Bibliometric Analysis and Visualization of Clinical Trials on Psychological Stress and Oral Health (1967-2024)

Stress is ubiquitous in modern life, influencing various facets of human health and well-being. While the impact of stress on mental and physical health is well-documented, its effects on oral health have garnered increasing attention in recent years. This bibliometric analysis explores the literature on the impact of stress on oral health. The study utilizes data from the PubMed database, focusing on publication trends, influential contributors and the temporal analysis of their publications, coauthorship analysis of authors and institutions, key thematic clusters, thematic evolution, and collaboration between various countries. Examining clinical trials investigating the impact of stress on oral health unveils significant trends and insights. Over time, there has been a steady rise in publication frequency, although with occasional fluctuations, indicating an increasing interest in the subject. The University of California has been identified as a leading institution, while Psychoneuroendocrinology emerges as a pivotal journal for disseminating research findings in the field. Keyword analysis reveals diverse thematic clusters, reflecting the multifaceted nature of the impact of stress on oral health. The analysis of topic trends showcases significant shifts over different periods, from basic correlations between mental health conditions and physiological indicators to a broader exploration of psychological interventions and social contexts in recent years. Thematic evolution analysis further elucidates this progression, categorizing themes into motor, basic, niche, and emerging or declining categories. Additionally, the analysis of corresponding authors' countries uncovers patterns of collaborative efforts, with the United States leading in collaboration levels. In summary, these analyses collectively highlight an evolving comprehension of the impact of stress on oral health, providing valuable insights for clinical practice and guiding future research endeavors.

Comparative Effectiveness of Active Recovery and Static Stretching During Post-Exercise Recovery in Elite Youth Basketball

Purpose: To compare the effectiveness of active recovery (AR) versus static stretching (SS) during post-exercise recovery in basketball. Methods: Using a counterbalanced crossover design, 17 elite youth male players completed two 90-min training sessions, followed by either AR or SS. Differences in jump height (CMJ), heart rate variability (Ln-rMSSD), muscle soreness (VAS), perceived recovery (TQR) and hormonal biomarkers (cortisol, testosterone, testosterone:cortisol ratio) between interventions were assessed at pre-session, post-session (except hormonal biomarkers), post-recovery and 24 h post-session. Differences in Ln-rMSSD were additionally assessed upon awakening on training day, and the following morning. Results: No significant differences were found between interventions at corresponding time points (p > .05). However, the within-intervention time course of recovery differed, as CMJ values were lower at post-recovery, compared with all other time points, in SS only (p < .05, effect size [ES] moderate-to-very large). Additionally, Ln-rMSSD values failed to return to baseline at post-recovery in AR only (p < .05, ES large-to-very large). Similarly, TQR scores were impaired at post-session and post-recovery in AR only (p < .05, ES moderate-to-large). No differences were reported for the remaining variables (p > .05). Conclusion: Differences between AR and SS were probably due to short-term phenomena, indicating that neither strategy was likely superior for improving recovery in the longer term. Overall, neither strategy seemed to significantly improve post-exercise recovery.

Salivary Brain-Derived Neurotrophic Factor and Cortisol Associated with Psychological Alterations in University Students

INTRODUCTION

Recent evidence reported mental health issues in university students such as anxiety and depressive symptoms and poor sleep quality. Decreased plasma brain-derived neurotrophic factor (BDNF) levels have been proposed as a biomarker of depressive symptoms, whereas cortisol levels are an index of energy mobilization and stress and have been linked to sleep quality. Given that salivary biomarkers represent an interesting new field of research, the aim of this cross-sectional study was to evaluate salivary BDNF and cortisol levels in university students to assess whether they have associations with psychological disturbances such as anxiety and depressive symptoms, sleep quality, and stress level.

METHODS

Salivary BDNF and cortisol levels were measured by specific immunoassays in 70 students whose mental health was also evaluated on the same day through the evaluation of anxiety and depression symptoms (Goldberg scale), sleep quality (Pittsburg Sleep Quality Index and Athens Insomnia Scale), and stress (self-perceived stress scale) and healthy lifestyle habits (alcohol consumption, smoking, regular exercise, and body mass index) were also measured. Multivariate regression analyses were performed in order to identify the strengths of associations between psychological alterations and the concentrations of BDNF, cortisol, and other variables.

RESULTS

Salivary BDNF levels were significantly higher in students with more depressive symptoms, whereas no significant differences were found for cortisol levels. When performing the binary logistic regression model, BDNF levels are included as a predictor variable for a high-depressive-symptoms burden (p < 0.05). Students with worse sleep quality on the Pittsburg Scale had higher cortisol levels (p < 0.05). The subdomains of sleep latency and sleep medication were those significantly associated with salivary cortisol levels in logistic regression analyses (OR = 15.150, p = 0.028). Sleep medication only appeared to be related to cortisol levels (OR = 185.142, p = 0.019). Perceived stress levels and anxiety symptoms were not associated with BDNF or cortisol levels.

CONCLUSIONS

BDNF could play a key role in the pathophysiology of mood-related disorders, and elevation of its peripheral levels could contribute to protecting neurons from the development of mental illness. Higher salivary cortisol levels measured in the morning are accompanied by poorer sleep quality. More research is needed, focusing on salivary biomarkers of disorders related to depressive symptoms and poor sleep quality as a potential tool for the diagnosis and prevention of mental illness.

Salivary levels of inflammatory and anti-inflammatory biomarkers in periodontitis patients with and without acute myocardial infarction: implications for cardiovascular risk assessment

Background

Periodontitis is initiated by a dysbiotic activity and furthermore leads to a chronic inflammatory response. The presence of pro-inflammatory markers plays an important role in the inflammatory load. Macrophage inflammatory protein-1 alpha (MIP-1α) and C-reactive protein (CRP) are pro- inflammatory biomarkers that quantify clinical and subclinical inflammation in cardiac ischemia in cardiac inflammation and disease. Adiponectin is an anti-inflammatory marker associated with good health. The susceptibility of periodontitis patients to cardiovascular events needs to be evaluated.

Objective

This study aims to assess the levels of biomarkers in periodontitis patients with and without acute myocardial infarction (AMI) compared to controls.

Material and methods

Pro-inflammatory and anti-inflammatory analytes were examined by collecting unstimulated saliva from three groups (n = 20/each): healthy individuals, individuals with stage III periodontitis, and post-myocardial infarction patients with stage III periodontitis. The samples were collected within 48 h of AMI.

Results

Adiponectin levels were significantly lower in patients with periodontitis with and without AMI compared to controls, while CRP and MIP-1α were significantly higher in patients with periodontitis with and without AMI compared to controls. The highest titers for MIP-1α and CRP were detected among patients with periodontitis with and AMI.

Conclusion

Our study provides possible evidence of the association between periodontitis and salivary analytes that occur in tandem with cardiovascular disease. The lower levels of Adiponectin and higher levels of CRP and MIP-1α in patients with periodontitis indicate that this condition is a potential risk factor for cardiovascular disease. The findings emphasize the importance of early detection and intervention for periodontitis patients to prevent cardiovascular events.

Salivary Biomarkers and Temporomandibular Disorders: A Systematic Review conducted according to PRISMA guidelines and the Cochrane Handbook for Systematic Reviews of Interventions

BACKGROUND

The present review aimed to investigate the association between salivary biomarkers and temporomandibular disorders (TMD). TMD is a multifactorial condition characterised by pain and dysfunction in the temporomandibular joint (TMJ) and surrounding structures. Salivary biomarkers have emerged as potential diagnostic tools due to their non-invasiveness and easy accessibility. However, the literature on salivary biomarkers in relation to TMD is limited and inconsistent.

METHODS

Electronic databases of Pubmed, Embase, Web of Science, Scopus, Cochrane Library, PsychINFO, CINAHL and Medline were searched using specific search terms and Boolean operators. The search was limited to articles published in English that assessed salivary biomarkers in individuals diagnosed with TMD. Two reviewers independently screened the articles and extracted data. ROB-2 was used to assess the risk of bias.

RESULTS

Eleven clinical papers met the inclusion criteria and were included in the review. The findings provided consistent evidence of a clear association between salivary biomarkers and TMD. Various biomarkers, including cortisol, IL-1, glutamate and several others, were assessed. Some studies reported higher levels of cortisol and IL-1 in TMD patients, indicating potential involvement in stress and inflammation. Glutamate levels were found to be elevated, suggesting a role in pain modulation. Other biomarkers also showed alterations in TMD patients compared to controls: CONCLUSION: The findings from the included studies suggest that salivary biomarkers may play a role in TMD pathophysiology. Though a definitive conclusion can be drawn regarding the specific salivary biomarkers and their association with TMD, the results must be interpreted with caution considering the heterogeneity of the biomarkers assessed. Further research with larger sample sizes, standardised methodology and rigorous study designs is needed to elucidate the role of salivary biomarkers in TMD.

