Mouth breathing, another risk factor for asthma: the Nagahama Study

Increased blood eosinophils and airflow obstruction as new-onset asthma predictors in the elderly: The Nagahama study

BACKGROUND

Asthma in the elderly needs more attention in an aging society. However, it is likely to remain underdiagnosed and undertreated. This study aimed to clarify clinical characteristics of new-onset asthma in the elderly, describing the prevalence, predictive factors, and comorbidities after asthma diagnosis of new-onset asthma in the elderly in the general population.

METHODS

This community-based prospective cohort study enrolled 9804 generally healthy participants (30-74 years old) in Nagahama City, and conducted a follow-up assessment after 5 years. Elderly participants were those aged ≥65 years at baseline. Patients with new-onset asthma were defined as participants without asthma at baseline assessment and with asthma at the follow-up assessment.

RESULTS

Among the 7948 participants analyzed in this study, 28 (1.4%) elderly and 130 (2.2%) non-elderly had new-onset asthma. Multiple logistic regression analysis revealed low forced expiratory volume in 1 s (FEV1)/forced vital capacity (FVC) and high blood eosinophil counts at baseline as predicting factors for new-onset asthma in the elderly. Additionally, subsequent incidence of new-onset asthma was higher in elderly participants with both predictors (high blood eosinophil counts and low FEV1/FVC at baseline) than those with none or one of the predictors before asthma diagnosis. Lastly, elderly patients with new-onset asthma had more frequent comorbidity of moderate to severe sleep disordered breathing than those non-elderly.

CONCLUSIONS

Eosinophilic inflammation and airflow obstruction may predict subsequent new-onset asthma after the age of 65 years. Revealing the characteristics of new-onset asthma in the elderly can aid in the prevention of underdiagnosed asthma.

Health effects associated with exposure to secondhand smoke: a Burden of Proof study

Despite a gradual decline in smoking rates over time, exposure to secondhand smoke (SHS) continues to cause harm to nonsmokers, who are disproportionately children and women living in low- and middle-income countries. We comprehensively reviewed the literature published by July 2022 concerning the adverse impacts of SHS exposure on nine health outcomes. Following, we quantified each exposure-response association accounting for various sources of uncertainty and evaluated the strength of the evidence supporting our analyses using the Burden of Proof Risk Function methodology. We found all nine health outcomes to be associated with SHS exposure. We conservatively estimated that SHS increases the risk of ischemic heart disease, stroke, type 2 diabetes and lung cancer by at least around 8%, 5%, 1% and 1%, respectively, with the evidence supporting these harmful associations rated as weak (two stars). The evidence supporting the harmful associations between SHS and otitis media, asthma, lower respiratory infections, breast cancer and chronic obstructive pulmonary disease was weaker (one star). Despite the weak underlying evidence for these associations, our results reinforce the harmful effects of SHS on health and the need to prioritize advancing efforts to reduce active and passive smoking through a combination of public health policies and education initiatives.

The Link between Periodontal Disease and Asthma: How Do These Two Diseases Affect Each Other?

A growing body of evidence suggests that the effects of poor oral hygiene extend beyond the oral cavity and are associated with a variety of systemic diseases, including asthma. Asthma, which results in symptoms of cough, wheezing, and dyspnoea, and is characterized by airflow limitation with variability and (partial or complete) reversibility, is amongst the most prevalent respiratory diseases with approximately 262 million patients worldwide, and its prevalence and disease burden is on the increase. While asthma can occur at a young age, it can also develop later in life and affects a variety of age groups. Both of these diseases have a chronic course, and various researchers have suggested a link between the two. In this article, we aim to provide a literature review focusing on the association between the two diseases. The results demonstrate that medications (primarily, inhaler medicine), hypoxia induced by asthma, and the breathing behaviour of patients potentially trigger periodontal disease. In contrast, oral periodontopathogenic microorganisms and the inflammatory mediators produced by them may be involved in the onset and/or exacerbation of asthma. Common contributing factors, such as smoking, gastro-oesophageal reflux, and type-2 inflammation, should also be considered when evaluating the relationship between the two diseases.

International consensus statement on allergy and rhinology: Allergic rhinitis - 2023

BACKGROUND

In the 5 years that have passed since the publication of the 2018 International Consensus Statement on Allergy and Rhinology: Allergic Rhinitis (ICAR-Allergic Rhinitis 2018), the literature has expanded substantially. The ICAR-Allergic Rhinitis 2023 update presents 144 individual topics on allergic rhinitis (AR), expanded by over 40 topics from the 2018 document. Originally presented topics from 2018 have also been reviewed and updated. The executive summary highlights key evidence-based findings and recommendation from the full document.

METHODS

ICAR-Allergic Rhinitis 2023 employed established evidence-based review with recommendation (EBRR) methodology to individually evaluate each topic. Stepwise iterative peer review and consensus was performed for each topic. The final document was then collated and includes the results of this work.

RESULTS

ICAR-Allergic Rhinitis 2023 includes 10 major content areas and 144 individual topics related to AR. For a substantial proportion of topics included, an aggregate grade of evidence is presented, which is determined by collating the levels of evidence for each available study identified in the literature. For topics in which a diagnostic or therapeutic intervention is considered, a recommendation summary is presented, which considers the aggregate grade of evidence, benefit, harm, and cost.

