Better Hearing in Norway: A Comparison of Two HUNT Cohorts 20 Years Apart

Nationwide Hearing Loss Trends Over Two Decades

OBJECTIVES

Hearing loss (HL) is one of the most common chronic health conditions in the United States (US). This study aims to evaluate trends in HL prevalence among US adults over the past two decades.

METHODS

Audiometric data of adults from the National Health and Nutrition Examination Survey (NHANES) from 1999 to 2018 were analyzed in 2-year intervals to evaluate changes in HL (defined as pure tone average greater than 25 dB in at least one ear) over time in using odds ratios (ORs). Multivariate logistic regression was used to control for age and sex, and linear regression was used to evaluate trends in HL prevalence over time.

RESULTS

The study included 13,468 participants. In adult participants (20-69 years old), HL remained stable over time, with some fluctuations ranging from 14.8% to 16.8%. In elderly participants (70-years and older), HL remained stable over time, with some fluctuations ranging from 71.7% to 77.1%. Based on univariate and linear regression analysis, there were no differences in HL rates in the adult and elderly cohorts. Subjects 40-49 years old and adults with education level of less than high school had significant downward trends in HL prevalence over two decades (p < 0.001 and p = 0.029).

CONCLUSIONS

HL prevalence may be declining in the adult population when correcting for age and gender; however, there has not been a significant downward trend for the elderly population. HL may be decreasing over time among adults 40-49 years old and with shorter education backgrounds.

LEVEL OF EVIDENCE

IV Laryngoscope, 2024.

Prevalence and risk factors of self-reported hearing loss, tinnitus, and dizziness in a population-based sample from rural northeastern Germany

A close anatomical and physiological relationship is known between the senses of hearing and balance, while an additional pathophysiological interaction is supposed. The mechanisms underlying this association are not yet fully understood, especially in individuals without a known specific otologic disorder. In particular, only scarce information on the combined occurrence of audiovestibular sensory impairment is available so far. Therefore, this study aims to provide further insight into the prevalence and co-prevalence of the audiovestibular symptoms hearing loss, tinnitus and dizziness. Additionally, the influence of potential risk factors from lifestyle habits as well as cardiovascular and metabolic conditions on the development of those symptoms is studied. Data was analyzed from 8134 individuals from the population-based Study of Health in Pomerania (SHIP). SHIP pursues a broad and comprehensive examination program in chronologically separated cohorts with longitudinal follow-up. Cohorts are sampled from Western Pomerania, a rural region of north-eastern Germany. The study population represents a cross-sectional analysis from the cohorts SHIP-START (recruited 1997-2001) and SHIP-TREND (recruited 2008-2012), sampled for baseline investigations (SHIP-START-0 and SHIP-TREND-0) at the age of 20-79 years. Audiovestibular symptoms as outcome variables were assessed by structured questionnaires. Additionally, individuals were comprehensively characterized regarding modifiable lifestyle factors as well as cardiovascular and metabolic disorders, allowing the assessment of their role as exposure variables. We calculated a weighted prevalence of 14.2% for hearing loss, 9.7% for tinnitus, and 13.5% for dizziness in the population. Prevalence increased with age and differed among the sexes. A considerable share of 28.0% of the investigated individuals reported more than one symptom at once. The prevalence of hearing loss as well as tinnitus increased between the two cohorts. A moderate positive correlation was found between the occurrence of hearing loss and tinnitus (phi-coefficient 0.318). In multivariable regression analyses, education was identified as a significant protective factor while only smoking was significantly associated with all three symptoms. Furthermore, several cardiovascular risk factors contributed to both hearing loss and dizziness. In conclusion, audiovestibular symptoms are highly prevalent in the investigated population. A considerable but complex influence of risk factors points towards a relation with neuronal as well as cardiovascular disease processes. To clarify the underlying mechanisms, the interaction between the senses of hearing and balance as well as the mode of action of the risk factors should be evaluated in more detail in the future.

