The importance of genetic variants in TNFα for periodontal disease in a cohort of coronary patients

The association of tumor necrosis factor alpha, lymphotoxin alpha, tumor necrosis factor receptor 1 and tumor necrosis factor receptor 2 gene polymorphisms and serum levels with periodontitis and type 2 diabetes in Serbian population

OBJECTIVES

Aiming to show that periodontitis (PD) and type 2 diabetes (T2D) are bidirectionally related and potentially linked by inflammatory cytokines, we searched for association between -308 G/A Tumor necrosis factor-alpha (TNFα), +252A/G Lymphotoxin-alpha (LTα), +36A/G Tumor necrosis factor receptor 1 (TNFR1) and +676 T/G tumor necrosis factor receptor 2 (TNFR2) single nucleotide polymorphisms (SNPs) and: risk of PD or PD + T2D; periodontitis parameters in PD and PD + T2D; serum levels of cytokines/their receptors. Relationship between periodontal inflammation and serum cytokine/receptor levels was also assessed.

DESIGN

Subjects were stratified as: 57 healthy controls (HC); 58 PD; 65 PD + T2D. Sociodemographic, environmental, behavioral and periodontal clinical data were recorded. SNPs were genotyped using polymerase chain reaction-restriction fragment length polymorphism, while cytokines/receptors levels were quantified by enzyme-linked immunosorbent assay. Impact of periodontal inflammation was measured using periodontal inflamed surface area (PISA).

RESULTS

TNFα AA genotype showed protective effect in T2D + PD compared to PD, even adjusted for behavioral/environmental factors (OR 0.18; 95 %CI 0.037-0.886; p = 0.035). LTα AG heterozygotes had increased risk of PD (OR 3.27; 95 %CI 1.35-7.96; p = 0.016), while TNFR2 TG genotype had protective effect (OR = 0.44; 95 %CI 0.954-0.9794; p = 0.043). TNFR1 AA was predictor of periodontal pocket depth and clinical attachment loss in PD. Correlation between TNFR2 concentration and PISA was negative in PD, positive in PD + T2D.

CONCLUSIONS

None of the SNPs showed cross-susceptibility between PD and T2D. + 252A/G LTα and +676 T/G TNFR2 SNPs are associated with PD risk. Periodontal destruction in healthy individuals is influenced by TNFR1 genotype. Impact of periodontal on systemic inflammation is masked by T2D.

Detection of association between periodontitis and polymorphisms of IL-1β + 3954 and TNF-α -863 in the Korean population after controlling for confounding risk factors

Background and Objective

Interleukin (IL)‐1 and tumor necrosis factor (TNF)‐α are inflammatory cytokines that play an important role in periodontitis, and their genetic variations have been suggested to be associated with increased risk of periodontitis. Focusing on three single nucleotide polymorphisms (SNPs) of IL‐1α + 4845, IL‐1β + 3954, and TNF‐α −863, we aimed to investigate the relationship between periodontitis risk and the polymorphisms of IL‐1 α/β and TNF‐α in Koreans.

Material and Methods

Mouthwash samples from 548 subjects (135 controls without periodontitis, 387 generalized chronic periodontitis patients, and 26 generalized aggressive periodontitis patients) were collected for isolation of genomic DNA. Genotyping of selected SNPs was performed using real‐time PCR. Univariable associations between the polymorphisms and periodontitis were assessed by chi‐squared test or Fisher's exact test. To evaluate the association after controlling for confounding effects of various risk factors, we stratified the subjects according to the presence or absence of self‐reported diseases and employed multiple logistic regression model to adjust for age, smoking status, and oral hygiene indices and behaviors.

Results

Significant association of IL‐1β + 3954 and TNF‐α −863 polymorphisms with periodontitis was observed after adjusting for the confounding risk factors, but not in univariable association analysis. The significant association between genotype CT of IL‐1β + 3954 and increased risk of advanced periodontitis was consistently detected regardless of the status of self‐reported diseases. In the polymorphism of TNF‐α −863, the genotype with minor allele (CA + AA) was significantly associated with periodontitis susceptibility, which was observed only in the subjects with self‐reported diseases.

Conclusion

The results suggest that genetic variations of IL‐1β + 3954 and TNF‐α −863 are associated with increased risk of periodontitis in Koreans. In addition, our findings underscore the importance of controlling for confounding risk factors to detect significant association between genetic factors and risk of periodontitis. A further well‐designed large‐scale study is needed to warrant our results.