CONCLUSION

The ICAR-Allergic Rhinitis 2023 update provides a comprehensive evaluation of AR and the currently available evidence. It is this evidence that contributes to our current knowledge base and recommendations for patient evaluation and treatment.

Feasibility of a nasal breathing training during pulmonary rehabilitation. A pilot randomized controlled study

Hyperventilation syndrome (HVS) is a common source of dyspnea and disability. While pulmonary rehabilitation (PR) including breathing exercises is indicated, randomized controlled trial are warranted to recommend one type of breathing exercise than another. We aimed to compare during PR, the effect of 5 sessions of nasal ventilation exercise (NV+PR) versus voluntary hypoventilation (vHV+PR) on exercise dyspnea (primary outcome) and capacity and health-related quality of life in patients. In this open label randomized controlled trial, 19 HVS patients (age=48.3 ± 15.2 y.o, female/male=18/1, Nijmegen score=33 ± 7.7) were randomized in a NV+PR (n = 9) or vHV+PR (n = 10) group. Modified Medical Research Council (mMRC) dyspnea, 6-minute walking distance (6MWD) with nasal/oral ventilation were assessed before and after 3 months of PR, and questionnaires (Nijmegen, VQ-11). There was a significant effect of PR of but no significant difference between groups in the improvements of dyspnea@max exercise (time effect (T): p < 0.01; group (G): p = 0.63; group*time interaction (G*T): p = 0.49), mMRC dyspnea (T: p < 0.01; G: p = 0.45; G*T: p = 0.62), 6MWD (T: p < 0.05; G: p = 0.36; G*T: p = 0.31), VQ-11 (T: p < 0.001; G: p = 0.16; G*T: p = 0.09) and plasma HCO₃^- (T: p < 0.05; G: p = 0.93; G*T; p = 0.36), Yet, Nijmegen score (T: p < 0.01; G: p = 0.32; G*T: p < 0.05) improvement was larger in NV+PR group. The exercise oronasal breathing shift during the 6MWT was significantly delayed in all patients (T: p < 0.05; G: p = 0.30; G*T: p = 0.32) and positively correlated with plasma HCO₃^-(r = 0.42; p < 0.05). Nasal exercise was not superior versus voluntary hypoventilation during PR in HVS patients. Yet, nasal exercise appeared feasible, leading to acquisition of a nasal breathing pattern during walking, improvement of PR outcomes and ventilatory alkalosis. The link between nasal breathing and hyperventilation is discussed in the light of the nasal ventilation rhythm in the limbic system and its role on the limbic emotional and ventilatory functions.

Postoperative complications in asthmatic patients following orthognathic surgery: A two-year follow-up study

BACKGROUND

Lack of evidence exists related to the incidence of postoperative complications in asthmatic patients following orthognathic surgery. The present study aimed to assess the incidence and risk factors of postoperative complications in asthmatic patients following orthognathic surgery.

MATERIAL AND METHODS

A retrospective cohort study was conducted which consisted of two groups of patients i.e., asthmatic and systemically healthy patients, who underwent conventional orthognathic surgical procedures (Le Fort I osteotomy, bilateral sagittal split osteotomy, and genioplasty). The recorded postoperative complications in both groups of patients included infection, relapse, altered facial sensation, temporomandibular joint disorder, respiratory complications, and hemorrhage-related events. The association between baseline variables and complications for identifying the possible risk factors was assessed using bivariate analysis and a logistic regression model.

RESULTS

A total of 886 patients underwent orthognathic surgery over a period of 6-years. Following the eligibility criteria, 16 patients were recruited in the asthmatic group and 278 patients were systemically healthy. The most common complications in the asthmatic patients were altered sensation (37.5%) followed by TMJ disorder (25.0%) and relapse (18.8%). These patients were associated with an increased risk of relapse (P = 0.048) compared to healthy patients. Following adjustment of baseline variables, increased risk of relapse was still associated with asthma (odds ratio [OR]. = 4.704, P = 0.027).

CONCLUSION

Asthmatic patients suffer from a significantly higher risk of relapse and need to be closely monitored following orthognathic surgery to ensure a stable outcome. Asthma does not seem to have a significant impact on other postoperative complications.

Evaluation of orofacial dysfunctions and oral health-related quality of life in children with asthma

Objective: This study aimed to investigate the impact of asthma on oro-facial muscle dysfunction (OFD) and oral health-related quality of life (OHRQoL) in children. Materials and Method: A total of 158 children, 79 diagnosed with asthma and 79 healthy, were included in the study. Children diagnosed with asthma were divided into controlled and uncontrolled asthma groups. The OFD and OHRQoL of all participants were evaluated with Nordic Orofacial Test and Screening (NOT-S) and Child Perception Questionnaire (CPQ8-10). The differences and correlations between the groups were statistically evaluated (Mann-Whitney and Spearman and Chi-Square test). Results: NOT-S interview, examination, and total scores were statistically higher in the asthma group compared to healthy children and between uncontrolled and controlled asthma groups (p&lt;0.001). Higher scores were obtained in all areas of CPQ8-10 in the asthma group (p&lt;0.001). NOT-S and CPQ8-10 scores elevated compatibly in the groups diagnosed with asthma. Conclusion: OFD in asthmatic children predicts worse OHRQoL.

