Salivary cytokines and the association between obstructive sleep apnea syndrome and periodontal disease

Effects of dental insurance and dental care utilization on oral health-related daily life activities among federally qualified healthcare center patients in the United States

OBJECTIVES

To assess the association between dental insurance, dental care utilization and oral health-related impact on daily activities among patients visiting Health Resources and Services Administration (HRSA)-funded health centers in the United States.

METHODS

This cross-sectional study examined the 2014 Health Center Patient Survey (HCPS), a survey of patients who received care at US health centers. Logistic regression analyses were conducted to explore the likelihood of the oral health-related impact on daily activities domains such as school/work performance, sleeping, eating/chewing, social and home activities considering sociodemographic, dental insurance, and dental care utilization.

RESULTS

Among 7002 total participants, 6890 self-reported oral health-related impact on daily activities. Adults aged 18-44 were 2.6 times more likely to report an overall impact on everyday life activities compared to children and adolescents. After adjusting for sociodemographics, Hispanic patients were less likely to report any oral health-related impacts, while patients visiting rural centres reported higher odds of oral health related impairment. Patients who experienced delays in receiving dental care or were unable to access dental care when needed were 4.5 times more likely to encounter difficulties in their daily activities.

CONCLUSIONS

This study linked limited dental insurance and care to increased oral health issues impacting daily life, particularly among adults, rural populations, and those facing delay in dental care. This highlights the need for policy reforms and interventions aimed at improving dental care access to mitigate the detrimental effects of poor oral health on daily functions for vulnerable populations.

Genetically predicted obstructive sleep apnea is causally associated with an increased risk for periodontitis

BACKGROUND

Although obstructive sleep apnea (OSA) and periodontitis are associated, whether this association is causative is uncertain.

METHODS

We conducted a bidirectional Mendelian randomization (MR) analysis using data from publically accessible genome-wide association studies. The single-nucleotide polymorphisms (SNPs) for OSA were derived from 16,761 cases and 201,194 controls. The pooled data of periodontitis association involved up to 17,353 individuals. Disease-associated single-nucleotide polymorphisms were selected as an instrumental variable at the genome-wide significance level (p < 5.0 × 10- 6). Subsequently, the causal effects were estimated using three different methods: inverse variance weighting (IVW), MR-Egger, and weighted median. Then, these causal estimates were expressed as dominance ratios [odds ratio (OR)].

RESULTS

The MR analysis revealed that genetically determined OSA promotes the development of periodontitis [ IVW OR = 1.117, 95% confidence interval (CI) = 1.001-1.246, p = 0.048). Furthermore, no causal effect of genetically predicted periodontitis on OSA was noted in the reverse MR analysis (IVW OR = 1, 95% CI: 0.95-1.06, p = 0.87). The trend in results from the MR-Egger regression and weighted median (WM) was consistent with that in results from the IVW method. The robustness of the results was confirmed by the sensitivity analysis.

CONCLUSIONS

In summary, the results of our MR investigation suggest an association between OSA and periodontitis, proposing that early screening and treatment of OSA is beneficial for the prevention and prognosis of periodontitis.

Relationship of obstructive sleep apnea with periodontal condition and its local and systemic risk factors

OBJECTIVE

Obstructive sleep apnea (OSA) and periodontitis share risk factors, such as age, obesity, stress, and cardiovascular events, which have a bidirectional cause-effect relationship through systemic inflammation. Our objective was to determine the relationship between OSA and the periodontal condition and its associated local and systemic risk factors.

MATERIAL AND METHODS

This was an observational case-control study involving 60 patients. Local oral risk factors and the systemic condition of each patient were evaluated. All patients underwent polysomnography for the diagnosis of OSA. Chi-squared, one-way ANOVA, and Bonferroni's tests were performed.

RESULTS

A higher percentage of patients with periodontitis had severe OSA (66.66%); however, no statistically significant association was found between the two pathologies (p = 0.290). In terms of systemic risk factors, an association was found between arterial hypertension and severe OSA (p = 0.038), and in terms of local factors, an association was found between the use of removable prostheses and severe OSA (p = 0.0273).

CONCLUSION

In the general population, patients with periodontitis showed a higher prevalence of severe OSA. Obesity and hypothyroidism were the most prevalent systemic findings in patients with OSA and periodontitis. Arterial hypertension and osteoarthritis were found to be associated with severe OSA. The local risk factors associated with periodontitis and severe OSA were removable partial dentures and misfit resins.

CLINICAL RELEVANCE

To study the factors that can facilitate the progression of OSA and periodontitis, physicians and dentists should be advised to provide comprehensive care for patients with both pathologies.

Biomarkers for the severity of periodontal disease in patients with obstructive sleep apnea:IL-1 β, IL-6, IL-17A, and IL-33

Objective

This study aims to compare the salivary and gingival crevicular fluid (GCF) concentrations of five cytokines: IL-1β, IL-6, IL-17A, IL-33, and Tumor Necrosis Factor-alpha (TNF-α) in patients with OSA and their association with periodontitis.

