Sensorineural hearing loss and risk of stroke: a systematic review and meta-analysis

[Increase in the natural hearing threshold after treatment with cochlear implants]

More than 5% of the world's population suffers from disabling hearing loss. If the cause of hearing loss is unclear, it is referred to as idiopathic sudden sensorineural hearing loss (ISSNHL). After failure of standard treatment, the use of hearing aids or a cochlear implant is generally recommended. In this case, a 55-year-old patient was treated with cochlear implantation (CI) after ISSNHL and unsuccessful conservative therapy. Approximately 1 year after implantation and 7 years after the sudden hearing loss, subjective measurements revealed restoration of the hearing threshold.

Association between Sudden Sensorineural Hearing Loss and the Risk of Cardio Cerebrovascular Disease

OBJECTIVES

This study investigated the association between sudden sensorineural hearing loss (SSNHL) and the risk of cardio-cerebrovascular disease (CCVD) among older adults in South Korea.

METHODS

Data from 38,426 patients in the Korean National Health Insurance Service-Senior Cohort from 2002 to 2019 were collected. The risk of CCVD includes both stroke and acute myocardial infarction. Propensity score matching (1:1) was used to identify pairs of individuals with and without SSNHL (n = 19,213 for cases and controls). Cox proportional hazards regression models were used to analyze the associations between variables.

RESULTS

Patients with SSNHL had a higher risk of CCVD (hazard ratio [HR] = 1.17, 95% confidence interval [CI] = 1.11-1.24) compared to those without. The risk of CCVD was higher among those who experienced a stroke than those who did not (HR = 1.17 95% CI = 1.10-1.25). Compared to their matched controls, patients with SSNHL were 1.69 times (HR = 1.69 CI = 1.46-1.94) more likely to have CCVD during the first 12 months of the follow-up period.

CONCLUSION

Older patients with SSNHL are at an increased risk of CCVD. Hence, a more attentive approach featuring aggressive monitoring of patients with SSNHL is required to lessen their risk of CCVD.

LEVEL OF EVIDENCE

3 Laryngoscope, 134:2372-2376, 2024.

Association Between Hearing Loss and Cardiovascular Disease: A Meta-analysis

OBJECTIVE

Hearing loss (HL) has been postulated to be linked to cardiovascular diseases (CVDs) via vascular mechanisms, but epidemiological associations remain unclear. The study aims to clarify the association between HL and stroke, coronary artery disease (CAD), and any CVD.

DATA SOURCES

PubMed, Embase, and SCOPUS from inception until April 27, 2022.

REVIEW METHODS

Three blinded reviewers selected observational studies reporting stroke, CAD, and any CVD in patients with HL, compared to individuals without HL. We extracted data, evaluated study bias using the Newcastle-Ottawa scale, following Preferred Reporting Items for Systematic Reviews and Meta-analyses guidelines and a PROSPERO-registered protocol (CRD42022348648). We used random-effects inverse variance meta-analyses to pool the odds ratios (ORs) for the association of HL with stroke, CAD, and any CVD.

RESULTS

We included 4 cohort studies (N = 940,771) and 6 cross-sectional studies (N = 680,349). Stroke, CAD, and any CVD were all strongly associated with HL. The overall pooled OR of the association between HL and stroke was 1.26 (95% confidence interval [CI] = 1.16-1.37, I2  = 78%), and was 1.33 (95% CI = 1.12-1.58) and 1.29 (95% CI = 1.14-1.45) for low- and high-frequency HL, respectively. Minimal publication bias was observed, with minimal change to pooled effect size following trim and fill. Similarly, the pooled OR of the association between HL and CAD was 1.36 (95% CI = 1.13-1.64, I2  = 96%), while that between HL and any CVD was 1.38 (95% CI = 1.07-1.77, I2  = 99%).

CONCLUSION

Our findings suggest that HL and CVD are closely related. Physicians treating patients with HL should be cognizant of this association and view HL in the broader context of general health and aging.

L-shaped association of triglyceride glucose index and sensorineural hearing loss: results from a cross-sectional study and Mendelian randomization analysis

Background

The association between the sensorineural hearing loss (SNHL) and triglyceride-glucose (TyG) index remains inadequately understood. This investigation seeks to elucidate the connection between the TyG index and SNHL.

