Association of ambient air pollution and Air Quality Index with risk of sudden sensorineural hearing loss: a cross-sectional study.

OBJECTIVES: To explore the associations of air pollutants and Air Quality Index (AQI) with risk of sudden sensorineural hearing loss (SSNHL) DESIGN: Cross-sectional study SETTING: Medical record data and local population data collected between 2014 and 2022 in Changshu, China were retrospectively reviewed. PARTICIPANTS: Adults aged 18 years and above who were diagnosed with SSNHL in Changshu No. 1 People's Hospital or Changshu No. 2 People's Hospital from the spring of 2014 to the fall of 2022 were included in the study. OUTCOME MEASURE: SSNHL was diagnosed by clinicians using the Chinese diagnostic criteria for SSNHL. RESULTS: Compared with those exposed to the lowest tertile of carbon monoxide (CO), the prevalence ratio for those exposed to middle and high tertiles of CO were 1.113 (95% CI 1.022 to 1.213) and 1.230 (95% CI 1.105 to 1.369), respectively. The risk of SSNHL was increased by 30.6% (95% CI 9.9% to 55.4%) per doubling increment of CO. No categorical association was found between ozone (O3) exposure and risk of SSNHL, however, an increased risk of 22.2% (0.8%-48.2%) was identified for each doubling of O3. No association was identified between other pollutants and AQI and risk of SSNHL. CONCLUSIONS: In this study, CO and O3 were associated with an increased risk of SSNHL in Changshu, China. Further studies are warranted to confirm our findings.

Sudden sensorineural hearing loss during the Covid-19 pandemic; experience of a tertiary referral center.

OBJECTIVE: This study aimed to highlight the differences in the clinical management and treatment of sudden sensorineural hearing loss (SSNHL) due to the impact of the Coronavirus Disease 2019 (COVID-19) pandemic. METHODS: This study compared patients diagnosed with SSNHL between March 2020 and March 2022, following the first reported case of COVID-19 in our country, with patients diagnosed between March 2018 and March 2020. The evaluation encompassed demographic characteristics, comorbidities, other ear-related complaints, hearing loss thresholds at each frequency, medical treatment administered, treatment duration, and post-treatment follow-up audiograms. RESULTS: The demographic characteristics and comorbidities of patients before and during the pandemic showed similar distribution. There was no significant difference in the duration from the onset of symptoms to hospital admission during the pandemic compared to the previous period. When evaluating the treatment responses of hospitalized and treated patients according to Siegel's criteria during the pandemic, a similar trend to the pre-pandemic period was observed. It was noted that the use of systemic steroids and hyperbaric oxygen therapy decreased during the pandemic period, while the use of antivirals increased. CONCLUSIONS: In our study conducted as a reference center, we want to emphasize that no clear data indicating a relationship between COVID-19 infection and NHL. Also, we believe that COVID-19 infection does not affect the course and prognosis of SSNHL.

Association of Metabolic Syndrome or Weather Conditions with the Severity and Prognosis of Sudden Sensorineural Hearing Loss.

It is reported that sudden sensorineural hearing loss (SSNHL) is closely related to diabetes, hypertension, and hyperlipidemia. While the metabolic syndrome (MetS) is a multifactorial disease that includes diabetes, hypertension, dyslipidemia, and obesity, which are known to be associated with SSNHL. Weather conditions have long been known to affect the SSNHL. This study aimed to make a clear connection between MetS, or weather conditions, and the severity and prognosis of SSNHL. 127 SSNHL patients have been divided into the MetS group and the non-MetS group, and the demographic and clinical characteristics of the 2 groups have been analyzed retrospectively. There were 52 (40.9%) patients in the MetS group, while there were 75 (59.1%) patients in the non-MetS group. The rate of vertigo, hypertension, diabetes, lower high-density lipoprotein cholesterol (HDL-C) levels, high triglyceride (TG), and body mass index (BMI) ≥25 (kg/m2 ) were significantly higher in the MetS group than those in non-MetS group. Vertigo, hypertension, and Mets were linked to the severity of hearing loss. The rate of complete recovery and partial recovery in the MetS group was clearly lower than that in non-MetS group. According to the multivariate analysis, MetS was significantly associated with a poorer prognosis of SSNHL; a high ambient temperature difference at onset and hypertension were correlated with a poor prognosis. These results demonstrate that the severity and prognosis of SSNHL can be influenced by the MetS. High ambient temperature differences at onset and hypertension were indicators of a poor prognosis for SSNHL.