Methods

Samples of saliva and GCF were obtained from 84 patients classified into four groups according to periodontal and OSA diagnosis: G1(H) healthy patients, G2(P) periodontitis and non-OSA patients, G3(OSA) OSA and non-periodontitis patients, and G4(P-OSA) periodontitis and OSA patients. The cytokines in the samples were quantified using multiplexed bead immunoassays. Data were analyzed with the Kruskal-Wallis test, Dunn's multiple comparisons test, and the Spearman correlation test.

Results

Stage III periodontitis was the highest in patients with severe OSA (69%; p=0.0142). Similar levels of IL-1β and IL-6 in saliva were noted in G2(P) and G4(P-OSA). The IL-6, IL-17A and IL-33 levels were higher in the GCF of G4(P-OSA). There was a significant positive correlation between IL-33 in saliva and stage IV periodontitis in G4(P-OSA) (r _s  = 0.531). The cytokine profile of the patients in G4(P-OSA) with Candida spp. had an increase of the cytokine's levels compared to patients who did not have the yeast.

Conclusions

OSA may increase the risk of developing periodontitis due to increase of IL-1β and IL-6 in saliva and IL-6, IL-17A and IL-33 in GCF that share the activation of the osteoclastogenesis. Those cytokines may be considered as biomarkers of OSA and periodontitis.

Patients with obstructive sleep apnea can favor the predisposing factors of periodontitis by the presence of P. melaninogenica and C. albicans, increasing the severity of the periodontal disease

Objective

The aim of this study was to analyze the cultivable oral microbiota of patients with obstructive sleep apnea (OSA) and its association with the periodontal condition.

Methods

The epidemiology profile of patients and their clinical oral characteristics were determined. The microbiota was collected from saliva, subgingival plaque, and gingival sulcus of 93 patients classified into four groups according to the periodontal and clinical diagnosis: Group 1 (n = 25), healthy patients; Group 2 (n = 17), patients with periodontitis and without OSA; Group 3 (n = 19), patients with OSA and without periodontitis; and Group 4 (n = 32), patients with periodontitis and OSA. Microbiological samples were cultured, classified, characterized macroscopically and microscopically, and identified by MALDI-TOF-MS. The distribution of complexes and categories of microorganisms and correlations were established for inter- and intra-group of patients and statistically evaluated using the Spearman r test (p-value <0.5) and a multidimensional grouping analysis.

Result

There was no evidence between the severity of OSA and periodontitis (p = 0.2813). However, there is a relationship between the stage of periodontitis and OSA (p = 0.0157), with stage III periodontitis being the one with the highest presence in patients with severe OSA (prevalence of 75%; p = 0.0157), with more cases in men. The greatest distribution of the complexes and categories was found in oral samples of patients with periodontitis and OSA (Group 4 P-OSA); even Candida spp. were more prevalent in these patients. Periodontitis and OSA are associated with comorbidities and oral conditions, and the microorganisms of the orange and red complexes participate in this association. The formation of the dysbiotic biofilm was mainly related to the presence of these complexes in association with Candida spp.

Conclusion

Periodontopathogenic bacteria of the orange complex, such as Prevotella melaninogenica, and the yeast Candida albicans, altered the cultivable oral microbiota of patients with periodontitis and OSA in terms of diversity, possibly increasing the severity of periodontal disease. The link between yeasts and periodontopathogenic bacteria could help explain why people with severe OSA have such a high risk of stage III periodontitis. Antimicrobial approaches for treating periodontitis in individuals with OSA could be investigated in vitro using polymicrobial biofilms, according to our findings.

Association between obstructive sleep apnea and periodontitis in Chinese male adults: A cross-sectional study

STATEMENT OF PROBLEM

An association between obstructive sleep apnea and periodontitis has been suggested, but supporting data are lacking.

PURPOSE

The purpose of this cross-sectional study was to investigate any association between obstructive sleep apnea and periodontitis in Chinese male adults.

MATERIAL AND METHODS

Ninety-three male adults (aged between 24 and 35 years) were recruited and examined between June and September 2019. Obstructive sleep apnea was diagnosed by using portable, overnight polysomnography, and all participants were classified into study and control groups based on the apnea-hypopnea index. Periodontal examinations were conducted before polysomnography measuring probing depth, clinical attachment level, and bleeding on probing. An objective nasal airway resistance assessment was also performed before polysomnography to quantify mouth breathing during sleep.

