Trajectories of Occupational Cognitive Demands and Risk of Mild Cognitive Impairment and Dementia in Later Life: The HUNT4 70+ Study

BACKGROUND AND OBJECTIVES

The cognitive reserve hypothesis posits that cognitively stimulating work delays the onset of mild cognitive impairment (MCI) and dementia. However, the effect of occupational cognitive demands across midlife on the risk of these conditions is unclear.

METHODS

Using a cohort study design, we evaluated the association between registry-based trajectories of occupational cognitive demands from ages 30-65 years and clinically diagnosed MCI and dementia in participants in the HUNT4 70+ Study (2017-19). Group-based trajectory modeling identified trajectories of occupational cognitive demands, measured by the routine task intensity (RTI) index (lower RTI indicates more cognitively demanding occupation) from the Occupational Information Network. Multinomial regression was implemented to estimate the relative risk ratios (RRRs) of MCI and dementia, after adjusting for age, sex, education, income, baseline hypertension, obesity, diabetes, psychiatric impairment, hearing impairment, loneliness, smoking status, and physical inactivity assessed at HUNT1-2 in 1984-1986 and 1995-1997. To handle missing data, we used inverse probability weighting to account for nonparticipation in cognitive testing and multiple imputation.

RESULTS

Based on longitudinal RTI scores for 305 unique occupations, 4 RTI trajectory groups were identified (n = 7,003, 49.8% women, age range 69-104 years): low RTI (n = 1,431, 20.4%), intermediate-low RTI (n = 1,578, 22.5%), intermediate-high RTI (n = 2,601, 37.1%), and high RTI (n = 1,393, 19.9%). Participants in the high RTI group had a higher risk of MCI (RRR 1.74, 95% CI 1.41-2.14) and dementia (RRR 1.37, 95% CI 1.01-1.86), after adjusting for age, sex, and education compared with participants in the low RTI group. In a sensitivity analysis, controlling for income and baseline health-related factors, the point estimates were not appreciably changed (RRR 1.66, 95% CI 1.35-2.06 for MCI, and RRR 1.31, 95% CI 0.96-1.78 for dementia).

DISCUSSION

People with a history of cognitively stimulating occupations during their 30s, 40s, 50s, and 60s had a lower risk of MCI and dementia older than 70 years, highlighting the importance of occupational cognitive stimulation during midlife for maintaining cognitive function in old age. Further research is required to pinpoint the specific occupational cognitive demands that are most advantageous for maintaining later-life cognitive function.

Hearing impairment after asphyxia and neonatal encephalopathy: a Norwegian population-based study

The purpose of this study is to evaluate the association between perinatal asphyxia, neonatal encephalopathy, and childhood hearing impairment. This is a population-based study including all Norwegian infants born ≥ 36 weeks gestation between 1999 and 2014 and alive at 2 years (n = 866,232). Data was linked from five national health registries with follow-up through 2019. Perinatal asphyxia was defined as need for neonatal intensive care unit (NICU) admission and an Apgar 5-min score of 4-6 (moderate) or 0-3 (severe). We coined infants with seizures and an Apgar 5-min score < 7 as neonatal encephalopathy with seizures. Infants who received therapeutic hypothermia were considered to have moderate-severe hypoxic-ischemic encephalopathy (HIE). The reference group for comparisons were non-admitted infants with Apgar 5-min score ≥ 7. We used logistic regression models and present data as adjusted odds ratios (aORs) with 95% confidence intervals (CI). The aOR for hearing impairment was increased in all infants admitted to NICU: moderate asphyxia aOR 2.2 (95% CI 1.7-2.9), severe asphyxia aOR 5.2 (95% CI 3.6-7.5), neonatal encephalopathy with seizures aOR 7.0 (95% CI 2.6-19.0), and moderate-severe HIE aOR 10.7 (95% CI 5.3-22.0). However, non-admitted infants with Apgar 5-min scores < 7 did not have increased OR of hearing impairment. The aOR for hearing impairment for individual Apgar 5-min scores in NICU infants increased with decreasing Apgar scores and was 13.6 (95% CI 5.9-31.3) when the score was 0.          Conclusions: An Apgar 5-min score < 7 in combination with NICU admission is an independent risk factor for hearing impairment. Children with moderate-severe HIE had the highest risk for hearing impairment. What is Known: • Perinatal asphyxia and neonatal encephalopathy are associated with an increased risk of hearing impairment. • The strength of the association, and how other co-morbidities affect the risk of hearing impairment, is poorly defined. What is New: • Among neonates admitted to a neonatal intensive care unit (NICU), decreased Apgar 5-min scores, and increased severity of neonatal encephalopathy, were associated with a gradual rise in risk of hearing impairment. • Neonates with an Apgar 5-min score 7, but without NICU admission, did not have an increased risk of hearing impairment.