Methods

In this cross-sectional study, we utilized datasets sourced from the National Health and Nutrition Examination Survey (NHANES). A comprehensive analysis was conducted on 1,851 participants aged 20 to 69, utilizing complete audiometry data from the NHANES database spanning from 2007 to 2018. All enrolled participants had accessible hearing data, and the average thresholds were measured and calculated as both low-frequency pure-tone average and high-frequency pure-tone average. Sensorineural hearing loss (SNHL) was defined as an average pure tone of 20 dB or higher in at least one better ear. Our analysis involved the application of multivariate linear regression models to examine the linear relationship between the TyG index and SNHL. To delineate any non-linear associations, we utilized fitted smoothing curves and conducted threshold effect analysis. Furthermore, we conducted a two-sample Mendelian randomization (MR) study, leveraging genetic data from genome-wide association studies (GWAS) on circulating lipids, blood glucose, and SNHL. The primary analytical method for the MR study was the application of the inverse-variance-weighted (IVW) approach.

Results

In our multivariate linear regression analysis, a substantial positive correlation emerged between the TyG index and SNHL [2.10 (1.80-2.44), p < 0.0001]. Furthermore, using a two-segment linear regression model, we found an L-shaped relationship between TyG index, fasting blood glucose and SNHL with an inflection point of 9.07 and 94 mg/dL, respectively. Specifically, TyG index [3.60, (1.42-9.14)] and blood glucose [1.01, (1.00-1.01)] concentration higher than the threshold values was positively associated with SNHL risk. Genetically determined triglyceride levels demonstrated a causal impact on SNHL (OR = 1.092, p = 8.006 × 10-4). In addition, blood glucose was found to have a protective effect on SNHL (OR = 0.886, p = 1.012 × 10-2).

Conclusions

An L-shaped association was identified among the TyG index, fasting blood glucose, and SNHL in the American population. TyG index of more than 9.07 and blood glucose of more than 94 mg/dL were significantly and positively associated with SNHL risk, respectively.

The Association Between Dehydration and the Prognosis of Sudden Sensorineural Hearing Loss

Background

There is an urgent need to identify undetermined risk factors for sudden sensorineural hearing loss (SSNHL) for the development of effective treatment strategies. SSNHL is likely associated with vascular insufficiency; however, no study has evaluated the relationship between dehydration and SSNHL.

Objective

This study aimed to investigate the role of dehydration in the development and prognosis of sudden sensorineural hearing loss.

Study Design

Retrospective case-control study.

Setting

Secondary referral hospital.

Patients and Interventions

This was a comparative study that compared dehydration parameters between healthy subjects without SSNHL (n = 94) and patients with SSNHL (n = 94). The study also evaluated the effect of dehydrated conditions on the prognosis of SSNHL.

Main Outcome Measures

We compared dehydration parameters, such as the blood urea nitrogen-to-creatinine ratio (BUN/Cre) and plasma osmolality (Posm), between matched healthy subjects without SSNHL and patients with SSNHL. To evaluate the effect of dehydrated conditions on the SSNHL prognosis, the SSNHL patients were divided into 2 groups based on the cutoff value obtained from the receiver operating characteristic analysis: hydrated (n = 50; BUN/Cre <21.4) and dehydrated (n = 44; BUN/Cre ≥21.4) groups. Subsequently, the severity and prognosis of SSNHL were analyzed.

Results

The dehydration parameters, BUN/Cre and Posm, were significantly higher in patients with SSNHL than in healthy subjects. The initial hearing levels and SSNHL grades were worse in the dehydrated group than in the hydrated group. Moreover, a dehydrated condition (BUN/Cre ≥21.4) was associated with a poor SSNHL prognosis in all models of the multiple logistic regression analysis.

Conclusions

The dehydration parameters of BUN/Cre and Posm were higher in patients with SSNHL than in healthy subjects. Additionally, a dehydrated condition (BUN/Cre ≥21.4) was an independent prognostic factor for SSNHL. Level of evidence: Level 4.

Correlation between right-to-left shunt and sudden sensorineural hearing loss: protocol for a case-control study

BACKGROUND AND PURPOSE

Sudden sensorineural hearing loss (SSNHL) is a neurological and otolaryngological emergency during which rapid diagnosis and early treatment are of great importance. Clinical experience indicates that a considerable number of patients with SSNHL have concurrent right-to-left shunt (RLS). With limited reports, the association between SSNHL and RLS is yet unclear and there is a need for large observational studies to explore their latent relationship.