RESULTS

Overall, 40 (43.0%) participants had periodontitis, and 19 (20.4%) had obstructive sleep apnea; in those diagnosed with periodontitis, 13 of 40 (32.5%) also had obstructive sleep apnea. Obstructive sleep apnea was positively associated with periodontitis (odds ratio =3.719, 95% CI=1.234 to 11.209, P=.020). The obstructive sleep apnea group showed significantly higher bleeding on probing (P=.034) and clinical attachment level (P=.046). Correlation analysis showed a weak but positive correlation between the severity of obstructive sleep apnea and that of periodontitis. The regression analysis identified the lowest oxygen saturation (odds ratio=0.894, 95% CI=0.842 to 0.949, P=.002) to be significantly associated with the prevalence of periodontitis.

CONCLUSIONS

A significant association was observed between obstructive sleep apnea and periodontitis. Low oxygen saturation might be a predictive index for periodontitis, suggesting that hypoxia caused by obstructive sleep apnea might be related to the symptoms of periodontitis.

Obstructive Sleep Apnea and Periodontal Disease: A Systematic Review

Background and Objectives: The objective of this study was to evaluate the association between periodontal disease and obstructive sleep apnea syndrome (OSAS). Materials and Methods: Electronic search using PubMed, Scopus, LILACS, and Cochrane library was carried out for randomized controlled trials, cohort, case-control, longitudinal and epidemiological studies on humans published from January 2009 until September 2020. The participants had to be male and female adults who were diagnosed with OSAS either by overnight polysomnography (carried out at a sleep laboratory or at home) or by a home sleep testing monitor (Apnea Risk Evaluation System). Methodological quality assessment was carried out using the Newcastle-Ottawa Quality Assessment Scale (NOS) for case-control studies while an adapted form of NOS was used for cross-sectional studies. Results: Ten studies fulfilled the inclusion criteria of our review, 5 were case-control studies, and 5 cross-sectional. Sample size ranged from 50 to 29,284 subjects, for a total of 43,122 subjects, 56% of them were male, their age ranged from 18 to 85 years old. The heterogeneity among the studies regarding the classification of periodontal disease, and the different methods for OSAS severity assessment, complicated the comparison among the studies. Conclusions: There is low evidence of a possible association between OSAS and periodontitis. The pathophysiological mechanism, cause-effect, or dose-response relationship are still unclear. Further studies are needed and should use a precise classification of OSAS subjects, while the new classification of periodontitis from the World Workshop of Chicago 2017 should be used for the periodontal assessment.

Pentraxin-3 detected in human saliva shows limited correlation with biomarkers associated with systemic inflammation

Pentraxin-3 (PTX3) is a conserved protein of the innate immune system which has been less studied than the pentraxin C-reactive protein (CRP), but it is of relevance in, for example, vascular pathology and pregnancy morbidities. Since the interest in salivary biomarkers in general is increasing, we asked whether PTX3 could be detected in saliva and if any substantial diurnal variation occurs. In addition, we evaluated association with biomarkers of systemic inflammation (interleukin (IL)-1β, IL-6, and IL-8 and CRP), body mass index (BMI), smoking, and age. PTX3 in morning and evening saliva from 106 middle-aged participants of the general population was investigated by ELISA and total protein levels by spectrophotometry. PTX3 was detectable in saliva, and concentrations varied over the day with higher morning concentrations, but the PTX3 relative protein levels (percentage of total protein) were significantly higher in the evening. Sex and age did not impact salivary PTX3, but smoking was associated with lower PTX3 levels. BMI correlated positively with PTX3 in evening saliva. There was no general association with biomarkers of systemic inflammation, except for IL-6. Salivary PTX3 likely reflects the local inflammatory milieu, and adjustments for sampling time, smoking habits, and BMI are needed to adequately interpret PTX3 in saliva.

Cytokines in saliva as biomarkers of oral and systemic oncological or infectious diseases: A systematic review

Recent evidence suggests that salivary cytokines provide information about both oral conditions and systemic diseases. This review summarizes evidence for the use of salivary cytokines as biomarkers for oral and systemic diseases. We included studies in adults and children with a focus on the latter, due to the importance of non-invasive diagnostic methods in the paediatric age group. A systematic review was performed using Medline and Web of Science covering the period of January 1996 to December 2019 according to the preferred reporting items for systematic reviews. Thirty-four studies were included in the final analysis, for a total of 2407 patients and healthy controls. Pro-inflammatory cytokines including interleukin (IL)-1β, IL-2, IL-6 and tumor necrosis factor (TNF)-α were associated with the severity of oral mucosal tissue damage in patients with cancer, and IL-1β may be an early marker of graft-versus-host disease. Salivary interferon-γ levels were correlated with oral complications and the presence of the underlying disease in HIV-infected individuals, and salivary cytokine patterns may be useful for diagnosing tuberculosis. In summary, current data illustrate that salivary cytokines are associated with oral inflammation, making them potential biomarkers for disease diagnosis and treatment efficacy. Because of the simplicity of saliva collection, this method may be useful in pediatric studies and in resource-limited settings.

Study on the association between sleep disorders versus oral health related variables

Background

To study the association between sleep quality and oral health related variables, which still have conflicts in the literature.