Periodontal inflammation: Integrating genes and dysbiosis

Biofilm bacteria co‐evolve and reach a symbiosis with the host on the gingival surface. The disruption of the homeostatic relationship between plaque bacteria and the host can initiate and promote periodontal disease progression. Recent advances in sequencing technologies allow researchers to profile disease‐associated microbial communities and quantify microbial metabolic activities and host transcriptional responses. In addition to confirming the findings from previous studies, new putative pathogens and novel genes that have not previously been associated with periodontitis, emerge. For example, multiple studies have reported that Synergistetes bacteria are associated with periodontitis. Genes involved in epithelial barrier defense were downregulated in periodontitis, while excessive expression of interleukin‐17 was associated with a hyperinflammatory response in periodontitis and with a unique microbial community. Bioinformatics‐enabled gene ontology pathway analyses provide a panoramic view of the bacterial and host activities as they shift from periodontal health to disease. Additionally, host innate factors, such as genetic variants identified by either a candidate‐gene approach or genome‐wide association analyses, have an impact on subgingival bacterial colonization. Transgenic mice carrying candidate genetic variants, or with the deletion of candidate genes mimicking the deleterious loss‐of‐function variant effect, provide experimental evidence validating the biologic relevance of the novel markers associated with the microbial phenotype identified through a statistical approach. Further refinement in bioinformatics, data management approaches, or statistical tools, are required to gain insight into host‐microbe interactions by harmonizing the multidimensional “big” data at the genomic, transcriptional, and proteomic levels.

Effectiveness of comprehensive cardiac rehabilitation in coronary artery disease patients treated according to contemporary evidence based medicine: Update of the Cardiac Rehabilitation Outcome Study (CROS-II)

Background

Despite numerous studies and meta-analyses the prognostic effect of cardiac rehabilitation is still under debate. This update of the Cardiac Rehabilitation Outcome Study (CROS II) provides a contemporary and practice focused approach including only cardiac rehabilitation interventions based on published standards and core components to evaluate cardiac rehabilitation delivery and effectiveness in improving patient prognosis.

Design

A systematic review and meta-analysis.

Methods

Randomised controlled trials and retrospective and prospective controlled cohort studies evaluating patients after acute coronary syndrome, coronary artery bypass grafting or mixed populations with coronary artery disease published until September 2018 were included.

Results

Based on CROS inclusion criteria out of 7096 abstracts six additional studies including 8671 patients were identified (two randomised controlled trials, two retrospective controlled cohort studies, two prospective controlled cohort studies). In total, 31 studies including 228,337 patients were available for this meta-analysis (three randomised controlled trials, nine prospective controlled cohort studies, 19 retrospective controlled cohort studies; 50,653 patients after acute coronary syndrome 14,583, after coronary artery bypass grafting 163,101, mixed coronary artery disease populations; follow-up periods ranging from 9 months to 14 years). Heterogeneity in design, cardiac rehabilitation delivery, biometrical assessment and potential confounders was considerable. Controlled cohort studies showed a significantly reduced total mortality (primary endpoint) after cardiac rehabilitation participation in patients after acute coronary syndrome (prospective controlled cohort studies: hazard ratio (HR) 0.37, 95% confidence interval (CI) 0.20–0.69; retrospective controlled cohort studies HR 0.64, 95% CI 0.53–0.76; prospective controlled cohort studies odds ratio 0.20, 95% CI 0.08–0.48), but the single randomised controlled trial fulfilling the CROS inclusion criteria showed neutral results. Cardiac rehabilitation participation was also associated with reduced total mortality in patients after coronary artery bypass grafting (retrospective controlled cohort studies HR 0.62, 95% CI 0.54–0.70, one single randomised controlled trial without fatal events), and in mixed coronary artery disease populations (retrospective controlled cohort studies HR 0.52, 95% CI 0.36–0.77; two out of 10 controlled cohort studies with neutral results).

Conclusion

CROS II confirms the effectiveness of cardiac rehabilitation participation after acute coronary syndrome and after coronary artery bypass grafting in actual clinical practice by reducing total mortality under the conditions of current evidence-based coronary artery disease treatment. The data of CROS II, however, underscore the urgent need to define internationally accepted minimal standards for cardiac rehabilitation delivery as well as for scientific evaluation.

Periodontal Infectogenomics

Periodontal diseases are chronic infectious disease in which the pathogenic bacteria initiate the host immune response leading to the destruction of tooth supporting tissue and eventually result in the tooth loss. It has multifactorial etiological factors including local, systemic, environmental and genetic factors. The effect of genetic factors on periodontal disease is already under extensive research and has explained the role of polymorphisms of immune mediators affecting disease response. The role genetic factors in pathogens colonisation is emerged as a new field of research as "infectogenomics". It is a rapidly evolving and high-priority research area now days. It further elaborates the role of genetic factors in disease pathogenesis and help in the treatment, control and early prevention of infection. The aim of this review is to summarise the contemporary evidence available in the field of periodontal infectogenomics to draw some valuable conclusions to further elaborate its role in disease pathogenesis and its application in the clinical practice. This will open up opportunity for more extensive research in this field.

The prognostic effect of cardiac rehabilitation in the era of acute revascularisation and statin therapy: A systematic review and meta-analysis of randomized and non-randomized studies - The Cardiac Rehabilitation Outcome Study (CROS)

Background

The prognostic effect of multi-component cardiac rehabilitation (CR) in the modern era of statins and acute revascularisation remains controversial. Focusing on actual clinical practice, the aim was to evaluate the effect of CR on total mortality and other clinical endpoints after an acute coronary event.