Walking and balance in older adults with age-related hearing loss: A cross-sectional study of cases and matched controls

BACKGROUND

Hearing loss (HL) is prevalent in older individuals. It is suggested that there is an association between age-related HL, walking and balance, leading to poorer function and increased risk of falls in older individuals.

RESEARCH QUESTION

Is HL associated with physical performance, gait variability, and postural sway in older adults, and will additional dizziness moderate the effect of HL on balance?

METHODS

In this cross-sectional study we examined 100 older individuals (age ≥70 years, 60 % females), divided in two groups, with or without age-related HL. Physical function and balance were evaluated by the Short Physical Performance Battery (SPPB), postural sway measured on a force platform (posturography), and balance in walking (gait variability) measured with a body-worn sensor. Multiple linear regression was used to examine the relationships between the variables, with physical function and balance as outcomes and HL as a dichotomous exposure (>30 dB). For all analyses, we further tested if associations were modified by self-reported dizziness.

RESULTS

Multiple regression analysis with HL, age, sex, education, diabetes, and cardiovascular disease revealed a significant association between reduced SPPB and HL. Multiple linear regression analysis also showed that HL was associated with increased postural sway on firm surface with eyes open and closed after adjusting for age, sex, education, diabetes, and cardiovascular disease. There was significant association between HL and increased gait variability during dual task walking in all directions after adjusting for age, sex, education, diabetes, and cardiovascular disease. Further, we found that the association between HL and SPPB was significantly stronger in those with dizziness compared with those without dizziness. Dizziness also modified the association of HL with the other SPPB sub-scores but not for the other outcomes of postural sway or gait variability.

SIGNIFICANCE

In this study, age-related HL was associated with worse physical performance as measured by SPPB, postural sway, and gait variability. This relationship illustrates the importance of assessing physical performance in people with HL to prevent risk of falls and disability.

Prevalence and predictors of self-reported hearing aid use and benefit in Norway: the HUNT study

BACKGROUND

Knowledge on hearing aid use and benefit is important to ensure appropriate and effective treatment. We aimed to assess prevalence and predictors of hearing aid use and benefit in Norway, as well as possible birth cohort changes.

METHODS

We analyzed two large cross-sectional, population-based hearing surveys of 63,182 adults in 1996-1998 and 2017-2019 (the HUNT study). We used multivariable regression models to examine independent predictors of hearing aid use and benefit, including demography, hearing-related variables, known risk factors for hearing loss and birth cohort.

RESULTS

The nationally weighted hearing aid use in the adult population increased from 4.2% in 1997 to 5.8% in 2018. The use among individuals with disabling hearing loss (≥ 35 dB HL) increased from 46.3% to 64.4%. Most users reported some (47%) or great (48%) help from their hearing aids. In addition to the level of hearing loss and birth cohort, factors associated with hearing aid use included lower age, tinnitus, childhood-onset hearing loss, higher education, marriage, having children, being exposed to occupational noise or impulse noise, recurrent ear infections, and head injury. In addition to the level of hearing loss, factors related to hearing aid benefit included younger age, female gender, and higher income. Being bothered by tinnitus reduced the benefit.

CONCLUSION

Our study shows an increase in self-reported hearing aid usage over time in Norway, with lower adoption rates and perceived benefits observed among the elderly. The results suggest that having a spouse and children positively influences the adoption of hearing aids. These findings emphasize the necessity of customized strategies to address demographic disparities and the need for innovative enhancements in hearing rehabilitation programs.

Hearing loss, hearing aid use, and performance on the Montreal cognitive assessment (MoCA): findings from the HUNT study in Norway

Purpose

To evaluate the associations between hearing status and hearing aid use and performance on the Montreal Cognitive Assessment (MoCA) in older adults in a cross-sectional study in Norway.

Methods

This study utilized data from the fourth wave of the Trøndelag Health Study (HUNT4, 2017-2019). Hearing thresholds at frequencies of 0.5, 1, 2, and 4 kHz (or PTA4) in the better hearing ear were used to determine participants' hearing status [normal hearing (PTA4 hearing threshold, ≤ 15 dB), or slight (PTA4, 16-25 dB), mild (PTA4, 26-40 dB), moderate (PTA4, 41-55 dB), or severe (PTA4, ≥ 56 dB) hearing loss]. Both standard scoring and alternate MoCA scoring for people with hearing loss (deleting MoCA items that rely on auditory function) were used in data analysis. The analysis was adjusted for the confounders age, sex, education, and health covariates.