Material and Methods

This was a population-based case-control study between subjects with versus without sleep disorders from the Brazilian Public Health System (SUS), city of Maringá (N=1,643). Subjects answered self-reported questionnaires: a) Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD), b) Sleep Assessment Questionnaire (SAQ) and c) North York Dental Health Survey (NYDHS).

Results

No significant difference was found for gender, marital status, or income; however, non-Caucasians, people with lower levels of education, and those between 20 to 50 years old had worse scores of sleep disorders in the SAQ. Self-perceived oral health, masticatory capacity to eat foods, and gingival bleeding was significantly worse among subjects with self-reported sleep disorders. Self-reported tooth loss, edentulism and use of removable partial dentures (with clasps) or complete dentures showed no significant difference between groups. Self-reported sleep disorder subjects presented significantly higher prevalence of both self-reported tooth and TMJ pain.

Conclusions

It can be concluded that individuals with self-reported sleep disorders presented worse self-perceived oral health for most studied variables.

Key words:Oral health, case control study, sleep; review, gingivitis, periodontitis, tooth loss.

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.

Salivary Inflammatory Molecules as Biomarkers of Sleep Alterations: A Scoping Review

Poor sleep quality and sleep disorders are the most common problems in people, affecting health-related quality of life. Various studies show an association between sleep disorders and altered levels of stress hormones and inflammatory cytokines measured in saliva. The main objective of this article is to provide an analysis of the current evidence related to changes in inflammatory markers in the saliva and their associations with sleep quality measurement (both objective and subjective methods) in healthy subjects and in sleep-related disorders. To that end, a scoping review was carried out, following the PRISMA criteria in the bibliographic search in several databases: PubMed, EBSCO, and SCOPUS. Eleven of the articles are from the adult population and two from the child-youth population. They mainly measure the relationship between sleep and interleukin-1β (IL-1β), interleukin-6 (IL-6), and tumor necrosis factor alpha (TNFα) alpha, as well as other inflammatory markers such as myeloperoxidase (MPO) and prostaglandin-endoperoxide synthase 2. An analysis shows the relationship between these salivary biomarkers and sleep quality, especially in the case of IL-6 in both healthy subjects and several pathologies associated with sleep-disorders. The results for TNFα and IL-1β measurements are still inconclusive and the difference with IL-6 was assessed. Two studies reported interventions that result in sleep improvement and are accompanied by the normalization of inflammatory changes detected in the saliva. As it is an easy-to-apply and non-invasive method, the measurement of salivary cytokines can be very useful in chronobiology studies. Further studies are required to determine the sensitivity of salivary inflammatory markers in monitoring biological rhythms and acting as biomarkers in the detection of sleep disorders and sleep interventions.

Salivary biomarkers associated with obstructive sleep apnea: a systematic review

Introduction: This study aimed to define and characterize current literature describing salivary biomarker changes with the goal of improving diagnosis and treatment outcomes for sleep apnea.Area Covered: A search of six databases yielded 401 peer-reviewed articles published through October 2019 corresponded to 221 unique references following deduplication. Twenty studies were selected. The sample size ranged from 17 to 99. The samples were mostly whole saliva and selected glandular areas.Expert Opinion: Most targeted studies focused on the level of salivary cortisol and ɑ-amylase. One study used RNA transcriptome analysis of 96 genes. Only two explored novel targets using mass spectrometry. ɑ-amylase, myeloperoxidase, and IL-6 were among those biomarkers found associated with OSA. Cytokeratin, CystatinB, calgranulin A, and alpha-2-HS-glycoprotein are upregulated in OSA patients based on non-targeting mass spectrometry. Salivary cortisol and ɑ-amylase and others appeared to be associated with severity of OSA and OSA treatment. There were inconsistencies in saliva collection and processing protocols. More studies are needed in exploring novel biomarkers to examine if these biomarkers are capable of diagnosing and monitoring OSA through proteomics or transcriptomics. Salivary biomarkers have a potential to be a noninvasive measure for the disease diagnosis and treatment outcome monitoring for sleep apnea.

A review of T helper 17 cell-related cytokines in serum and saliva in periodontitis

Periodontitis is a chronic inflammatory disease with a complex underlying immunopathology. Cytokines, as molecular mediators of inflammation, play a role in all stages of disease progression. T helper 17 (Th17) cells are thought to play a role in periodontitis. Th17 cell development and maintenance requires a pro-inflammatory cytokine milieu, with many of the cytokines implicated in the pathogenesis of periodontitis. Serum and saliva are easily accessible biofluids which can represent the systemic and local environment to promote the development of Th17 cells. Here we review human clinical studies that investigate IL-1β, IL-4, IL-6, IL-10, IL-17A, IL-17F, IL-21, IL-22, IL-23, IL-25, IL-31, IL-33, IFN-γ, sCD40L and TNF-α in serum and saliva in periodontitis. We highlight their putative role in the pathogenesis of periodontitis and place them within a wider context of animal and other clinical studies.

