Histologic changes in the auditory tube mucosa of rats after long-term exposure to cigarette smoke

Smoking Pack Years and Eustachian Tube Dysfunction

Objective

To determine the effect of smoking history on the risk of developing obstructive eustachian tube dysfunction (OETD).

Study Design

Cross-sectional review.

Setting

National database.

Methods

Data from the National Health and Nutrition Examination Survey (1999 to present) was analyzed. OETD was defined as middle ear pressure less than -100 decapascals (daPa). Nonsmokers, current smokers, with tympanometry data were analyzed. Patients under the age of 18, with myringotomy tubes, or with a sinus problem/earache/cold in the past 24 hours were excluded. The relative risks (RRs) for developing OETD were calculated for nonsmokers versus smokers and those with greater versus less than 10, 20, and 30 pack years (py).

Results

A total of 9472 patients met inclusion criteria (54.1% female, 75.9% non-Hispanic, mean age 43, 20.3% smokers). The RR of having OETD for smokers versus nonsmokers was 1.75 [95% confidence interval, CI: 1.45-2.11]. The RR of having OETD for patients with a 10+ py was 1.97 [95% CI 1.57-2.47], 20+ py was 2.29 [95% CI 1.76-2.95], and 30 py or greater was 2.08 [95% CI 1.49-2.90].

Conclusion

In this study, smoking roughly doubled the risk of developing OETD, as represented by a single measurement of negative middle ear pressure less than -100 daPa. The definition of OETD used in this study was limited, as it did not include symptomology, and more work is needed to examine additional covariates. However, these results may guide future research to better counsel and screen patients for OETD.

Analysis of factors that influence the occurrence of otitis media with effusion in pediatric patients with adenoid hypertrophy

Objective

Adenoid hypertrophy (AH) and otitis media with effusion (OME) are common pediatric otolaryngological diseases and often occur concurrently. The purpose of this study was to comprehensively analyze the factors that influence the occurrence of OME pediatric patients with AH.

Methods

Patients younger than 12 years with AH, who were hospitalized for treatment at Beijing Tsinghua Changgung Hospital in Beijing, China, between March 2018 and February 2022 were enrolled. The patients were divided into an AH group and an AH + OME group based on the presence of OME. The authors collected the following clinical data for univariable analysis: sex; age; body mass index (BMI); comorbid nasal congestion/rhinorrhea, recurrent tonsillitis, or allergic rhinitis (AR); adenoid and tonsil grade; tonsillar hypertrophy; food/drug allergy; history of adenoidectomy and congenital diseases; breastfeeding status; preterm birth; exposure to environmental tobacco smoke (ETS); family history of adenotonsillectomy, otitis media, and AR; main data of polysomnography and oropharyngeal conditional pathogen culture data of some patients. Univariate analysis was performed as a basis for logistic regression analysis.

Results

A total of 511 children (329 boys and 182 girls) were included, their mean age was 5.37 ± 2.10 years. Of them, 407 (79.6%) were in the AH group and 104 (20.4%) in the AH + OME group. Univariate analysis revealed statistically significant differences in age, BMI, adenoid grade, AR, breastfeeding status, and ETS exposure between the two groups. Multivariate stepwise logistic regression analysis showed that age, adenoid grade, AR, breastfeeding status, and ETS influenced the occurrence of OME in pediatric patients with AH. The risk of OME decreased with increasing age. High adenoid grade, ETS exposure, and comorbid AR were risk factors for OME in pediatric patients with AH, but breastfeeding was a protective factor. The final analytical results of the oropharyngeal conditional pathogen culture data showed that Streptococcus pneumoniae positivity was associated with OME in AH.

Conclusion

The pathogenesis of AH with OME is complex. Young age, high adenoid grade, ETS exposure, non-breastfed status, comorbid AR, and the presence of S. pneumoniae in the oropharynx are risk factors for OME in pediatric patients with AH.

Effects of cigarette smoke on Haemophilus influenzae-induced otitis media in a rat model

Exposure to cigarette smoke (CS) is a factor that could delay or worsen the recovery of otitis media (OM) by causing inflammatory swelling of the Eustachian tube (ET). However, despite the suggested relationship, little is known about the association between OM and CS. Therefore, we aimed to evaluate the effects of CS on the development, progression, and recovery of OM, as well as the histological and molecular changes caused by CS exposure, by using a rat model of OM infected with non-typeable Haemophilus influenzae (NTHi). Eighty Sprague-Dawley rats with normal middle ears (MEs) were divided into four groups (n = 20 rats/group): control, CS, OM, and CS + OM. The CS and CS + OM groups were exposed to CS for 2 weeks. The inflammatory reaction to NTHi was more intense and lasted longer in the CS + OM group than in the other groups. Goblet cell proliferation and mucus secretion in the ET were more significant in the CS and CS + OM groups than in the other groups. These findings suggested that because CS directly affects the ET and ME mucosa, bacterial OM can become more severe and may resolve more slowly in the presence of CS exposure rather than in its absence.