METHODS AND ANALYSIS

This proposed study is a prospective, observational case-control study. A total of 194 eligible participants matched in age and sex will be divided equally into two groups: 97 patients with SSNHL included in the case group and 97 individuals without SSNHL in the control group. Medical evaluations, including clinical characteristics, laboratory examination, audiological examination and ultrasonography examination, will be performed in all subjects. The primary outcome of the study is the difference in RLS rates between the groups. Differences in patent foramen ovale rates and other measured variables will be further assessed. A conditional logistic regression as a correlation analysis will be used to evaluate the relationship between RLS and SSNHL.

DISCUSSION

This study may provide evidence on the correlation between RLS and SSNHL in order to enrich the aetiology of SSNHL.

ETHICS AND DISSEMINATION

The study protocol has been approved by the Ethics Committee of Peking University Shenzhen Hospital. A written informed consent form will be signed and dated by the participants and the researchers before the study begins. The results will be disseminated in peer-reviewed publications.

TRIAL REGISTRATION NUMBER

ChiCTR2200064067.

Early detection of stroke at the sudden sensorineural hearing loss stage

Background and purpose

Sudden sensorineural hearing loss (SSNHL) can be a prodromal symptom of ischemic stroke, especially posterior circulation strokes in the anterior inferior cerebellar artery (AICA) area. Early diagnosis and optimal treatment for vascular SSNHL provide an opportunity to prevent more extensive area infarction. The objective of our research was to find clues that suggest stroke at the stage of isolated sudden hearing loss.

Methods

We retrospectively investigated the medical records of patients who received an initial diagnosis of sudden sensorineural hearing loss upon admission from January 2017 to December 2022 at Capital Medical University Affiliated Beijing Tiantan Hospital. Among these patients, 30 individuals who developed acute ischemic stroke during their hospital stay were enrolled as the case group. To create a control group, we matched individuals from the nonstroke idiopathic SSNHL patients to the case group in terms of age (±3 years old) at a ratio of 1:4. We collected the clinical characteristics, pure tone hearing threshold test results, and imaging information for all patients included in the study.

Results

Three models were constructed to simulate different clinical situations and to identify vascular sudden sensorineural hearing loss (SSNHL). The results revealed that patients with SSNHL who had three or more stroke risk factors, bilateral hearing loss, moderately severe to total hearing loss, and any intracranial large artery stenosis and occlusion (≥50%) were at a higher risk of developing ischemic stroke during hospitalization. Consistent with previous studies, the presence of vertigo at onset also played a significant role in the early detection of upcoming stroke.

Conclusion

Clinicians should be alert to SSNHL patients with bilateral hearing loss, moderately severe to total hearing loss and other aforementioned features. Early pure tone audiometric hearing assessment and vascular assessment are necessary for high-risk patients with SSNHL.

Vertebrobasilar System Laterality and Idiopathic Sudden Sensorineural Hearing Loss

INTRODUCTION

The etiology of idiopathic sudden sensorineural hearing loss (ISSNHL) remains elusive, with vascular compromise as a proposed cause. This study aimed to explore the correlation between the vertebrobasilar vascular system laterality (VBVSL) and ISSNHL laterality.

METHODS

We conducted a retrospective analysis of consecutive patients diagnosed with ISSNHL from 2015 to 2020. The VBVSL pattern was established via magnetic resonance imaging scans by a neuroradiologist. ISSNHL occurring contralaterally to the basilar artery (BA) curvature or ipsilaterally to the dominant vertebral artery (VA) was designated as a "positive match," with all other scenarios classified as a "negative match."

RESULTS

Our study included 191 ISSNHL patients (median age 57 years, 89 males, 93 right ears). The majority of patients did not exhibit a positive match between ISSNHL laterality and the sides of BA curvature or dominant VA (28.8% and 36.6% for BA and VA, respectively). Notably, VA-positive match patients were significantly older than VA-negative match patients (59 vs. 53 years, p = 0.043), with a similar trend observed in BA-positive match compared to BA-negative match (59 vs. 54.5 years, p = 0.057). However, there was no significant difference in any other clinical, audiometric, or outcome factors between the positive and negative match groups.