[Obstructive Sleep disordered breathing, sleep bruxism and periodontal diseases]

Sleep disordered breathing (SDB) may be associated with sleep bruxism and periodontal diseases. Through a review of the current literature, this article aims to describe the characteristics of sleep bruxism and its relationship with SDB as well as the current evidence supporting an association between periodontal diseases and SDB. Sleep bruxism is characterized by muscle clenching and tooth grinding during sleep, typically during N2 sleep stage and in association with micro-arousals. The probability of observing sleep bruxism is almost 4 times higher in the presence of SDB, with a close temporal relationship between the episode of upper airway obstruction or oxygen desaturation and the episode of bruxism, which most often occurs in the 0-10 seconds following the obstruction. These findings support the hypothesis that sleep bruxism is triggered by SDB and may have a "protective" role being a muscular activity that helps restore the permeability of the upper airways. On the other hand, SDB have been linked to periodontal diseases. Periodontal diseases are inflammatory and dysbiotic disorders that can have a negative impact on oral health (leading to the destruction of the periodontium and tooth loss) and on general health. Recently, it has been observed that SDB patients have a 1.6 to 4-fold higher risk of having or developing severe periodontitis, suggesting that SDB may be a new risk factor for periodontal diseases. Dentists, who are part of the team of sleep medicine specialists, have a key role in the detection, prevention and treatment of SDB and their relationship with sleep bruxism and periodontal diseases.

Correlations between Interleukin-33 and -1α Levels in Gingival Crevicular Fluid and Plasma in Patients with Chronic or Aggressive Periodontitis and Disease-free Subjects

Interleukin (IL)-33 is a dual-function protein that may play important roles as both a cytokine and intracellular nuclear factor. It may also function similarly to prototypical alarmin IL-1α, as an endogenous danger signal to alert innate immune system cells to tissue damage during trauma or infection, as it can be released in the extracellular space after endothelial cell damage or mechanical injury. The aim of this study was to determine possible correlations between concentrations of IL-33 and IL-1α in gingival crevicular fluid (GCF) and plasma obtained from healthy patients, those with chronic periodontitis (CP), and those with generalized aggressive periodontitis (GAP) patients. Forty-five patients with an age range of 20-60 years were enrolled and divided into 3 groups: Group H, 30 samples (15 GCF and 15 plasma) from 15 patients with healthy periodontium; Group CP, 30 samples from 15 patients with CP; and Group GAP, 30 samples from 15 patients with GAP. The clinical periodontal parameters investigated in all groups comprised the gingival index score, probing pocket depth, and clinical attachment level. The GCF and plasma levels of IL-33 and IL-1α were quantitated using enzyme linked immunosorbent assay. The mean IL-33 concentrations in GCF and plasma were highest in Group GAP, followed by Group CP, with the lowest in Group H; the difference among them was statistically significant (p<0.05). Concentration of IL-1α followed the same trend as that of IL-33 in GCF, but was lower than detection levels in plasma. The GCF and plasma concentrations of IL-33 correlated with IL-1α concentrations in GCF. Concentrations of IL-33 and IL-1α in GCF varied significantly between healthy patients and those with disease, allowing healthy patients to be distinguished from those with GAP or CP. The results of this study suggest that IL-33 offers a potential inflammatory marker of periodontal disease, similar to IL-1α.

IL-33 Mediated Inflammation in Chronic Respiratory Diseases-Understanding the Role of the Member of IL-1 Superfamily

Interleukin 33 (IL-33) is an alarmin cytokine from the IL-1 family. IL-33 is localized in the nucleus and acts there as a gene regulator. Following injury, stress or cell death, it is released from the nucleus, and exerts its pro-inflammatory biological functions via the transmembrane form of the ST2 receptor, which is present mainly as attached to immune cells. In recent years, IL-33 became a focus of many studies due to its possible role in inflammatory disorders. Among respiratory disorders, the contribution of IL-33 to the development of asthma, in particular, has been most identified. Increased level of IL-33 in lung epithelial cells and blood serum has been observed in asthma patients. The IL-33/ST2 interaction activated the Th2 mediated immune response and further production of many pro-inflammatory cytokines. Single nucleotide polymorphisms in the IL-33 gene cause a predisposition to the development of asthma. Similarly, in chronic pulmonary obstructive disease (COPD), both increased expression of IL-33 and the ST2 receptor has been observed. Interestingly, cigarette smoke, a key inducer of COPD, not only activates IL-33 production by epithelial and endothelial cells, but also induces the expression of IL-33 in peripheral blood mononuclear cells. Knowledge regarding its contribution in other respiratory disorders, such as obstructive sleep apnea, remains greatly limited. Recently it was shown that IL-33 is one of the inflammatory mediators by which levels in blood serum are increased in OSA patients, compared to healthy control patients. This mini review summarizes current knowledge on IL-33 involvement in chosen chronic respiratory disorders and proposes this interleukin as a possible link in the pathogenesis of these diseases.