Sudden Hearing Loss in the Active Duty Population: An Epidemiological Study.

INTRODUCTION: Hearing loss among military personnel is a well-known challenge, reported as the second most common VA service-connected disability. Although most hearing loss occurs gradually, a subset occurs suddenly and significantly impacts quality of life and military readiness and is considered as a medical emergency. This study aims to evaluate the incidence of sudden hearing loss among different subpopulations within the military system to better identify at-risk groups. MATERIALS AND METHODS: This study was a retrospective population-based study reviewing all cases of diagnosed sudden hearing loss between January 1, 2016 and December 31, 2021 within active duty service members in the U.S. DoD. Statistical analysis of multiple subpopulations was performed. RESULTS: There were 2,650 cases of sudden hearing loss diagnosed in active duty service members during the study period, with an average incidence of 32.9 cases per 100,000 people per year, compared with 5 to 27 cases per 100,000 people per year reported in civilian populations. Senior officers demonstrated significantly increased rates of sudden hearing loss with 103.9 cases per 100,000 people per year, likely as a result of increased age, as did Air Force personnel with 45.1 cases per 100,000 people per year. There was no difference in incidence based on military occupational specialty, though service members located overseas were noted to have decreased incidence compared with those stationed within the USA. There was no significant difference during the years before coronavirus-19 pandemic (2016-2019) compared to the years following the start of the pandemic (2020-2021). CONCLUSIONS: Sudden hearing loss appears to occur more frequently in military personnel than in the civilian population. The increased incidence in senior officers is likely driven by increased age, though further evaluation into the discrepancies between reported incidence of hearing loss among enlisted service members and officers is warranted. Although military occupational specialty did not demonstrate any significant difference in incidence, for thus far unknown reasons those in the Air Force demonstrated increased rates of sudden hearing loss. Although other potentially at-risk groups were identified, focused efforts to better understand contributing factors to elevated incidence in senior officers and Air Force personnel will help to better mitigate the incidence and effects of sudden hearing loss.

Sudden Sensorineural Hearing Loss Before COVID-19, During COVID-19, and After Inactivated Vaccination: Experience From a Tertiary Referral Center in China.

OBJECTIVE: The purpose of this study was to investigate the incidence rate and audiological characteristics of sudden sensorineural hearing loss (SSHL) before the COVID-19 pandemic, during the COVID-19 pandemic, and after inactivated vaccination, and to analyze whether the novel coronavirus or inactivated vaccination have an impact on hearing loss. MATERIALS AND METHODS: The clinical data of all patients who visited the hospital in July 2019 (before pandemic), July 2020 (during pandemic) and July 2021 (after the inactivated vaccination at least the first basic dose of COVID-19 vaccination) were retrospective analyzed. All patients diagnosed with sudden sensorineural hearing loss in these three periods were screened, and their incidence rate, hearing characteristics, and prognosis were compared. RESULTS: Overall, the incidence rates of sudden hearing loss in July 2019, July 2020, and July 2021 were 0.59, 0.60, and 0.52% (25 of 4225, 20 of 3322, 28 of 5432), respectively, without significant difference ( χ2 = 0.372, p = 0.830). A significant difference was noted in the incidence of hypertension ( p = 0.02), whereas no significant difference was noted in age ( p = 0.591, p = 0.66), sex ( p = 0.19, p = 0.08), main symptoms ( p = 0.18, p = 0.15), side ( p = 0.483, p = 0.89), audiogram shape ( p = 0.56, p = 0.989), average hearing threshold of affected frequency ( p = 0.81, p = 0.89), average hearing threshold of normal ear affected frequency ( p = 0.65, p = 0.68), average hearing threshold of affected frequency after treatment ( p = 0.49, p = 0.38), days between symptoms onset and hospital visit ( p = 0.62, p = 0.85), treatment plan ( p = 0.551, p = 0.474), and effectiveness ( p = 0.104, p = 0.050). CONCLUSION: Our study failed to find a correlation between the novel coronavirus pandemic and inactivated vaccination and SSHL, and there was no direct evidence supporting that COVID-19 or inactivated vaccination had an impact on the incidence rate and prognosis of SSHL patients.