Mouth opening/breathing is common in sleep apnea and linked to more nocturnal water loss

OBJECTIVES

Mouth opening/breathing during sleep is common in patients with obstructive sleep apnea (OSA), which is probably associated with more water loss and higher risk for nocturnal ischemic heart attack. This study aimed to evaluate nocturnal changes in hematocrit/hemoglobin levels and estimated plasma volume loss in OSA patients and its relation to their OSA severity and mouth open/breathing.

METHODS

Sixty OSA patients and fifteen healthy controls were enrolled and underwent overnight polysomnography. Mouth status was evaluated via an infrared camera and nasal/mouth airflow. Hematocrit and hemoglobin levels in peripheral venous blood were measured before and after sleep to estimate the change of plasma volume.

RESULTS

Compared to controls, OSA patients had a greater nocturnal increase in hematocrit (1.35% vs. 1.0%, p=0.013), hemoglobin (0.50% vs. 0.30%, p=0.002) and more estimated water loss (5.5% vs 3.7% of plasma volume, p<0.013). The extent of increase was correlated to apnea-hypopnea index_the marker of OSA severity (Spearman's ρ=0.332, p=0.004; ρ=0.367, p=0.001 for hematocrit, hemoglobin, respectively), which remained significant after serial multivariate adjustment. OSA patients had more sleep time with mouth open (96.7% vs 26.7% of total sleep time, p<0.001) and time with complete mouth breathing (14.1% vs 2.7%, p<0.001). The extent of mouth breathing was correlated to apnea-hypopnea index (ρ=0.487, p<0.001), nocturnal increase in hematocrit/hemoglobin levels (ρ=0.236, p=0.042; ρ=0.304, p=0.008, respectively) and estimated plasma volume loss (ρ=0.262, p=0.023).

CONCLUSIONS

OSA patients had a greater increase in hematocrit/hemoglobin levels after sleep, which is probably linked to more water loss and more sleep time with mouth open/breathing.

Evaluation and Management of Snoring

Snoring can be harmless (primary) or a symptom of sleep-disordered breathing (secondary) and should alert the physician to evaluate the patient for risks thereof. Phenotypes of snoring and sleep-disordered breathing (SDB) are anatomic and nonanatomic and identifying these phenotypes and their interrelationships are critical to effective therapy. Mouth breathing alerts the physician to nasal airway obstruction, signals orofacial growth changes in children, and heralds the progression of SDB. Systematic evaluation to establish phenotypes includes assessing sleep habits, comorbidities, upper airway examination, polysomnography, and drug-induced sleep endoscopy. Strategies for treatment should be personalized and precise to the phenotype(s) to achieve the most benefit.

Blood eosinophil counts in the general population and airways disease: a comprehensive review and meta-analysis

BACKGROUND

The clinical context for using blood eosinophil (EOS) counts as treatment-response biomarkers in asthma and COPD requires better understanding of EOS distributions and ranges. We describe EOS distributions and ranges published in asthma, COPD, control (non-asthma/COPD) and general populations.

METHODS

We conducted a comprehensive literature review and meta-analysis of observational studies (January 2008 to November 2018) that included EOS counts in asthma, severe asthma, COPD, control and general populations. Excluded studies had total sample sizes <200, EOS as inclusion criterion, hospitalised population only and exclusively paediatric participants.

RESULTS

Overall, 91 eligible studies were identified, most had total-population-level data available: asthma (39 studies), severe asthma (12 studies), COPD (23 studies), control (seven studies) and general populations (14 studies); some articles reported data for multiple populations. Reported EOS distributions were right-skewed (seven studies). Reported median EOS counts ranged from 157-280 cells·µL-1 (asthma, 22 studies); 200-400 cells·µL-1 (severe asthma, eight studies); 150-183 cells·µL-1 (COPD, six studies); and 100-160 cells·µL-1 (controls, three studies); and 100-200 cells·µL-1 (general populations, six studies). The meta-analysis showed that observed variability was mostly between studies rather than within studies. Factors reportedly associated with higher blood EOS counts included current smoking, positive skin-prick test, elevated total IgE, comorbid allergic rhinitis, age ≤18 years, male sex, spirometric asthma/COPD diagnosis, metabolic syndrome and adiposity.

CONCLUSION

EOS distribution and range varied by study population, and were affected by clinical factors including age, smoking history and comorbidities, which, regardless of severity, should be considered during treatment decision-making.

Risk factors of asthma in the Asian population: a systematic review and meta-analysis

Background and objective

An increasing trend of asthma prevalence was observed in Asia; however, contributions of environmental and host-related risk factors to the development of this disease remain uncertain. This study aimed to perform a systematic review and meta-analysis for asthma-associated risk factors reported in Asia.

Methods

We systematically searched three public databases (Web of Science, PubMed, and Scopus) in Feb 2021. We only included articles that reported environmental and host-related risk factors associated with asthma in the Asian population. Random-effect meta-analyses were conducted for frequently reported asthma-associated risk factors to provide an overall risk estimate of asthma development.

