Is the relation of social class to change in hearing threshold levels from childhood to middle age explained by noise, smoking, and drinking behaviour?

Postoperative Recurrent Cholesteatoma in Rural Versus Urban Populations

OBJECTIVE

Chronic ear disease presents a unique challenge to otolaryngologists in both rural and urban settings. Cholesteatoma remains a difficult disease to treat in rural populations due to limited healthcare access and high risk of recurrence. The purpose of this study was to determine if there are differences in surgical outcomes among patients with acquired cholesteatoma residing in rural versus urban settings.

STUDY DESIGN

Single-surgeon retrospective case series with chart review.

SETTING

Tertiary care private otolaryngology practice.

PATIENTS

One hundred twenty-two patients presenting to the Kentuckiana ENT otology and neurotology practice from January 2011 to May 2017.

MAIN OUTCOME MEASURES

Surgical outcomes including recurrence, air-bone gap improvement, ossicular integrity, and complications were reviewed and compared between the rural and urban cohorts.

RESULTS

Presence of postoperative residual cholesteatoma (OR = 8.667, 95% CI = 2.022-37.141, p = 0.008) and number of surgeries per patient (OR = 5.185, 95% CI = 1.086-24.763, p = 0.024) were significantly increased among patients in rural nonmetropolitan areas. No significant differences were found when comparing risk of recurrence, size of cholesteatoma, presence of complications, air-bone gap improvement, and ossicular chain integrity. There were significantly more second-look surgeries performed in privately insured patients (OR = 8.582, 95% CI = 1.937-38.017, p = 0.001).

CONCLUSIONS

Patients in rural communities have an increased number of surgeries and postoperative risk for residual cholesteatoma compared to patients residing in urban settings. This study provides the basis for larger, multicenter, prospective examinations of outcomes among urban versus rural patients, which would enable a better understanding of difference in surgical outcomes between rural and urban cohorts.Level of Evidence: IV.

Conceptual Model of Hearing Health Inequalities (HHI Model): A Critical Interpretive Synthesis

Hearing loss is a major health challenge that can have severe physical, social, cognitive, economic, and emotional consequences on people's quality of life. Currently, the modifiable factors linked to socioeconomic inequalities in hearing health are poorly understood. Therefore, an online database search (PubMed, Scopus, and Psych) was conducted to identify literature that relates hearing loss to health inequalities as a determinant or health outcome. A total of 53 studies were selected to thematically summarize the existing literature, using a critical interpretive synthesis method, where the subjectivity of the researcher is intimately involved in providing new insights with explanatory power. The evidence provided by the literature can be summarized under four key themes: (a) There might be a vicious cycle between hearing loss and socioeconomic inequalities and lifestyle factors, (b) socioeconomic position may interact with less healthy lifestyles, which are harmful to hearing ability, (c) increasing health literacy could improve the diagnosis and prognosis of hearing loss and prevent the adverse consequences of hearing loss on people's health, and (d) people with hearing loss might be vulnerable to receiving low-quality and less safe health care. This study uses elements from theoretical models of health inequalities to formulate a highly interpretive conceptual model for examining hearing health inequalities. This model depicts the specific mechanisms of hearing health and their evolution over time. There are many modifiable determinants of hearing loss, in several stages across an individual's life span; tackling socioeconomic inequalities throughout the life-course could improve the population's health, maximizing the opportunity for healthy aging.

Mouse screen reveals multiple new genes underlying mouse and human hearing loss

Adult-onset hearing loss is very common, but we know little about the underlying molecular pathogenesis impeding the development of therapies. We took a genetic approach to identify new molecules involved in hearing loss by screening a large cohort of newly generated mouse mutants using a sensitive electrophysiological test, the auditory brainstem response (ABR). We review here the findings from this screen. Thirty-eight unexpected genes associated with raised thresholds were detected from our unbiased sample of 1,211 genes tested, suggesting extreme genetic heterogeneity. A wide range of auditory pathophysiologies was found, and some mutant lines showed normal development followed by deterioration of responses, revealing new molecular pathways involved in progressive hearing loss. Several of the genes were associated with the range of hearing thresholds in the human population and one, SPNS2, was involved in childhood deafness. The new pathways required for maintenance of hearing discovered by this screen present new therapeutic opportunities.