Evaluation of salivary transferrin in patients with oral squamous cell carcinoma

OBJECTIVES

About 94% of oral cancers are squamous cell carcinomas (OSCCs). Its occurrence is age-related due to some factors. Salivary biomarkers have good susceptibility to OSCC's early diagnosis. Moreover, since the clinical diagnosis of advanced stages of OSCC is feasible, its prognosis is very poor.

MATERIAL AND METHODS

According to inclusion and exclusion criteria, 40 OSCC patients and 40 healthy people were selected, and 5 mL of saliva were prepared from each person. The quantity of saline transferrin was computed. After that, the data were analyzed.

RESULTS

Our study results demonstrated that the mean and standard deviation of the salivary transferrin in the control group were 1.234 mL and 0.374, respectively, and in the case group, it was equal to 2.512 mL for the mean and 0.463 for the standard deviation. There was a statistically substantial difference between the mean of the salivary transferrin variable in the two study groups.

CONCLUSION

In conclusion, the mean concentration of salivary transferrin in the case group was higher than in the control group.

Artificial intelligence in salivary biomarker discovery and validation for oral diseases

Salivary biomarkers can improve the efficacy, efficiency, and timeliness of oral and maxillofacial disease diagnosis and monitoring. Oral and maxillofacial conditions in which salivary biomarkers have been utilized for disease-related outcomes include periodontal diseases, dental caries, oral cancer, temporomandibular joint dysfunction, and salivary gland diseases. However, given the equivocal accuracy of salivary biomarkers during validation, incorporating contemporary analytical techniques for biomarker selection and operationalization from the abundant multi-omics data available may help improve biomarker performance. Artificial intelligence represents one such advanced approach that may optimize the potential of salivary biomarkers to diagnose and manage oral and maxillofacial diseases. Therefore, this review summarized the role and current application of techniques based on artificial intelligence for salivary biomarker discovery and validation in oral and maxillofacial diseases.

Exploring the Potential of Exosomal Biomarkers in Mild Traumatic Brain Injury and Post-Concussion Syndrome: A Systematic Review

BACKGROUND

Alongside their long-term effects, post-concussion syndrome (PCS) and mild traumatic brain injuries (mTBI) are significant public health concerns. Currently, there is a lack of reliable biomarkers for diagnosing and monitoring mTBI and PCS. Exosomes are small extracellular vesicles secreted by cells that have recently emerged as a potential source of biomarkers for mTBI and PCS due to their ability to cross the blood-brain barrier and reflect the pathophysiology of brain injury. In this study, we aimed to investigate the role of salivary exosomal biomarkers in mTBI and PCS.

METHODS

A systematic review using the PRISMA guidelines was conducted, and studies were selected based on their relevance to the topic.

RESULTS

The analyzed studies have shown that exosomal tau, phosphorylated tau (p-tau), amyloid beta (Aβ), and microRNAs (miRNAs) are potential biomarkers for mTBI and PCS. Specifically, elevated levels of exosomal tau and p-tau have been associated with mTBI and PCS as well as repetitive mTBI. Dysregulated exosomal miRNAs have also been observed in individuals with mTBI and PCS. Additionally, exosomal Prion cellular protein (PRPc), coagulation factor XIII (XIIIa), synaptogyrin-3, IL-6, and aquaporins have been identified as promising biomarkers for mTBI and PCS.

CONCLUSION

Salivary exosomal biomarkers have the potential to serve as non-invasive and easily accessible diagnostic and prognostic tools for mTBI and PCS. Further studies are needed to validate these biomarkers and develop standardized protocols for their use in clinical settings. Salivary exosomal biomarkers can improve the diagnosis, monitoring, and treatment of mTBI and PCS, leading to improved patient outcomes.

Prosthodontic implications of saliva and salivary gland dysfunction

PURPOSE

To provide a detailed overview of the fundamentals of saliva constituents and production. The review outlines the clinical manifestations as a consequence of salivary gland dysfunction and management strategies for patients with salivary gland dysfunction. Prosthodontic implications of saliva and salivary gland dysfunction are presented.

MATERIALS AND METHODS

English-language literature relating to saliva constituents, physiologic saliva production, clinical manifestations secondary to salivary gland dysfunction, salivary biomarkers, and management strategies were retrieved via electronic search. Relevant articles were summarized for this manuscript with a view toward providing pragmatic information.

RESULTS

Saliva is produced by three pairs of major and minor salivary glands. The major salivary glands, namely, the parotid, submandibular, and sublingual glands, contribute approximately 90% of saliva production. Saliva contains serous and mucinous secretions produced by different types of cells within salivary glands. Parasympathetic and sympathetic fibers innervate the major salivary glands, and upon stimulation, the parasympathetic innervation increases serous secretions, while the sympathetic innervation increases protein secretion. Stimulated saliva is mainly derived from the parotid glands which are composed of serous acini, while unstimulated saliva is mainly derived from the submandibular glands which are composed of mixed seromucous acini. As major salivary glands contribute the most to salivary flow, local or systemic factors influencing those glands can disrupt saliva production resulting in clinically significant oral manifestations.

CONCLUSION

This review provides a fundamental overview of saliva production. In addition, the review highlights the various clinical manifestations secondary to salivary gland dysfunction, explores salivary biomarkers for screening of systemic diseases, discusses management strategies for patients with salivary gland dysfunction, and outlines the prosthodontic implications of saliva and salivary gland dysfunction.

Potential relevance of salivary legumain for the clinical diagnostic of hand, foot, and mouth disease

The fight against hand, foot, and mouth disease (HFMD) remains an arduous challenge without existing point-of-care (POC) diagnostic platforms for accurate diagnosis and prompt case quarantine. Hence, the purpose of this salivary biomarker discovery study is to set the fundamentals for the realization of POC diagnostics for HFMD. Whole salivary proteome profiling was performed on the saliva obtained from children with HFMD and healthy children, using a reductive dimethylation chemical labeling method coupled with high-resolution mass spectrometry-based quantitative proteomics technology. We identified 19 upregulated (fold change = 1.5-5.8) and 51 downregulated proteins (fold change = 0.1-0.6) in the saliva samples of HFMD patients in comparison to that of healthy volunteers. Four upregulated protein candidates were selected for dot blot-based validation assay, based on novelty as biomarkers and exclusions in oral diseases and cancers. Salivary legumain was validated in the Singapore (n = 43 healthy, 28 HFMD cases) and Taiwan (n = 60 healthy, 47 HFMD cases) cohorts with an area under the receiver operating characteristic curve of 0.7583 and 0.8028, respectively. This study demonstrates the feasibility of a broad-spectrum HFMD POC diagnostic test based on legumain, a virus-specific host systemic signature, in saliva.

Increased Salivary IL-1 Beta Level Is Associated with Poor Sleep Quality in University Students

Poor sleep quality is a major public health concern for all ages. In particular, university students often face stress levels and changes in social life habits that negatively influence their quality of sleep. This could be associated with psychological well-being in terms of anxiety and depressive symptoms, stress levels, and a poor self-perceived health status. The increases in the pro-inflammatory cytokine interleukin 6 (IL-6), IL-1 beta (IL-1β), and tumor necrosis factor alpha (TNFα), in blood have been linked to poor sleep quality in many diseases, but data on salivary cytokine levels in students are missing or are seldom analyzed. In this study we determined the quality of sleep in a sample of university students and the role of psychological assessment and factors affecting sleep (alcohol intake, tobacco, consumption of stimulant drinks, exercise, and body mass index). We also aimed to shed new light on the associations between sleep quality and salivary inflammatory cytokines (IL-1β, IL-6, and TNFα). Sleep quality was measured with the Athens Insomnia Scale (AIS) and Pittsburgh Sleep Quality Index (PSQI). Perceived stress was assessed using Cohen's Perceived Stress Scale (PSS), and the Goldberg Anxiety and Depression Scale (GADS) was used to assess the level of anxiety or depression. Perceived health status was measured with a visual analogue. Saliva samples was taken in the morning and the inflammatory cytokines was measured via enzyme-linked immunoassay. There was a direct and significant association between the salivary IL-1β concentration and AIS score (r = 0.248; p = 0.038, Pearson correlation) and Pittsburgh scale score (r = 0.274; p = 0.022, Pearson correlation). The relationship between IL-1β and AIS controlling for sex, age, and chronic disease, is still significant (r = 0.260; p = 0.033). The relationship between IL-1β and PSQI controlling for the influence of these variables is also significant (r = 0.279; p = 0.022). Salivary IL-1β concentrations were not significantly associated with any of the scores of the other psychological assessments (PSS, anxiety, depression symptoms, or self-perceived health). Salivary TNFα was significantly and inversely associated with self-perceived health (r = -0.259; p = 0.033, Pearson correlation), but the salivary IL-6 concentration was not associated with any of the sleep quality scale or psychological assessment scores. Our results provide a novel relationship between pro-inflammatory cytokine IL-1β in saliva and poor sleep quality. However, the role of inflammation in poor sleep quality requires further study to identify strategies that could lower inflammation and thus, likely improve sleep quality.