Short-term effects of continuous positive airway pressure on oxidative stress in severe sleep apnea

PURPOSE

Obstructive sleep apnea (OSA) is associated with oxidative stress that is involved in the pathogenesis of cardiovascular and metabolic complications. The concentrations of salivary markers of oxidative stress in patients with OSA increase considerably during the night. The dynamics is not affected by continuous positive airway pressure (CPAP) in mild to moderate OSA. The aim of this study was to analyze the short-term effects of CPAP on salivary oxidative stress markers in patients with severe OSA.

METHODS

Salivary samples were collected from 24 patients with apnea-hypopnea index higher than 30 during the first (diagnostic) night, who were treated by CPAP during the second (therapeutic) night.

RESULTS

The salivary markers of oxidative stress (TBARS, AGEs, and AOPP) were higher in the morning after the diagnostic night when compared to the evening concentrations (p < 0.01 for TBARS and p < 0.05 for AGEs and AOPP). Treatment by CPAP significantly decreased the morning concentrations of TBARS, AOPP (p < 0.01 for both), and AGEs (p < 0.05). Also, TBARS and AGEs positively correlated with apnea-hypopnea index (r = 0.48 and 0.49, respectively; p < 0.05). Antioxidant statuss was not affected.

CONCLUSION

Severe OSA is associated with increased levels of saliva markers for lipid peroxidation, protein oxidative damage, and carbonyl damage. Even short-term CPAP partially prevents oxidative and carbonyl stress during the night and this can be monitored non-invasively using saliva.

Interleukin-21 and its association with chronic periodontitis

Context:

Interleukin-21 (IL-21) is a pleiotropic cytokine, well documented to contribute to the development of Th17 cells which have been shown to play an important role in the pathogenesis of periodontitis. Periodontal disease is a chronic infection of tooth-supporting tissue.

Aim:

This study evaluates the saliva and serum levels of IL-21 in patients with chronic periodontitis and periodontally healthy individuals.

Settings and Design:

The present study was carried out in the Department of Microbiology in association with Department of Oral Medicine and Radiology, Maratha Mandal's N.G.H Institute of Dental Sciences and Research Centre, Belgavi, Karnataka.

Materials and Methods:

Fifty samples of each group were included in the present study. The levels of IL-21 were assessed using a commercially available enzyme-linked immunosorbent assay (ELISA) kit and the results were expressed as pg/mL.

Statistical Analysis Used:

Statistical analysis was performed using SPSS 17.0 software. Data were expressed as mean ± standard deviation and interquartile ranges and comparison of controls and cases by Mann–Whitney test.

Results:

Serum and salivary levels of IL-21 were significantly higher in chronic periodontitis group than in controls (P < 0.001). Clinical periodontal parameters correlated positively with serum IL-21 levels.

Conclusions:

IL-21 is highly expressed in patients with chronic periodontitis and correlated well with clinical parameters of periodontal destruction. Therefore, IL-21 appears to play a role in tissue destruction and can be used as diagnostic biomarker in chronic periodontitis. Saliva can be considered to be a useful alternative to serum as a diagnostic sample.

Changes in inflammatory mediators as a result of intermittent hypoxia in obstructive sleep apnea syndrome

BACKGROUND

Inflammation plays an important role in obstructive sleep apnea syndrome (OSAS). The objective of this study was to investigate the relationship of serum C-reactive protein (CRP), pentraxin-3 (PTX-3), procalcitonin (ProCT), interleukin-33 (IL-33) and its soluble receptor ST2 (sST2) with the syndrome severity and to show theirs importance as biomarkers.

METHODS

This study comprises a total of 84 identical (sex and age wise) cases. Full-night polysomnography was performed in each patient. OSAS diagnosis and severity index being based on the widely used criterion known as Apnea Hypopnea Index(AHI). Subgroups were as follows: 24(AHI < 5) controls, 28 mild-moderate OSAS(AHI 5-30) and 32 severe OSAS(AHI > 30).

RESULTS

PTX-3, IL-33 and sST2 receptors were significantly higher in OSAS groups than the control group (P < .001). However, both CRP and ProCT levels were similar in all subjects. There was a positive correlation between PTX-3 and BMI (r = 0.446; P < .01), ODI (r = 0.555; P < .01), IL-33 (r = 0.348; P = .001) and sST2 (r = 326; P = .002), while there was a negative correlation with minimum SaO₂ (r = -0.672; P < .01) in patient group. PTX-3 as a predictor of OSAS showed highest specificity (%91.7) and sensitivity (%91.7) (P < .001).

CONCLUSIONS

PTX-3 can be a new indicator reflecting the inflammatory state in patients with OSAS. Since patients with OSAS could have more hypoxic state during sleep, we found higher PTX-3 level in those patients and a negative correlation between PTX-3 and minimum SaO₂ , which could explain that PTX-3 levels can increase with the severity of disease. Our results suggest that PTX-3 as an inflammatory biomarker may play a crucial role as an indicator of syndrome severity in OSAS.

