Hearing Loss and Risk of Overall, Injury-Related, and Cardiovascular Mortality: The Kangbuk Samsung Health Study

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.

A Novel Deleterious MYO15A Gene Mutation Causes Nonsyndromic Hearing Loss

Introduction

Hearing loss (HL) is the most frequent sensory neurodeficiency, affecting a broad spectrum of individuals globally. Within this context, the role of genetic factors takes center stage, particularly in cases of hereditary HL.

Case Report

Here, we present a nonsyndromic HL (NSHL) case report. The patient is a 21-year-old man with progressive HL. The whole-exome sequencing (WES) demonstrated a novel homozygous missense mutation, c.9908A>C; p.Lys3303Thr, in the proband's exon 61 of the MYO15A gene. Further analysis has revealed that the detected mutation is present in a heterozygous state in the parents.

Conclusion

WES analysis in this study revealed a novel mutation in the MYO15A gene. Our data indicates that the MYO15A-p.Lys3303Thr mutation is the likely pathogenic variant associated with NSHL. Additionally, this finding enhances genetic counseling for individuals with NSHL patients, highlighting the value of the WES method in detecting rare genetic variants.

Association between hearing loss and high-sensitivity C-reactive protein: the Kangbuk Samsung Cohort Study

Background

Hearing loss (HL) is linked to an elevated risk of cardiovascular diseases (CVDs). The pathogeneses of HL and CVD commonly involve inflammatory responses. Previous studies investigated elevated levels of inflammatory biomarkers in subjects with HL, however, their findings did not demonstrate statistical significance. In our cross-sectional and longitudinal study, we investigated the correlation between HL and increased high-sensitivity C-reactive protein (hsCRP) levels to determine how HL is associated with CVDs.

Methods

We conducted a cross-sectional study with workers aged over 18 years who underwent health check-ups at our institution between 2012 and 2018 (n = 566,507), followed by conducting a longitudinal study of workers aged > 18 who underwent health checkups at least twice at our institution between 2012 and 2018 (n = 173,794). The definition of HL was as an average threshold of ≥ 20 dB in pure-tone air conduction at 0.5, 1.0, and 2.0 kHz in both ears. The incidence of increased hsCRP levels throughout the follow-up period was defined as a level exceeding 3 mg/L. Logistic regression and generalized estimating equations were performed to estimate the risk of increased hsCRP levels according to the occurrence of HL in groups stratified by age.

Results

In the cross-sectional study, the multivariate-adjusted odds ratio (OR) was 1.17 (95% confidence interval [CI]: 1.02-1.34); the OR was 0.99 (95% CI: 0.80-1.22) in those under 40 and 1.28 (1.08-1.53) in those over 40. In the longitudinal study, the multivariable-adjusted OR was 1.05 (95% CI: 0.92-1.19); the OR was 1.10 (95% CI: 0.90-1.35) in those under 40 and 1.20 (1.01-1.43) in those over 40.

Conclusions

This cross-sectional and longitudinal study identified an association between HL and increased hsCRP levels in workers aged over 40 years.

Hearing loss increases all-cause and cardiovascular mortality in middle-aged and older Chinese adults: the Dongfeng-Tongji Cohort Study