Changes in Eustachian Tube Mucosa in Mice After Short-Term Tobacco and E-cigarette Smoke Exposure

OBJECTIVES

To evaluate histologic changes in middle ear and eustachian tube (ET) mucosa of mice after exposure to tobacco or electronic cigarette (e-cigarette) smoke. To determine whether there were any mitigating effects of middle ear application of anti-IL-13 or the epidermal growth factor receptor antagonist AG1478 on noted changes within ET mucosa.

STUDY DESIGN

Controlled animal study.

METHODS

Fifty BALB/cJ mice were randomly assigned to one of five groups: A control group with no smoke exposure, two groups exposed to tobacco smoke, and two groups exposed to e-cigarette vapor. Within the exposed groups after 4 weeks of exposure, one ear was infiltrated with a saline hydrogel and the other ear with hydrogel of either Anti-IL-13 or AG1478. After four more weeks of exposure, the animals were euthanized and the ETs were evaluated for mucosal changes.

RESULTS

Compared to control animals with no smoke exposure, there were significant decreases in the numbers of goblet cells within the ET mucosa of mice exposed to tobacco smoke and e-cigarette vapor. No significant differences in cilia, mucin, or squamous metaplasia were noted. Neither anti-IL-13 nor AG178 significantly altered goblet cell count in the ET mucosa of mice exposed to tobacco smoke; however, both agents significantly increased goblet cells within the ET mucosa of mice exposed to e-cigarette vapor.

CONCLUSION

Short-term tobacco smoke and e-cigarette vapor significantly decrease goblet cell count in mouse ET mucosa. Middle ear application of both anti-IL-13 and AG1478 resulted in an increase in goblet cell count among mice exposed to e-cigarette vapor, but not to tobacco smoke.

LEVEL OF EVIDENCE

NA Laryngoscope, 2021.

Asian Sand Dust Particles Increased Pneumococcal Biofilm Formation in vitro and Colonization in Human Middle Ear Epithelial Cells and Rat Middle Ear Mucosa

INTRODUCTION

Air pollutants such as Asian sand dust (ASD) and Streptococcus pneumoniae are risk factors for otitis media (OM). In this study, we evaluate the role of ASD in pneumococcal in vitro biofilm growth and colonization on human middle ear epithelium cells (HMEECs) and rat middle ear using the rat OM model.

METHODS

S. pneumoniae D39 in vitro biofilm growth in the presence of ASD (50-300 μg/ml) was evaluated in metal ion-free BHI medium using CV-microplate assay, colony-forming unit (cfu) counts, resazurin staining, scanning electron microscopy (SEM), and confocal microscopy (CF). Biofilm gene expression analysis was performed using real-time RT-PCR. The effects of ASD or S. pneumoniae individually or on co-treatment on HMEECs were evaluated by detecting HMEEC viability, apoptosis, and reactive oxygen species (ROS) production. In vivo colonization of S. pneumoniae in the presence of ASD was evaluated using the rat OM model, and RNA-Seq was used to evaluate the alterations in gene expression in rat middle ear mucosa.

RESULTS

S. pneumoniae biofilm growth was significantly (P < 0.05) elevated in the presence of ASD. SEM and CF analysis revealed thick and organized pneumococcal biofilms in the presence of ASD (300 μg/ml). However, in the absence of ASD, bacteria were unable to form organized biofilms, the cell size was smaller than normal, and long chain-like structures were formed. Biofilms grown in the presence of ASD showed elevated expression levels of genes involved in biofilm formation (luxS), competence (comA, comB, ciaR), and toxin production (lytA and ply). Prior exposure of HMEECs to ASD, followed by treatment for pneumococci, significantly (P < 0.05) decreased cell viability and increased apoptosis, and ROS production. In vivo experiment results showed significantly (P < 0.05) more than 65% increased bacteria colonization in rat middle ear mucosa in the presence of ASD. The apoptosis, cell death, DNA repair, inflammation and immune response were differentially regulated in three treatments; however, number of genes expressed in co-treatments was higher than single treatment. In co-treatment, antimicrobial protein/peptide-related genes (S100A family, Np4, DEFB family, and RATNP-3B) and OM-related genes (CYLD, SMAD, FBXO11, and CD14) were down regulated, and inflammatory cytokines and interleukins, such as IL1β, and TNF-related gene expression were elevated.