CONCLUSION

The findings suggest no association between VBVSL and ISSNHL laterality. Furthermore, patients in the positive match group did not exhibit distinct clinical or audiometric features compared to those without a match.

Familial aggregation of multimorbidity in Sweden: national explorative family study

Objectives

To examine whether multimorbidity aggregates in families in Sweden.

Design

National explorative family study.

Setting

Swedish Multigeneration Register linked to the National Patient Register, 1997-2015. Multimorbidity was assessed with a modified counting method of 45 chronic non-communicable diseases according to ICD-10 (international classification of diseases, 10th revision) diagnoses.

Participants

2 694 442 Swedish born individuals (48.73% women) who could be linked to their Swedish born first, second, and third degree relatives. Twins were defined as full siblings born on the same date.

Main outcome measures

Multimorbidity was defined as two or more non-communicable diseases. Familial associations for one, two, three, four, and five or more non-communicable diseases were assessed to examine risks depending on the number of non-communicable diseases. Familial adjusted odds ratios for multimorbidity were calculated for individuals with a diagnosis of multimorbidity compared with relatives of individuals unaffected by multimorbidity (reference). An initial principal component decomposition followed by a factor analysis with a principal factor method and an oblique promax rotation was used on the correlation matrix of tetrachoric correlations between 45 diagnoses in patients to identify disease clusters.

Results

The odds ratios for multimorbidity were 2.89 in twins (95% confidence interval 2.56 to 3.25), 1.81 in full siblings (1.78 to 1.84), 1.26 in half siblings (1.24 to 1.28), and 1.13 in cousins (1.12 to 1.14) of relatives with a diagnosis of multimorbidity. The odds ratios for multimorbidity increased with the number of diseases in relatives. For example, among twins, the odds ratios for multimorbidity were 1.73, 2.84, 4.09, 4.63, and 6.66 for an increasing number of diseases in relatives, from one to five or more, respectively. Odds ratios were highest at younger ages: in twins, the odds ratio was 3.22 for those aged ≤20 years, 3.14 for those aged 21-30 years, and 2.29 for those aged >30 years at the end of follow-up. Nine disease clusters (factor clusters 1-9) were identified, of which seven aggregated in families. The first three disease clusters in the principal component decomposition were cardiometabolic disease (factor 1), mental health disorders (factor 2), and disorders of the digestive system (factor 3). Odds ratios for multimorbidity in twins, siblings, half siblings, and cousins for the factor 1 cluster were 2.79 (95% confidence interval 0.97 to 8.06), 2.62 (2.39 to 2.88), 1.52 (1.34 to 1.73), and 1.31 (1.23 to 1.39), and for the factor 2 cluster, 5.79 (4.48 to 7.48) 3.24 (3.13 to 3.36), 1.51 (1.45 to 1.57), and 1.37 (1.341.40).

Conclusions

The results of this explorative family study indicated that multimorbidity aggregated in Swedish families. The findings suggest that map clusters of diseases should be used for the genetic study of common diseases to show new genetic patterns of non-communicable diseases.

Cardiocerebrovascular risk in sensorineural hearing loss: results from the National Health and Nutrition Examination Survey 2015 to 2018

Objective

This study aims to determine whether the risks of cardiocerebrovascular disease are relevant to sensorineural hearing loss (SNHL) based on a national database.

Methods

A total of 1,321 participants aged from 18 to 69 with complete data including medical history and audiometry from the NHANES database (2015-2018) were analyzed. All included participants had available hearing data and the average thresholds of the hearing data were measured and calculated as low-frequency pure-tone average (LFPTA; 500, 1,000, and 2,000 Hz) and high-frequency pure-tone average (HFPTA; 3,000, 4,000, 6,000, and 8,000 kHz). SNHL was defined as an average pure tone of more than or equal to 20 dB in at least one better ear. Multivariable models to assess the association between cardiocerebrovascular risks and SNHL were used in this study.