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.

Incidence rates of treated mental disorders before and during the COVID-19 pandemic-a nationwide study comparing trends in the period 2015 to 2021

BACKGROUND

There is a concern that exposure to psychosocial stressors during the COVID-19 pandemic may have led to a higher incidence of mental disorders. Thus, this study aimed to compare trends in incidence rates of depressive disorder, anxiety disorders, obsessive-compulsive disorder (OCD), post-traumatic stress disorder (PTSD), and eating disorders in primary- and specialist health care before (2015-2019) and during the COVID-19 pandemic (2020-2021).

METHODS

We used aggregated population registry data to calculate incidence rates of mental disorders from primary- (The Norwegian Control and Payment of Health Reimbursements Registry (KUHR)) and specialist (The Norwegian Patient Registry (NPR)) health care. The analyses included all Norwegian residents aged 18-65 during the study period. Incident cases were defined as having no previous registration with the same mental disorder in KUHR (from 2006) or NPR (from 2008). We used linear prediction models and mean models to compare incidence rates and test trends before and during the pandemic.

RESULTS

During the pandemic, the incidence rates among women were higher or as predicted for OCD in specialist health care and for eating disorders in both primary- and specialist health care. These findings were strongest among women aged 18-24 years. Incidence rates for depression and phobia/OCD among both genders in primary health care and phobic anxiety disorders among both genders in specialist health care were lower or as predicted.

CONCLUSION

The COVID-19 pandemic may have led to more women needing treatment for OCD and eating disorders in the Norwegian population. The decreased incidence rates for some disorders might indicate that some individuals either avoided seeking help or had improved mental health during the pandemic.

Marital Histories and Associations With Later-Life Dementia and Mild Cognitive Impairment Risk in the HUNT4 70+ Study in Norway

Objectives: Earlier studies suggest that being married in later life protects against dementia, and that being single in old age increases the risk of dementia. In this study, we examine midlife marital status trajectories and their association with dementia and mild cognitive impairment (MCI) at ages 70 plus using a large population based sample from Norway. Methods: Based on a general population sample linked to population registries (N = 8706), we used multinomial logistic regression to examine the associations between six types of marital trajectories (unmarried, continuously divorced, intermittently divorced, widowed, continuously married, intermittently married) between age 44 and 68 years from national registries and a clinical dementia or a MCI diagnosis after age 70. We estimated relative risk ratios (RRR) and used mediation analyses adjusting for education, number of children, smoking, hypertension, obesity, physical inactivity, diabetes, mental distress, and having no close friends in midlife. Inverse probability weighting and multiple imputations were applied. The population attributable fraction was estimated to assess the potential reduction in dementia cases due to marital histories. Results: Overall, 11.6% of the participants were diagnosed with dementia and 35.3% with MCI. Dementia prevalence was lowest among the continuously married (11.2%). Adjusting for confounders, the risk of dementia was higher for the unmarried (RRR = 1.73; 95% CI: 1.24, 2.40), continuously divorced (RRR = 1.66; 95% CI: 1.14, 2.43), and intermittently divorced (RRR = 1.50; 95% CI: 1.09, 2.06) compared to the continuously married. In general, marital trajectory was less associated with MCI than with dementia. In the counterfactual scenario, where all participants had the same risk of receiving a dementia diagnosis as the continuously married group, there would be 6.0% fewer dementia cases. Discussion: Our data confirm that staying married in midlife is associated with a lower risk of dementia and that divorced people account for a substantial share of dementia cases.