This study uses an electrophysiological screen of over a thousand new mutant mouse lines to identify 38 new genes underlying deafness, some associated with human hearing function, revealing a wide range of molecular and pathological mechanisms.

Progressive hearing loss with age is extremely common in the population, leading to difficulties in understanding speech, increased social isolation, and associated depression. We know it has a significant heritability, but so far we know very little about the molecular pathways leading to hearing loss, hampering the development of treatments. Here, we describe a large-scale screen of 1,211 new targeted mouse mutant lines, resulting in the identification of 38 genes underlying hearing loss that were not previously suspected of involvement in hearing. Some of these genes reveal molecular pathways that may be useful targets for drug development. Our further analysis of the genes identified and the varied pathological mechanisms within the ear resulting from the mutations suggests that hearing loss is an extremely heterogeneous disorder and may have as many as 1,000 genes involved.

Socioeconomic differences in hearing among middle-aged and older adults: cross-sectional analyses using the Health Survey for England

BACKGROUND

Hearing loss impacts on cognitive, social and physical functioning. Both hearing loss and hearing aid use vary across population subgroups. We examined whether hearing loss, and reported current hearing aid use among persons with hearing loss, were associated with different markers of socioeconomic status (SES) in a nationally representative sample of community-dwelling middle-aged and older adults.

METHODS

Hearing was measured using an audiometric screening device in the Health Survey for England 2014 (3292 participants aged 45 years and over). Hearing loss was defined as >35 dB HL at 3.0 kHz in the better-hearing ear. Using sex-specific logistic regression modelling, we evaluated the associations between SES and hearing after adjustment for potential confounders.

RESULTS

26% of men and 20% of women aged 45 years and over had hearing loss. Hearing loss was higher among men in the lowest SES groups. For example, the multivariable-adjusted odds of hearing loss were almost two times as high for those in the lowest versus the highest income tertile (OR 1.77, 95% CI 1.15 to 2.74). Among those with hearing loss, 30% of men and 27% of women were currently using a hearing aid. Compared with men in the highest income tertile, the multivariable-adjusted odds of using a hearing aid nowadays were lower for men in the middle (OR 0.50, 95% CI 0.25 to 0.99) and the lowest (OR 0.47, 95% CI 0.23 to 0.97) income tertiles. Associations between SES and hearing were weaker or null among women.

CONCLUSIONS

While the burden of hearing loss fell highest among men in the lowest SES groups, current hearing aid use was demonstrably lower. Initiatives to detect hearing loss early and increase the uptake and the use of hearing aids may provide substantial public health benefits and reduce socioeconomic inequalities in health.

Social inequalities in pure-tone hearing assessed using occupational stratification schemes

OBJECTIVE

The objective of this study is to analyse the performance of two occupational stratification approaches and the impact of social position on adult hearing.

DESIGN

The prevalence of hearing impairment, pure-tone averages (PTA) and prevalence ratios (PR) for relative hearing loss, which focuses on the position of one's PTA in the age- and gender-specific distribution, were compared in groups defined by ISCO Skill Level and the International Socio-Economic Index (ISEI).

STUDY SAMPLE

About 1571 subjects aged 30-89, including 677 highly screened adults, from the cross-sectional study HÖRSTAT.

RESULTS

ISCO Skill Level and ISEI yielded qualitatively the same results. The prevalence difference between the socially least and most advantaged group ranges between 10 and 16%, varying with the scheme applied. Low- and high-frequency PTA and PR for relative hearing loss confirm the gradient. Screening reduced, but did not negate the social differences. The prevalence difference dropped to 6-7% in the otologically normal subsample.

CONCLUSIONS

Social groups defined by hierarchical, occupational measures differ in their pure-tone hearing, even if the main risk factors are controlled for. This underlines the need for population-based sampling, the relevance of reporting the study group's social composition and the importance of advancing the discussion on appropriate social measures in hearing research.