Results

The pattern of results for the alternate scoring was similar to that for standard scoring. Compared with the normal-hearing group, only individuals with moderate or severe hearing loss performed worse in the MoCA. In addition, people with slight hearing loss performed better in the MoCA than those with moderate or severe hearing loss. Within the hearing loss group, hearing aid use was associated with better performance in the MoCA. No interaction was observed between hearing aid use and participants' hearing status with performance on the MoCA test.

Conclusion

While hearing loss was associated with poorer performance in the MoCA, hearing aid use was found to be associated with better performance in the MoCA. Future randomized control trials are needed to further examine the efficacy of hearing aid use on the MoCA performance. When compared with standard scoring, the alternate MoCA scoring had no effect on the pattern of results.

Quantitative levels of noise exposure and 20-year hearing decline: findings from a prospective cohort study (the HUNT Study)

OBJECTIVE

We aimed to assess the association between occupational noise exposure and long-term hearing decline.

DESIGN

This prospective cohort study used linear regression to investigate the association between occupational noise exposure and 20-year hearing decline, adjusted for important confounders.

STUDY SAMPLE

The Norwegian cohort (N = 4,448) participated in two population-based health studies with pure-tone audiometry; HUNT2 1996-1998 and HUNT4 2017-2019. Exposure assessments included a quantitative job exposure matrix (JEM) and questionnaires.

RESULTS

The participants (40.2% men, 20-39 years at baseline) had a mean 20-year decline (3-6 kHz) of 11.3 ± 9.8 decibels (dB). There was a positive association between 20-year logarithmic average noise level (JEM-based, LEX,20y) and 20-year hearing decline among men. Compared with no exposure ≥80 dB during follow-up, minimum 5 years of exposure ≥85 dB (JEM-based) predicted 2.6 dB (95% CI: 0.2-5.0) larger 20-year decline for workers aged 30-39 years at baseline, and -0.2 dB (95% CI: -2.2 to 1.7) for workers aged 20-29 years. Combining JEM information with self-reported noise exposure data resulted in stronger associations.

CONCLUSION

This large longitudinal study shows an association between JEM-based noise exposure level and increased 20-year hearing decline among men. Contrary to expectations, the associations were weaker among younger workers, which might reflect a latency period.

No accelerated 20-year hearing decline after occupational noise exposure has ceased: The HUNT study

OBJECTIVES

It has been suggested that noise exposure can accelerate hearing decline after the noise exposure has ceased. We aimed to assess long-term hearing decline in persons with and without prior occupational noise exposure.

METHODS

We conducted a population-based longitudinal study in Norway using the Trøndelag Health Study (HUNT) from 1996 to 1998 (baseline) and from 2017 to 2019 (follow-up). The sample included 1648 participants with baseline age ≥55 years (42% men, mean age 60 years) and <5 years occupational noise exposure after baseline. We analyzed the association between occupational noise exposure before baseline and mean hearing decline between 1998 and 2018 (20-year decline) at each frequency, adjusted for age, sex, education, and impulse noise exposure before baseline.

RESULTS

Occupational noise exposure before baseline (N = 603) was associated with baseline hearing loss, but not with later accelerated 20-year decline, at any frequency. Noise-exposed persons had less subsequent 20-year decline at 3 kHz than did nonexposed. Restricting the noise-exposed group to persons who also had a baseline Coles notch (hearing thresholds at 3, 4, or 6 kHz of 10 dB or more compared with thresholds at 1 or 2 kHz and 6 or 8 kHz; N = 211), the exposed group showed less 20-year decline at both 3 and 4 kHz, as well as less accelerated 20-year decline at 8 kHz, compared with the nonexposed.