Bidirectional causality between idiopathic sudden sensorineural hearing loss and depression: a Mendelian randomization study.

Idiopathic Sudden Sensorineural Hearing Loss (ISSHL) is a sudden onset, unexplained sensorineural hearing loss. Depression is a common mental disorder and a leading cause of disability. Here, We used a two-sample Mendelian randomization approach using pooled statistics from genome-wide association studies of ISSHL (1491 cases, 196,592 controls) and depression (23,424 cases, 192,220 controls) in European populations. This study investigated the bidirectional relationship between single nucleotide polymorphisms associated with depression and ISSHL using inverse variance weighting.Additional sensitivity analyses, such as Mendelian randomization-Egger (MR-Egger), weighted median estimates, and leave-one-out analysis, were performed to assess the reliability of the findings. Significant causal association between genetic susceptibility to ISSHL and depression in a random-effects IVW approach (OR = 1.037, 95% CI = 1.004-1.072, P = 0.030). In contrast, genetic depression was not risk factors for ISSHL (OR = 1.134, 95% CI = 0.871-1.475, P = 0.350). After validation by different MR methods and the sensitivity analysis, all of the above results are consistent. The evidence we have gathered suggests a causal relationship between ISSHL and depression. The presence of the former induces or further exacerbates the latter, whereas a similar situation does not exist when the latter is an influencing factor.

Association of sudden sensorineural hearing loss with meteorological factors: a time series study in Hefei, China, and a literature review.

Air pollution can cause disease and has become a major global environmental problem. It is currently believed that air pollution may be related to the progression of SSNHL. As a rapidly developing city in recent years, Hefei has serious air pollution. In order to explore the correlation between meteorological variables and SSNHL admissions, we conducted this study. This study investigated the short-term associations between SSNHL patients admitted to the hospital and Hefei climatic variables. The daily data on SSNHL-related hospital admissions and meteorological variables containing mean temperature (T-mean; °C), diurnal temperature range (DTR; °C), atmospheric pressure (AP; Hp), and relative humidity (RH; %), from 2014 to 2021 (2558 days), were collected. A time-series analysis integrating distributed lag non-linear models and generalized linear models was used. PubMed, Embase, Cochrane Library, and Web of Science databases were searched. Literature published up to August 2023 was reviewed to explore the potential impact mechanisms of meteorological factors on SSNHL. The mechanisms were determined in detail, focusing on wind speed, air pressure, temperature, humidity, and air pollutants. Using a median of 50.00% as a baseline, the effect of exceedingly low T-mean in the single-day hysteresis effect model began at a lag of 8 days (RR = 1.032, 95% CI: 1.001 ~ 1.064). High DTR affected the admission rate for SSNHL on lag 0 day. The significance of the effect was the greatest on that day (RR = 1.054, 95% CI: 1.007 ~ 1.104) and then gradually decreased. High and exceedingly high RH affected the admission rate SSNHL on lag 0 day, and these effects lasted for 8 and 7 days, respectively. There were significant associations between all grades of AP and SSNHL. This is the first study to assess the effect of meteorological variables on SSNHL-related admissions in China using a time-series approach. Long-term exposures to high DTR, RH values, low T-mean values, and all AP grades enhance the incidence of SSNHL in residents. Limiting exposure to extremes of ambient temperature and humidity may reduce the number of SSNHL-related hospital visits in the region. It is advisable to maintain a suitable living environment temperature and avoid extreme temperature fluctuations and high humidity. During periods of high air pollution, it is recommended to stay indoors and refrain from outdoor exercise.

