, prevalence and DALY rates increased by 0.18%, 0.22%, and 0.23% per year, respectively. Spatially, the hot spots of age-standardized incidence, prevalence and DALY rates were located in Southern Asia, besides, these rates all showed increasing trends in most countries, and the increases were clustered in Southeastern Asia. Further, SDI showed a negative association with incidence (coef = -14.44; 95% CI: -24.63, -4.25) and prevalence (coef = -40.09; -51.81, -28.36), and a positive association with DALY rates (coef = 0.31; 0.23; 0.38). CONCLUSIONS: Severe periodontitis poses a serious public health challenge in Asian countries with increasing temporal trends and substantial spatial inequalities. Effective geographically targeted public health interventions and strategies are needed to address the growing burden associated with severe periodontitis.

Oral microbiota in the oral-genitourinary axis: identifying periodontitis as a potential risk of genitourinary cancers.

Periodontitis has been proposed as a novel risk factor of genitourinary cancers: although periodontitis and genitourinary cancers are two totally distinct types of disorders, epidemiological and clinical studies, have established associations between them. Dysbiosis of oral microbiota has already been established as a major factor contributing to periodontitis. Recent emerging epidemiological evidence and the detection of oral microbiota in genitourinary organs indicate the presence of an oral-genitourinary axis and oral microbiota may be involved in the pathogenesis of genitourinary cancers. Therefore, oral microbiota provides the bridge between periodontitis and genitourinary cancers. We have carried out this narrative review which summarizes epidemiological studies exploring the association between periodontitis and genitourinary cancers. We have also highlighted the current evidence demonstrating the capacity of oral microbiota to regulate almost all hallmarks of cancer, and proposed the potential mechanisms of oral microbiota in the development of genitourinary cancers.

Continuous exposure of isoprenaline inhibits myoblast differentiation and fusion through PKA/ERK1/2-FOXO1 signaling pathway.

AIM: The objective of this study is to determine if exuberant sympathetic nerve activity is involved in muscle satellite cell differentiation and myoblast fusion. METHODS AND RESULTS: By using immunoassaying and western blot analyses, we found that ß1 and ß2-adrenergic receptors (AdR) were expressed in C2C12 cells. The differentiated satellite cells exhibited an increased expression of ß2-AdR, as compared with the proliferating cells. Continuous exposure of isoprenaline (ISO), a ß-AdR agonist, delayed C2C12 cell differentiation, and myoblast fusion in time- and dose-dependent manner. ISO also increased short myotube numbers while decreasing long myotube numbers, consistent with the greater reduction in MyHC1, MyHC2a, and MyHC2x expression. Moreover, continuous exposure of ISO gradually decreased the ratio of PKA RI/RII, and PKA RI activator efficiently reversed the ISO effect on C2C12 cell differentiation and myoblast fusion while PKA inhibitor H-89 deteriorated the effects. Continuous single-dose ISO increased ß1-AdR expression in C2C12 cells. More importantly, the cells showed enhanced phospho-ERK1/2 levels, resulting in increasing phospho-ß2-AdR levels while decreasing ß2-AdR levels, and the specific effects could be abolished by ERK1/2 inhibitor. Furthermore, continuous exposure of ISO induced FOXO1 nuclear translocation and increased the levels of FOXO1 in nuclear extracts while reducing pAKT, p-p38MAPK, and pFOXO1 levels. Conversely, blockade of ERK1/2 signaling partially abrogated ISO effects on AKT, p38MAPK, and FOXO1signaling, which partially restored C2C12 cell differentiation and myoblast fusion, leading to an increase in the numbers of medium myotube along with the increased expression of MyHC1 and MyHC2a. CONCLUSION: Continuous exposure of ISO impedes satellite cell differentiation and myoblast fusion, at least in part, through PKA-ERK1/2-FOXO1 signaling pathways, which were associated with the reduced ß2-AdR and increased ß1-AdR levels.

Tooth Loss Is Associated With Increased Risk of Dementia and With a Dose-Response Relationship.