We aimed to investigate the association between hearing loss and all-cause and cardiovascular disease (CVD) mortality, and whether the relationship could be modified by chronic conditions in middle-aged and older Chinese adults. We selected 18,625 participants who underwent audiometry in 2013 from the Dongfeng-Tongji Cohort conducted in China, and followed them until December 2018. Hearing loss was grouped as normal, mild, and moderate or severe by pure-tone hearing threshold at speech (0.5, 1, and 2 kHz) and high frequency (4 and 8 kHz). We applied Cox regression models to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for all-cause and CVD mortality. Among the 18,625 participants, the mean age was 64.6 (range: 36.7-93.0) years, and 56.2% were women. A total of 1185 died, with 420 CVD deaths during a mean follow-up period of 5.5 years. The adjusted HR for all-cause and CVD mortality increased gradually with the increasing hearing threshold (All p for trend < 0.05). Compared to participants with normal hearing at speech frequency, the adjusted HRs (95% CIs) of moderate or severe hearing loss were 1.42 (1.21-1.67), 1.44 (1.10-1.89), and 1.92 (1.21-3.04) for all-cause, CVD, and stroke mortality, respectively. While moderate or severe hearing loss at high frequency was only related to an increased risk of all-cause mortality (HR, 1.60; 95% CI, 1.18-2.17). The associations were generally consistent across subgroups (All p for interaction > 0.05). Additionally, individuals with a combination of moderate or severe hearing loss and occupational noise exposure, diabetes, or hypertension had higher risk of all-cause or CVD mortality, ranging from 1.45 to 2.78. In conclusion, hearing loss was independently associated with an increased risk of all-cause and CVD mortality, in a dose-response manner. Meanwhile, hearing loss and diabetes or hypertension could jointly increase the risk of all-cause and CVD mortality.

Association between hearing loss and trauma based on population data of Korea

BACKGROUND

Although several studies have been conducted to assess the association between hearing loss (HL) and trauma, no studies have analyzed trauma comprehensively based on population-based data.

OBJECTIVES

To investigate the association between HL and trauma in daily life using National Health Insurance Service National Sample Cohort data of Korea.

MATERIALS AND METHODS

People who were registered with severe or mild hearing disability by the Korean government from 2002 to 2015, were included in this study. Trauma was defined as an outpatient visit or admission under diagnostic codes associated with trauma. The risk for trauma was analyzed using multiple logistic regression model.

RESULTS

There were 5,114 subjects in the mild hearing disability group and 1,452 in the severe hearing disability group. The risk for trauma was significantly higher in the mild and severe hearing disability groups than in the control group. The risk was higher in the mild hearing disability group than in the severe hearing disability group.

CONCLUSIONS AND SIGNIFICANCE

Individuals with hearing disability are at a higher risk for trauma based on population-based data in Korea, which indicates that HL increases the risk for trauma.

Hearing loss is associated with increased risk of incident stroke but not coronary heart disease among middle-aged and older Chinese adults: the Dongfeng-Tongji cohort study

Hearing loss has been associated with increased risk of cardiovascular disease (CVD) prevalence in cross-sectional studies. However, little is known about the prospective association between hearing loss and CVD incidence. We aimed to examine the associations of hearing loss with risk of incident CVD, coronary heart disease (CHD), and stroke in a Chinese population. We included 13,880 individuals aged 63.3 years from the Dongfeng-Tongji cohort study (2013-2018). Hearing loss was categorized into normal, mild, moderate, severe, or greater by the pure-tone average of thresholds at speech and high frequency in both ears. Cox proportional hazard models and linear regression models were used for multivariate longitudinal analyses. After multivariate adjustments, we observed suggestive dose-response associations of increased high-frequency hearing loss with elevated risk of CVD and stroke incidence. Compared with normal hearing loss at high frequency, those with moderate and severe or greater hearing loss had a 4% (95% CI: 0.92, 1.18) or 13% (95% CI: 0.98, 1.30) higher risk of CVD and 52% (95% CI: 1.06, 2.17) or 51% (95% CI: 1.03, 2.20) higher risk of stroke, while the associations were almost consistent across most subgroups. No significant associations were observed for CHD and high-frequency hearing loss, as well as CVD and speech-frequency hearing loss. In addition, higher high-frequency hearing loss was related to unfavorably altered lipid profiles and fasting glucose. Our data suggested that increased hearing loss might increase the risk of incident CVD and stroke among middle-aged and older Chinese, which was partially explained by altered CVD-related biomarkers.