Assessing risk of stroke after idiopathic sudden sensorineural hearing loss using data from general practice.

The cause of sudden sensorineural hearing loss (SSNHL) remains unknown in a significant number of cases, but vascular involvement in its pathophysiology has been proposed. Our study aimed to assess the incidence of stroke following idiopathic SSNHL (iSSNHL) and to evaluate associated cardiovascular risk factors and comorbidities. We extracted electronic medical record data from iSSNHL patients aged ≥ 50 years retrospectively from 84 general practices. Patients were matched for age, sex and general practice in a 1:4 ratio to controls. Primary outcome was the 5-years stroke risk following iSSNHL diagnosis. 480 iSSNHL cases could be matched to 1911 controls. The hazard ratio for iSSNHL compared with controls was 1.25 (95%CI 0.50-3.27; P = 0.646) for CVA (cerebrovascular accident) alone and 0.92 (95% CI 0.50-1.71; P = 0.804) for CVA and TIA (transient ischemic attack) combined. The hazard ratio for the interaction term between iSSNHL and age ≥ 60 years was 4.84 (95% CI 1.02-23.05; P = 0.048) for CVA and TIA combined. Patients with iSSNHL used antihypertensives and beta-blocking agents more frequently than controls (P = 0.006 and P = 0.022, respectively). In conclusion, no overall significant difference in the risk of stroke was observed, but the hazard ratio for stroke increased in iSSNHL patients aged 60 and older, suggesting potential vascular involvement in older subjects presenting with sudden sensorineural hearing loss.

Importance of small vessel disease as a possible cause of sudden sensorineural hearing loss.

OBJECTIVE: Vascular disease like small-vessel disease (SVD) is the most likely cause among the potential causes of Sudden sensorineural hearing loss (SSNHL). Understanding the relationship between SVD and SSNHL is crucial for developing effective prevention and treatment strategies. To confirm the relationship between SVD and SSNHL, the effect of SVD is confirmed by focusing on the duration and recurrence of SSNHL. METHODS: This article reports a retrospective observational study that investigated the relationship between SVD and SSNHL using the South Korea Health Insurance Review and Assessment Service (HIRA) database from 2010 to 2020. This retrospective observational study included 319,569 SSNHL patients between 2010 and 2020. RESULTS: Participant demographics were controlled using Propensity Score Matching. The hazard ratios (HR) for the effect of SVD on the duration of SSNHL were 1.045 for the group with SVD before the onset of SSNHL and 1.234 for the group with SVD after the onset of SSNHL. SVD was statistically significant for the recurrence of SSNHL, with an odds ratio of 1.312 in the group with SVD compared to the group without SVD. The HR for the period until a recurrence in the group with SVD was 1.062. CONCLUSIONS: The study identified SVD as a possible cause of SSNHL and found that the duration of SSNHL increased only in the presence of SVD. SVD also affected the recurrence of SSNHL, with the recurrence rate being 1.312 times higher in the group with SVD.

Prevalence of hearing loss, tinnitus, vertigo and sudden deafness among patients with polymyositis and dermatomyositis.

Little is known about a possible association of autoimmune inner ear disease among patients diagnosed with polymyositis (PM)/dermatomyositis (DM). This study aimed to explore differences in the prevalence of inner ear symptoms among patients with and without PM/DM using a nationwide population-based dataset. Data for this study were retrieved from the Taiwan National Health Insurance Research Database. The study sample included 1622 patients diagnosed with PM/DM and 8109 propensity-score matched comparison patients without PM/DM. We performed multivariate logistic regressions to calculate odds ratios (ORs) and 95% confidence interval (CI) for tinnitus, hearing loss, sudden deafness, and vertigo among patients with PM/DM versus comparison patients. Chi-square tests showed statistically significant differences between patients with PM/DM and comparison patients in the prevalence of tinnitus (16.1% vs. 12.7%, p < 0.001), non-conductive hearing loss (9.2% vs. 6.8%, p < 0.001), and vertigo (14.4% vs. 11.1%, p < 0.001). The adjusted ORs for tinnitus, non-conductive hearing loss, and vertigo, respectively, were 1.332 (95% CI = 1.147-1.547), 1.399 (95% CI = 1.154-1.696), and 1.374 (95% CI = 1.173-1.611) for patients with PM/DM when compared to comparison patients. Our study finds that patients with PM/DM have higher prevalence rates of tinnitus, non-conductive hearing loss, and vertigo than comparison patients.