Results

Of 4030 records obtained from public databases, 289 articles were selected for review. The most frequently reported asthma-associated risk factor was the family history of allergy-related conditions. The random-effect asthma risk estimates (pooled odds ratio, OR) were 4.66 (95% confidence interval (CI): 3.73–5.82) for the family history of asthma, 3.50 (95% CI: 2.62–4.67) for the family history of atopy, 3.57 (95% CI: 3.03–4.22) for the family history of any allergic diseases, 1.96 (95% CI: 1.47–2.61) for the family history of allergic rhinitis, and 2.75 (95% CI: 1.12–6.76) for the family history of atopic dermatitis. For housing-related factors, including the presence of mold, mold spots, mold odor, cockroach, water damage, and incense burning, the random-effect pooled OR ranged from 1.43 to 1.73. Other risk factors with significant pooled OR for asthma development included male gender (1.30, 95% CI: 1.23–1.38), cigarette smoke exposure (1.44, 95% CI: 1.30–1.60), cigarette smoking (1.66, 95% CI: 1.44–1.90), body mass index (BMI)–related parameters (pooled OR ranged from 1.06 to 2.02), various types of air pollution (NO₂, PM10, and O₃; pooled OR ranged from 1.03 to 1.22), and pre- and perinatal factors (low birth weight, preterm birth, and cesarean section; pooled OR ranged from 1.14 to 1.32).

Conclusions

The family history of asthma was the most frequently reported risk factor for asthma development in Asia with the highest risk estimate for asthma development. This suggests a major role of the genetic component in asthma pathogenesis. Further study on asthma genetics is required to improve the current understanding of asthma etiology.

Supplementary Information

The online version contains supplementary material available at 10.1186/s40101-021-00273-x.

Impacts of lipid-related metabolites, adiposity, and genetic background on blood eosinophil counts: the Nagahama study

Blood eosinophil count is a useful measure in asthma or COPD management. Recent epidemiological studies revealed that body mass index (BMI) is positively associated with eosinophil counts. However, few studies focused on the role of adiposity and fatty acid-related metabolites on eosinophil counts, including the effect of genetic polymorphism. In this community-based study involving 8265 participants (30-74 year old) from Nagahama city, we investigated the relationship between eosinophil counts and serum levels of fatty acid-related metabolites. The role of MDC1, a gene that is related to eosinophil counts in our previous study and encodes a protein that is thought to be involved in the repair of deoxyribonucleic acid damage, was also examined taking into account its interaction with adiposity. Serum levels of linoleic acid (LA) and β-hydroxybutyric acid (BHB) were negatively associated with eosinophil counts after adjustment with various confounders; however, there were positive interactions between serum LA and BMI and between serum BHB and BMI/body fat percentages in terms of eosinophil counts. In never-smokers, there was positive interaction for eosinophil counts between the CC genotype of MDC1 rs4713354 and BMI/body fat percentages. In conclusion, both serum LA and BHB have negative impacts on eosinophil counts, while adiposity shows robust positive effects on eosinophil counts, partly via genetic background in never-smokers.

Dental Caries in Adults with Atopic Dermatitis: A Nationwide Cross-Sectional Study in Korea

Background

Dental caries is the most prevalent chronic infectious oral disease of multifactorial etiology. Increased risk of dental caries development in patients with asthma and allergic rhinitis has been frequently reported. In contrast, only a few studies on dental caries in patients with atopic dermatitis (AD) have been reported.

Objective

We investigated the association between AD and dental caries development in an adult population in the Republic of Korea.

Methods

A total of 21,606 adults who participated in the Korean National Health and Nutrition Examination Survey, a nationwide, population-based, cross-sectional survey between 2010 and 2015, were included in the study. Multiple logistic regression analyses with confounder adjustment suggested odds ratios (ORs) to identify the possible association between AD and decayed, missing, filled teeth (DMFT) experience compared to non-AD participants. Multiple Poisson regression analyses estimated the mean ratio of the DMFT index according to the presence of AD.

Results

After adjusting for various confounding factors, the prevalence of DMFT was significantly associated with AD (OR, 1.58; 95% confidence interval (CI), 1.08~2.29; p=0.017). In addition, the mean value of the DMFT index was significantly different between the AD and non-AD groups (mean ratio, 1.07; 95% CI, 1.00~1.14; p=0.046).

Conclusion

AD was significantly associated with the development of dental caries. Dermatologists should be aware of the dental manifestations of AD patients and recommend regular dental check-ups for the early detection of caries.

Identification of Breathing Patterns through EEG Signal Analysis Using Machine Learning

This study was to investigate the changes in brain function due to lack of oxygen (O₂) caused by mouth breathing, and to suggest a method to alleviate the side effects of mouth breathing on brain function through an additional O₂ supply. For this purpose, we classified the breathing patterns according to EEG signals using a machine learning technique and proposed a method to reduce the side effects of mouth breathing on brain function. Twenty subjects participated in this study, and each subject performed three different breathings: nose and mouth breathing and mouth breathing with O₂ supply during a working memory task. The results showed that nose breathing guarantees normal O₂ supply to the brain, but mouth breathing interrupts the O₂ supply to the brain. Therefore, this comparative study of EEG signals using machine learning showed that one of the most important elements distinguishing the effects of mouth and nose breathing on brain function was the difference in O₂ supply. These findings have important implications for the workplace environment, suggesting that special care is required for employees who work long hours in confined spaces such as public transport, and that a sufficient O₂ supply is needed in the workplace for working efficiency.