Associations of Hearing Loss and Dual Sensory Loss With Mortality: A Systematic Review, Meta-analysis, and Meta-regression of 26 Observational Studies With 1 213 756 Participants

IMPORTANCE

Hearing loss (HL) and dual sensory loss (DSL) are prevalent, disabling, and associated with numerous age-related health conditions, including dementia and frailty. To date, no evidence-based summary of their mortality risk is available.

OBJECTIVE

To clarify the epidemiological associations between HL/DSL and mortality.

DATA SOURCES

PubMed, Embase, and Cochrane Library, from inception until June 18, 2021.

STUDY SELECTION

Two blinded reviewers selected observational or interventional studies, published as full-length English articles in peer-reviewed journals, that reported the presence or severity of HL or DSL (ie, comorbid HL and vision loss), whether objectively measured or self-reported, in association with any mortality estimate, among adults 18 years and older.

DATA EXTRACTION AND SYNTHESIS

Two reviewers extracted data and evaluated study bias using the Newcastle-Ottawa Scale, following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA)/Meta-analysis of Observational Studies in Epidemiology (MOOSE) guidelines and a PROSPERO-registered protocol. The analysis pooled maximally adjusted estimates using mixed-effects models, measured heterogeneity using I2, investigated sources of heterogeneity using meta-regression and subgroup meta-analyses, examined and adjusted for publication bias, performed influence and cumulative meta-analyses, and assessed evidence quality using the Grading of Recommendations, Assessment, Development and Evaluations (GRADE) framework.

MAIN OUTCOMES AND MEASURES

Hazard ratios (HRs) for all-cause, cardiovascular, or other mortality estimates.

RESULTS

This review included 14 retrospective and 12 prospective observational studies (1 213 756 participants) from 3220 records. Risk of bias was low to moderate; exclusion of 3 high-risk studies did not alter conclusions. Hearing loss was associated with excess all-cause mortality (HR, 1.13; 95% CI, 1.07-1.19; I2 = 77%; n = 21; 95% prediction interval [PI], 0.93-1.37) and cardiovascular mortality (HR, 1.28; 95% CI, 1.10-1.50; I2 = 60%; n = 6; 95% PI, 0.84-1.96), while DSL was associated with larger excess risks (all-cause: HR, 1.40; 95% CI, 1.30-1.51; I2 = 34%; n = 10; 95% PI, 1.18-1.66; cardiovascular: HR, 1.86; 95% CI, 1.31-2.65; I2 = 0%; n = 2), after adjustment for demographics and comorbidities. Prespecified meta-regression sufficiently explained heterogeneity, with longer follow-up duration weakening the pooled association, leaving low (29%) residual heterogeneity. Meta-regression among audiometric studies showed a dose-response association (doubling of HR per 30-dB increase in HL). Self-reported and audiometric effect sizes were similar, with lower heterogeneity in the latter. Associations were robust to trim-and-fill adjustment for publication bias and single-study influence and cumulative meta-analyses. Associations with accident/injury, cancer, and stroke mortality were inconclusive, with only 1 to 3 studies. Overall evidence quality was moderate.

CONCLUSIONS AND RELEVANCE

In this systematic review and meta-analysis, HL and DSL were associated with excess all-cause and cardiovascular mortality. Physicians caring for patients with HL should consider its relevance to general health and longevity.

Association of Sensory Loss With the Knowledge of Heart Attacks

INTRODUCTION

Awareness of heart attack symptoms and the best response is a national public health priority, especially among those at higher risk of heart disease. Adults with sensory loss are more likely to develop heart disease than those without and may be at risk of poor heart attack knowledge owing to limited patient-provider communication and access to health information. The aim of this study is to examine the association between sensory loss and heart attack knowledge.

METHODS

Cross-sectional, nationally representative data from the 2014 and 2017 National Health Interview Survey were used. Analyses were conducted in 2021. Participants aged ≥20 years were included (N=61,168). Being aware of heart attack symptoms and the best response was considered as recognizing the 5 examined symptoms of heart attacks and the proper emergency response, as defined in the Healthy People 2020 objectives. Functional hearing and vision losses were defined as self-reported difficulty in hearing and seeing.