Prognosis of Bilateral Sudden Sensorineural Hearing Loss: A Systematic Review and Meta-Analysis.

OBJECTIVES: To comprehensively examine the characteristics and prognosis of bilateral sudden sensorineural hearing loss (BSSHL) and its subtypes compared to unilateral sudden sensorineural hearing loss (USSHL). DATA SOURCES: PubMed, Scopus, and CINAHL. REVIEW METHODS: Databases were searched from inception to December 5, 2023, for studies reporting patient characteristics and audiometric outcomes for BSSHL and its simultaneous (Si-BSSHL) and sequential (Se-BSSHL) subtypes. Meta-analysis of continuous measures, proportions (%), mean differences (Δ), and odds ratio (OR) were performed. RESULTS: Eleven studies were included, consisting of 368 patients with BSSHL and 2,705 patients with USSHL. The pooled prevalence among all SSHL cases was 88.1% (95% CI: 81.2%-93.6%) for USSHL and 11.9% (95% CI: 6.4% to 18.8%) for BSSHL. PTA improvement following treatment with steroids was significantly worse in patients with BSSHL (Δ15.3 dB; 95% CI: 14.6 to 15.9; p < 0.0001) compared to patients with USSHL. There was no significant difference in post-treatment PTA improvement between the BSSHL subtypes. Patients with Si-BSSHL were significantly less likely to have an idiopathic etiology (OR: 0.4; 95% CI: 0.2 to 0.8; p = 0.01) and significantly more likely to have an autoimmune disease etiology (OR: 27.4; 95% CI: 2.2 to 336.1; p = 0.01), comorbid cardiovascular disease (OR: 2.3; 95% CI: 1.1 to 5.1; p = 0.03), and comorbid hypertension (OR: 2.5; 95% CI: 1.6 to 3.8; p < 0.0001) compared to patients with USSHL. CONCLUSIONS: BSSHL is a considerably rarer form of SSHL with worse prognosis compared to USSHL. BSSHL, and Si-BSSHL in particular, has significantly greater associations with systemic pathologies compared to USSHL. Laryngoscope, 134:3883-3891, 2024.

Increased prevalence of hearing loss, tinnitus and sudden deafness among patients with Sjögren's syndrome.

BACKGROUND: This study aimed to provide an updated prevalence of hearing loss, tinnitus, vertigo and sudden deafness on patients with Sjögren's syndrome and matched comparison patients. METHODS: Data for this study were retrieved from the Taiwan Longitudinal Health Insurance Database and Taiwan's registered catastrophic illness dataset. This study included 20 266 patients with Sjögren's syndrome as the study group and 60 798 propensity score-matched comparison patients as the comparison group. We used multivariable logistic regressions to estimate the ORs and 95% CI for tinnitus, hearing loss, vertigo and sudden deafness among Sjögren's syndrome patients versus comparison patients. RESULTS: χ2 tests showed there were statistically significant differences between the study group and comparison group in the prevalence of tinnitus (10.1% vs 6.3%, p<0.001), hearing loss (5.6% vs 3.3%, p<0.001), vertigo (4.6% vs 3.2%, p<0.001) and sudden deafness (0.8% vs 0.6%, p<0.001). Multiple logistic regression revealed that patients with Sjögren's syndrome had a greater tendency to have tinnitus (OR=1.690, 95% CI 1.596-1.788), sudden deafness (OR=1.368, 95% CI 1.137-1.647), hearing loss (OR=1.724, 95% CI 1.598-1.859) and vertigo (OR=1.473, 95% CI 1.360-1.597) relative to comparison patients after adjusting for age, income, geographic location, residential urbanisation level, diabetes, hypertension, hyperlipidaemia and rheumatoid arthritis. CONCLUSIONS: We found higher prevalence of hearing loss, vertigo, tinnitus and sudden deafness among patients with Sjögren's syndrome relative to comparison patients. Findings may provide guidance to physicians in counselling patients with Sjögren's syndrome regarding a higher risk of hearing loss, tinnitus, sudden deafness and vertigo.