Occupational noise exposure and tinnitus: the HUNT Study

OBJECTIVE

We aimed to assess the association between occupational noise exposure and tinnitus. Further, to assess whether the association depends on hearing status.

DESIGN

In this cross-sectional study, tinnitus (>1 h daily) was regressed on job exposure matrix (JEM)-based or self-reported occupational noise exposure, adjusted for confounders.

STUDY SAMPLE

The 14,945 participants (42% men, 20-59 years) attended a population-based study in Norway (HUNT4, 2017-2019).

RESULTS

JEM-based noise exposure, assessed as equivalent continuous sound level normalised to 8-h working days (LEX 8 h), over the working career or as minimum 5 years ≥85 dB) was not associated with tinnitus. Years of exposure ≥80 dB (minimum one) was not associated with tinnitus. Self-reported high noise exposure (>15 h weekly ≥5 years) was associated with tinnitus overall and among persons with elevated hearing thresholds (prevalence ratio (PR) 1.3, 1.0-1.7), however not statistically significantly among persons with normal thresholds (PR 1.1, 0.8-1.5).

CONCLUSIONS

Our large study showed no association between JEM-based noise exposure and tinnitus. This may to some extent reflect successful use of hearing protection. High self-reported noise exposure was associated with tinnitus, but not among normal hearing persons. This supports that noise-induced tinnitus to a large extent depends on audiometric hearing loss.

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.

Consistent pattern between physical activity measures and chronic pain levels: the Tromsø Study 2015 to 2016

ABSTRACT

Epidemiological literature on the relationship between physical activity and chronic pain is scarce and inconsistent. Hence, our aim was to assess the relationship applying comprehensive methodology, including self-reported and accelerometer measures of physical activity and different severity levels of chronic pain. We used data from the Tromsø Study (2015-2016). All residents in the municipality, aged 40 years and older were invited to participate (n = 32,591, 51% women). A total of 21,083 (53%) women reported on questionnaires. Additionally, 6778 participants (54% women) were invited to wear accelerometers (6125 with complete measurements). Our exposure measures were self-reported leisure time physical activity, exercise frequency, duration, and intensity and 2 accelerometer measures (steps per day and minutes of moderate to vigorous physical activity per day). Outcome measurements were chronic pain and moderate-to-severe chronic pain. We used Poisson regression to estimate chronic pain prevalence and prevalence ratios for each physical activity measure, with adjustments for sex, age, education level, smoking history, and occupational physical activity. Our main analyses showed an inverse dose-response relationship between all physical activity measures and both severity measures of chronic pain, except that the dose-response relationship with exercise duration was only found for moderate-to-severe pain. All findings were stronger for the moderate-to-severe pain outcomes than for chronic pain. Robustness analyses gave similar results as the main analyses. We conclude that an inverse dose-response association between physical activity and chronic pain is consistent across measures. To summarize, higher levels of physical activity is associated with less chronic pain and moderate-to-severe chronic pain.

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.

Occupation and 20-year hearing decline: findings from The HUNT Study

BACKGROUND

Studies show that certain occupations are associated with an increased risk of hearing loss. However, many studies are cross-sectional, and the few longitudinal studies are mostly small or focus on only one occupation.

AIMS

We aimed to quantify the long-term hearing decline among workers in different occupations and assess whether the change differs between the occupations.

METHODS

The study population was 4525 adults who participated in two population-based health studies in Norway, HUNT2 1996-1998 and HUNT4 2017-2019. Linear regression models assessed the association between occupations (clerks as reference) and 20-year hearing decline (hearing thresholds at 3-6 kHz, averaged over both ears) from HUNT2 to HUNT4. Models were adjusted for age, sex, recurrent ear infections, smoking and ear pathology.