Association between pro-inflammatory cytokine interleukin-33 and periodontal disease in the elderly: A retrospective study

Background:

Senescence is a multifactorial process that in humans may be accompanied by inflammation and immune dysfunction in the oral cavity. Notably, periodontal disease, considered one of the most common inflammatory disorders in the oral cavity, has also been linked to the onset of other chronic inflammatory diseases common in the elderly. Thus, investigating immunity and inflammation during senescence may not only illuminate the pathophysiology of periodontal disease, but also identify new therapeutic targets.

Materials and Methods:

To this end, we retrospectively and systematically reviewed studies of immune molecules associated with periodontal disease. These studies were identified in PubMed from three independent searches based on distinct sets of search terms.

Results:

The data highlight the need to further investigate inflammatory molecules involved in chronic periodontal disease in the elderly, but strongly suggest that interleukin (IL)-33 is involved. Indeed, various genetic and environmental factors appear to contribute to pathogenesis via IL-33.

Conclusion:

The IL-33 axis may be promising therapeutic target in elderly patients.

Increased levels of interleukin-33 in gingival crevicular fluids of patients with chronic periodontitis

The purpose of this clinical study is to comparatively investigate the interleukin-33 (IL-33) levels in gingival crevicular fluid (GCF), saliva and plasma of patients with periodontal disease as well as periodontally healthy subjects and the association between these levels and clinical parameters. GCF, saliva and plasma samples were collected from systemically healthy, non-smoker chronic periodontitis patients (CP group, n = 20), gingivitis patients (G group, n = 20) and periodontally healthy control groups (H group, n = 20). Full-mouth clinical periodontal parameters were also recorded. IL-33 levels were determined by ELISA. The total amount of GCF IL-33 was greater in the G and CP groups compared to the H group (p < 0.05). The GCF IL-33 concentration was significantly lower in the CP group than in the H and G groups (p < 0.001). Salivary or plasma IL-33 levels were similar in the study groups. The total amount of GCF IL-33 was positively correlated with the GI, PI and BOP (%) (p < 0.05). Considering the present findings, the increase in total amounts of GCF IL-33 may have a role in the pathogenesis of periodontal disease.

Periodontal Status in Morbidly Obese Patients With and Without Obstructive Sleep Apnea Syndrome Risk: A Cross-Sectional Study

BACKGROUND

This cross-sectional study aims to investigate the correlation between obstructive sleep apnea syndrome (OSAS) risk with periodontal disease and anthropometric measures in Class III obese patients.

METHODS

Anthropometric measurements were taken from 108 patients of both sexes, aged 30 to 60 years. The Berlin questionnaire (Bq) and the Epworth sleepiness scale (ESS) were applied to determine the risk for OSAS. Full-mouth periodontal status was determined by probing depth, clinical attachment level, gingival bleeding index, and the presence of calculus. Unpaired Student t, χ(2), Fisher exact, and Mann-Whitney U tests were applied to analyze the differences between high and low risk for OSAS groups.

RESULTS

Overall, 81.5% of the patients showed high risk for OSAS, 46.3% had excessive daytime sleepiness, 41.5% were positive for both the Bq and ESS, and 97.2% had periodontal disease (periodontitis = 85.2% and gingivitis = 60.2%). Patients with periodontal disease showed high risk for OSAS (82.9%) and ESS (45.7%). However, there was no influence of periodontal disease on OSAS risk. Periodontitis was not associated with the ESS (odds ratio [OR] = 1.84, 95% confidence interval [CI] = 0.54 to 6.26) or Bq (OR = 0.87, 95% CI = 0.10 to 7.84), nor was gingivitis associated with the ESS (OR = 1.25, 95% CI = 0.48 to 3.25) or Bq (OR = 0.23, 95% CI = 0.03 to 1.84). Waist circumference (P = 0.03), neck circumference (NC, P <0.001), and the percentage of predicted NC (PPNC, P <0.001) were significantly larger in the patients at high risk for OSAS than in those at low risk for OSAS. Daytime sleepiness was also associated with NC (P = 0.02) and PPNC (P = 0.02).

CONCLUSION

There was no association between periodontal disease and OSAS risk in Class III obese patients, but OSAS risk was associated with both NC and PPNC.