A Systematic Review on Heritability of Sudden Sensorineural Hearing Loss.

OBJECTIVE: To assess the evidence supporting the heritability and genetic basis of sudden sensorineural hearing loss (SSNHL). DATA SOURCE: Records were extracted from PubMed, Scopus, and Cochrane databases. REVIEW METHODS: The protocol was registered on PROSPERO (CRD42022357389) and includes a systematic review on the genetic contribution to SSNHL. The search strategy yielded 1.483 articles from electronic databases. After quality assessment, 34 records were selected, including 369.650 patients with SSNHL from nine prevalence studies, two familial aggregation studies, one twin study, and 22 genetic studies. The prevalence of SSNHL was calculated from data on its incidence from population-based studies (period prevalence). To evaluate the heritability of SSNHL, the sibling recurrence risk ratio (λs) was calculated, by comparing the prevalence of SSNHL among siblings within the same generation to the estimated prevalence in the overall population. Genetic variants were grouped, based on the pathological mechanism related to SSNHL. RESULTS: The prevalence of SSNHL ranged from 0.1% to 0.0003% in America to 0.12%-0.0093% in Asia. The estimated sibling recurrence risk ratio for SSNHL (λs = 20.8-83.3) supports a significant familial aggregation. Although several genetic variants were reported to be associated with SSHL in controlled studies, neither was replicated in an independent cohort. CONCLUSIONS: Evidence supporting heritability of SSNHL is limited to epidemiological studies showing prevalence differences across different populations and familial aggregation. Genetic studies are of low quality and they lack replication cohort to confirm their findings. According to its low prevalence, exome or genome sequencing familial-based studies are needed to identify rare genetic variants in SSNHL. LEVEL OF EVIDENCE: NA Laryngoscope, 134:3447-3457, 2024.

A Nationwide Population-Based Study for the Recurrence and Comorbidities in Sudden Sensorineural Hearing Loss.

OBJECTIVES: The aims of this study were to investigate the cumulative recurrence rate of SSNHL and to determine association between comorbidities and recurrence of SSNHL by comparing patients with and without recurrence. METHODS: Using the National Health Insurance Claims Database (NHICD) from 2009 to 2020, we conducted a population-based study. We only enrolled patients whose records showed a prescription for steroid and audiometry findings as well as an appropriate diagnostic code. Recurrence of SSNHL was defined as an episode of SSNHL greater than or equal to 3 months after the first episode of SSNHL. We compared the recurrence rate of SSNHL according to age and number of SSNHL recurrences. We also explored comorbidities including autoimmune, metabolic, chronic renal diseases, cancer, and migraine associated with recurrent SSNHL. RESULTS: A total of 257,123 patients were identified. We found that 6.7% (17,270/257,123) of the patients had at least one recurrence of SSNHL. The recurrence rate increases with the number of recurrences and over time. The incidence per 100,000 people tended to increase with age, and the recurrence rate appeared to decrease with age. We found an increase in the incidence of ankylosing spondylitis (AS) and a decrease in the incidence of type 2 diabetes mellitus (T2DM), myocardial infarction (MI), and hemorrhagic stroke in patients with recurrence. CONCLUSION: For patients with recurrence or AS, considerable efforts should be made to prevent recurrence. As SSNHL is an emergent otologic condition, when symptoms occur, they should receive immediate treatment. Additional well-designed population-based studies are required to generalize our results. LEVEL OF EVIDENCE: 3 Laryngoscope, 134:1417-1425, 2024.