Objective: Both tooth loss and dementia are age-related and frequently-occurring diseases. Increasing attention has been given to explore the pathogenesis related to oral-brain function disorders. The present study was performed to evaluate the association between tooth loss and dementia through a dose-response meta-analysis. Methods: Relevant cohort studies were searched from online databases up until June 20, 2018, which examined the association between tooth loss and the risk of dementia. Literature selection according to inclusion and exclusion criteria, as well as data extraction from included studies were completed independently by two reviewers. Data syntheses in this meta-analysis were performed using Stata 12.0 software. Results: A total of 8 cohort studies were included, containing a total of 14,362 samples and 2,072 dementia patients. The result of the meta-analysis indicated that patients with tooth loss faced a 1.34 times greater risk of developing dementia (RR = 1.34,95% CI = 1.19-1.51). The result from this dose-response meta-analysis in a linear model, suggested that every missed tooth might increase the risk of dementia by 1.01 times (RR = 1.01, 95%CI = 1.00-1.02). Further subgroup analyses pointed out that tooth loss patients without dentures may have a higher risk of dementia than those with dentures (with denture: RR = 0.98, 95% CI = 0.87-1.10; without denture: RR = 1.53, 95% CI = 1.19-1.97); at the same time, the study design, study area and education level of the study participants, might also have some effect on the results. Conclusions: Tooth loss may be a risk factor for the development of dementia. In addition, there is a dose-response relationship with the increase of missing teeth.

Periodontal Disease and Breast Cancer: A Meta-Analysis of 1,73,162 Participants.

Objective: To investigate the correlation between periodontal disease and breast cancer. Materials and Methods: PubMed and China National Knowledge Infrastructure (CNKI) databases were searched up to February 8, 2018 for observational studies examining the association between periodontal disease and breast cancer. Study selection was conducted according to predesigned eligibility criteria, and two authors independently extracted data from included studies. Meta-analysis was performed using the Comprehensive Meta-Analysis v2 software and risk estimates were calculated as relative risks (RRs) with corresponding 95% confidence intervals (CIs). Results: A total of 11 study were included. Meta-analysis indicated that periodontal disease significantly increased the risk of breast cancer by 1.22-fold (RR = 1.22, 95% CI = 1.06-1.40). Amongst participants with periodontal patients and a history of periodontal therapy, the risk of developing breast cancer was not significant (RR = 1.23; 95% CI = 0.95-1.60). The association results between periodontal diseases and breast cancer were found to be robust, as evident in the leave-one-out sensitivity analysis. Conclusions: Periodontal disease may be a potential risk factor for the development of breast cancer among women, and thus effective periodontal therapy may present as a valuable preventive measure against breast cancer.

Periodontal Disease and Risk of Bladder Cancer: A Meta-Analysis of 298476 Participants.

Objective: It has been reported that the periodontal disease is linked to a number of malignant tumors such as lung cancer and pancreatic cancer. In this study, we aimed to investigate the association of periodontal disease with risk of bladder cancer by a meta-analysis. Methods: PubMed, Scopus, ScienceDirect, and Chinese National Knowledge Infrastructure (CNKI) were searched for eligible publications up to December 15, 2017. Cohort and nested case-control studies on the association between periodontal disease and risk of bladder cancer were included. After study selection and data extraction, pooled hazard ratios (HRs) and their 95% confidence intervals (95%CIs) were calculated using a fixed-effect inverse-variance model. All analyses were performed using the RevMan 5.3 software. Results: Finally, five cohort studies were identified and included in this meta-analysis, involving 1,104 bladder cancer cases of 298,476 participants. Summary estimates based on adjusted data showed that periodontal disease was not significantly associated with the risk of bladder cancer (HR = 1.09, 95% CI = 0.95-1.25, I2 = 0%). A similar result was also observed after cumulative, subgroup and sensitivity analyses. Conclusions: Current evidence from cohort studies suggests that patients with periodontal disease may not be at an increased risk of developing bladder cancer.

Cumulative meta-analysis and trial sequential analysis of correlation between hOGG1 Ser326Cys polymorphism and the risk of head and neck squamous cell carcinoma.