CONCLUSION

ASD presence increased the generation of pneumococcal biofilms and colonization.

Effects of Smoking on the Auditory System: Is There a Gender Difference?

The main aim of our study is to evaluate whether the effect of smoking on the auditory system shows gender differences. Another aim is to evaluate whether smoking has any influence on the absorbance of sound. There were 236 volunteers including 90 nonsmokers (42 females and 48 males) and 146 smokers (72 females and 74 males) in the study. Smokers were grouped according to pack-years of smoking as 5 to 10 pack-years, 11 to 20 pack-years, and more than 20 pack-years. Pure tone audiometry and wideband tympanometry were performed in all individuals. Both female and male smokers who consume more than 20 pack-years had significantly higher hearing thresholds at 4 and 6 kHz and significantly lower sound energy absorbance rates at 4, 6, and 8 kHz. Moreover, female smokers with a consumption of 11 to 20 pack-years had significantly higher hearing thresholds at 6 kHz and significantly lower sound energy absorbance rates at 6 and 8 kHz. Smoking causes hearing loss at high frequencies in both females and males, especially in a dose-dependent manner affecting individuals with a consumption of more than 20 pack-years. The sound energy absorbance is significantly reduced at 4, 6, and 8 kHz. In addition, these effects may occur in women with even less exposure.

Air Pollution and Otitis Media in Children: A Systematic Review of Literature

Young children are particularly vulnerable to otitis media (OM) which globally affects over 80% of children below the age of 3 years. Although there is convincing evidence for an association between environmental tobacco smoke exposure and OM in children, the relationship with ambient air pollution is not clear. We aimed to systematically review the literature on the relationship between ambient air pollution exposure and OM in children. A systematic search was performed in PubMed and EMBASE databases. Of 934 references identified, 24 articles were included. There is an increasing body of evidence supporting an association between higher ambient air pollution exposure and a higher risk of OM in children. While NO₂ showed the most consistent association with OM, other specific pollutants showed inconsistent associations. Studies were mainly conducted in high/middle income countries with limited evidence from low-income countries. Although there was a general consensus that higher air pollution exposure is associated with a greater prevalence of OM, the evidence for associations with specific pollutants is inconsistent. More well-designed studies on associations between specific air pollutants as risk factors for OM are warranted, especially in low income countries with high air pollution levels.

Newborn hearing screening failure and maternal factors during pregnancy

OBJECTIVE

Temporary conductive hearing loss due to amniotic fluid accumulation in the middle ear cavity may lead to failure (false positive) in newborn hearing screening tests. The aim of this study was to identify whether amniotic fluid index has association with failure of the initial newborn otoacoustic emission (OAE) screening test.

METHODS

A cohort study in a tertiary hospital center (Royal Victoria Hospital, Montréal) was constructed from 70 newborns that failed the OAE test, but passed a subsequent auditory brainstem response (ABR) test, and 75 randomly selected newborns that passed initial otoacoustic emission testing. Maternal (including the amniotic fluid index in the third trimester) and newborn clinical data were extracted from medical records. Statistical association models were built to determine variables that influenced hearing screen passage or failure.

RESULTS

The two arms of the cohort had no significant differences in maternal or child clinical indices, including in amniotic fluid index. Calculated as individual odds ratios, maternal tobacco [95% CI of odds ratio: 0.04, 0.59, p = 0.0078], and drug use [95% CI of odds ratio: 0.0065, 0.72, p = 0.058] [borderline significance] were associated with failing the otoacoustic emission testing.

CONCLUSIONS

Amniotic fluid index was not found to be associated with failure of otoacoustic emission screening in newborns. However, our study unveiled an interesting unexpected association of OAE failure with maternal smoking and/or drug use. This finding can help alleviate some of the time, cost and parental anxiety related to failed OAE screening. In selected cases of maternal smoking or drug use we might want to replace or add OAE to the ABR test in newborn hearing screening protocols, that don't perform both tests before discharge.

Impact of environmental volatile organic compounds on otitis media in children: Correlation between exposure and urinary metabolites

INTRODUCTION

Volatile organic compounds (VOCs) induce inflammatory responses. Tobacco smoke contains numerous VOCs and is a risk factor for otitis media effusion (OME); however, no previous studies have investigated the association between VOCs and OME.