CONCLUSION

Our large long-term longitudinal study shows no increased risk of continuing hearing decline after occupational noise exposure has ceased. The finding supports a conclusion that ear damage stops when the noise exposure is ended.

Hearing impairment and risk of dementia in The HUNT Study (HUNT4 70+): a Norwegian cohort study

Background

Hearing impairment is strongly associated with future dementia. No studies have reported objectively measured hearing impairment in a cohort with a long period of follow-up (>20 years), and few have reported follow-up over 10 years. Hence, there is a need for high quality studies with sufficient follow-up time and data to account for reverse causality and confounding. We aimed to address this knowledge gap.

Methods

This cohort study used individual participant data from The Trøndelag Health Study (HUNT) in Norway. All current residents aged at least 20 years in the former Norwegian Nord-Trøndelag County were invited to participate in four decennial surveys: HUNT1 (1984-1986), HUNT2 (1995-1997), HUNT3 (2006-2008), and HUNT4 (2017-2019) with individuals aged at least 70 years included in a substudy, known as HUNT4 70+. Here, we report the findings of this substudy. HUNT4 70+ comprised 7135 participants who were assessed for dementia using the Diagnostic and Statistical Manual of Mental Disorders 5 criteria and who had audiometry between 1996 and 1998. The primary objective was to investigate, with gold standard audiometric testing and dementia diagnostic assessment, whether hearing impairment was an independent risk factor for all-cause dementia. The secondary objective was to investigate if a risk also applied to Alzheimer dementia and non-Alzheimer dementia. We analysed the association using Poisson regression and adjusted for confounders. This study is registered with ClinicalTrials.gov (NCT04284384).

Findings

At baseline, 1058 (15%) individuals had acquired hearing impairment with a hearing threshold of at least 25 decibel (dB) and, at follow-up, 1089 (15%) had dementia. In the total group, people with hearing impairment had a relative risk (RR) 1.04 (95% confidence interval (CI) 1.00-1.09) per 10 dB increase in hearing thresholds. For individuals younger than 85 years at follow-up the RR was 1.12 (95% CI 1.05-1.21). Associations between hearing impairment and Alzheimer dementia and non-Alzheimer dementia were similar. There was no association for individuals aged at least 85 years.

Interpretation

We found a moderate association between objectively measured hearing impairment and dementia in the younger age group (<85 years). The findings of no association in the older age group (≥85 years) might be due to the competing risk of death. The present study adds to the literature showing that acquired hearing impairment is a risk for dementias over a period which is too long for reverse causation, and with thorough consideration of confounders. Further research is needed to investigate associations between the different aetiologies of hearing loss and dementia subtypes, and risk differences for sexes.

Funding

The Norwegian National Centre for Ageing and Health with a grant from Health South-East.

COPD and 20-year hearing decline: The HUNT cohort study

BACKGROUND

We aimed to assess the association between chronic obstructive pulmonary disease (COPD) and long-term hearing decline. A further aim was to study sex differences.

METHODS

Population-based cohort study in Norway (the HUNT study) with baseline measurements in 1996-1998 and follow-up in 2017-2019. The sample included 12,082 participants (43% men, mean age at follow-up 64 years). We used multiple linear regression to assess the association between COPD (minimum one registered ICD-10 code with emphysema or other COPDs during follow-up) and 20-year hearing decline in the low/mid/high frequency area (0.25-0.5/1-2/3-8 kHz). We adjusted for age, sex, education, smoking, noise exposure, ear infections, hypertension and diabetes.

RESULTS

Persons registered with COPD (N = 403) had larger 20-year hearing decline at low frequencies (1.5 dB, 95% confidence interval (CI) 0.6-2.3) and mid frequencies (1.2 dB, 95% CI 0.4-2.1), but not at high frequencies. At high frequencies, the association was stronger and statistically significant only among women (1.9 dB, 95% CI 0.6-3.2). Persons registered with both COPD and respiratory failure (N = 19) had larger 20-year hearing decline at low and mid frequencies: 7.4 dB (95% CI 3.6-11.2) and 4.5 dB (95% CI 0.7-8.4), respectively.