BACKGROUND: The human 8-oxoguanine glycosylase 1 (hOGG1) Ser326Cys polymorphism has been involved in the risk of head and neck squamous cell carcinoma (HNSCC), but the results of published studies on this topic still inconsistent. RESULTS: Finally 11 qualified publications with 13 independent case-control studies were yielded. Overall, we observed significant differences in CysCys vs. SerSer [odds ratio (OR) = 1.55, 95% confidence interval (95% CI) = 1.01-2.38] and CysCys vs. SerCys+SerSer (OR = 1.42, 95% CI = 1.005-1.99) genetic models. Sensitivity analyses showed the results were not robust, cumulative meta-analyses and trial sequential analysis indicated the results didn't not need more studies to identification. Subgroup analyses showed there was a significant association in Caucasian, laryngeal squamous cell carcinoma, studies agreement with Hardy-Weinberg equilibrium, and alcohol drinkers subgroups under the corresponding contrasts. In addition, the results of Egger's test were contradictory. MATERIALS AND METHODS: All eligible studies were searched from the online databases including PubMed, Web of Science, China Knowledge Resource Integrated Database, and Wanfang databases up to February 10, 2017. After study selection and data extraction, the meta-analysis was performed using STATA 12.0 software and TSA software version 0.9 Beta. CONCLUSIONS: Our meta-analysis results indicated that hOGG1 Ser326Cys polymorphism may be associated with increased risk of HNSCC, especially in Caucasians, alcohol drinkers and the patients with laryngeal squamous cell carcinoma.

Comprehensive analysis of interleukin-8 gene polymorphisms and periodontitis susceptibility.

BACKGROUND: Associations between interleukin-8 (IL-8) gene polymorphisms and periodontitis susceptibility have been investigated in many published studies, but the conclusions are still inconsistent. Therefore, we performed this systematic review and meta-analysis to review which polymorphisms have been researched and to obtain a precise result of the same polymorphism from different studies. RESULTS: Finally 10 publications involving 1938 patients and 1569 controls were yielded, including 12 polymorphisms. Six studies investigated rs4073 polymorphism; two focused on rs2227306 and rs2227307; two referred to rs2227532 and T-738A; one detected rs2230054, rs1126579 and rs1126580; one inspected A2767T, T11722T2 and C1633T, and one for rs2234671 polymorphism. Of them, IL-8 C1633T and rs1126580 polymorphisms showed positive association while the other ten polymorphisms revealed negative results. MATERIALS AND METHODS: A comprehensive literature search from PubMed, Web of Science, and Chinese National Knowledge Infrastructure was conducted for all potentially relevant studies published before January 2, 2017. Two authors selected the studies and extracted data. The pooled analysis was conducted using the RevMan 5.1 software if a polymorphism was reported by two or more studies. CONCLUSIONS: Based on current evidence, the IL-8 rs4073, A2767T, T11722T2, rs2234671, rs2230054, rs1126579, rs2227306, rs2227307, rs2227532, and T-738A polymorphisms were not associated with periodontitis susceptibility; the IL-8 C1633T and rs1126580 polymorphisms were associated with increased risk of periodontitis.

Acupuncture therapy in the management of the clinical outcomes for temporomandibular disorders: A PRISMA-compliant meta-analysis.

PURPOSE: The purpose of this study was to evaluate conventional acupuncture therapy in the management of clinical outcomes for temporomandibular disorders (TMD) in adults. METHODS: The electronic databases PubMed, EMBASE, Cochrane Central Register of Controlled Trials, and Clinical Trails.gov were searched for reports published until March 31, 2016. RESULTS: Nine eligible studies from 8 publications involving 231 patients were included in the meta-analysis. A comparison of the main outcome of visual analog scale (VAS) values of pain between the acupuncture group and control group showed a significant decrease (MD = -0.98, 95% CI [-1.62, -0.34], I=54%, P = 0.003) in the VAS following acupuncture treatment. However, subgroup analysis according to the type of sham control group indicated that there were significant differences in the results when sham acupuncture was used as the control group (MD = -1.54, 95% CI [-2.63, -0.45], I=58%, P = 0.006) as well as when sham laser treatment was used as the control group (MD = -1.29, 95% CI [-2.32, -0.27], I = 0%, P = 0.01). However, there was no significant difference when the splint treatment group was used as the control group (MD = -0.09, 95% CI [-0.69, 0.50], I = 0%, P = 0.76). Subgroup analyses of VAS for pain by the classification of diseases indicated that the myogenous TMD subgroup demonstrated a significant difference (MD = -1.49, 95% CI [-2.45, -0.53], I = 47%, P = 0.002), and TMD showed no statistically significant difference (MD = -0.42, 95% CI [-1.14, 0.30], I = 46%, P = 0.25). Subgroup analysis according to whether the subgroup penetrated the skin showed that nonpenetrating sham acupuncture as the control group showed a significant difference (MD = -1.56, 95% CI [-2.70, -0.41], I = 58%, P = 0.008) compared with the conventional acupuncture as the treatment modality, while penetrating sham acupuncture as the control group showed no significant difference (MD = -1.29, 95% CI [-3.40, 0.82], I = not applicable, P = 0.23). No publication bias was observed considering the symmetry of the funnel plots. CONCLUSIONS: Our results indicate that conventional acupuncture therapy is effective in reducing the degree of pain in patients with TMD, especially those with myofascial pain symptoms.