Effects of combined exposure to metals, solvents, and noise on permanent threshold shifts

BACKGROUND

Studies suggest metal and solvent exposure may damage hearing. This study evaluated the association between exposures classified as high for metals, solvents, and noise on permanent threshold shift (PTS) development.

METHODS

A total of 1,546 personnel at an industrial shipyard were divided into five exposure groups based on level of concentration: high noise, high metals/solvents, high metals/noise, high metals/solvents/noise, and a low metals/solvents/noise reference group. Hearing threshold changes were analyzed to identify development of a PTS.

RESULTS

Logistic regression indicated high metals/solvents and high metals/solvent/noise groups had significantly greater odds ratios of 2.4; 95%CI [1.02, 2.85] and 1.7; 95%CI [1.46, 3.94], respectively, compared to a reference group. Both groups were associated with PTSs while controlling for age, gender, and exposure duration.

CONCLUSIONS

Simultaneous exposures classified as high for metals and solvents may damage hearing. Results suggest the need for expanding hearing conservation programs to consider combinations of exposures to metals, solvents, and noise. Am. J. Ind. Med. 60:227-238, 2017. © 2017 Wiley Periodicals, Inc.

S1PR2 variants associated with auditory function in humans and endocochlear potential decline in mouse

Progressive hearing loss is very common in the population but we still know little about the underlying pathology. A new spontaneous mouse mutation (stonedeaf, stdf ) leading to recessive, early-onset progressive hearing loss was detected and exome sequencing revealed a Thr289Arg substitution in Sphingosine-1-Phosphate Receptor-2 (S1pr2). Mutants aged 2 weeks had normal hearing sensitivity, but at 4 weeks most showed variable degrees of hearing impairment, which became severe or profound in all mutants by 14 weeks. Endocochlear potential (EP) was normal at 2 weeks old but was reduced by 4 and 8 weeks old in mutants, and the stria vascularis, which generates the EP, showed degenerative changes. Three independent mouse knockout alleles of S1pr2 have been described previously, but this is the first time that a reduced EP has been reported. Genomic markers close to the human S1PR2 gene were significantly associated with auditory thresholds in the 1958 British Birth Cohort (n = 6099), suggesting involvement of S1P signalling in human hearing loss. The finding of early onset loss of EP gives new mechanistic insight into the disease process and suggests that therapies for humans with hearing loss due to S1P signalling defects need to target strial function.

Occupational noise exposure and hearing: a systematic review

Purpose

To give a systematic review of the development of noise-induced hearing loss (NIHL) in working life.

Methods

A literature search in MEDLINE, Embase, Web of Science, Scopus, and Health and Safety Abstracts, with appropriate keywords on noise in the workplace and health, revealed 22,413 articles which were screened by six researchers. A total of 698 articles were reviewed in full text and scored with a checklist, and 187 articles were found to be relevant and of sufficient quality for further analysis.

Results

Occupational noise exposure causes between 7 and 21 % of the hearing loss among workers, lowest in the industrialized countries, where the incidence is going down, and highest in the developing countries. It is difficult to distinguish between NIHL and age-related hearing loss at an individual level. Most of the hearing loss is age related. Men lose hearing more than women do. Heredity also plays a part. Socioeconomic position, ethnicity and other factors, such as smoking, high blood pressure, diabetes, vibration and chemical substances, may also affect hearing. The use of firearms may be harmful to hearing, whereas most other sources of leisure-time noise seem to be less important. Impulse noise seems to be more deleterious to hearing than continuous noise. Occupational groups at high risk of NIHL are the military, construction workers, agriculture and others with high noise exposure.

Conclusion

The prevalence of NIHL is declining in most industrialized countries, probably due to preventive measures. Hearing loss is mainly related to increasing age.

Electronic supplementary material

The online version of this article (doi:10.1007/s00420-015-1083-5) contains supplementary material, which is available to authorized users.

Association of Socioeconomic Position With Sensory Impairment Among US Working-Aged Adults

OBJECTIVES

We examined the relationship between socioeconomic position (SEP) and sensory impairment.