Design

Structured review and meta-analysis.

Methods

Randomised controlled trials (RCTs), retrospective controlled cohort studies (rCCSs) and prospective controlled cohort studies (pCCSs) evaluating patients after acute coronary syndrome (ACS), coronary artery bypass grafting (CABG) or mixed populations with coronary artery disease (CAD) were included, provided the index event was in 1995 or later.

Results

Out of n = 18,534 abstracts, 25 studies were identified for final evaluation (RCT: n = 1; pCCS: n = 7; rCCS: n = 17), including n = 219,702 patients (after ACS: n = 46,338; after CABG: n = 14,583; mixed populations: n = 158,781; mean follow-up: 40 months). Heterogeneity in design, biometrical assessment of results and potential confounders was evident. CCSs evaluating ACS patients showed a significantly reduced mortality for CR participants (pCCS: hazard ratio (HR) 0.37, 95% confidence interval (CI) 0.20–0.69; rCCS: HR 0.64, 95% CI 0.49–0.84; odds ratio 0.20, 95% CI 0.08–0.48), but the single RCT fulfilling Cardiac Rehabilitation Outcome Study (CROS) inclusion criteria showed neutral results. CR participation was also associated with reduced mortality after CABG (rCCS: HR 0.62, 95% CI 0.54–0.70) and in mixed CAD populations.

Conclusions

CR participation after ACS and CABG is associated with reduced mortality even in the modern era of CAD treatment. However, the heterogeneity of study designs and CR programmes highlights the need for defining internationally accepted standards in CR delivery and scientific evaluation.

Rehabilitation in Patients With Coronary Heart Disease: Participation and Its Effect on Prognosis

BACKGROUND

In Germany, rehabilitation is considered to be indicated after an acute hospital stay for the treatment of a severe cardiac condition. In comparative studies, at least 51% of German hospital patients with coronary heart disease (CHD) who were entitled to rehabilitative measures actually took part n rehabilitation.

METHODS

We examined data on 1910 patients with CHD who took part in two prospective cohort studies at the University Hospital of Halle (Saale) in the years 2007-2011. We contacted these patients again with a questionnaire to determine which ones had undergone rehabilitation. For patients who died before we could contact them, the attempt was made to obtain the dates and causes of death from the local authorities. The primary endpoint of was overall mortality.

RESULTS

The median duration of follow-up was 136 ± 71 weeks. 727 patients (38.1%) had applied for rehabilitation during their acute hospitalization, but only 552 patients (28.9%) actually underwent it. Patients who did not undergo rehabilitation were older than those who did (68.6 ± 10.3 vs. 64.9 ± 10.5 years) and suffered more commonly from diabetes (41.3% vs. 33.7%; p = 0.002), arterial hypertension (89.2% vs. 85.3%; p = 0.017), and peripheral arterial occlusive disease (15.3% vs. 9.8%; p = 0.002). There were more smokers in the rehabilitation group. Kaplan-Meier analysis and multivariate Cox regression analysis both showed that the patients who underwent rehabilitation had lower mortality (hazard ratio 0.067, 95% confidence interval 0.025-0.180, p < 0.001).

CONCLUSION

Rehabilitation for cardiac patients was associated with lower mortality. Fewer patients underwent rehabilitation in this study than in other, comparable studies. Those who did not were older and had a greater burden of accompanying disease.

Polymorphisms in the interleukin-10 gene and chronic periodontitis in patients with atherosclerotic and aortic aneurysmal vascular diseases

Background

Chronic periodontitis (CP), atherosclerotic and aortic aneurysmal vascular diseases (VD) are chronic inflammatory conditions with multifactorial etiologies, including involvement of predisposing genetic factors. In a previous study, polymorphisms in the gene for the anti-inflammatory interleukin-1 receptor antagonist were associated with CP in patients with VD.

Objective

This study investigates whether polymorphisms in the gene for the anti-inflammatory interleukin-10 (IL10) could be related to CP in the same manner.

Methods

Seventy-two patients with VD of whom 35 had CP were genotyped for single nucleotide polymorphisms (SNPs) in the IL10 −592 (rs1800872), −819 (rs1800871), and −1,082 (rs1800896) gene by Taqman rtPCR method and by DNA sequencing.

Results

The C alleles and C/C genotypes of IL10 −592 and IL10 −819 frequencies were significantly higher, while the frequencies of the IL10 −592 (C/A) and IL10 −819 (C/T) heterozygote genotypes were significantly lower in the VD group with CP compared to those without CP. The IL10 haplotype ATA frequency (−1,082, −819, −592) showed a trend to a significant difference between the two groups indicating protection against CP.

Conclusions

Taken together, our findings suggest an independent association of genetic polymorphisms in the IL-10 gene locus with CP in patients with VD. Development of CP and the implications on vascular disease emphasize the importance of early detection and adequate treatment of periodontitis among these patients.