CONCLUSION

Our large cohort study shows an association between COPD and increased long-term hearing decline. Women seem to be more susceptible to COPD-related hearing loss at high frequencies. The findings support that COPD can affect the cochlear function.

Hearing threshold and physical performance in older people: a cross-sectional study from the HUNT4 cohort

PURPOSE

To evaluate the association between increased hearing loss and reduced physical performance in older people.

METHODS

Cross-sectional population-based study using data from the fourth wave of the Trøndelag Health Survey (HUNT4) in Norway. Data were obtained from the subproject HUNT4 Hearing which collected audiometric data of people > 70 years (N = 13,197). Analyses were performed on all participants who had completed audiometry and measured balance using the Short Physical Performance Battery (SPPB), which was scored from 0 (worst score) to 12. The hearing threshold was expressed as a pure tone average (PTA). Associations between the hearing threshold for the best and worst ear and physical performance were analyzed by linear regression models adjusted for age, sex, education, diabetes, and cardiovascular disease. Hearing threshold was indicated with steps of 10 dB.

RESULTS

Of 13,197 eligible participants, 4101 who completed audiometry and SPPB (52.3% women. mean age 76.3 years) were included. The analyses revealed an association between reduced SPPB and increased hearing threshold in the best ear (b = - 0.296; 95% CI - 0.343 to - 0. 249; P < 0.001) and the worst ear (b = - 0.229; 95% CI - 0.270 to - 0.189; P < 0.001).

CONCLUSIONS

In this population study, we found that the increased hearing threshold was associated to reduced physical performance as measured by SPPB. The association seemed to be strongest for the best ear. The association between hearing threshold and physical performance illustrates the importance of assessing physical performance in people with hearing loss to prevent the risk of falls and disability. The underlying causes of the associations between hearing loss and poorer physical performance are not fully understood and should be further investigated.

LEVEL OF EVIDENCE

Level 3.

Hearing loss, hearing aid use, and subjective memory complaints: Results of the HUNT study in Norway

Objective

This study aimed to explore the association between hearing loss severity, hearing aid use, and subjective memory complaints in a large cross-sectional study in Norway.

Methods

Data were drawn from the fourth wave of the Trøndelag Health Study (HUNT4 Hearing, 2017-2019). The hearing threshold was defined as the pure-tone average of 0.5, 1, 2, and 4 kHz in the better ear. The participants were divided into five groups: normal hearing or slight/mild/moderate/severe hearing loss. Subjective self-reported short-term and long-term memory complaints were measured by the nine-item Meta-Memory Questionnaire (MMQ). The sample included 20,092 individuals (11,675 women, mean age 58.3 years) who completed both hearing and MMQ tasks. A multivariate analysis of variance (adjusted for covariates of age, sex, education, and health cofounders) was used to evaluate the association between hearing status and hearing aid use (in the hearing-impaired groups) and long-term and short-term subjective memory complaints.

Results

A multivariate analysis of variance, followed by univariate ANOVA and pairwise comparisons, showed that hearing loss was associated only with more long-term subjective memory complaints and not with short-term subjective memory complaints. In the hearing-impaired groups, the univariate main effect of hearing aid use was only observed for subjective long-term memory complaints and not for subjective short-term memory complaints. Similarly, the univariate interaction of hearing aid use and hearing status was significant for subjective long-term memory complaints and not for subjective short-term memory complaints. Pairwise comparisons, however, revealed no significant differences between hearing loss groups with respect to subjective long-term complaints.

Conclusion

This cross-sectional study indicates an association between hearing loss and subjective long-term memory complaints but not with subjective short-term memory complaints. In addition, an interaction between hearing status and hearing aid use for subjective long-term memory complaints was observed in hearing-impaired groups, which calls for future research to examine the effects of hearing aid use on different memory systems.

Hearing loss, sick leave, and disability pension: findings from the HUNT follow-up study

Background

Evidence on the association between hearing loss and sick leave or disability pension is to a great extent based on few cross-sectional studies and remains unclear. We aim to assess the associations in a long-term follow-up population study.