Salivary biomarkers in burning mouth syndrome: A systematic review and meta-analysis

The objective of this systematic review was to evaluate which salivary biomarkers are altered in patients with burning mouth syndrome (BMS) compared to a control group (CG). A comprehensive literature search was conducted in four databases. Case-control studies evaluating salivary biomarkers in BMS patients were included. Risk of bias was assessed using the Newcastle-Ottawa tool. RevMan was used for meta-analysis. Seventeen studies were selected. The included studies collected 54 different biomarkers. Of these biomarkers, only three (cortisol, α-amylase, and dehydroepiandrosterone) were analyzed in three or more studies. Dehydroepiandrosterone obtained contradictory results among the studies. However, cortisol and α-amylase levels were found to be higher in BMS patients. Cortisol was the only biomarker which could be included for meta-analysis. Cortisol levels were significantly higher in the BMS group compared to the CG (Mean Difference = 0.39; 95% CI [0.14-0.65]; p = 0.003). In conclusion, different studies investigated salivary biomarkers in patients with BMS compared to a CG, with controversial results. Meta-analysis, confirmed by trial-sequential analysis, showed how cortisol levels were significantly higher in BMS. Cortisol emerges as an interesting salivary biomarker in BMS, but future properly designed studies are needed to evaluate its role in diagnosis and/or response to treatment.

MALAT1 as a potential salivary biomarker in oral squamous cell carcinoma through targeting miRNA-124

OBJECTIVES

To determine the diagnostic accuracy of the long non-coding RNA "MALAT1" measured in the saliva of patients with oral squamous cell carcinoma (OSCC) and assess the salivary expression of microRNA-124, which MALAT1 targets.

SUBJECTS AND METHODS

Forty subjects were collected in a consecutive pattern and allocated into two groups. Group A included 20 patients with OSCC, while Group B included 20 healthy subjects. Salivary expression of MALAT1 and microRNA (miRNA)-124 was evaluated in the two study groups using quantitative real-time polymerase chain reaction and correlated with histopathological examination of OSCC subjects.

RESULTS

OSCC yielded a statistically significant higher expression of MALAT1 than healthy controls and a lower expression of miRNA-124 in OSCC than controls. There is a statistically significant inverse relationship between salivary MALAT1 and miRNA-124. Moreover, there is a statistically significant difference in the MALAT1 expression in saliva samples from metastatic cases compared with non-metastatic cases, as well as in patients with lymph node involvement compared with those without involvement. At a cut-off value of 2.24, salivary MALAT1 exhibited 95% sensitivity and 90% specificity in differentiating OSCC from healthy subjects.

CONCLUSION

Salivary MALAT1 acts as a sponge for miRNA-124 and could be a potential salivary biomarker for OSCC.

The Potential Role of Salivary NT-proBNP in Heart Failure

BACKGROUND

Serum natriuretic peptides (NPs) have an established role in heart failure (HF) diagnosis. Saliva NT-proBNP that may be easily acquired has been studied little.

METHODS

Ninety-nine subjects were enrolled; thirty-six obese or hypertensive with dyspnoea but no echocardiographic HF findings or raised NPs served as controls, thirteen chronic HF (CHF) patients and fifty patients with acute decompensated HF (ADHF) requiring hospital admission. Electrocardiogram, echocardiogram, 6 min walking distance (6MWD), blood and saliva samples, were acquired in all participants.

RESULTS

Serum NT-proBNP ranged from 60-9000 pg/mL and saliva NT-proBNP from 0.64-93.32 pg/mL. Serum NT-proBNP was significantly higher in ADHF compared to CHF (p = 0.007) and in CHF compared to controls (p < 0.05). There was no significant difference in saliva values between ADHF and CHF, or between CHF and controls. Saliva and serum levels were positively associated only in ADHF patients (R = 0.352, p = 0.012). Serum NT-proBNP was positively associated with NYHA class (R = 0.506, p < 0.001) and inversely with 6MWD (R = -0.401, p = 0.004) in ADHF. Saliva NT-proBNP only correlated with age in ADHF patients.

CONCLUSIONS

In the current study, saliva NT-proBNP correlated with serum values in ADHF patients, but could not discriminate between HF and other causes of dyspnoea. Further research is needed to explore the value of saliva NT-proBNP.

Saliva as Biomarker for Oral and Chronic Degenerative Non-Communicable Diseases

Saliva is a very complex fluid and it is essential to maintain several physiological processes and functions, including oral health, taste, digestion and immunological defenses. Saliva composition and the oral microbiome can be influenced by several factors, like diet and smoking habits, and their alteration can represent an important access point for pathogens and, thus, for systemic illness onset. In this review, we explore the potentiality of saliva as a new tool for the early detection of some pathological conditions, such as oral diseases, chronic degenerative non-communicable diseases, among these chronic kidney disease (CKD). We also examined the possible correlation between oral and systemic diseases and oral and gut microbiota dysbiosis. In particular, we deeply analyzed the relationship between oral diseases and CKD. In this context, some salivary parameters can represent a new device to detect either oral or systemic pathologies. Moreover, the positive modulation of oral and gut microbiota induced by prebiotics, postbiotics, or symbiotics could represent a new possible adjuvant therapy in the clinical management of oral diseases and CKD.

Brain Health Indicators Following Acute Neuro-Exergaming: Biomarker and Cognition in Mild Cognitive Impairment (MCI) after Pedal-n-Play (iPACES)

Facing an unrelenting rise in dementia cases worldwide, researchers are exploring non-pharmacological ways to ameliorate cognitive decline in later life. Twenty older adults completed assessments before and after a single bout of interactive physical and cognitive exercise, by playing a neuro-exergame that required pedaling and steering to control progress in a tablet-based video game tailored to impact executive function (the interactive Physical and Cognitive Exercise System; iPACES v2). This study explored the cognitive and biomarker outcomes for participants with mild cognitive impairment (MCI) and normative older adults after 20 min of pedal-to-play exercise. Neuropsychological and salivary assessments were performed pre- and post-exercise to assess the impact. Repeated-measures ANOVAs revealed significant interaction effects, with MCI participants experiencing greater changes in executive function and alpha-amylase levels than normative older adults; within-group changes were also significant. This study provides further data regarding cognitive effects and potential mechanisms of action for exercise as an intervention for MCI.

Assessment and Correlation of Salivary Ca, Mg, and pH in Smokers and Non-Smokers with Generalized Chronic Periodontitis

Background and Objectives: Diagnostic evaluation with the aid of biomarkers has reached newer heights to assess disease activity. Salivary calcium, magnesium, and pH are one of the biochemical parameters which can be helpful in assessing the progression of periodontal disease. Smokers are at topnotch threat for having oral diseases, predominantly periodontal diseases. The aim of this study was to assess the salivary calcium, magnesium, and pH levels in smokers compared with non-smokers with chronic periodontitis. Materials and Methods: The current study was conducted on 210 individuals affected with generalized chronic periodontitis, with the age group between 25 and 55 years. Based on their smoking habit, an equal number of patients were categorized into two groups; namely, group I consisted of non-smokers and group II consisted of smokers. The clinical parameters that were measured included Plaque Index (PI), Gingival Index (GI), Probing Pocket Depth (PPD), and Clinical Attachment Loss (CAL). The biochemical variables that were evaluated in the current study included salivary calcium, magnesium, and pH using an AVL9180 electrolyte analyzer (Roche, Germany). The gathered data were analyzed with an unpaired t test was using SPSS 20.0. Results: A statistically significant higher PPD (p < 0.01), CAL (p < 0.05), and salivary calcium levels (p < 0.001) were observed in the smokers' compared with their non-smoking counterparts. Among the biochemical parameters, calcium showed a significantly (p < 0.001) higher level in smokers (5.79 ± 1.76) in contrast to non-smokers (3.87 ± 1.03). Additionally, a significant negative correlation (p < 0.05) between calcium and PPD was observed in non-smokers, whereas a non-significant inverse relation (p > 0.05) was seen in smokers. Conclusions: The present study indicates that the salivary calcium level can be a potential biochemical parameter to assess the progression of periodontal disease in smokers and non-smokers. Within the limitations of the current study, the salivary biomarkers appear to have an essential role in the identification and indication of the status of periodontal diseases.