OBJECTIVES

We used urinary metabolites and exposure to environmental risk factors to investigate the association between VOC and polycyclic aromatic hydrocarbon exposure and recurrent OME in children.

METHODS

Children with recurrent OME who visited the Otorhinolaryngology Department of Seoul National University Hospital between November 2014 and June 2015 were prospectively enrolled in the study. Recurrent OME was defined as more than two OME episodes over a 6-month period lasting longer than 2 months. The control group consisted of children without OME in the last year. Demographic information, including age, sex, and previous medical history was obtained, and endoscopic examinations of the tympanic membrane were performed. Urinary concentrations of 1-hydroxypyrene, 2-naphthol, hippuric acid, trans, trans-muconic acid (t,t-MA), mandelic acid, phenyl glyoxylic acid, and methyl hippuric acid were analyzed using high-performance liquid chromatography/tandem mass spectroscopy. Environmental factors assessed included house type, age, renovations, the presence of furniture <6 months old, proximity to a road, and exposure to passive smoking.

RESULTS

We enrolled 11 children with OME and 39 controls. Age and sex did not differ between groups. Exposure to passive smoking was significantly more common in the OME group than in the controls (P < 0.001). Urinary concentrations of t.t.-MA were significantly higher in the OME group (126.33 μg/g cr) than in controls (52.661 μg/g cr; P = 0.003). Other metabolites including 1-hydroxypyrene, 2-naphthol, hippuric acid, mandelic acid, phenyl glyoxylic acid, and methyl hippuric acid did not demonstrated significant relation with the OME.

CONCLUSIONS

Levels of t,t-MA, a biomarker of benzene exposure, were significantly higher in the OME group than in controls. Passive smoking was significantly more common in the OME group. Our findings suggest that high t,t-MA levels which were probably originated from passive smoking and other pollutants could be indicative OME in children.

Tobacco Smoke Exposure and Eustachian Tube Disorders in US Children and Adolescents

OBJECTIVES

To describe the association between active, environmental tobacco smoke (ETS) exposure and the prevalence of eustachian tube dysfunction (ETD) in the U.S. pediatric population.

STUDY DESIGN

Cross-sectional.

SETTING

U.S. representative demographic and audiometric data from the National Health and Nutrition Examination Survey (NHANES);2005-2010.

SUBJECTS AND METHODS

The study consisted of 2,977 children aged 12-19 years. ETD was defined as middle ear pressure <100mm H20. ETS was defined as non-active smoking in individuals with serum cotinine over the limit of detection (≥0.015 ng/mL) and <10 ng/mL(N = 1559).

RESULTS

The prevalence of ETD was 6.1%. After multivariate adjustment for age, sex, body mass index, education level, ethnicity, or having a cold, sinus problem or earache during the last 24 hours, compared to unexposed children, the odds ratios (95% confidence interval) of ETD for those exposed to ETS ages 12-15 in the first, second and third tertile of cotinine concentrations were, respectively, 1.38 (0.53-3.60), 0.99 (0.53-3.60) and 2.67 (1.12-6.34). Similarly, the odds ratios (95% confidence interval) of ETD for those exposed to ETS ages 16-19 in the first, second and third tertile of cotinine concentrations were, respectively, 1.28 (0.48-3.41), 0.99 (0.40-2.48) and 2.86 (1.19-6.88).

CONCLUSION

These data suggest that children and adolescents exposed to high concentrations of ETS may have an increased prevalence of ETD.

Effect of side-stream smoking on random-pattern skin flap survival in rats

The secondhand exposure to cigarette smoke is being considered evil, and damage caused by this passive exposure has been proven by several studies. To investigate the effects of sidestream smoke exposure on random-pattern skin flap survival, 20 female rats were separated into 2 groups: group A (n = 10) was exposed 6 weeks to the smoke from the burning cigarette (passive smoking) and group B (n = 10) was the control group. After 6 weeks of exposition, a dorsal McFarlane flap of 4 × 10 cm was performed in all rats. Two weeks after this procedure, the ratio of necrotic and total areas was calculated using computer programs. The median area of necrosis in group A was 29.5%, significantly higher than that in group B with 17.5% (P < 0.024). In conclusion, this study suggests increased risk of random-pattern skin flap necrosis after sidestream exposure to cigarette smoke.