RESULTS

Among the participants (40% men), the mean age at HUNT2 was 31.2 ± 5.4 years (range 20-39) and the average 20-year hearing decline was 11.3 ± 9.8 dB. Occupations that were associated with larger hearing decline included other craft and related trades workers (3.9 dB, 95% confidence interval [CI] 0.2-7.7) and building frame and related trades workers (3.4 dB, 95% CI 1.3-5.4). Among occupations with larger hearing decline, a higher proportion of the workers reported exposure to noise.

CONCLUSIONS

This large longitudinal study shows a larger long-term hearing decline among building frame workers and craft and related trades workers. Differences between occupations were modest, which may indicate successful preventive measures in Norway during the last two decades.

The association between age at menarche and chronic pain outcomes in women: the Tromsø Study, 2007 to 2016

ABSTRACT

Sex differences in chronic pain are well established with documented predominance in women. This study assessed relationships between age at menarche and chronic pain, site-specific chronic pain, pain characteristics, and chronic widespread pain (CWP). We used data from the Tromsø Study conducted in 2007 to 2008 and 2015 to 2016 (Tromsø 6 and Tromsø 7 waves) including participants aged 30 to 99 years. The associations between age at menarche and chronic pain were examined in Tromsø 6 (n = 6449), Tromsø 7 (n = 5681), and the combination of Tromsø 6 and Tromsø 7 (n = 12,130). Tromsø 7 data were used further to examine the associations between age at menarche and site-specific chronic pain, 4 pain characteristics (pain duration, pain intensity, episode duration, and episode frequency), and CWP. All analyses were adjusted for body mass index, age, and economic status of the household in childhood. Lower age at menarche was associated with an increased risk of chronic pain in all 3 samples (risk ratio for each year delay in menarche 0.98, 95% CI [0.97 to 0.99] across samples). Risk differences were -0.014, CI 95% (-0.02 to -0.005) in Tromsø 6, -0.011, CI 95% (-0.02 to -0.02) in Tromsø 7, and -0.012, CI 95% (-0.02 to -0.01) in the combined sample. Age at menarche was significantly associated with chronic pain in the neck, abdomen, and both arms, and CWP. Of the 4 pain characteristics, pain duration was statistically significant. We conclude that early menarche is an independent risk factor for pain across a broad spectrum of pain outcomes.

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.

Suicide trends in Norway during the first year of the Covid-19 pandemic. A register-based cohort study

Background

There is a concern that the COVID-19 pandemic will lead to an increase in suicides. Several reports from the first months of the pandemic showed no increase in suicide rates while studies with longer observation times report contrasting results. In this study, we explore the suicide rates in Norway during the first year of the pandemic for the total population as well as for relevant subgroups such as sex, age, geographical areas, and pandemic phases.

Methods

This is a cohort study covering the entire Norwegian population between 2010 and 2020. The main outcome was age-standardized suicide rates (per 100,000 inhabitants) in 2020 according to the Norwegian Cause of Death Registry. This was compared with 95% prediction intervals (95% PI) based on the suicide rates between 2010 and 2019.

Results

In 2020, there were 639 suicides in Norway corresponding to a rate of 12.1 per 100,000 (95% PI 10.2–14.4). There were no significant deviations from the predicted values for suicides in 2020 when analyzing age, sex, pandemic phase, or geographical area separately. We observed a trend toward a lower than predicted suicide rate among females (6.5, 95% PI 6.0–9.2), and during the two COVID-19 outbreak phases in 2020 (2.8, 95% PI 2.3–4.3 and 2.8, 95% CI 2.3–4.3).

Conclusion

There is no indication that the COVID-19 pandemic led to an increase in suicide rates in Norway in 2020.

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.