Salivary ATR-FTIR Spectroscopy Coupled with Support Vector Machine Classification for Screening of Type 2 Diabetes Mellitus

The blood diagnosis of diabetes mellitus (DM) is highly accurate; however, it is an invasive, high-cost, and painful procedure. In this context, the combination of ATR-FTIR spectroscopy and machine learning techniques in other biological samples has been used as an alternative tool to develop a non-invasive, fast, inexpensive, and label-free diagnostic or screening platform for several diseases, including DM. In this study, we used the ATR-FTIR tool associated with linear discriminant analysis (LDA) and a support vector machine (SVM) classifier in order to identify changes in salivary components to be used as alternative biomarkers for the diagnosis of type 2 DM. The band area values of 2962 cm^-1, 1641 cm^-1, and 1073 cm^-1 were higher in type 2 diabetic patients than in non-diabetic subjects. The best classification of salivary infrared spectra was by SVM, showing a sensitivity of 93.3% (42/45), specificity of 74% (17/23), and accuracy of 87% between non-diabetic subjects and uncontrolled type 2 DM patients. The SHAP features of infrared spectra indicate the main salivary vibrational modes of lipids and proteins that are responsible for discriminating DM patients. In summary, these data highlight the potential of ATR-FTIR platforms coupled with machine learning as a reagent-free, non-invasive, and highly sensitive tool for screening and monitoring diabetic patients.

Salivary Biomarkers Analysis and Neurobehavioral Assessment in Nurses Working Rotation Shifts: A Pilot Study

Currently, about one in five workers is employed in night shift work in Europe. Shift work including nighttime hours is essential in several activities, especially the healthcare sector. Importantly, night working may be associated with the occurrence of sleep disorders or work-related stress, both potentially augmenting the risk of errors and accidents at work. This study aims to examine the presence of neurobehavioral alterations that can be a consequence of shift working and concurrent misalignment of the sleep times and circadian rhythms. Nurses (n = 102) employed at a University Hospital located in North-Eastern Sicily, Italy, voluntarily participated in this pilot study. During medical surveillance, morning and evening salivary samples were collected, and seven psychodiagnostics questionnaires were administered to all the subjects. On one hand, the salivary levels of stress-related biomarkers (cortisol and alpha-amylase) and a circadian biomarker (melatonin) were evaluated. On the other hand, several neurobehavioral features were assessed, including depression, anxiety, work-related, and sleep issues. Interestingly, a positive relationship between salivary morning cortisol and depression scale, as well as a negative relationship between salivary morning alpha-amylase and work ability scale, were observed. Based on these results, the integration of subjective questionnaire outcomes and objective salivary biomarker quantification can help to identify workers with increased susceptibility to developing neurobehavioral alterations. This approach may contribute to ameliorating preventive strategies towards sensitive categories, such as nurses working rotation shifts.

Salivary Adiponectin and Albumin Levels on the Gingival Conditions of Patients Undergoing Bariatric Surgery: A Cohort Study

This study analyzed the salivary proteomics, adiponectin and albumin, related to weight loss and periodontitis in patients undergoing bariatric surgery. This study included fourteen patients with morbid obesity (body mass index, BMI > 40 kg/m²) who underwent bariatric surgery Roux-en-Y gastric bypass (RYGB) in System Health Public in Brazil. Data on demographic and anthropometric measures were extracted from medical records preoperatively and 6 and 12 months post-surgery. The variables assessed were: probing pocket depth (PPD), clinical attachment loss (CAL), bleeding on probing (BOP), and stimulated whole-mouth saliva. In this study, saliva samples were analyzed by electrophoresis and immunoblotting. The ELISA kit was used to measure the MMP8 levels to determine potential markers for obesity. Adiponectin and albumin levels were also evaluated. Weight loss was associated with significant changes in patients' periodontal clinical data. Although 7 out of 10 periodontal patients showed an increase in salivary adiponectin levels after root planning treatment, when analyzed by Western blotting, the increase was not statistically significant (21.1 ± 4.8 to 26.3 ± 9.4 arbitrary units, p > 0.99). There was no correlation between albumin levels and salivary adiponectin pre-surgery, nor 6 months or 12 months after surgery. Weight loss was not improved by low-grade inflammation in bariatric patients, since albumin levels were similar between periods. Periodontitis is an inflammatory disease that is modulated by several factors, among which adiponectin plays an important role for the treatment of periodontal disease.

Salivary Diagnostics in Pediatrics and the Status of Saliva-Based Biosensors

Salivary biomarkers are increasingly being used as an alternative to diagnose and monitor the progression of various diseases due to their ease of use, on site application, non-invasiveness, and most likely improved patient compliance. Here, we highlight the role of salivary biosensors in the general population, followed by the application of saliva as a diagnostic tool in the pediatric population. We searched the literature for pediatric applications of salivary biomarkers, more specifically, in children from 0 to 18 years old. The use of those biomarkers spans autoimmune, developmental disorders, oncology, neuropsychiatry, respiratory illnesses, gastrointestinal disorders, and oral diseases. Four major applications of salivary proteins as biomarkers are: (1) dental health (caries, stress from orthodontic appliances, and gingivitis); (2) gastrointestinal conditions (eosinophilic esophagitis, acid reflux, appendicitis); (3) metabolic conditions (obesity, diabetes); and (4) respiratory conditions (asthma, allergic rhinitis, small airway inflammation, pneumonia). Genomics, metabolomics, microbiomics, proteomics, and transcriptomics, are various other classifications for biosensing based on the type of biomarkers used and reviewed here. Lastly, we describe the recent advances in pediatric biosensing applications using saliva. This work guides scientists in fabricating saliva-based biosensors by comprehensively overviewing the potential markers and techniques that can be employed.

Point-of-Care Diagnostic Biosensors to Monitor Anti-SARS-CoV-2 Neutralizing IgG/sIgA Antibodies and Antioxidant Activity in Saliva

Monitoring biomarkers is a great way to assess daily physical condition, and using saliva instead of blood samples is more advantageous as the process is simple and allows individuals to test themselves. In the present study, we analyzed the titers of neutralizing antibodies, IgG and secretory IgA (sIgA), in response to the SARS-CoV-2 vaccine, in saliva. A total of 19 saliva and serum samples were collected over a 10-month period 3 weeks after the first vaccine, 8 months after the second vaccine, and 1 month after the third vaccine. The ranges of antibody concentrations post-vaccination were: serum IgG: 81-15,000 U/mL, salivary IgG: 3.4-330 U/mL, and salivary IgA: 58-870 ng/mL. A sharp increase in salivary IgG levels was observed after the second vaccination. sIgA levels also showed an increasing trend. A correlation with trends in serum IgG levels was observed, indicating the possibility of using saliva to routinely assess vaccine efficacy. The electrochemical immunosensor assay developed in this study based on the gold-linked electrochemical immunoassay, and the antioxidant activity measurement based on luminol electrochemiluminescence (ECL), can be performed using portable devices, which would prove useful for individual-based diagnosis using saliva samples.

Role of Salivary Biomarkers in Diagnosis and Detection of Dental Caries: A Systematic Review

Saliva plays a significant role in oral health and tooth integrity. Salivary components reduce tooth surface exposure to demineralization, protect against teeth wear and aid in enamel remineralization. There is a growing attempt to use salivary markers in diagnosing or predicting caries. However, despite the current information, there has yet to be an agreement among scholars. This study seeks to contribute more evidence on the suitability of salivary biomarkers in dental caries diagnosis. Eligible studies were electronically searched on online databases PubMed, Elsevier's Scopus, EMBASE and Web of Science, and all the studies that met the inclusion criteria were considered. The PECOS criteria guided the study selection process based on the study question. The risk of bias was assessed using the STROBE checklist. Eighteen articles were included in the analysis. All the studies presented relevant data concerning the study objectives. There was evidence of associations between salivary biomarkers and dental caries, and the correlations were either positive or negative. The studies presented significant heterogeneity; thus, a meta-analysis was not possible. Salivary biomarkers appeared to perform crucial and complementary functions toward tooth integrity and thus may be reliable in predicting or diagnosing dental caries in patients.

Salivary Biomarkers in Periodontitis Post Scaling and Root Planing

OBJECTIVES

This study was conducted to evaluate the levels of salivary uric acid and arginase in patients with periodontitis, generalized gingivitis, and in healthy individuals. Then, the effects of non-surgical periodontal therapy on levels of salivary arginase and uric acid were also investigated.

METHODS

A total of 60 subjects were divided into three groups based on periodontal health: group I comprised 20 healthy individuals; group II comprised 20 subjects who had generalized gingivitis; group III comprised 20 subjects who had generalized periodontitis. On day 0, the clinical examination of periodontal status was recorded, following which saliva samples were collected. Group II and group III subjects underwent non-surgical periodontal therapy. These patients were recalled on day 30 to collect saliva samples. The periodontal parameters were reassessed on day 90, and saliva samples were collected for analysis of salivary arginase and uric acid levels.

RESULTS

Group II and group III showed improvement in clinical parameters following non-surgical periodontal therapy on the 90th day. The MGI score, PPD, and CAL showed improvement. On day 0, at baseline, salivary arginase levels in group III and group II were higher than those in healthy subjects, whereas on day 0, salivary uric acid levels in group III and group II were lower than those in healthy subjects. Both on day 0 and day 90, the salivary arginase level showed a positive correlation with the periodontal parameters, whereas the salivary uric acid level was positively correlated with the periodontal parameters on day 90.