Prevalence of perilymphatic fistula in patients with sudden-onset sensorineural hearing loss as diagnosed by Cochlin-tomoprotein (CTP) biomarker detection: its association with age, hearing severity, and treatment outcomes.

PURPOSE: To determine the prevalence of perilymphatic fistula (PLF) in sudden-onset sensorineural hearing loss (SSNHL) patients by employing the Cochlin-tomoprotein (CTP) detection test, a specific diagnostic marker for perilymph. We also analyzed the clinical characteristics associated with hearing outcomes in this cohort. METHODS: A total of 74 eligible patients were prospectively enrolled. Following myringotomy, middle ear lavage (MEL) samples underwent the CTP test to identify perilymph leakage. Intratympanic dexamethasone (IT-DEX) therapy was administered, and hearing outcomes were assessed. Control groups comprised patients with chronic otitis media (n = 40) and non-inflammatory middle ears (n = 51) with concurrent MEL sample collection. RESULTS: CTP was positive in 16 (22%) patients. No control samples showed positive results. Multiple regression analysis indicated that age and pre-treatment hearing levels significantly contributed to the CTP value. We found a positive correlation between CTP values, age, and pre-treatment pure-tone averages. Notably, CTP values in SSNHL cases aged 60 and above were significantly higher than in those below 60 years. Patients with positive CTP had significantly worse recovery rates after IT-DEX treatment. CONCLUSION: This study is the first prospective investigation demonstrating a positive relationship between CTP values, age, and hearing severity in SSNHL, indicating that PLF might be the essential cause of SSNHL, particularly in the elderly. Our findings suggest that IT-DEX may be less effective for PLF-associated SSNHL. Future research could reveal that PLF repair surgery is a viable treatment strategy for SSNHL. This study was registered under the UMIN Clinical Trials Registry (UMIN000010837) on 30/May/2013.

Association between air pollution and sudden sensorineural hearing loss (SSHL): A systematic review and meta-analysis.

Recent studies have indicated that air pollution (AP) has harmful effects on hearing and ear diseases such as Sudden Sensorineural Hearing Loss (SSHL). The purpose of this study was to evaluate the impact of exposure to AP on SSHL incidence. Valid electronic databases were searched to retrieve studies published until December 1, 2022, using appropriate keywords. The result of the search was 1146 studies, and after screening according to the defined criteria, in total 8 studies were obtained. The risk of bias (ROB) in the studies and their quality were assessed. Finally, the meta-analysis with a significance level of 5% was performed. The findings revealed that the mean level of SO2, CO, NO2, and PM10 in the patient group was more than that of the control group, and p-values were 0.879, 0.144, 0.077, and 0.138, respectively. There was an indirect relation between air pollutants and SSHL, and PM2.5 showed a significant effect (p < 0.05). Given the limited research and the use of different statistical methods, more research is suggested to confirm this association and to determine the mechanisms by which AP exposure may cause SSHL.

Recovery From Idiopathic Sudden Sensorineural Hearing Loss: Association With Cardiovascular Disease Risk.