Tooth loss is associated with increased risk of esophageal cancer: evidence from a meta-analysis with dose-response analysis.

Epidemiological studies have revealed the association between tooth loss and the risk of esophageal cancer (EC); however, consistent results were not obtained from different single studies. Therefore, we conducted the present meta-analysis to evaluate the association between tooth loss and EC. We conducted electronic searches of PubMed until to February 10, 2015 to identify relevant observational studies that examined the association between tooth loss and the risk of EC. Study selection and data extraction from eligible studies were independently performed by two authors. The meta-analysis was conducted using Stata 12.0 software. Finally eight eligible publications with ten studies involving 3 cohort studies, 5 case-control studies, and 1 cross-sectional study were yielded. Meta-analysis identified tooth loss increased risk of EC 1.30 times (Relative risk = 1.30, 95% confidence interval = 1.06-1.60, I(2) = 13.5%). Dose-response analysis showed linear relationship between tooth loss and risk of EC (RR = 1.01, 95%CI = 1.00-1.03; P for non-linearity test was 0.45). Subgroup analysis proved similar results and publication bias was not detected. In conclusion, tooth loss could be considered to be a significant and dependent risk factor for EC based on the current evidence.

Periodontal disease and carotid atherosclerosis: A meta-analysis of 17,330 participants.

BACKGROUND AND OBJECTIVES: The association between periodontal disease and carotid atherosclerosis has been evaluated primarily in single-center studies, and whether periodontal disease is an independent risk factor of carotid atherosclerosis remains uncertain. This meta-analysis aimed to evaluate the association between periodontal disease and carotid atherosclerosis. METHODS: We searched PubMed and Embase for relevant observational studies up to February 20, 2015. Two authors independently extracted data from included studies, and odds ratios (ORs) with 95% confidence intervals (CIs) were calculated for overall and subgroup meta-analyses. Statistical heterogeneity was assessed by the chi-squared test (P<0.1 for statistical significance) and quantified by the I(2) statistic. Data analysis was conducted using the Comprehensive Meta-Analysis (CMA) software. RESULTS: Fifteen observational studies involving 17,330 participants were included in the meta-analysis. The overall pooled result showed that periodontal disease was associated with carotid atherosclerosis (OR: 1.27, 95% CI: 1.14-1.41; P<0.001) but statistical heterogeneity was substantial (I(2)=78.90%). Subgroup analysis of adjusted smoking and diabetes mellitus showed borderline significance (OR: 1.08; 95% CI: 1.00-1.18; P=0.05). Sensitivity and cumulative analyses both indicated that our results were robust. CONCLUSIONS: Findings of our meta-analysis indicated that the presence of periodontal disease was associated with carotid atherosclerosis; however, further large-scale, well-conducted clinical studies are needed to explore the precise risk of developing carotid atherosclerosis in patients with periodontal disease.

Periodontal Disease and Incident Lung Cancer Risk: A Meta-Analysis of Cohort Studies.

BACKGROUND: Periodontal disease is linked to a number of systemic diseases such as cardiovascular diseases and diabetes mellitus. Recent evidence has suggested periodontal disease might be associated with lung cancer. However, their precise relationship is yet to be explored. Hence, this study aims to investigate the association of periodontal disease and risk of incident lung cancer using a meta-analytic approach. METHODS: PubMed, Scopus, and ScienceDirect were searched up to June 10, 2015. Cohort and nested case-control studies investigating risk of lung cancer in patients with periodontal disease were included. Hazard ratios (HRs) were calculated, as were their 95% confidence intervals (CIs) using a fixed-effect inverse-variance model. Statistical heterogeneity was explored using the Q test as well as the I(2) statistic. Publication bias was assessed by visual inspection of funnel plots symmetry and Egger's test. RESULTS: Five cohort studies were included, involving 321,420 participants in this meta-analysis. Summary estimates based on adjusted data showed that periodontal disease was associated with a significant risk of lung cancer (HR = 1.24, 95% CI = 1.13 to 1.36; I(2) = 30%). No publication bias was detected. Subgroup analysis indicated that the association of periodontal disease and lung cancer remained significant in the female population. CONCLUSION: Evidence from cohort studies suggests that patients with periodontal disease are at increased risk of developing lung cancer.