Genome-wide association identifies the first risk loci for psychosis in Alzheimer disease

Psychotic symptoms, defined as the occurrence of delusions or hallucinations, are frequent in Alzheimer disease (AD with psychosis, AD + P). AD + P affects ~50% of individuals with AD, identifies a subgroup with poor outcomes, and is associated with a greater degree of cognitive impairment and depressive symptoms, compared to subjects without psychosis (AD - P). Although the estimated heritability of AD + P is 61%, genetic sources of risk are unknown. We report a genome-wide meta-analysis of 12,317 AD subjects, 5445 AD + P. Results showed common genetic variation accounted for a significant portion of heritability. Two loci, one in ENPP6 (rs9994623, O.R. (95%CI) 1.16 (1.10, 1.22), p = 1.26 × 10^-8) and one spanning the 3'-UTR of an alternatively spliced transcript of SUMF1 (rs201109606, O.R. 0.65 (0.56-0.76), p = 3.24 × 10^-8), had genome-wide significant associations with AD + P. Gene-based analysis identified a significant association with APOE, due to the APOE risk haplotype ε4. AD + P demonstrated negative genetic correlations with cognitive and educational attainment and positive genetic correlation with depressive symptoms. We previously observed a negative genetic correlation with schizophrenia; instead, we now found a stronger negative correlation with the related phenotype of bipolar disorder. Analysis of polygenic risk scores supported this genetic correlation and documented a positive genetic correlation with risk variation for AD, beyond the effect of ε4. We also document a small set of SNPs likely to affect risk for AD + P and AD or schizophrenia. These findings provide the first unbiased identification of the association of psychosis in AD with common genetic variation and provide insights into its genetic architecture.

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.

Tinnitus and associations with chronic pain: The population-based Tromsø Study (2015-2016)

Tinnitus and pain have many similarities. Both are subjective sensations that may turn chronic, they are often accompanied by hypersensitivity in their respective sensory system, and overlapping brain changes have been observed. Since no population study has examined the empirical association between chronic pain and tinnitus, the present study aimed to explore the relationship in a general adult population. We used data from the seventh survey of the Tromsø Study (2015–2016). Participants (aged ≥40) responded to questions about pain and tinnitus. Using multiple logistic regression, we analysed the adjusted relationship between chronic pain and tinnitus in the full sample (n = 19,039), using several tinnitus definitions ranging from tinnitus >5 minutes within the past 12 months (broadest definition) to at least weekly and highly bothersome tinnitus (strictest definition). We also analysed relationships between number of body regions with pain, pain intensity and bothering, and tinnitus >5 minutes, among participants with chronic pain (n = 11,589). We found an association between chronic pain and tinnitus that was present irrespective of tinnitus definition, but was stronger with more bothersome tinnitus. With chronic pain, the odds of tinnitus >5 minutes was 64% higher, while odds of at least weekly, highly bothersome tinnitus was 144% higher than without chronic pain. Among participants with chronic pain, the number of pain regions was the pain variable most strongly associated with tinnitus >5 minutes (OR = 1.17 (95% CI: 1.14–1.20) for an increase of one region), whereas the other pain variables (intensity and bothering) showed weaker associations. All chronic pain variables had significant interactions with age, with the strongest associations for the youngest individuals (40–54 years). Our findings support the existence of an association between chronic pain and tinnitus and emphasises the importance of examining for comorbid pain in tinnitus patients to provide a more comprehensive treatment of tinnitus.

A possible effect of montelukast on neurological aging examined by the use of register data

Background The leukotriene receptor antagonist montelukast has been shown to rejuvenate aged brains in rats; however, data on humans are still scarce. Objective To investigate if montelukast may alleviate degenerative neurological changes using a register data. Setting Norwegian registry data analyses. Method The present observational study was based on data from the Norwegian Prescription Database and the Tromsø Study. The former has information regarding the use of prescription medicine; the latter includes tests for brain function such as subjective memory and finger-tapping. Multivariate linear regression analyses were performed to see how the use of various medications correlated with the test results, correcting for likely confounders. Main outcome measure Results on seven different tests considered relevant for neurological health were used as outcome. Results Previous use of montelukast correlated with improved scores on cognitive or neurological functioning (F = 2.20, p = 0.03 in a multivariate test). A range of other medications were tested with the same algorithm, including drugs acting on the immune system, but none of them correlated with (overall) significantly improved test results. Conclusion The present data suggest that montelukast may alleviate degenerative neurological changes associated with human aging.

Occupational noise exposure and asymmetric hearing loss: Results from the HUNT population study in Norway

BACKGROUND

A large population study with adequate data on confounders is required to determine whether asymmetric hearing loss (AHL) is associated with occupational noise exposure.