Results

The prevalence of stroke was 1.6% in individuals with SNHL and 0.4% in individuals without SNHL (p = 0.023). A higher cardiovascular risk score was observed in SNHL patients compared to participants without SNHL (1.58 vs. 0.90, p < 0.001). Stroke was associated with a 3.67-fold increase in the risk of SNHL (95% CI: 1.12-12.00, p = 0.032) in univariable logistic regression, and the association (OR = 4.22, 95%CI = 1.28-13.93, p = 0.020) remained significant after adjusting for several covariates. Multivariable logistic regression models indicated a positive correlation between cardiovascular risk and SNHL (OR = 1.66, 95% CI = 1.40-1.96, p < 0.001), but no significant relationship was shown with all covariates adjusted. However, significant associations were found between SNHL and both age and sex in both univariable and multivariable logistic regression models.

Conclusion

Our findings suggested that a higher cardiocerebrovascular risk burden was associated with an increased risk of SNHL, and the relationship may be influenced by age and sex. Future longitudinal studies are needed to investigate the mechanistic and pathologic vascular hypothesis of SNHL.

Cardiovascular Risk Factors in Patients With Sudden Sensorineural Hearing Loss: A Systematic Review and Meta-Analysis

OBJECTIVE

The interruption of vascular supply to the inner ear is one of several proposed etiologies of sudden sensorineural hearing loss (SSNHL). The increased presence of cardiovascular risk factors may predispose patients to SSNHL through this pathway. This systematic review and meta-analysis studies the presence of cardiovascular risk factors in patients diagnosed with SSNHL.

DATA SOURCES

Databases included PubMed/Medline, OVID, EMBASE, Cochrane, and Web of Science.

REVIEW METHODS

Inclusion criteria included studies featuring SSNHL patients presenting with 1+ cardiovascular risk factors. Exclusion criteria included case reports and studies without outcome measures. Two investigators independently reviewed all manuscripts and performed quality assessments using validated tools.

RESULTS

Of 532 identified abstracts, 27 studies met inclusion criteria (19 case-control, 4 cohorts, 4 case series). Of these, 24 underwent meta-analysis encompassing a total of 77,566 patients (22,620 SSNHL patients, 54,946 matched controls). The mean age was 50.43 years. SSNHL patients were more likely to have concomitant diabetes (odds ratio [OR] 1.61 [95% confidence interval [CI]: 1.31, 1.99; p < .00001]) and hypertension (OR 1.5 [95% CI: 1.16, 1.94; p = .002]). An increased standard mean difference of total cholesterol of 11.09 mg/dL (95% CI; 3.51, 18.67; p = .004) was noted in the SSNHL group compared with the controls. No significant differences in smoking, high-density lipoprotein, triglycerides, or body mass index were detected.

CONCLUSION

Patients presenting with SSNHL have a significantly higher risk of concomitant diabetes, hypertension, and higher total cholesterol in comparison to matched controls. This may indicate a higher cardiovascular risk profile in this population. More prospective and matched cohort studies are needed to understand the role of cardiovascular risk factors in SSNHL.

Update on Findings about Sudden Sensorineural Hearing Loss and Insight into Its Pathogenesis

Sudden sensorineural hearing loss (SSNHL) is routinely encountered and is one of the most common emergent diseases in otolaryngology clinics. However, the etiology of SSNHL remains unclear. Due to the inaccessibility of the living human inner ear for biopsy, studies investigating the etiology of SSNHL have been performed by analyzing data obtained from examinations using peripheral blood or imaging. We updated the findings obtained from serological, magnetic resonance imaging, genetic, and viral examinations to reveal the etiology of SSNHL. Regarding viral examination, we focused on sensorineural hearing loss associated with coronavirus disease (COVID-19) because the number of correlated reports has been increasing after the outbreak. The updated findings revealed the following three possible mechanisms underlying the development of SSNHL: thrombosis and resulting vascular obstruction in the cochlea, asymptomatic viral infection and resulting damage to the cochlea, and cochlear inflammation and resulting damage to the cochlea. Thrombosis and viral infection are predominant, and cochlear inflammation can be secondarily induced through viral infection or even thrombosis. The findings about sensorineural hearing loss associated with COVID-19 supported the possibility that asymptomatic viral infection is one of the etiologies of SSNHL, and the virus can infect inner ear tissues and directly damage them.

Metformin Reduces the Incidence of Sensorineural Hearing Loss in Patients With Type 2 Diabetes Mellitus: A Retrospective Chart Review

Introduction and objectives

Acquired sensorineural hearing loss (SNHL) has become a critical societal issue in recent years. SNHL is considered a risk factor for type 2 diabetes mellitus (T2DM). Metformin is commonly used to treat T2DM. However, its effects on SNHL have not been reported yet. Hence, this study aimed to evaluate the association between the use of metformin and SNHL incidence.