Association between nasal patency and orofacial myofunctional changes in patients with asthma and rhinitis

PURPOSE

To verify the association between orofacial myofunctional changes and nasal patency.

METHOD

Observational study of 43 children and adolescents with asthma and/or rhinitis, aged between 5 and 14 years, from May 2017 to September 2019. Patients underwent peak nasal inspiratory flow (PNIF) for nasal patency assessment and orofacial myofunctional assessment. Clinical data were obtained from an interview on the day of the patients' medical evaluation. The relationship between orofacial myofunctional changes and PNIF was analyzed using a logistic regression model. Estimates were reported as odds ratio (OR) and 95% confidence interval (95%CI). We evaluated multicollinearity using the variance inflation factor and analyzed the adjusted fit with the Akaike information criterion and McFadden's R² metric; p value < 0.05 was considered statistically significant.

RESULTS

Inadequate positioning of the mandible (OR = 11.22; 95%CI 1.83-69; p = 0.009) and the presence of tension in the facial muscles during the swallowing of liquid (OR = 4.61; 95%CI 1.31-16.20; p = 0.017) were associated with altered PNIF in children and adolescents with asthma and rhinitis.

CONCLUSION

Children and adolescents with asthma and rhinitis along with reduced nasal patency presented orofacial myofunctional changes, such as inadequate positioning of the jaw and the presence of tension in the facial muscles during swallowing of liquid.

Alterations in Oral-Nasal-Pharyngeal Microbiota and Salivary Proteins in Mouth-Breathing Children

Mouth breathing induces a series of diseases, while the influence on microbiota of oral cavity and salivary proteins remains unknown. In this study, for the first time, profiles of oral-nasal-pharyngeal microbiota among mouth-breathing children (MB group, n = 10) were compared with paired nose-breathing children (NB group, n = 10) using 16S ribosomal DNA (rDNA) (V3-V4 region) high-throughput sequencing. The differentially expressed salivary proteins were revealed using label-free quantification (LFQ) method, and their associations with bacterial abundance were measured by canonical correspondence analysis (CCA). The overall bacterial profiles differed between the two groups, and the differences were related to the duration of mouth breathing. The diversity of oral-pharyngeal microbiota was significantly higher, and the nasal-pharyngeal species tended to be consistent (unweighted UniFrac, p = 0.38) in the MB group. Opportunistic pathogens were higher in relative abundance as follows: Acinetobacter in the anterior supragingival plaque, Neisseria in unstimulated saliva, Streptococcus pneumoniae in the pharynx, and Stenotrophomonas in the nostrils. The expression level of oxidative-stress-related salivary proteins (lactoylglutathione lyase and peroxiredoxin-5) were upregulated, while immune-related proteins (integrin alpha-M and proteasome subunit alpha type-1) were downregulated in MB group. The differentially expressed proteins were associated with specific bacteria, indicating their potentials as candidate biomarkers for the diagnosis, putatively early intervention, and therapeutic target of mouth breathing. This study showed that mouth breathing influences the oral-nasal-pharyngeal microbiota and enriches certain pathogens, accompanied with the alterations in the salivary environment. Further research on the pathological mechanisms and dynamic changes in longitudinal studies are warranted.

Investigation of Functional Connectivity Differences between Voluntary Respirations via Mouth and Nose Using Resting State fMRI

The problems of mouth breathing have been well-studied, but the neural correlates of functional connectivity (FC) still remain unclear. We examined the difference in FC between the two types of breathing. For our study, 21 healthy subjects performed voluntary mouth and nasal breathing conditions during a resting state functional magnetic resonance imaging (fMRI). The region of interest (ROI) analysis of FC in fMRI was conducted using a MATLAB-based imaging software. The resulting analysis showed that mouth breathing had widespread connections and more left lateralization. Left inferior temporal gyrus had the most left lateralized connections in mouth breathing condition. Furthermore, the central opercular cortex FC showed a significant relationship with mouth breathing. For nasal breathing, the sensorimotor area had symmetry FC pattern. These findings suggest that various FCs difference appeared between two breathing conditions. The impacts of these differences need to be more investigated to find out potential link with cognitive decline in mouth breathing syndrome.

Association Between Mouth Breathing and Asthma: a Systematic Review and Meta-analysis

PURPOSE OF REVIEW

This systematic review and meta-analysis evaluated the association between asthma and mouth breathing. We performed a systematic search in the PubMed, SCOPUS, Lilacs, Web of Science, Google Scholar and OpenThesis databases.

RECENT FINDINGS

Asthma is defined as a heterogeneous disease characterized by variable symptoms of wheezing, shortness of breath, chest oppression and/or cough, and limitation of expiratory airflow. Although several studies have examined the association between asthma and mouth breathing, there are no systematic reviews or meta-analyses that synthesize the available bodies of evidence. We used the odds ratio as a measure of the association between asthma and mouth breathing. Summary estimates were calculated using random-effects models, and the risk of bias was estimated using the Newcastle-Ottawa Scale for case-control studies and the National Institutes of Health tool for cross-sectional studies. Nine studies were included in the present systematic review. Data from 12,147 subjects were analyzed, of which 2083 were children and adolescents and 10,064 were adults. We found an association between mouth breathing and asthma in children and adolescents (OR 2.46, 95% CI 1.78-3.39) and in adults (OR 4.60, 95% CI 1.49-14.20). However, limitations were found in the methodological description of the included studies, as well as high heterogeneity among studies evaluating adult populations. This meta-analysis showed an association between mouth breathing and asthma in children, adolescents and adults, but the results should be interpreted with caution. Further studies with standardized criteria for the investigation of mouth breathing are needed.