CONCLUSION

the level of salivary arginase was a pro-inflammatory marker and a raised level of salivary uric acid was an anti-inflammatory marker following periodontal therapy, suggesting their pivotal role in assessing periodontal status and evaluation of treatment outcome.

Salivary Biomarkers in Oral Squamous Cell Carcinoma: A Proteomic Overview

BACKGROUND

Oral squamous cell carcinoma (OSCC) is one of the most frequent cancers worldwide. Endoscopic methods may be useful in the evaluation of oral injuries even though the diagnostic gold standard is a biopsy. Targeted screenings could be considered the best way to prevent the occurrence of oral cancer. Aimed to elucidate the potential identification of specific biomarkers of OSCC, the use of saliva is convenient and noninvasive. Many studies reported more than a hundred putative saliva biomarkers for OSCC, and proteogenomic approaches were fundamental to disclosing this issue.

METHODS

Relevant literature published in the last few years was systematically searched on PubMed and we focused on articles about the use and study of salivary biomarkers in the diagnostics of head and neck cancer (n = 110). Thereafter, we performed a selection focusing on diagnosis with salivary proteomics in OSCC (n = 8).

RESULTS

Saliva proteomics can be a source of biomarkers for OSCC. We reviewed literature of biomarker proteins in saliva that could also be evaluated as probable targets for non-invasive screening of oral neoplasm such as cytokines, matrix metalloproteinases, and acute-phase response proteins.

CONCLUSIONS

The measurement of salivary biomarkers is a highly hopeful technique for the diagnosis of OSCC. Proteogenomic approaches could permit an accurate and early diagnosis of OSCC. This review seeks to generate an up-to-date view on translational OSCC issues by raising awareness of researchers, physicians, and surgeons. Renewed clinical studies, which will validate the sensitivity and specificity of salivary biomarkers, are necessary to translate these results into possible strategies for early diagnosis of OSCC, thus improving patient outcomes.

Salivary mental stress biomarkers in COVID-19 patients

BACKGROUND

During the COVID-19 pandemic, mental health disorders and level of stress show a major increase compared to before the pandemic. Coronavirus-related stress is recently the leading cause of negative impacts on global mental health. Thus, maintaining positive mental health is as important as maintaining physical health during COVID-19. The aim of this study was to analyze salivary mental stress biomarkers as cortisol, alpha-amylase, and chromogranin A in hospitalized patients with COVID-19 to compare their potential relationship with stress symptoms.

MATERIAL AND METHODS

A total of 80 adult hospitalized patients with moderate COVID-19 disease and a control group (n = 80) randomly selected were conducted as participants. Saliva cortisol (sCort), saliva alpha-amylase (sAA), and saliva and chromogranin A (sCgA) were determined by the ELISA method (Bio Vendor, USA). Symptoms of stress were measured with a stress symptom checklist (SSCL).

RESULTS

The patients group presented significantly higher levels of sCort, sAA, and sCgA compared with the control group. The correlation analysis showed a positive correlation with strong strength between sCort and sAA (r = 0.934, p < 0.01), as well as sAA with sCgA (r = 0.714, p < 0.01). A moderate positive correlation was found between sCort with sCgA (r = 0.618, p < 0.05). Based on their stress scores from the SSCL the patients were associated with high stress level (30.00%) and very high stress levels (67.5%). In terms of the controls, all the participants showed a low to moderate stress level. We found significant positive correlation between levels of stress and salivary biomarkers.

CONCLUSION

Data from our study demonstrated that salivary biomarkers are promising tools of exploring COVID-19 related stress.

Science of interdisciplinary salivary bioscience: history and future directions

Salivary bioscience is noteworthy in its history, as well as in the breadth and scope of its impact. The minimally invasive nature of sampling oral fluid allows for evaluation of individual and intra-individual change in biological processes in ways and settings not possible with traditional biospecimens. The range of measurements is expansive (e.g., DNA, hormones, cytokines, antibodies) and modern technologies enable simultaneous multisystem assessment from a singlet specimen. Used in combination with modern multivariate analytical models, the capacity to repeatedly assess multisystem and level measurements collected from the same individual over time enable operationalization, testing and refinement of complex biobehavioral models. This review describes the emerging narrative of salivary bioscience, and aims to inform and reveal opportunity for innovation and discovery.

Salivary biomarkers and esophageal disorders

Saliva is a complex physiologic fluid that contains an abundance of biological analytes, or biomarkers. Recent research has shown that these biomarkers may be able to convey the physiologic health of a person. Work has been done linking derangements in these salivary biomarkers to a wide variety of pathologic disorders ranging from oncologic diseases to atopic conditions. The specific area of interest for this review paper is esophageal disorders. Particularly because the diagnosis and management of esophageal disorders often includes invasive testing such as esophagogastroduodenoscopy, prolonged pH monitoring, and biopsy. The aim of this review will be to explore salivary biomarkers (pepsin, bile, epidermal growth factor, and micro-RNA) that are being studied as they relate specifically to esophageal disorders. Finally, it will explore the benefits of salivary testing and identify areas of possible future research.

Role of Nidogen-2 in diagnosis and prognosis of head and neck squamous cell carcinoma: A systematic review

Context

Nidogen-2 (NID-2) hypermethylation has been implicated in many types of cancers, such as lung, bladder, and gastric carcinomas. However, its role has not yet been studied adequately in head and neck squamous cell carcinomas (HNSCC). HNSCCs constituting a major portion of the global cancer load, it is of importance to diagnose and treat them at earliest. This systematic review was performed to assess the role of NID-2 in HNSCCs and assess its utility as a diagnostic and prognostic marker.

Materials and Methods

A systematic search was performed across multiple databases to identify studies pertaining to analysis of expression or methylation of NID-2 in HNSCCs. The sample size, type of cancer/premalignant condition studied, type of tissue/fluid analysed, and the various methodologies used and their results were extracted. PROSPERO registration number: CRD42021245326.

Results

Four studies were identified after a systematic search of literature. The studies analysed NID-2 expression or methylation in conditions such as nasopharyngeal carcinoma, esophageal carcinoma, and oral squamous cell carcinoma (OSCC). NID-2 was found to be a highly specific marker for HNSCCs, and serum NID-2 levels also correlated with poor survival.

Conclusion

Data from the reviewed studies indicate that hypermethylation of NID-2 is highly specific for HNSCC. The high specificity is maintained in salivary and serum samples, facilitating accurate and non-invasive prognostication of HNSCC. The relatively lower sensitivity of NID-2 methylation may be overcome by analysing it along with a panel of multiple biomarkers such as HOX-A2 and YKL20.

The Association of Salivary Serotonin With Mood and Cardio-Autonomic Function: A Preliminary Report

BACKGROUND

Serotonin plays an important role in mood regulation and depression. However, it is not clear whether the levels of serotonin in saliva are related to current mood.

AIM

To test the association of salivary serotonin concentrations with mood, as well as cardiovascular and autonomic parameters.

MATERIALS AND METHODS

Saliva samples were obtained from collegiate runners and output parameters were examined before and after physical activity.

RESULTS

Salivary serotonin concentration was negatively associated with current mood (β = -0.32, 95%CI -0.62 to -0.02, p = 0.037, analysis adjusted for potential confounders), but insignificantly with measured cardiovascular and autonomic parameters.

CONCLUSIONS

Salivary serotonin may reflect current mood. The results are preliminary and require further evaluation.

Anopheles salivary antigens as serological biomarkers of vector exposure and malaria transmission: A systematic review with multilevel modelling

Background

Entomological surveillance for malaria is inherently resource-intensive and produces crude population-level measures of vector exposure which are insensitive in low-transmission settings. Antibodies against Anopheles salivary proteins measured at the individual level may serve as proxy biomarkers for vector exposure and malaria transmission, but their relationship is yet to be quantified.

Methods

A systematic review of studies measuring antibodies against Anopheles salivary antigens (PROSPERO: CRD42020185449). Multilevel modelling (to account for multiple study-specific observations [level 1], nested within study [level 2], and study nested within country [level 3]) estimated associations between seroprevalence with Anopheles human biting rate (HBR) and malaria transmission measures.

Results

From 3981 studies identified in literature searches, 42 studies across 16 countries were included contributing 393 study-specific observations of anti-Anopheles salivary antibodies determined in 42,764 samples. A positive association between HBR (log transformed) and seroprevalence was found; overall a twofold (100% relative) increase in HBR was associated with a 23% increase in odds of seropositivity (OR: 1.23, 95% CI: 1.10-1.37; p<0.001). The association between HBR and Anopheles salivary antibodies was strongest with concordant, rather than discordant, Anopheles species. Seroprevalence was also significantly positively associated with established epidemiological measures of malaria transmission: entomological inoculation rate, Plasmodium spp. prevalence, and malarial endemicity class.