RESULTS

Overall, 16.2% reported functional hearing loss, and 10.1% reported vision loss. Having vision loss was associated with a lack of knowledge of heart attacks symptoms or the best response (prevalence ratio=1.08, 95% CI=1.06, 1.11). In a separate model, having vision loss only and dual sensory loss (concurrent vision and hearing loss) were associated with not having this knowledge (prevalence ratio=1.09, 95% CI=1.06, 1.12 and PR=1.08, 95% CI=1.01, 1.15, respectively), but having hearing loss only was not (prevalence ratio=1.03, 95% CI=0.99, 1.06).

CONCLUSIONS

Non-institutionalized adults with sensory loss may represent a group to target for improving the knowledge of heart attacks in the population.

Cohort study of long working hours and increase in blood high-sensitivity C-reactive protein (hsCRP) concentration: Mechanisms of overwork and cardiovascular disease

OBJECTIVES

We aimed to find evidence of the inflammation-mediated mechanism by which long working hours contribute to cardiovascular disease (CVD).

METHODS

This cohort study was performed in 56 953 Korean adults free of CVD who underwent a comprehensive screening examination and were followed for up to 7 years. An increase in blood high-sensitivity C-reactive protein (hsCRP) of 1 mg/L or more at the follow-up visit was defined as an incidence. The average weekly working hours in the past year were categorized as ≤40, 41-52, 53-60, and ≥60 h per week. Odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using generalized estimating equations to calculate the risk of an incidental increase of hsCRP.

RESULTS

Participants with longer working hours had a higher incidence of hsCRP. Multivariable-adjusted ORs (95% CIs) of incident cases for ≥61 h compared with ≤40 h was 1.69 (1.04-2.75). In subgroup analyses according to sex and the presence of hypertension and diabetes, the risk of hsCRP incidence were highest in the group working more than 61 h in all subgroups, but none of them were statistically significant.

CONCLUSIONS

Working hours are independently associated with increased risk of elevated hsCRP in a dose-response relationship. Excessive long-time work is a risk factor for CVD, and it was found that an increase in hsCRP was associated with the pathogenesis.

The Importance of Age in the Prediction of Mortality by a Frailty Index: A Machine Learning Approach in the Irish Longitudinal Study on Ageing

The quantification of biological age in humans is an important scientific endeavor in the face of ageing populations. The frailty index (FI) methodology is based on the accumulation of health deficits and captures variations in health status within individuals of the same age. The aims of this study were to assess whether the addition of age to an FI improves its mortality prediction and whether the associations of the individual FI items differ in strength. We utilized data from The Irish Longitudinal Study on Ageing to conduct, by sex, machine learning analyses of the ability of a 32-item FI to predict 8-year mortality in 8174 wave 1 participants aged 50 or more years. By wave 5, 559 men and 492 women had died. In the absence of age, the FI was an acceptable predictor of mortality with AUCs of 0.7. When age was included, AUCs improved to 0.8 in men and 0.9 in women. After age, deficits related to physical function and self-rated health tended to have higher importance scores. Not all FI variables seemed equally relevant to predict mortality, and age was by far the most relevant feature. Chronological age should remain an important consideration when interpreting the prognostic significance of an FI.

Dietary fat intake and risk of disabling hearing impairment: a prospective population-based cohort study

Purpose

To examine the associations of specific dietary fats with the risk of disabling hearing impairment in the UK Biobank study.

Methods

This cohort study investigated 105,592 participants (47,308 men and 58,284 women) aged ≥ 40 years. Participants completed a minimum of one valid 24-h recall (Oxford Web-Q). Dietary intake of total fatty acids, polyunsaturated fatty acids (PUFA), saturated fatty acids (SFA), and monounsaturated fatty acids (MUFA) was assessed at baseline. Functional auditory capacity was measured with a digit triplet test (DTT), and disabling hearing impairment was defined as a speech reception threshold in noise > − 3.5 dB in any physical exam performed during the follow-up.