Infection Screening System Using Thermography and CCD Camera with Good Stability and Swiftness for Non-contact Vital-Signs Measurement by Feature Matching and MUSIC Algorithm

Screening systems for infectious diseases based on fever have been implemented at international airports to prevent the spread of infection for over a decade. Currently, only Infrared Thermography (IRT) is used for screening and measuring facial skin temperature, which is one of clinical indicators of potential infection. Aiming at higher accuracy in screening, our group adopted heart rate (HR) and respiration rate (RR) for the first time as the new screening parameters. In our previous study, we proposed a screening system based on dual image sensors, which include IRT and a charged-coupled devices (CCD) camera. The sensors can measure three vital signs simultaneously, namely HR, RR, and facial skin temperature. For the measurement of RR in this system, stability and swiftness must be applied for application in airports. In this study, we introduce feature matching and multiple signal classification (MUSIC) algorithm in this system. Feature matching between thermal images and RGB images captured by a CCD camera and IRT, respectively, is used to detect the nose and mouth in IRT, which helps extract respiration signals corresponding to airflow from breathing. In addition, the MUSIC algorithm improves the accuracy of RR frequency estimations in limited time respiration signal and achieves swiftness. The proposed method improves stability by simultaneously detecting the nose and mouth in thermal images, and enhances the accuracy of estimated RR using the MUSIC algorithm. By using this system, we evaluate the accuracy of the estimated vital signs. The performance of this screening system was evaluated using data obtained from 12 influenza patients and 13 healthy subjects at a clinical facility in Fukushima, Japan.

Contactless Vital Signs Measurement System Using RGB-Thermal Image Sensors and Its Clinical Screening Test on Patients with Seasonal Influenza

Background: In the last two decades, infrared thermography (IRT) has been applied in quarantine stations for the screening of patients with suspected infectious disease. However, the fever-based screening procedure employing IRT suffers from low sensitivity, because monitoring body temperature alone is insufficient for detecting infected patients. To overcome the drawbacks of fever-based screening, this study aims to develop and evaluate a multiple vital sign (i.e., body temperature, heart rate and respiration rate) measurement system using RGB-thermal image sensors. Methods: The RGB camera measures blood volume pulse (BVP) through variations in the light absorption from human facial areas. IRT is used to estimate the respiration rate by measuring the change in temperature near the nostrils or mouth accompanying respiration. To enable a stable and reliable system, the following image and signal processing methods were proposed and implemented: (1) an RGB-thermal image fusion approach to achieve highly reliable facial region-of-interest tracking, (2) a heart rate estimation method including a tapered window for reducing noise caused by the face tracker, reconstruction of a BVP signal with three RGB channels to optimize a linear function, thereby improving the signal-to-noise ratio and multiple signal classification (MUSIC) algorithm for estimating the pseudo-spectrum from limited time-domain BVP signals within 15 s and (3) a respiration rate estimation method implementing nasal or oral breathing signal selection based on signal quality index for stable measurement and MUSIC algorithm for rapid measurement. We tested the system on 22 healthy subjects and 28 patients with seasonal influenza, using the support vector machine (SVM) classification method. Results: The body temperature, heart rate and respiration rate measured in a non-contact manner were highly similarity to those measured via contact-type reference devices (i.e., thermometer, ECG and respiration belt), with Pearson correlation coefficients of 0.71, 0.87 and 0.87, respectively. Moreover, the optimized SVM model with three vital signs yielded sensitivity and specificity values of 85.7% and 90.1%, respectively. Conclusion: For contactless vital sign measurement, the system achieved a performance similar to that of the reference devices. The multiple vital sign-based screening achieved higher sensitivity than fever-based screening. Thus, this system represents a promising alternative for further quarantine procedures to prevent the spread of infectious diseases.

Correlation between eosinophil count, its genetic background and body mass index: The Nagahama Study

BACKGROUND

Obesity affects the pathogenesis of various chronic diseases, including asthma. Research on correlations between obesity/BMI and eosinophilic inflammation in asthma has yielded contradictory results, which could be partly ascribed to the absence of epidemiological data on the correlations. We aimed to elucidate the correlations between blood eosinophil count, its genetic backgrounds, and BMI in the general population.

METHODS

This community-based Nagahama study in Japan enrolled 9789 inhabitants. We conducted self-reporting questionnaires, lung function tests, and blood tests in the baseline and 5-year follow-up studies. A genome-wide association study (GWAS) was performed in 4650 subjects at the baseline and in 4206 of these at the follow-up to determine single-nucleotide polymorphisms for elevated blood eosinophil counts. We assessed the correlations between BMI and eosinophil counts using a multifaceted approach, including the cluster analysis.