Conclusions

Anopheles salivary antibody biomarkers can serve as a proxy measure for HBR and malaria transmission, and could monitor malaria receptivity of a population to sustain malaria transmission. Validation of Anopheles species-specific biomarkers is important given the global heterogeneity in the distribution of Anopheles species. Salivary biomarkers have the potential to transform surveillance by replacing impractical, inaccurate entomological investigations, especially in areas progressing towards malaria elimination.

Funding

Australian National Health and Medical Research Council, Wellcome Trust.

Stress and its contribution to the development of depression symptoms are reduced in caregivers of elderly with higher educational level

Caregivers of elderly people with neurodegenerative diseases are highly vulnerable to stressful situations and mood disorders due to their work conditions. Stress has been associated with an increased risk of developing depression, and studies have supported that caffeine consumption can act as an independent protective factor for disorder. This study investigated indexes of stress and depression symptoms in caregivers of the elderly with neurodegenerative diseases, their caffeine intake and the association between stress and depressive symptoms with the salivary biomarkers cortisol, nitric oxide and DNA damage. Participants (n = 81) were recruited from the community between July 2018 and April 2019. Stress was assessed using Lipp's Inventory of Stress Symptoms, and depressive symptoms were measured using the Hamilton Depressive Rating Scale. Participants provided a 72-hour recall of their diet to measure caffeine intake. Saliva samples were used to measure cortisol and nitric oxide. DNA damage was measured through micronuclei frequency after swabbing on the buccal mucosa. The majority of caregivers displayed stress and depressive symptoms. Stress was associated with educational level, tobacco use and total DNA damage. The indexes found in this population were not associated with caffeine intake or other salivary biomarkers, indicating that only some salivary molecules could be used as biomarkers for stress-related disorders. Caregivers of the elderly are exposed to stressful situations daily, however, we observed that educational level can reduce the psychological symptoms of stress and thus reduce the negative impact on quality of life.

Comparative Evaluation of Salivary Biomarker Levels in e-Cigarette Smokers and Conventional Smokers

BACKGROUND

The cigarette smoking and its effect on the inflammatory cytokine levels in the smoker's saliva depicted the influence of electronic cigarettes on oral cytokine levels in oral fluids are scarce in the literature.

OBJECTIVES

The present trial was conducted to compare and determine the proinflammatory and anti-inflammatory cytokines in whole stimulated saliva samples of electronic cigarette smokers, conventional smokers, and participants with no smoke exposure.

MATERIALS AND METHODS

Sixty adult participants were divided into the following four groups of nonsmokers, current smokers, smokers smoking both conventional and e-cigarettes, and e-cigarette smokers. The saliva samples were assessed for Interleukins (IL-1B, 6, 8, 10, and IL-1RA), C-reactive protein (CRP), and tumor necrosis factor-alpha (TNF-α) using enzyme-linked immunosorbent assay. Plaque scores and Gingival Index, and body mass index were also calculated.

RESULTS

Statistically significant (P < 0.05) and remarkable relationship was seen in plaque scores and IL 1RA, 1 β, and 10 with the respective values as-0.285, 0.268, and 0.267. Regarding anti-inflammatory cytokines, CRP, IL-10, and IL-RA had the P-value of 0.073, 0.945, and 0.834 respectively. When these values were evaluated for proinflammatory cytokines, the P values were 0.0001, 0.019, 0.991, and 903 for TNF-α, IL-1 β, IL-6, and IL-8, respectively. These results were statistically significant for TNF-α (P = 0.001).

CONCLUSION

Within its limitations, the present study concludes that smoking e-cigarettes whether solely or in combination with conventional smoking increases the levels of proinflammatory cytokines such as TNF-α and IL-1 β with decreased counter IL-1RA levels.

Recognizing the salivary panomics for the clinical application in oral potentially malignant disorders

Oral cancer arises as a result of multistep carcinogenic progress from precursor lesion to oral squamous cell carcinoma through collective mutational process occur in the stem cells of mucosal epithelium. The detection of such oral potentially malignant disorders (OPMDs)/cancer in subclinical level will greatly improve the prognosis of a patient. The highly specific and sensitive salivary biomarkers have functioned in detection, prediction, surveillance and therapeutic monitoring of the diseases of interest. The aim of the review is to appraise various salivary biomarkers for the clinical utility in OPMDs. An electronic web-supported search was performed via PubMed, ScienceDirect and Google Scholar search engine since the year 2015–2019. A total of 28 research articles were selected for the review after screening and assessment. The various genomic, transcriptomic, proteomic, metabolomic and miscellaneous markers were analyzed and their characteristics and clinical application in OPMD patients were discussed. miR-21, miR-31, miR-84, H3F3A mRNA + IL-8P, matrix metalloproteinase-9, chemerin, tumor necrosis factor-alpha, cytokeratin-10, ornithine + O-hydroxybenzoate + R5F, 8-hydroxy-2-deoxyguanosine, malondialdehyde, Vitamin E and Vitamin C are identified as potential markers for OPMD patients. Scientifically validated, reliable and economical clinical biomarkers in OPMDs would serve as evidence-based treatment from patient point of view. Further longitudinal studies are needed to verify the accuracy and validate the applicability of these diagnostic/prognostic markers. Saliva has been reported as a valuable noninvasive valuable tool in biomarker identification. Recent advancements in salivary biomarker identification techniques lead to various potential biomarkers with precise outcome. The utilization of these biomarkers for the clinical application in OPMDs depends on the feasibility and personal choice of the clinician.

Association between biomarkers of tobacco consumption and lung cancer risk among daily smokers

BACKGROUND

Biomarkers of tobacco consumption may play a role in the lung cancer risk assessment. However, the role of salivary biomarkers has not been well studied. The aim of this study is to assess the use of salivary biomarkers of tobacco consumption as lung cancer screening criterion.

RESEARCH DESIGN AND METHODS

Data came from the Determinants of cotinine phase 3 project (Barcelona, 2013-2014). We compared the concentrations of TSNAs, including NNAL, NNN and NNK, and cotinine, in saliva samples of 142 daily smokers from the general population according to their risk of lung cancer. High risk of lung cancer was defined as per the inclusion criteria in the US National Lung Screening Trial (NLST) and in the Dutch-Belgian lung cancer screening trial (NELSON).

RESULTS

Among daily smokers accomplishing the age criterion for lung cancer screening, salivary concentrations of cotinine, NNAL and NNK adjusted for sex were significantly higher (p-value < 0.05) in daily smokers at high risk of lung cancer compared to smokers not at high risk according to both NELSON and NLST criteria.

CONCLUSIONS

Saliva concentrations of cotinine, NNAL and NNK may be used as additional criteria for lung cancer screening. Further research on this topic is guaranteed.

Diagnostic salivary biomarkers in oral cancer and oral potentially malignant disorders and their relationships to risk factors - A systematic review

INTRODUCTION

Oral squamous cell carcinoma (OSCC) and oral potentially malignant disorders (OPMD) are a significant health burden globally. Smoking, alcohol, and betel quid are the main risk factors. Lack of screening methods has been highlighted as a significant challenge in management. Salivary biomarkers are proposed as noninvasive diagnostic tools. The aim of this systematic review was to study salivary biomarkers reported in OSCC and OPMD. Specific objectives were to select a salivary biomarker panel suitable for early detection of OSCC and OPMD and to assess relationships between salivary biomarkers and risk factors.

METHODS

Electronic literature search was conducted in academic databases (Scopus, Medline, Embase and Web of Science) without any restrictions. Following calibration, two blinded reviewers screened the studies and extracted data. A risk of bias assessment was conducted using Newcastle Ottawa scale. 295 studies were included with descriptive data analysis.

EXPERT OPINION

A salivary biomarker panel including Interleukin (IL) 1β, IL6, and IL8 was selected for OSCC and OPMD. Reported relationships between salivary biomarkers and risk factors are discussed and research gaps are highlighted. Future research should be directed to assess potential salivary biomarkers and their relationships to risk factors in order to understand the biomarker's role in disease initiation.

Assessment of Growth Factors, Cytokines, and Cellular Markers in Saliva of Patients with Trigeminal Neuralgia

We proposed to perform a comparative analysis of growth factors, cytokines, and chemokine receptors on the salivary cells in the saliva obtained from trigeminal neuralgia (TN) and normal subjects. Saliva was collected from TN and healthy subjects. Salivary cells were isolated by centrifugation. The expression of the cell surface marker was analyzed by flow cytometry. A cytometric bead array was done to measure the levels of cytokines and growth factors on the flow cytometer. Saliva from TN subjects showed lower growth factor levels of Angiopoietin-2, bFGF, HGF, SCF, TGF-α, and VEGF and higher cytokine levels of IL-1β, TNF-α, CCL2, IL-17A, IL-6, and CXCL8, as well as higher expression levels of chemokine receptors CCR1 (CD191), CR3 (CD11b), CCR2 (CD192), CXCR5 (CD185), and CCR5 (CD196) in the cells from TN saliva. A certain set of cytokines and growth factors in the saliva, as well as chemokine receptors on salivary cells, could be a useful tool in the diagnostics and prognostics of trigeminal neuralgia. Trigeminal neuralgia is one of the significant pathological conditions in the class of chronic diseases around the world. Many targeted approaches are being tried by various research groups to utilize the information of the inflammatory microenvironment to resolve the pathology of chronic TN.