Methods

We used baseline data from a large population-based hearing study in Norway, the HUNT Hearing study (1996–1998). The sample included 21 754 adults (48.5% men, mean age at baseline 36.6 years). We used register data on sick leave and disability pension (1996–2011). Cox regression was used to assess the association between hearing loss at baseline (Pure tone average/PTA 0.5–4 kHz > 20 dB) and time to first physician-certified sick leave episode, as well as time to first disability pension payment.

Results

Hearing loss at baseline (yes/no) was weakly associated with time to first physician-certified sick leave episode: Hazard ratio (HR) 1.2 (95% confidence interval (CI) 1.1–1.3). Restricting the exposed group to people with both hearing loss and tinnitus, the HR was slightly increased: 1.3 (95% CI 1.1–1.6). Hearing loss in 1996–1998 was also associated with time to first received disability pension: HR 1.5 (95% CI 1.3–1.8). Stronger associations were found for disabling hearing loss (PTA > 35). Restricting the exposure to hearing loss and tinnitus, the HR was increased: 2.0 (95% CI 1.4–2.8).

Conclusions

This large population-based cohort study indicates that hearing loss is associated with increased risk of receiving disability pension, especially among younger adults and low educated workers. Hearing loss was weakly associated with sick leave.

Prevalence of Hearing Loss and Hearing Aid Use Among Adults in France in the CONSTANCES Study

IMPORTANCE

Although hearing loss is common in the population worldwide, the prevalence of hearing loss and hearing aid use is not known.

OBJECTIVE

To estimate the prevalence of hearing loss and hearing aid use in the adult French population.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study used data from the CONSTANCES cohort, a representative sample of the French population. Volunteers aged 18 to 75 years were recruited at 21 preventive health centers between January 1, 2012, and December 31, 2019. The present study included participants with audiometric data.

MAIN OUTCOMES AND MEASURES

The main outcomes were prevalence of hearing loss and disabling hearing loss overall and by sex and age group and prevalence of self-reported hearing aid use among those with disabling hearing loss. Hearing loss was defined as a pure-tone average (PTA) in the better ear of 20 dB or higher, and disabling hearing loss was defined as a PTA in the better ear of 35 dB or higher.

RESULTS

Of 200 870 participants in the CONSTANCES study, 186 460 had full audiometric data and were included in this study (mean [SD] age, 47.1 [13.5] years); 100 330 (53.8%) were female, and 86 130 (46.2%) were male. Of these participants, 24.8% (95% CI, 24.6%-25.0%) had hearing loss and 4.3% (95% CI, 4.2%-4.4%) had disabling hearing loss. The prevalence rates of hearing loss increased from 3.4% (95% CI, 2.8%-3.9%) at age 18 to 25 years to 73.3% (95% CI, 69.5%-77.2%) at age 71 to 75 years among men and from 4.4% (95% CI, 3.9%-5.0%) at age 18 to 25 years to 64.1% (95% CI, 59.7%-68.4%) at age 71 to 75 years among women. The prevalence of disabling hearing loss increased from 0.3% (95% CI, 0.2%-0.4%) among participants aged 18 to 25 years to 23.3% (95% CI, 20.7%-26.0%) among participants aged 71 to 75 years. Among the 8050 participants with disabling hearing loss, 36.8% (95% CI, 35.8%-37.9%) reported using hearing aids, including 56.7% (95% CI, 38.9%-74.4%) aged 18 to 25 years and 32.9% (95% CI, 26.8%-39.2%) aged 71 to 75 years.

CONCLUSIONS AND RELEVANCE

In this cohort study, hearing loss was prevalent in France, and the prevalence of hearing loss increased with age among both men and women. Hearing aids were underused, particularly among older individuals. These findings suggest that hearing loss prevention and screening in the French population are needed.

Cohort difference in the association between use of recreational firearms and hearing loss: findings from the HUNT study

OBJECTIVES

The risk of noise injury from recreational firearm use is well known. Despite preventive measures it is uncertain whether it has become less harmful. We assessed whether the association between recreational firearm use and hearing has changed during the last two decades.