Interleukin-1ß rs1143634 polymorphism and aggressive periodontitis susceptibility: a meta-analysis.

Multiple studies had focused on the association between interleukin-1 (IL-1) rs1143634 polymorphism and aggressive periodontitis (AgP) susceptibility, but the results remained inconclusive. Therefore, this meta-analysis was conducted to explore its role in the development of AgP. PubMed and Embase databases were searched up to April 15, 2014. After study selection and data extraction form eligible studies, meta-analysis was performed. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to evaluate the association. All the analysis was performed using Comprehensive Meta-Analysis software. Finally a total of 25 case-control studies were included. The pooled results showed non-association between AgP susceptibility and IL-1 rs1143634 polymorphism [for T vs. C: OR = 0.99, 95% CI = 0.79-1.23; for TT vs. CC: OR = 1.14, 95% CI = 0.78-1.66; for CT vs. CC: OR = 0.97, 95% CI = 0.70-1.36; for (CT + TT) vs. CC: OR = 1.02, 95% CI = 0.76-1.37; for TT vs. (CT + CC): OR = 1.22, 95% CI = 0.85-1.75]. Subgroup analyses remain did not find any association. No publication bias was detected. Hence, our meta-analysis showed that IL-1ß rs1143634 polymorphism is not linked to AgP susceptibility, regardless of ethnicity.

Meta-analysis on the association between toothbrushing and head and neck cancer.

BACKGROUND: Epidemiological studies have focused on the association between toothbrushing and head and neck cancer (HNC). However, the question of whether toothbrushing is associated with decreased risk of HNC remains unanswered. Since there is currently no systematic review or meta-analysis available to provide quantitative findings on this important clinical question; we consequently performed this meta-analysis to investigate the association between toothbrushing and HNC risk. METHODS: We searched PubMed and Embase up to January 13 (updated on October 20), 2014 to identify observational studies that investigated the association between toothbrushing and HNC. After study section and data extraction, the meta-analysis was conducted using RevMan 5.2 software. RESULTS: A total of 18 case-control studies involving 7068 cases and 9990 controls were included. The meta-analysis showed that compared with highest toothbrushing frequency, lowest level was significantly increased risk of HNC 2.08 times (odds ratio=2.08, 95% confidence interval=1.65-2.62). This significant association remained consistent after adjusting for smoking status and alcohol consumption. No publication bias was detected. CONCLUSIONS: This meta-analysis found frequency of toothbrushing was significantly associated with HNC risk. Effective toothbrushing may be potentially important for the prevention of HNC and we suggest that the frequency be twice per day (morning and night).

Meta-Analysis of Association Between Interleukin-1ß C-511T Polymorphism and Chronic Periodontitis Susceptibility.

BACKGROUND: Many studies have been conducted to explore the association between interleukin (IL)-1ß C-511T polymorphism and risk of chronic periodontitis (CP) but with different or even contradictory results. A meta-analysis was performed to further explore their association. METHODS: PubMed, Chinese National Knowledge Infrastructure, and EMBASE were searched up to September 30, 2014 for relevant case-control studies. Two authors (D-YL and L-YX) independently selected studies and extracted data from included studies. The meta-analysis was performed using comprehensive meta-analysis software. RESULTS: Nineteen case-control studies involving 2,173 patients with CP and 3,900 healthy controls were included. Using a random-effects meta-analysis model, a non-significant association between IL-1ß C-511T polymorphism and CP was identified (T versus C: odds ratio [OR] = 1.03, 95% confidence interval [CI] = 0.85 to 1.25; TT versus CC: OR = 1.03, 95% CI = 0.72 to 1.46; CT versus CC: OR = 0.96, 95% CI = 0.71 to 1.30; CT + TT versus CC: OR = 1.00, 95% CI = 0.74 to 1.34; TT versus CT + CC: OR = 1.05, 95% CI = 0.81 to 1.38), and sensitivity analysis indicated that the results were robust. Subgroup analyses also revealed a non-significant association. No publication bias was detected. CONCLUSIONS: Based on currently available evidence, IL-1ß C-511T polymorphism is not associated with the risk of developing CP. Additional research is warranted to further explore and confirm the association of genetic polymorphism and CP.