Salivary Biomarkers in COVID-19 Patients: Towards a Wide-Scale Test for Monitoring Disease Activity

The ongoing outbreak of coronavirus disease 2019 (COVID-19), which impairs the functionality of several organs, represents a major threat to human health. One of the hardest challenges in the fight against COVID-19 is the development of wide-scale, effective, and rapid laboratory tests to control disease severity, progression, and possible sudden worsening. Monitoring patients in real-time is highly demanded in this pandemic era when physicians need reliable and quantitative tools to prioritize patients’ access to intensive care departments. In this regard, salivary biomarkers are extremely promising, as they allow for the fast and non-invasive collection of specimens and can be repeated multiple times. Methods: We compare salivary levels of immunoglobulin A subclasses (IgA1 and IgA2) and free light chains (kFLC and λFLC) in a cohort of 29 SARS-CoV-2 patients and 21 healthy subjects. Results: We found that each biomarker differs significantly between the two groups, with p-values ranging from 10⁻⁸ to 10⁻⁴. A Receiving Operator Curve analysis shows that λFLC level is the best-suited candidate to discriminate the two groups (AUC = 0.96), with an accuracy of 0.94 (0.87–1.00 95% CI), a precision of 0.91 (0.81–1.00 95% CI), a sensitivity of 1.00 (0.96–1.00 95% CI), and a specificity of 0.86 (0.70–1.00 95% CI). Conclusion: These results suggest λFLC as an ideal indicator of patient conditions. This hypothesis is strengthened by the consideration that the λFLC half-life (approximately 6 h) is significantly shorter than the IgA one (21 days), thus confirming the potential of λFLC for effectively monitoring patients’ fluctuation in real-time.

Salivary Biomarker Levels and Oral Health Status of Children with Cerebral Palsy and Their Healthy Siblings: A Comparative Study

BACKGROUND

The dental needs of cerebral palsy children are an area of study much in need of attention. The neglect of this aspect should be rectified, and simpler diagnostic methodologies should be established and used to serve this purpose.

AIM

This study aimed to determine oral health status and salivary biomarkers (salivary flow rate, pH, buffering capacity) among children with cerebral palsy (CP), to compare their data with that of their healthy siblings, and to evaluate the relationship between salivary biomarkers and dental caries.

METHODS

A total of 30 CP children (study group) and 30 normal healthy siblings (controls) were selected between the ages of 5 and 12 years. Salivary biomarkers were assessed, and oral health status was examined.

STATISTICAL ANALYSIS

Chi-square test was used for comparison of oral health status. Unpaired t test was used to compare caries indexes (decay/filled teeth-primary dentition [dft] and decay/missing/filled teeth-permanent dentition [DMFT]) and salivary biomarkers between the groups. Pearson correlation was used to find the correlation between salivary biomarkers and caries.

RESULTS

The dft scores were significantly higher in the study group (P<0.05). The pH values and salivary flow rates were significantly lower in the study group (P<0.05 and P<0.001, respectively). There was a significant correlation between DMFT scores and salivary flow rate in the study group (P<0.05).

CONCLUSION

Low pH and low salivary flow rate might be risk factors for dental caries in CP populations; moreover, the significant correlation between DMFT score and salivary flow rate suggests that salivary flow rate could be used as a screening tool for assessing at-risk subjects in such populations.

Salivary Biomarkers and Oral Health in Liver Transplant Recipients, with an Emphasis on Diabetes

Salivary biomarkers have been linked to various systemic diseases. We examined the association between salivary biomarkers, periodontal health, and microbial burden in liver transplant (LT) recipients with and without diabetes, after transplantation. We hypothesized that diabetic recipients would exhibit impaired parameters. This study included 84 adults who received an LT between 2000 and 2006 in Finland. Dental treatment preceded transplantation. The recipients were re-examined, on average, six years later. We evaluated a battery of salivary biomarkers, microbiota, and subjective oral symptoms. Periodontal health was assessed, and immunosuppressive treatments were recorded. Recipients with impaired periodontal health showed higher matrix metalloproteinase-8 (MMP-8) levels (p < 0.05) and MMP-8/tissue inhibitor of matrix metalloproteinase 1 (TIMP1) ratios (p < 0.001) than recipients with good periodontal health. Diabetes post-LT was associated with impaired periodontal health (p < 0.05). No difference between groups was found in the microbial counts. Salivary biomarker levels did not seem to be affected by diabetes. However, the advanced pro-inflammatory state induced by and associated with periodontal inflammation was reflected in the salivary biomarker levels, especially MMP-8 and the MMP-8/TIMP-1 molar ratio. Thus, these salivary biomarkers may be useful for monitoring the oral inflammatory state and the course of LT recipients.

Predictive Periodontitis: The Most Promising Salivary Biomarkers for Early Diagnosis of Periodontitis

The primary cause of tooth loss in the industrialized world is periodontitis, a bacterial anaerobic infection whose pathogenesis is characterized by composite immune response. At present, the diagnose of periodontitis is made by a complete status check of the patient’s periodontal health; full-mouth plaque score, full-mouth bleeding score, probing depth, clinical attachment level, bleeding on probing, recessions, mobility, and migration are evaluated in order to provides a clear picture of the periodontal conditions of a single patient. Chair-side diagnostic tests based on whole saliva could be routinely used by periodontists for a very early diagnosis of periodontitis, monitoring, prognosis, and management of periodontal patients by biomarker detection, whose diagnostic validity is related to sensitivity and specificity. Recent paper reviews and meta-analyses have focused on five promising host derived biomarkers as candidate for early diagnosis of periodontitis: MMP-8 (Metalloproteinase-8), MIP-1α (Macrophage inflammatory protein-1 alpha), IL-1 β (Interleukin-1 beta), IL-6 (Interleukin-6), and HB (Hemoglobin), and their combinations. Chair-side Lab-on-a-chip (LOC) technology may soon become an important part of efforts to detect such biomarkers in saliva medium to improve worldwide periodontal health in developed nations as well as in underserved communities and poor countries. Their applications in preventive and predictive medicine is now fundamental, and is aimed at the early detection of risk factors or the presence or evolution of the disease, and in personalized medicine, which aims to identify tailor-made treatments for individual patients. The aim of the present paper is to be informative about host derived periodontal biomarkers and, in particular, we intend to report information about the most important immune response derived biomarkers and Hemoglobin as candidates to be routinely utilized in order to obtain a chair-side early diagnosis of periodontal disease.

Salivary Osteopontin as a Potential Biomarker for Oral Mucositis

Osteopontin (OPN), a multifunctional phosphoglycoprotein also presents in saliva, plays a crucial role in tumour progression, inflammation and mucosal protection. Mucosal barrier injury due to high-dose conditioning regimen administered during autologous and allogeneic peripheral stem cell transplantation (APSCT) has neither efficient therapy nor established biomarkers. Our aim was to assess the biomarker role of OPN during APSCT, with primary focus on oral mucositis (OM). Serum and salivary OPN levels were determined by ELISA in 10 patients during APSCT at four stages of transplantation (day -3/-7, 0, +7, +14), and in 23 respective healthy controls. Results: There was a negative correlation between both salivary and serum OPN levels and grade of OM severity during APSCT (r = -0.791, p = 0.019; r = -0.973, p = 0.001). Salivary OPN increased at days +7 (p = 0.011) and +14 (p = 0.034) compared to controls. Among patients, it was higher at day +14 compared to the time of admission (day -3/-7) (p = 0.039) and transplantation (day 0) (p = 0.011). Serum OPN remained elevated at all four stages of transplantation compared to controls (p = 0.013, p = 0.02, p = 0.011, p = 0.028). During APSCT elevated salivary OPN is a potential non-invasive biomarker of oral mucositis whereas the importance of high serum OPN warrants further studies.

Salivary Biomarkers and Work-Related Stress in Night Shift Workers

Work organization, such as shifts and night work, can interfere with the perception of work-related stress and therefore on the development of pathological conditions. Night shift work, particularly, can have a negative impact on workers’ wellbeing by interfering with the biological sphere. The aim of this study is to evaluate the associations between work activities, shift work effects and stress-related responses in 106 dock workers enrolled in southeast Italy. Dock workers’ tasks consist of complex activities that seemed to affect more sleep quality than work-related stress. An analysis of salivary biomarkers such as cortisol, α-amylase, melatonin and lysozyme was performed along with validated psycho-diagnostic questionnaires. Alpha-amylase showed a significant negative correlation with the effort/reward imbalance score; thus, the measurement of salivary α-amylase is proposed as a sensitive and non-invasive biomarker of work-related stress. This study may provide new insights into developing strategies for the management of night shift work. Salivary biomarkers should be further investigated in the future in order to develop simple and effective tools for the early diagnosis of work-related stress or its outcomes.