RESULTS

Eosinophil counts positively correlated with BMI, observed upon the interchange of an explanatory variable, except for subjects with the highest quartile of eosinophils (≥200/μL), in whom BMI negatively correlated with eosinophil counts. GWAS and human leukocyte antigen (HLA) imputation identified rs4713354 variant (MDC1 on chromosome 6p21) for elevated eosinophil counts, independent of BMI and IgE. Rs4713354 was accumulated in a cluster characterized by elevated eosinophil counts (mean, 498 ± 178/μL) but normal BMI.

CONCLUSIONS

Epidemiologically, there may be a positive association between blood eosinophil counts and BMI in general, but there was a negative correlation in the population with high eosinophil counts. Factors other than BMI, particularly genetic backgrounds, may contribute to elevated eosinophil counts in such populations.

History of allergic rhinitis and risk of asthma; a systematic review and meta-analysis

Background

Allergic rhinitis has been suspected to be a risk factor for asthma in several studies but this association is not firmly established. The objective of this study was to synthesize the evidence of the association between allergic rhinitis and the risk of asthma through a systematic review and meta-analysis.

Methods

We performed a search in Medline, Scopus, ISI Proceedings databases and other databases from inception until February 2019, followed by manual search to identify potentially relevant case-control and cohort studies that reported relative risk estimates and confidence intervals of the association between allergic rhinitis and asthma. Cross-sectional studies were excluded. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using fixed and random effects models and quality of studies was assessed through a modified version of the Newcastle-Ottawa scale.

Results

Twenty-nine eligible studies, 22 cohort and 7 case-control studies, with a total of 274489 subjects, were included in the meta-analysis. The results show that history of allergic rhinitis is significantly associated with the occurrence of asthma (OR = 3.82; 95% CI: 2.92–4.99). European studies showed a stronger association (OR = 4.35; (95% CI: 3.12–6.06) than non-European studies (OR = 2.75; 95% CI: 2.16–3.50), and case-control studies showed a stronger association (OR = 4.71; 95% CI: 3.58–6.17) than cohort studies (OR = 3.42; 95% CI: 2.60–4.50).

Conclusions

This meta-analysis shows that allergic rhinitis is strongly associated with asthma. Further prospective studies on the effect of treatment of allergic rhinitis on the development of asthma are needed. Relief of airway allergic manifestations may need dual control of allergic rhinitis and asthma.

Registration

PROSPERO database with registration number CRD42017055156.

EEG signals during mouth breathing in a working memory task

Background: Continuous mouth breathing results not only morphological deformations but also poor learning outcomes. However, there were few studies that observed correlations between mouth breathing and cognition. This study aimed at investigating the changes in brain activity during mouth breathing while the participant simultaneously performed a cognitive task using electroencephalography (EEG).Methods: Twenty subjects participated in this study, and EEG electrodes (32 channels, 250-Hz sampling rate) were placed on their scalp. Brain waves during a resting state and n-back tasks (0-back and 2-back) and physiological parameters such as SpO2, ETCO2, and the airway respiratory rate were measured. The pre-processed EEG signals were analyzed based on their frequencies as delta waves (0.5 ∼ 4 Hz), theta waves (4 ∼ 8 Hz), alpha waves (8 ∼ 13 Hz), beta waves (13 ∼ 30 Hz) and gamma waves (30 ∼ 50 Hz) using fast Fourier transform (FFT).Results: When compared with nose breathing, theta and alpha powers were lower during mouth breathing at rest and alpha wave presented low power at 0-back and 2-back tasks. Furthermore, beta and gamma waves exhibited low powers at 2-back task. However, the behavioral results (accuracy and response time) have no significant difference between two breathing methods (mouth and nose). Mouth breathing showed different brain activity patterns, compared to nose breathing, and these changes are related to cognitive regions.Conclusion: The reason for this change seems to relate to the decreased oxygen saturation during mouth breathing, suggesting that when cognitive abilities are required, mouth breathing can act as one of the variables that cause different outcomes in brain activities.

Association Between Breastfeeding and Childhood Breathing Patterns: A Systematic Review and Meta-Analysis

OBJECTIVES

This systematic review aimed to evaluate the association between breastfeeding and breathing patterns in children.

MATERIALS AND METHODS

We searched PubMed, EMBASE, Web of Science, CINAHL, and the Cochrane Central Register of Controlled Trials for publications from inception to October 1, 2017. The breastfeeding duration and period of exclusive breastfeeding were selected as primary outcomes. The odds ratio (OR) and 95% confidence interval (CI) were calculated. A meta-analysis was conducted to synthesize the evidence. The Newcastle-Ottawa Score was used for quality and comparability assessment.

RESULTS

Of the 54 articles identified, three observational studies met the inclusion criteria for this meta-analysis, representing 1,046 participants. The results of the meta-analysis revealed that the prevalence rate of mouth breathing (OR = 2.04; 95% CI, 1.26-3.31; p = 0.004) was significantly higher in subjects who were breastfed for less than 6 months, but no significant difference was observed within the periods of exclusive breastfeeding (6 months or less) (OR = 1.27; 95% CI, 0.73-2.21; p = 0.40).

CONCLUSION

We found only limited evidence about the association between breastfeeding and breathing patterns. However, the current evidence supports the association between breastfeeding and childhood breathing patterns. Based on this review, we found that the frequency of normal nasal respiration increases with the duration of breastfeeding. The methodological quality of the studies included was moderate. Thus, future studies should aim to correct the confounding factors related to breathing patterns, to use standardized diagnostic criteria of mouth breathing, and to conduct a prospective research to reduce the recall bias.