Results

Over a median follow-up of 3.2 (SD: 2.1) years, 832 men and 872 women developed disabling hearing impairment. After adjustment for potential confounders, including lifestyles, exposure to high-intensity sounds, ototoxic medication and comorbidity, the hazard ratios (HRs), and 95% confidence interval (CI) of disabling hearing function, comparing extreme quintiles of intakes were 0.91 (0.71–1.17) for total fat, 1.09 (0.83–1.44) for PUFA, 0.85 (0.64–1.13) for SFA and 1.01 (0.74–1.36) for MUFA among men. Among women, HRs comparing extreme intakes were 0.98 (0.78–1.24) for total fat, 0.69 (0.53–0.91) for PUFA, 1.26 (0.96–1.65) for SFA, and 0.91 (0.68–1.23) for MUFA. Replacing 5% of energy intake from SFA with an equivalent energy from PUFA was associated with 25% risk reduction (HR: 0.75; 95% CI: 0.74–0.77) among women.

Conclusions

PUFA intake was associated with decreased risk of disabling hearing function in women, but not in men.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00394-021-02644-7.

Fall-related Injuries Mediate the Relationship between Self-Reported Hearing Loss and Mortality in Middle-Aged and Older Adults

BACKGROUND

Hearing loss is associated with a greater risk of death in older adults. This relationship has been attributed to an increased risk of injury, particularly due to falling, in individuals with hearing loss. However, the link between hearing loss and mortality across the lifespan is less clear.

METHODS

We used structural equation modeling and mediation analysis to investigate the relationship between hearing loss, falling, injury, and mortality across the adult lifespan in public-use data from the National Health Interview Survey and the National Death Index. We examined 1) the association between self-reported hearing problems and later mortality, 2) the associations between self-reported hearing problems and the risk of injury and degree and type of injury, 3) the mediating role of falling and injury in the association between self-reported hearing problems and mortality, and 4) whether these relationships differ in young (18-39), middle-aged (40-59) and older (60+) age groups.

RESULTS

In all three age ranges, those reporting hearing problems were more likely to fall, were more likely to sustain an injury, and were more likely to sustain a serious injury, than those not reporting hearing problems. While there was no significant association between hearing loss and mortality in the youngest category, there was for middle-aged and older participants and for both fall-related injury was a significant mediator in this relationship.

CONCLUSIONS

Fall-related injury mediates the relationship between hearing loss and mortality for middle-aged as well as older adults, suggesting a need for further research into mechanisms and remediation.

Self-reported and cotinine-verified smoking and increased risk of incident hearing loss

We examined the associations of smoking status and urinary cotinine levels, an objective measure of smoking, with the development of new-onset HL. This cohort study was performed in 293,991 Korean adults free of HL who underwent a comprehensive screening examination and were followed for up to 8.8 years. HL was defined as a pure-tone average of thresholds at 0.5, 1.0, and 2.0 kHz ≥ 25 dB in both ears. During a median follow-up of 4.9 years, 2286 participants developed new-onset bilateral HL. Self-reported smoking status was associated with an increased risk of new-onset bilateral HL. Multivariable-adjusted HRs (95% CIs) for incident HL comparing former smokers and current smokers to never-smokers were 1.14 (1.004-1.30) and 1.40 (1.21-1.61), respectively. Number of cigarettes, pack-years, and urinary cotinine levels were consistently associated with incident HL. These associations were similarly observed when introducing changes in smoking status, urinary cotinine, and other confounders during follow-up as time-varying covariates. In this large cohort of young and middle-aged men and women, smoking status based on both self-report and urinary cotinine level were independently associated with an increased incidence of bilateral HL. Our findings indicate smoking is an independent risk factor for HL.