DESIGN

We used a repeated cross-sectional design and determined hearing thresholds by pure-tone audiometry. Frequency-specific associations between recreational firearm use and hearing thresholds were assessed by multivariate linear regression stratified by sex and adjusted for age and other covariates.

STUDY SAMPLE

Two cross-sectional population-based cohorts 20 years apart (1998 and 2018) comprised 27,580 (53% women, mean age 53 years) and 26,606 individuals (56% women, mean age 54 years), respectively.

RESULTS

Recreational firearm use was reported by 28% in 1998 and 30% in 2018. The proportion that reported wearing hearing protection increased. Exposure to recreational firearms was associated with elevated thresholds at 3-6 kHz in both cohorts. The association increased with the number of lifetime shots. The associations increased by age and were substantially smaller in the most recent cohort.

CONCLUSIONS

Analyses of two cohorts revealed a reduction in the association between recreational firearm use and hearing over 20 years, coinciding with the introduction of hearing preservation measures.

Weaker association between hearing loss and non-employment in recent generations: the HUNT cohort study

OBJECTIVES

To examine the prevalence of hearing loss (HL) among employed persons, the association between HL and non-employment, assessing whether this has changed over the last two decades. To identify susceptible groups for HL-related work problems and examine the association between HL and co-worker relations.

DESIGN

Cross-sectional analyses of working-age participants (20-66 years). HL was defined as the pure-tone average threshold of 0.5-4 kHz in the better hearing ear: 20-34 dB (mild) or ≥35 dB (disabling). Associations were assessed with logistic regression.

STUDY SAMPLE

Data from two waves of the Trøndelag Health Study (HUNT): HUNT2 1996-1998 (N = 38,603), HUNT4 2017-2019 (N = 19,614).

RESULTS

The nationally weighted prevalence of HL among employees was 5.8%. HL was associated with non-employment, more strongly in HUNT2 (odds ratio (OR) 2.2, 95% confidence interval (CI) 2.0-2.4) than HUNT4 (OR 1.9, CI 1.7-2.1). HL was not associated with poorer co-worker relations. The association between HL and non-optimal work performance was stronger among white-collar workers than blue-collar workers.

CONCLUSIONS

Our study shows that HL is common in the employed population. It also indicates a weakened association between HL and non-employment in recent generations. White-collar workers appear to be more vulnerable to HL-related work problems than blue-collar workers.

Hearing loss in Norwegian adults with achondroplasia

Background

Achondroplasia is the most common form of disproportionate skeletal dysplasia. The condition is caused by a mutation in the FGFR3 gene, affecting endochondral bone growth, including the craniofacial anatomy. Recurrent otitis media infections, chronic middle ear effusion, and hearing loss are common in children with achondroplasia, but few studies have investigated hearing loss in adults with this condition.

Objectives

This population-based study investigated the prevalence, severity, and type of hearing loss in Norwegian adults with achondroplasia.

Methods

We collected data on 45 adults with genetically confirmed achondroplasia: 23 men and 22 women, aged 16–70 years. All participants underwent a comprehensive audiologic assessment, including medical history, pure-tone audiometry, speech audiometry, and impedance audiometry. According to the Global Burden of Disease classification, pure-tone average ≥ 20 decibel hearing level (dB HL) was considered clinically significant hearing loss.

Results

Insertion of ventilation tubes had been performed in 44% (20/45) of the participants, 49% (22/45) had a history of adenoidectomy, while 20% (9/45) used hearing aids. Hearing loss in at least one ear was found in 53% (24/45) of the participants; in 57% (13/23) of the men and 50% (11/22) of the women. In the youngest age group (age 16–44 years), 50% (14/28) had hearing loss, although predominantly mild (20–34 dB HL). An abnormal tympanometry (Type B or C) was found in 71% (32/45) of the participants. The majority (15/24) had conductive hearing loss, or a combination of conductive and sensorineural hearing loss (8/24).