International Consensus Statement on Allergy and Rhinology: Allergic Rhinitis

BACKGROUND

Critical examination of the quality and validity of available allergic rhinitis (AR) literature is necessary to improve understanding and to appropriately translate this knowledge to clinical care of the AR patient. To evaluate the existing AR literature, international multidisciplinary experts with an interest in AR have produced the International Consensus statement on Allergy and Rhinology: Allergic Rhinitis (ICAR:AR).

METHODS

Using previously described methodology, specific topics were developed relating to AR. Each topic was assigned a literature review, evidence-based review (EBR), or evidence-based review with recommendations (EBRR) format as dictated by available evidence and purpose within the ICAR:AR document. Following iterative reviews of each topic, the ICAR:AR document was synthesized and reviewed by all authors for consensus.

RESULTS

The ICAR:AR document addresses over 100 individual topics related to AR, including diagnosis, pathophysiology, epidemiology, disease burden, risk factors for the development of AR, allergy testing modalities, treatment, and other conditions/comorbidities associated with AR.

CONCLUSION

This critical review of the AR literature has identified several strengths; providers can be confident that treatment decisions are supported by rigorous studies. However, there are also substantial gaps in the AR literature. These knowledge gaps should be viewed as opportunities for improvement, as often the things that we teach and the medicine that we practice are not based on the best quality evidence. This document aims to highlight the strengths and weaknesses of the AR literature to identify areas for future AR research and improved understanding.

Regional evaluation of childhood acute lymphoblastic leukemia genetic susceptibility loci among Japanese

Genome-wide association studies (GWAS) performed mostly in populations of European and Hispanic ancestry have confirmed an inherited genetic basis for childhood acute lymphoblastic leukemia (ALL), but these associations are less clear in other races/ethnicities. DNA samples from ALL patients (aged 0–19 years) previously enrolled onto a Tokyo Children’s Cancer Study Group trial were collected during 2013–2015, and underwent single nucleotide polymorphism (SNP) microarray genotyping resulting in 527 B-cell ALL for analysis. Cases and control data for 3,882 samples from the Nagahama Study Group and Aichi Cancer Center Study were combined, and association analyses across 10 previous GWAS-identified regions were performed after targeted SNP imputation. Linkage disequilibrium (LD) patterns in Japanese and other populations were evaluated using the varLD score based on 1000 Genomes data. Risk associations for ARID5B (rs10821936, OR = 1.84, P = 6 × 10⁻¹⁷) and PIP4K2A (rs7088318, OR = 0.76, P = 2 × 10⁻⁴) directly transferred to Japanese, and the IKZF1 association was detected by an alternate SNP (rs1451367, OR = 1.52, P = 2 × 10⁻⁶). Marked regional LD differences between Japanese and Europeans was observed for most of the remaining loci for which associations did not transfer, including CEBPE, CDKN2A, CDKN2B, and ELK3. This study represents a first step towards characterizing the role of genetic susceptibility in childhood ALL risk in Japanese.

It Is Just Attention-Deficit Hyperactivity Disorder…or Is It?

Carly is a 5-year-old girl who presents for an interdisciplinary evaluation due to behaviors at school and home suggestive of attention-deficit hyperactivity disorder (ADHD). Parent report of preschool teacher concerns was consistent with ADHD. Psychological testing showed verbal, visual-spatial, and fluid reasoning IQ scores in the average range; processing speed and working memory were below average. Carly's behavior improved when her mother left the room, and she was attentive during testing with a psychologist. Tests of executive function (EF) skills showed mixed results. Working memory was in the borderline range, although scores for response inhibition and verbal fluency were average. Parent ratings of ADHD symptoms and EF difficulties were elevated.Carly's parents recently separated; she now lives with her mother and sees her father on weekends. Multiple caregivers with inconsistent approaches to discipline assist with child care while her mother works at night as a medical assistant. Family history is positive for ADHD and learning problems in her father. Medical history is unremarkable. Review of systems is significant for nightly mouth breathing and snoring, but no night waking, bruxism, or daytime sleepiness. She has enlarged tonsils and a high-arched palate on physical examination.At a follow-up visit, parent rating scales are consistent with ADHD-combined type; teacher rating scales support ADHD hyperactive-impulsive type. Snoring has persisted. A sleep study indicated obstructive sleep apnea. After adenotonsillectomy, Carly had significant improvement in ADHD symptoms. She developed recurrence of behavior problems 1 year after the surgery.

Lip muscle training improves obstructive sleep apnea and objective sleep: a case report

The present study assessed the potential of lip muscle training for improving sleep. A patient with heavy snoring, daytime sleepiness and dry mouth underwent lip muscle training. Lip closure force LCFmax increased by 67.3% and LCFmin by 152% post-training. AHI decreased from 12.2 to 3.9 events/h by reducing hypopneic episodes. TST, sleep stage N3 and REM sleep increased, and WASO, sleep stage N1, and AI decreased. The patient switched from mouth to nose breathing during sleep and stopped snoring. Improved LCF, by moving the tongue into the anterior-superior oral cavity, may increase upper airway space and reduce the hypopnea index.