Patients and methods

In this retrospective matched-cohort study, the medical records of 1219 patients with T2DM aged >18 years from our hospital’s inpatient database from January 1, 2012, to December 31, 2019, were examined, and matched cohorts were generated (76 patients receiving metformin and 76 not receiving metformin). A multivariable logistic regression analysis was performed to investigate the factors influencing the incidence of SNHL.

Results

After adjustment by propensity matching, multivariable logistic regression analysis revealed that the non-use of metformin increased the risk of developing SNHL (odds ratio, 0.26; 95% confidence interval, 0.07-0.93; p = 0.03).

Conclusions

This study demonstrated an association between the use of metformin and a reduced incidence of SNHL among patients with T2DM.

What factors are important to whom in what context, when adults are prescribed hearing aids for hearing loss? A realist review protocol

INTRODUCTION

Hearing aids are the gold standard treatment to help manage hearing loss. However, not everyone who needs them has them, and of those who do, a significant proportion of people do not use them at all, or use them infrequently. Despite literature reviews listing key barriers and enablers to the uptake and use of hearing aids, there is little evidence to describe how this varies by population and context. This review will describe what factors are important to whom in what context when considering the provision of hearing aids for hearing loss in adults.

METHODS AND ANALYSIS

The aims of this review are as follows: (1) To iteratively review and synthesise evidence surrounding the provision of hearing aids for hearing loss in adults. (2) To generate a theory-driven understanding of factors that are important, for whom, and in what context. (3) To develop a programme theory describing contexts that can support the provision of hearing aids to result in improved outcomes for adults with hearing loss. A scoping literature search will aid the development of programme theories, to explain how the intervention is expect to work, for whom, in what circumstances and in which contexts. We will locate evidence in the following databases: CINAHL, Cochrane Library, EMBASE, MEDLINE, PsycINFO, PubMED, Web of Science with no date restrictions. A realist analytic approach will be used to refute and refine these initial programme theories. Throughout the review, relevant key stakeholders (eg, patients and clinicians) will be consulted to test and refine the programme theories.

ETHICS AND DISSEMINATION

This study was approved by the University of Nottingham Faculty of Medicine and Health Sciences Research Ethics Committee: (FMHS 95-0820) and the London Brent NHS Research Ethics Committee (Ref: 21/PR/0259). The review will be reported according to the RAMESES guidelines and published in a peer-reviewed journal.

PROSPERO REGISTRATION NUMBER

CRD42021282049.

Serum Albumin Levels as a Potential Marker for the Predictive and Prognostic Factor in Sudden Sensorineural Hearing Loss: A Prospective Cohort Study

Objectives: As a common otology emergency, sudden sensorineural hearing loss (SSNHL) has a great impact on quality of life. The diagnosis and treatment of SSNHL remain challenging. This study aims to identify and investigate the association of liver functions with SSNHL.

Methods: A total of 135 SSNHL patients and 135 sex- and age-matched controls were prospectively enrolled. The baseline and clinical characteristics, along with liver function levels of participators, were collected. Linear correlation, logistic regression, and receiving operator characteristic curve analysis tests were applied to examine the association between liver function levels and SSNHL.

Results: There were no differences in baseline characteristics between SSNHL and control groups. The albumin (ALB) level of the SSNHL group was significantly lower than that in the control group (p < 0.001). The logistic regression showed that the low ALB level may be a predictive factor of SSNHL with an adjusted OR of 0.809 (95% CI, 0.742–0.882, p < 0.001). By comparing the indicators of different prognosis groups, we found that the effective group had a significantly lower hearing impair onset and higher ALB (p = 0.001) and AGR (p = 0.003) levels than the ineffective group. Logistic regression revealed that the hearing level onset (OR, 0.976; 95% CI, 0.956–0.997; p = 0.026) and ALB level (OR, 1.181; 95% CI, 1.071–1.301; p = 0.001) showed strong associations with treatment outcome.

Conclusions: Lower ALB levels, within the normal ranges, were associated with the occurrence and unfavorable outcome of SSNHL. However, further research on the underlying mechanisms needs to be conducted.