Panel 4: Recent advances in otitis media in molecular biology, biochemistry, genetics, and animal models

BACKGROUND

Otitis media (OM) is the most common childhood bacterial infection and also the leading cause of conductive hearing loss in children. Currently, there is an urgent need for developing novel therapeutic agents for treating OM based on full understanding of molecular pathogenesis in the areas of molecular biology, biochemistry, genetics, and animal model studies in OM.

OBJECTIVE

To provide a state-of-the-art review concerning recent advances in OM in the areas of molecular biology, biochemistry, genetics, and animal model studies and to discuss the future directions of OM studies in these areas.

DATA SOURCES AND REVIEW METHODS

A structured search of the current literature (since June 2007). The authors searched PubMed for published literature in the areas of molecular biology, biochemistry, genetics, and animal model studies in OM.

RESULTS

Over the past 4 years, significant progress has been made in the areas of molecular biology, biochemistry, genetics, and animal model studies in OM. These studies brought new insights into our understanding of the molecular and biochemical mechanisms underlying the molecular pathogenesis of OM and helped identify novel therapeutic targets for OM.

CONCLUSIONS AND IMPLICATIONS FOR PRACTICE

Our understanding of the molecular pathogenesis of OM has been significantly advanced, particularly in the areas of inflammation, innate immunity, mucus overproduction, mucosal hyperplasia, middle ear and inner ear interaction, genetics, genome sequencing, and animal model studies. Although these studies are still in their experimental stages, they help identify new potential therapeutic targets. Future preclinical and clinical studies will help to translate these exciting experimental research findings into clinical applications.

Panel 2

Objective

This report reviews the literature to identify the advances in our understanding of the middle ear (ME)–Eustachian tube (ET) system during the past 4 years and, on that basis, to determine whether the short-term goals elaborated in the last report were achieved and propose updated goals to guide future otitis media (OM) research.

Data Sources

Databases searched included PubMed, Web of Science (1945-present), Medline (1950 to present), Biosis Previews (1969-present), and the Zoological Record (1978 to present). The initial literature search covered the time interval from January 2007 to June 2011, with a supplementary search completed in February 2012.

Review Methods

The panel topic was subdivided; each contributor performed a literature search and provided a preliminary report. Those reports were consolidated and discussed when the panel met on June 9, 2011. At that meeting, the progress was evaluated and new short-term goals proposed.

Conclusions

Progress was made on 16 of the 19 short-term goals proposed in 2007. Significant advances were made in the characterization of ME gas exchange pathways, modeling ET function, and preliminary testing of treatments for ET dysfunction.

Implications for Practice

In the future, imaging technologies should be developed to noninvasively assess ME/ET structure and physiology with respect to their role in OM pathogenesis. The new data derived from form/function experiments should be integrated into the finite element models and used to develop specific hypotheses concerning OM pathogenesis and persistence. Finally, rigorous studies of treatments, medical or surgical, of ET dysfunction should be undertaken.

Relationship of environmental tobacco smoke to otitis media (OM) in children

INTRODUCTION

Many, but not all, studies have found a correlation between environmental tobacco smoke (ETS) and acute otitis media (AOM) and other adverse otologic outcomes. Given its high personal and societal costs and the divergent findings of the effect of ETS on middle ear disease, the aim of the current study was to assess the impact and possible determinant factors of ETS on recurrent (two or more) episodes of AOM.

METHODS

The study was performed at Heim Pal Children's Hospital, Ear, Nose and Throat (ENT) Department, Budapest, Hungary. Caregivers of a convenience sample of 412 children attending the ENT outpatient clinic were surveyed via a 22-item questionnaire regarding demographics, socioeconomics, and smoking behaviours of the child's family; as well as care-givers' self report of the number of AOM episodes of the child.

RESULTS

Of the 412 participants, 155 (38%) children's parents smoked. In bivariate analysis, two or more episodes of AOM correlated with reported hearing problems, day care enrolment, parental employment and increased age of the child. In multivariate logistic regression, parental smoking more than doubled a child's risk for recurrent AOM while increased maternal employment (e.g. part-time or full-time versus unemployed) boosted risk up to fourfold. Among children whose parents smoked, half-packs of cigarettes smoked per day and day care attendance doubled or nearly tripled, respectively, the risk of recurrent AOM episodes.

CONCLUSIONS

Childhood exposure to ETS is high among an ENT clinic population of Hungarian children. Such exposure correlates with AOM episodes, ENT operations and conductive hearing loss. Data such as these argue for strict laws smoke-free laws not only in Hungary, but also in Europe and around the world.