METHODS

We used data from the 2007 to 2010 National Health Interview Surveys (n = 69 845 adults). Multivariable logistic regressions estimated odds ratios (ORs) for associations of educational attainment, occupational class, and poverty-income ratio with impaired vision or hearing.

RESULTS

Nearly 20% of respondents reported sensory impairment. Each SEP indicator was negatively associated with sensory impairment. Adjusted odds of vision impairment were significantly higher for farm workers (OR = 1.41; 95% confidence interval [CI] = 1.01, 2.02), people with some college (OR = 1.29; 95% CI = 1.16, 1.44) or less than a high school diploma (OR = 1.36; 95% CI = 1.19, 1.55), and people from poor (OR = 1.35; 95% CI = 1.20, 1.52), low-income (OR = 1.28; 95% CI = 1.14, 1.43), or middle-income (OR = 1.19; 95% CI = 1.07, 1.31) families than for the highest-SEP group. Odds of hearing impairment were significantly higher for people with some college or less education than for those with a college degree or more; for service groups, farmers, and blue-collar workers than for white-collar workers; and for people in poor families.

CONCLUSIONS

More research is needed to understand the SEP-sensory impairment association.

Hearing in middle age: a population snapshot of 40- to 69-year olds in the United Kingdom

OBJECTIVES

To report population-based prevalence of hearing impairment based on speech recognition in noise testing in a large and inclusive sample of U.K. adults aged 40 to 69 years. The present study is the first to report such data. Prevalence of tinnitus and use of hearing aids is also reported.

DESIGN

The research was conducted using the UK Biobank resource. The better-ear unaided speech reception threshold was measured adaptively using the Digit Triplet Test (n = 164,770). Self-report data on tinnitus, hearing aid use, noise exposure, as well as demographic variables were collected.

RESULTS

Overall, 10.7% of adults (95% confidence interval [CI] 10.5-10.9%) had significant hearing impairment. Prevalence of tinnitus was 16.9% (95%CI 16.6-17.1%) and hearing aid use was 2.0% (95%CI 1.9-2.1%). Odds of hearing impairment increased with age, with a history of work- and music-related noise exposure, for lower socioeconomic background and for ethnic minority backgrounds. Males were at no higher risk of hearing impairment than females.

CONCLUSIONS

Around 1 in 10 adults aged 40 to 69 years have substantial hearing impairment. The reasons for excess risk of hearing impairment particularly for those from low socioeconomic and ethnic minority backgrounds require identification, as this represents a serious health inequality. The underuse of hearing aids has altered little since the 1980s, and is a major cause for concern.

Estrogen-related receptor gamma and hearing function: evidence of a role in humans and mice

Since estrogen is thought to protect pre-menopausal women from age-related hearing loss, we investigated whether variation in estrogen-signalling genes is linked to hearing status in the 1958 British Birth Cohort. This analysis implicated the estrogen-related receptor gamma (ESRRG) gene in determining adult hearing function and was investigated further in a total of 6134 individuals in 3 independent cohorts: (i) the 1958 British Birth Cohort; (ii) a London ARHL case-control cohort; and (iii) a cohort from isolated populations of Italy and Silk Road countries. Evidence of an association between the minor allele of single nucleotide polymorphism (SNP) rs2818964 and hearing status was found in females, but not in males in 2 of these cohorts: p = 0.0058 (London ARHL) and p = 0.0065 (Carlantino, Italy). Furthermore, assessment of hearing in Esrrg knock-out mice revealed a mild 25-dB hearing loss at 5 weeks of age. At 12 weeks, average hearing thresholds in female mice((-/-)) were 15 dB worse than in males((-/-)). Together these data indicate ESRRG plays a role in maintenance of hearing in both humans and mice.

German Oldenburg Sentence Test for Children: a useful speech audiometry tool for hearing-impaired children at kindergarten and school age

BACKGROUND/AIMS

In speech audiometry, sentence tests have the advantage of assessing more words within a given period of time than single-word tests do. Consequently, greater accuracy (steeper discrimination function) is achieved. The recently developed German Oldenburg Sentence Test for Children (OlKiSa) has been evaluated thus far for school-aged children in noise, and normative data for younger children in a quiet environment have been established. In this study, the focus is on its applicability in hearing-impaired children fitted with hearing aids or cochlear implants.