Conclusions

Adults with achondroplasia are at increased risk of early hearing loss. Our findings underline the importance of a regular hearing assessment being part of standard care in achondroplasia, including adolescents and young adults. In adult patients diagnosed with hearing loss, an evaluation by an otolaryngologist should be considered, and the need for hearing aids, assistive listening devices, and workplace and educational accommodations should be discussed.

Clinical trial registration ClinicalTrials.gov identifier NCT03780153.

Personal Music Players and Hearing Loss: The HUNT Cohort Study

It is unclear whether the current average use of personal music players (PMPs) including mobile phones has affected hearing in the general population. The association between the use of PMPs and hearing loss was assessed in a large population cross-sectional and follow-up study with the following distribution: cross-sectional (2018): n = 26,606, 56% women, mean age 54 years and 20-year follow-up (baseline 1998): n = 12,115, 57% women, mean age at baseline 43 years. Hearing threshold was determined as pure-tone average over the frequencies 3, 4, and 6 kHz. We used linear regression to assess relationships between hearing threshold and PMP use (yes), duration (1–2/2–6/>6 h per week), or sound volume (low/medium/high), with nonuse as reference. The PMP use increased from 8% in 1998 to 30% in 2018. Compared with nonusers, neither use nor duration was related to hearing threshold. As to sound volume, listening at low levels was associated with better thresholds (−2.5 dB [−4.1 to −0.8]), while listening at high levels was associated with worse thresholds (1.4 dB [0.1 to 2.8]). We adjusted for age, sex, baseline hearing threshold, education, noise exposure, ear infections, head injury, and daily smoking. The association with sound volume was nearly twice as strong when adjusting for hearing threshold at baseline. Accordingly, the possibility of reverse causality was reduced although not eliminated by the follow-up design. This large population study showed no association between normal PMP use and 20-year progression in hearing; however users listening to high levels increased their hearing threshold.

Explaining better hearing in Norway: a comparison of two cohorts 20 years apart - the HUNT study

Background

The hearing function at a given age seems to have improved in more recent born cohorts in industrialized countries. But the reasons for the improvement have not yet been explained.

Methods

We investigated the extent to which better hearing in Norway is attributed to modifiable risk factors by using representative demographic and audiometric data from two cohorts of the Trøndelag Health Study, HUNT2 (1996–1998) and HUNT4 (2017–2019). We estimated natural indirect effects using causal inference methods in order to assess whether cohort improvement in hearing thresholds (HTs) was mediated by occupational noise exposure, recurrent ear infections, smoking and education.

Results

The improvement in HTs from HUNT2 to HUNT4 was 2.8 and 3.0 dB at low respectively high frequencies. Together all risk factors mediated this improvement by 0.8 dB (95% CI 0.7–0.9) and 0.8 dB (95% CI 0.7–0.9) respectively, corresponding to mediated proportions of 27 and 28%. Substantial mediation was specifically found for occupational noise in men and recurrent ear infections in women (mediated proportions of 11 and 17% at high frequencies, respectively).

Conclusions

Increased education, less occupational noise exposure, ear infections and smoking contributed considerably to better hearing in Norway the last two decades.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12889-021-10301-1.

Prevalence and incidence of hearing impairment among adults: a 13-year follow-up study

OBJECTIVE

The aim of this study was to investigate the prevalence and incidence of hearing impairment (HI) in a longitudinal setting among adults.

DESIGN

An unscreened, population-based epidemiological 13-year follow-up study. Study sample: 850 randomly sampled 54 to 66-year-old baseline participants, of whom 559 participated in the follow-up study at the age of 68 to 79 years. A questionnaire-based interview, an otological examination and pure-tone audiometry were performed.

RESULTS

The overall prevalence of HI was 70.3%, defined by better ear hearing level (BEHL)  ≥ 20 dB in the 0.5-4 kHz frequency range. The prevalence was higher among men (78.6%) than among women (63.7%). The overall incidence rate for HI was 45.8 per 1000 person years and the 13-year cumulative incidence was 60.9%. The incidence was higher among men and older participants.

CONCLUSION

HI is highly prevalent and incident among older adults in Northern Finland.