PURPOSE: The purpose of this study is to investigate the association between cardiovascular disease (CVD) risk factors and idiopathic sudden sensorineural hearing loss (ISSNHL) disease severity and recovery. METHOD: A retrospective medical chart review was performed on 90 patients (n = 48 men; Mage = 59.8 years, SD = 15.8) evaluated for ISSNHL. Major CVD risk factors (current tobacco smoking, diabetes, total cholesterol ≥ 240 mg/dl or treatment, and hypertension [systolic blood pressure [BP]/diastolic BP ≥ 140/ ≥ 90 mmHg or treatment]) determined two CVD risk groups: lower (no major risk factors) and higher (one or more risk factors). Two pure-tone averages (PTAs) were computed: PTA0.5,1,2 and PTA3,4,6,8. Complete recovery of ISSNHL was defined as PTAinitial - PTAfollow-up ≥ 10 dB. Logistic regression estimated the odds of ISSNHL recovery by CVD risk status adjusting for age, sex, body mass index, noise exposure, and treatment. RESULTS: Most patients (67.8%) had one or more CVD risk factors. Severity of initial low- and high-frequency hearing loss was similar between CVD risk groups. Recovery was 53.2% for PTA0.5,1,2 and 32.9% for PTA3,4,6,8. With multivariable adjustment, current/former smoking was associated with lower odds of PTA0.5,1,2 recovery (OR = 0.27; 95% CI [0.08, 0.92]). Neither higher CVD risk status nor individual CVD risk factors had a significant association with recovery. For every one-unit increase in Framingham Risk Score, odds of PTA3,4,6,8 recovery were 0.95 times lower (95% CI [0.90, 1.00]) after accounting for age, sex, body mass index, noise exposure, and treatment/time-to-treatment grouping (p = .056). CONCLUSIONS: The prognosis of low-frequency ISSNHL recovery is worse among current/former smokers than nonsmokers. Other CVD risk factors and aggregate risk are not significantly related to recovery.

Effect of Herpes Zoster Treatment and Sudden Sensorineural Hearing Loss Using National Health Insurance Claims Data of South Korea.

Background and objectives: Herpes zoster (HZ) is caused by the reactivation of a pre-existing latent varicella zoster virus, which is one of the viruses that causes hearing loss, and hearing loss may occur due to a systemic immune response even if it does not invade the auditory nerve. This study aimed to determine the correlation between sudden sensorineural hearing loss (SSNHL) in older adult patients who received HZ treatment. Materials and Methods: We used the cohort data of patients aged 60 years and above (n = 624,646) between 2002 and 2015 provided by the National Health Insurance Service. The patients were divided into two groups: those who were diagnosed with HZ between 2003 and 2008 (group H, n = 36,121) and those who had not been diagnosed with HZ between 2002 and 2015 (group C, n = 584,329). Results: In the main model (adjusted HR = 0.890, 95% CI = 0.839-0.944, p < 0.001) adjusted for sex, age, and income, and the full model (adjusted HR = 0.894, 95% CI = 0.843-0.949, p < 0.001) adjusted for all comorbidities, group H had a lower risk of SSNHL than group C. Conclusions: This study showed that patients who received HZ treatment had a lower incidence of SSNHL within five years after diagnosis.

Bidirectional Association Between Sudden Sensorineural Hearing Loss and Glaucoma: A Cohort Study.

OBJECTIVES: To investigate the bidirectional association between sudden sensorineural hearing loss (SSNHL) and open-angle glaucoma (OAG) over a 12-year follow-up period using nationwide, population-based data. METHODS: The study was conducted using the National Health Information Database of the National Health Insurance Service (NHIS-NHID), which covered 3.5 million individuals from 2008 to 2019. In Study 1, we evaluated the effect of OAG on SSNHL, and in Study 2, we evaluated the effect of SSNHL on OAG. Participants of the control group were enrolled through "greedy nearest-neighbor" 1:1 propensity score matching. RESULTS: In Study 1, 26,777 people were included in each group. The hazard ratio (HR) for SSNHL of the OAG group was 1.27 (95% confidence interval [CI], 1.15-1.39). In subgroup analysis, there was significant HR value regarding (old age: 1.17, hyperlipidemia: 1.19). In Study 2, 15,433 people were included in each group. The HR for OAG of the SSNHL group was 1.18 (95% CI, 1.07-1.30). In subgroup analysis, the HRs were significant for old age (2.31), hypertension (1.17), diabetes (1.39), and hyperlipidemia (1.26). CONCLUSION: Over the 12-year follow-up, we found a bidirectional association between SSNHL and OAG, suggesting a shared pathogenesis. LEVEL OF EVIDENCE: N/A. Laryngoscope, 133:3169-3177, 2023.