The Role of Salivary Biomarkers in the Early Diagnosis of Alzheimer's Disease and Parkinson's Disease

Many neurodegenerative diseases present with progressive neuronal degeneration, which can lead to cognitive and motor impairment. Early screening and diagnosis of neurodegenerative diseases such as Alzheimer’s disease (AD) and Parkinson’s disease (PD) are necessary to begin treatment before the onset of clinical symptoms and slow down the progression of the disease. Biomarkers have shown great potential as a diagnostic tool in the early diagnosis of many diseases, including AD and PD. However, screening for these biomarkers usually includes invasive, complex and expensive methods such as cerebrospinal fluid (CSF) sampling through a lumbar puncture. Researchers are continuously seeking to find a simpler and more reliable diagnostic tool that would be less invasive than CSF sampling. Saliva has been studied as a potential biological fluid that could be used in the diagnosis and early screening of neurodegenerative diseases. This review aims to provide an insight into the current literature concerning salivary biomarkers used in the diagnosis of AD and PD. The most commonly studied salivary biomarkers in AD are β-amyloid_1-42/1-40 and TAU protein, as well as α-synuclein and protein deglycase (DJ-1) in PD. Studies continue to be conducted on this subject and researchers are attempting to find correlations between specific biomarkers and early clinical symptoms, which could be key in creating new treatments for patients before the onset of symptoms.

Salivary Biomarkers of Stress, Anxiety and Depression

Stress, anxiety and depressive disorders are often characterized by the activation of the stress axis, which results in similar symptoms at some point in these disorders. These disorders are closely related to each other—they occur simultaneously or follow one another. The diagnosis of stress, anxiety and depression is not a perfect procedure currently—it is based on patient observation and an interview with the patient and their family. There are no laboratory tests that would dispel the doubts of the doctor making the diagnosis and allow the appropriate treatment to be implemented as soon as possible. Therefore, this study will review the components of saliva that could be helpful in the quick diagnosis of stress, anxiety and/or depression. Such potential salivary biomarkers could also be useful in monitoring the effectiveness of pharmacological treatment prescribed by a psychiatrist. The following are promising salivary biomarkers of stress, anxiety or depression: cortisol, immunoglobulin A (sIgA), lysozyme, melatonin, α-amylase (sAA), chromogranin A (CgA) and fibroblast growth factor 2 (FGF-2). To the best valuable potential salivary markers of stress, we can include cortisol, lysozyme, sAA and CgA. To differentiate depression from stress, salivary cortisol and melatonin can be helpful. Fluctuations in the concentrations of the above-mentioned substances in saliva indicate a particularly strong relationship with typical human psychological problems, such as stress, depression or anxiety.

Green Salad Intake Is Associated with Improved Oral Cancer Survival and Lower Soluble CD44 Levels

Deficiencies in fruit and vegetable intake have been associated with oral cancer (oral cavity and oropharyngeal). Salivary rinses contain measurable biomarkers including soluble CD44 (solCD44) and total protein, which are known markers of oral cancer risk. This study investigates the effect of nutritional factors on solCD44 and protein levels to evaluate oral cancer risk and survival. We evaluated solCD44 and protein levels from 150 patients with oral and oropharyngeal squamous cell carcinoma and 150 frequency-matched controls. We subsequently characterized the effect of food group consumption and these biomarkers on progression-free survival (PFS) and overall survival (OS). Patients reported eating fewer servings of salad (p = 0.015), while controls reported eating fewer servings of potatoes (p < 0.001). Oral cancer patients who consumed at least one serving per week of green salad were found to have significantly lower CD44 levels than those who ate salad less frequently (mean of log₂[solCD44]1.73 versus 2.25, p = 0.014). Patients who consumed at least one serving per week of “salad or other vegetables” had significantly longer PFS (median 43.5 versus 9.1 months, p = 0.003, adjusted hazard ratio (HR) = 0.39 p = 0.014) and OS (median 83.6 versus 10 months, p = 0.008, adjusted HR = 0.04 p = 0.029). These findings suggest that dietary factors, namely greater green salad and vegetable intake, may be associated with lower CD44 levels and better prognosis in oral cancer patients.

Operational Evaluation of the Effectiveness of Long-lasting Insecticidal Nets on Human-Vector Contact in an African Urban Malaria Context

Background

Malaria is still a major public health concern in Côte d’Ivoire despite mass distribution of long-lasting insecticidal nets (LLINs) as a key preventive strategy. This study intended to evaluate the operational effectiveness of LLINs on the level of human-vector contact using 1 antibody-based biomarker of exposure to Anopheles in urban areas.

Methods

This cross-sectional study collected socio-demographic data and use of LLINs from 9 neighborhoods in the city of Bouaké (Côte d’Ivoire). Dry blood spots performed in children aged >6 months and adults were used to evaluate immunoglobulin G (IgG) responses to the Anopheles gSG6-P1 salivary peptide.

Results

IgG response levels to the salivary peptide were significantly lower in individuals who declared having “always” (n = 270) slept under an LLIN compared with those who had “often” (n = 2087) and “never” (n = 88) slept under an LLIN (P < .0001). IgG response levels to gSG6-P1 between those who declared having “always” and “not always” slept under an LLIN varied according to neighborhood, socio-professional category, and age group.

Conclusions

The human IgG level to this gSG6-P1 salivary peptide could be a useful tool to evaluate the actual effectiveness of LLINs and help design behavioral change interventions that are crucial for sustaining universal coverage.

Salivary biomarkers in cardiovascular disease: An insight into the current evidence

Cardiovascular diseases (CVDs) are the most common cause of mortality worldwide. In acute cardiovascular conditions, time is a crucial player in the outcomes of disease management. Given the ease and noninvasiveness of obtaining saliva, salivary biomarkers may provide a rapid and efficient diagnosis of CVD. Here, we reviewed the published data on the value of salivary molecules for diagnosis of CVD, especially in acute care settings. In this review, we show that some biomarkers such as salivary creatinine kinase myocardial band, C-reactive protein, troponin-1, and myoglobin exhibited promising diagnostic values that were comparable to their serum counterparts. Other molecules were also investigated and showed controversial results, including myeloperoxidase, brain natriuretic peptide, and some oxidative stress markers. Based on our review, we concluded that the clinical use of salivary biomarkers to diagnose CVD is promising; however, it is still in the early stage of development. Further studies are needed to validate these findings, determine cutoff values for diagnosis, and compare them to other established biomarkers currently in clinical use.

Functional Specialization of Human Salivary Glands and Origins of Proteins Intrinsic to Human Saliva

Salivary proteins are essential for maintaining health in the oral cavity and proximal digestive tract, and they serve as potential diagnostic markers for monitoring human health and disease. However, their precise organ origins remain unclear. Through transcriptomic analysis of major adult and fetal salivary glands and integration with the saliva proteome, the blood plasma proteome, and transcriptomes of 28+ organs, we link human saliva proteins to their source, identify salivary-gland-specific genes, and uncover fetal- and adult-specific gene repertoires. Our results also provide insights into the degree of gene retention during gland maturation and suggest that functional diversity among adult gland types is driven by specific dosage combinations of hundreds of transcriptional regulators rather than by a few gland-specific factors. Finally, we demonstrate the heterogeneity of the human acinar cell lineage. Our results pave the way for future investigations into glandular biology and pathology, as well as saliva's use as a diagnostic fluid.

Oral microbiome and mucosal trauma as risk factors for oral cancer: beyond alcohol and tobacco. A literature review

Oral and oropharyngeal cancer represents the sixth more common type of cancer affecting the worldwide population. It has been estimated the number of 650,000 new cases per year globally and a greater prevalence has been registered among men. The main risk factors for oral cancer such as tobacco smoking and alcohol are uncontroversial and have been deeply investigated and evidenced in the scientific literature. Recently, viral infections related to Human Papilloma Virus (HPV), with the genotype 16 and 32, have shown a correlation mainly with oropharyngeal cancer (OPC) especially in the non-smoking and non-drinkers young adults. Its transmission is mainly related to sexually transmitted diseases (STDs) although its involvement in oral squamous cell carcinoma (OSCC) is still unclear. This review aims to explore the hypotheses of the OSCC etiology and other possible risk factors, such as chronic traumatisms, chronic periodontitis, and poor oral hygiene that affect directly the oral mucosa and might trigger the carcinogenesis process that should not be underestimated. Furthermore, in the last 10 years, the role of oral microbiome gained attention as a predicting biomarker, for a possible bacterial, viral, and fungal involvement in tumorigenesis.