METHODS

The use of the OlKiSa in a quiet environment in hearing-impaired children aged 4 years or older was evaluated. One hundred and nineteen hearing-impaired children aged between 4 and 10 years performed the OlKiSa in a quiet environment. Individual speech reception thresholds (SRT) were measured aided and unaided and the slopes of the discrimination functions were calculated.

RESULTS

Independent of age, the mean slope of the discrimination function for SRT was about 7%/dB in both conditions, which is a high value of steepness for a speech audiometric test in a quiet environment.

CONCLUSION

The OlKiSa in quiet is a reliable test procedure for hearing-impaired children aged 4 years and older.

Hearing in 44-45 year olds with m.1555A>G, a genetic mutation predisposing to aminoglycoside-induced deafness: a population based cohort study

Background The mitochondrial DNA mutation m.1555A>G predisposes to permanent idiosyncratic aminoglycoside-induced deafness that is independent of dose. Research suggests that in some families, m.1555A>G may cause non-syndromic deafness, without aminoglycoside exposure, as well as reduced hearing thresholds with age (age-related hearing loss). Objectives To determine whether adults with m.1555A>G have impaired hearing, a factor that would inform the cost-benefit argument for genetic testing prior to aminoglycoside administration. Design Population-based cohort study. Setting UK. Participants Individuals from the British 1958 birth cohort. Measurements Hearing thresholds at 1 and 4 kHz at age 44-45 years; m.1555A>G genotyping. Results 19 of 7350 individuals successfully genotyped had the m.1555A>G mutation, giving a prevalence of 0.26% (95% CI 0.14% to 0.38%) or 1 in 385 (95% CI 1 in 714 to 1 in 263). There was no significant difference in hearing thresholds between those with and without the mutation. Single-nucleotide polymorphism analysis indicated that the mutation has arisen on a number of different mitochondrial haplogroups. Limitations No data were collected on aminoglycoside exposure. For three subjects, hearing thresholds could not be predicted because information required for modelling was missing. Conclusions In this cohort, hearing in those with m.1555A>G is not significantly different from the general population and appears to be preserved at least until 44-45 years of age. Unbiased ascertainment of mutation carriers provides no evidence that this mutation alone causes non-syndromic hearing impairment in the UK. The findings lend weight to arguments for genetic testing for this mutation prior to aminoglycoside administration, as hearing in susceptible individuals is expected to be preserved well into adult life. Since global use of aminoglycosides is likely to increase, development of a rapid test is a priority.

Prevalence of hearing loss in Black and White elders: results of the Cardiovascular Health Study

PURPOSE

The goal of this study was to determine the impact of age, gender, and race on the prevalence and severity of hearing loss in elder adults, aged 72-96 years, after accounting for income, education, smoking, and clinical and subclinical cardiovascular disease. Methods Air-conduction thresholds for standard and extended high-frequency pure-tones were obtained from a cohort of 548 (out of 717) elderly adults (ages 72-96 years) who were recruited during the Year 11 clinical visit (1999-2000) of the Cardiovascular Health Study (CHS) at the Pittsburgh, Pennsylvania site. Participant smoking, income, education, and cardiovascular disease histories were obtained from the CHS database and were included as factors.

RESULTS

Hearing loss was more common and more severe for the participants in their 80s than for those in their 70s-the men more than the women and the White participants more than the Black participants. The inclusion of education, income, smoking, and cardiovascular disease (clinical and subclinical) histories as factors did not substantively impact the overall results.

CONCLUSION

Although the data reported in this article were cross-sectional and a cohort phenomenon might have been operational, they suggested that hearing loss is more substantive in the 8th than the 7th decade of life and that race and gender influence this decline in audition. Given the high prevalence in the aging population and the differences across groups, there is a clear need to understand the nature and causes of hearing loss across various groups in order to improve prevention and develop appropriate interventions.