The Effect of Periodontitis on Expression of Interleukin-21: A Systematic Review

Purpose. Inflammation and tissue breakdown are led by an array of inflammatory destructive mediators associated with initiation and progression of inflammatory diseases like periodontitis. Current evidence shows that these inflammatory mediators have a definitive role in the pathogenesis of various systemic diseases with an inflammatory component. Interleukin-21 (IL-21) has been associated with systemic diseases like rheumatoid arthritis and Crohn's disease that follow a chronic inflammatory cascade. Similarly recent studies have associated Interleukin-21 levels with periodontitis. This systematic review was aimed to assess the levels of IL-21 in subjects with periodontitis. Methods. A complete literature search was done in PubMed, Medline, Science Direct, and Cochrane databases and Google Scholar based on the inclusion/exclusion criteria. Six relevant articles were procured. Full text was read individually by two reviewers and data extraction was done based on STROBE statement. Results. After data extraction five observational and one interventional study were obtained. All the studies showed an increased expression of IL-21 in periodontitis and the interventional study showed reduction in IL-21 levels after nonsurgical periodontal therapy (NSP). Conclusion. Interleukin-21 levels are higher in periodontitis than controls. With this limited evidence further longitudinal studies are required to consider this as a definitive inflammatory marker.

Periodontitis and Sleep Disordered Breathing in the Hispanic Community Health Study/Study of Latinos

STUDY OBJECTIVES

To investigate the association between sleep disordered breathing (SDB) and severe chronic periodontitis.

DESIGN

Cross-sectional data analysis from the Hispanic Community Health Study/Study of Latinos.

SETTING

Community-based setting with probability sampling from four urban US communities.

PARTICIPANTS

12,469 adults aged 18-74 y.

INTERVENTIONS

None.

MEASUREMENTS AND RESULTS

Severe chronic periodontitis was defined using the Centers for Disease Control and Prevention/American Academy of Periodontology case classification based on full-mouth periodontal assessments performed by calibrated dentists. SDB was evaluated in standardized home sleep tests, and defined as the number of apnea plus hypopnea events associated with ≥ 3% desaturation, per hour of estimated sleep. SDB was quantified using categories of the apnea-hypopnea index (AHI): 0.0 events (nonapneic); 0.1-4.9 (subclinical); 5.0-14.9 (mild); and ≥ 15 (moderate/severe). Covariates were demographic characteristics and established periodontitis risk factors. C-reactive protein was a potential explanatory variable. Using survey estimation, multivariable binary logistic regression estimated odds ratios (OR) and 95% confidence limits (CL). Following adjustment for confounding, the SDB and periodontitis relationship remained statistically significant, but was attenuated in strength and no longer dose-response. Compared with the nonapneic referent, adjusted odds of severe periodontitis were 40% higher with subclinical SDB (OR = 1.4, 95% CL: 1.0, 1.9), 60% higher with mild SDB (OR = 1.6, 95% CL: 1.1, 2.2) and 50% higher with moderate/severe SDB (OR = 1.5, 95% CL: 1.0, 2.3) demonstrating an independent association between SDB and severe periodontitis.

CONCLUSIONS

This study identifies a novel association between mild sleep disordered breathing and periodontitis that was most pronounced in young adults.

Associations among Inflammatory Biomarkers in the Circulating, Plasmatic, Salivary and Intraluminal Anatomical Compartments in Apparently Healthy Preschool Children from the Western Highlands of Guatemala

Background

Undernutrition and inflammation are related in many ways; for instance, non-hygienic environments are associated with both poor growth and immunostimulation in children.

Objective

To describe any existing interaction among different inflammation biomarkers measured in the distinct anatomical compartments of whole blood, feces, plasma and saliva.

Methods

In this descriptive, cross-sectional study, samples of whole blood, feces, plasma and saliva were collected on the 8^th and last week of observation among 87 attendees (42 girls and 45 boys) of 3 daycare centers offering a common 40-day rotating menu in Guatemala’s Western Highlands. Analyses included white blood cell count (WBC), fecal calprotectin, and plasmatic and salivary cytokines including IL-1B, IL-6, IL-8, IL-10 and TNF-α. Associations were assessed using Spearman rank-order and goodness-of-fit correlations, as indicated, followed by backwards-elimination multiple regression analyses to determine predictor variables for IL-10 in both anatomical compartments.

Results

Of a total of 66 cross-tabulations in the Spearman hemi-matrix, 22 (33%) were significantly associated. All 10 paired associations among the salivary cytokines had a significant r value, whereas 7 of 10 possible associations among plasma cytokines were significant. Associations across anatomical compartments, however, were rarely significant. IL-10 in both biological fluids were higher than corresponding reference values. When a multiple regression model was run in order to determine independent predictors for IL-10 in each anatomical compartment separately, IL-6, IL-8 and TNF-α emerged as predictors in plasma (r² = 0.514) and IL-1B, IL-8 and TNF-α remained as independent predictors in saliva (r² = 0.762). Significant cross-interactions were seen with WBC, but not with fecal calprotectin.

Conclusion

Interactions ranged from robust within the same anatomical compartment to limited to nil across distinct anatomical compartments. The prominence of the anti-inflammatory cytokine, IL-10, in both plasma and saliva is consistent with its counter-regulatory role facing a broad front of elevated pro-inflammatory cytokines in the same compartment.