METHODS

We performed a cross-sectional population study in Norway (the Health Investigation in Nord-Trøndelag: HUNT) with 24 183 participants, using pure-tone audiometry and questionnaires. AHL was defined as a difference in hearing threshold between the right and left ears of greater than or equal to 15 dB for the pure-tone average of 0.5 to 2 or 3 to 6 kHz.

RESULTS

The mean age of the participants was 53 years (range, 19-99); 53% were women. The prevalence of AHL in this general Norwegian population was 6% for the 0.5 to 2 kHz range and 15% for 3 to 6 kHz. In unadjusted regression models, subjects reporting prolonged occupational noise exposure to high-level noise sources (N = 1652) had a higher risk of AHL at 3 to 6 kHz than those reporting no prior exposure (odds ratio [OR], 1.98; 95% confidence interval [CI], 1.75-2.25). After adjustment for age and sex, OR was 1.08; (95% CI, 0.95-1.24). After additional adjustment for head trauma, ear infections, blasting or shooting (all associated with AHL), smoking, and diabetes, OR was 1.00 (95% CI, 0.87-1.16). No association between occupational noise and right-ear hearing threshold advantage (left-right ear difference) was observed after adjustment for confounders.

CONCLUSION

Our study suggests that AHL is relatively common in the general population, especially at the high-frequency range in men and elderly subjects. Our study showed no relation between occupational noise exposure and AHL after confounder adjustment.

Prescription database analyses indicates that the asthma medicine montelukast might protect against dementia: a hypothesis to be verified

BACKGROUND

It has recently been shown that the leukotriene receptor antagonist montelukast rejuvenates aged brains in rats. The question is whether this commonly used, systemic, anti-asthmatic medicine has a similar effect in humans?

RESULTS

We approached this issue by doing statistical analyses based on the Norwegian Prescription Database. The Database lists all prescription-based medications in Norway, but not drugs given to people who are in hospitals or nursing homes. The question asked was whether users of montelukast, compared to users of inhalation asthma medicine, live longer, and are less likely to develop dementia. A small, non-significant protective effect on the use of dementia medicine became significant when adjusting for other prescriptions (based on the notion that montelukast users on average are less healthy). A possible protective effect was substantiated by looking at the lack of prescriptions as a proxy for dementia-related residency in nursing homes, and the risk of death.

CONCLUSIONS

The present results suggest that montelukast may alleviate the cognitive decline associated with human aging. However, further data, preferably based on controlled clinical trials, are required.

Simplified risk assessment of noise induced hearing loss by means of 2 spreadsheet models

OBJECTIVES

The objective of this study has been to test 2 spreadsheet models to compare the observed with the expected hearing loss for a Norwegian reference population.

MATERIAL AND METHODS

The prevalence rates of the Norwegian and the National Institute for Occupational Safety and Health (NIOSH) definitions of hearing outcomes were calculated in terms of sex and age, 20-64 years old, for a screened (with no occupational noise exposure) (N = 18 858) and unscreened (N = 38 333) Norwegian reference population from the Nord-Trøndelag Hearing Loss Study (NTHLS). Based on the prevalence rates, 2 different spreadsheet models were constructed in order to compare the prevalence rates of various groups of workers with the expected rates. The spreadsheets were then tested on 10 different occupational groups with varying degrees of hearing loss as compared to a reference population.

RESULTS

Hearing of office workers, train drivers, conductors and teachers differed little from the screened reference values based on the Norwegian and the NIOSH criterion. The construction workers, miners, farmers and military had an impaired hearing and railway maintenance workers and bus drivers had a mildly impaired hearing. The spreadsheet models give a valid assessment of the hearing loss.

CONCLUSIONS

The use of spreadsheet models to compare hearing in occupational groups with that of a reference population is a simple and quick method. The results are in line with comparable hearing thresholds, and allow for significance testing. The method is believed to be useful for occupational health services in the assessment of risk of noise induced hearing loss (NIHL) and the preventive potential in groups of noise-exposed workers. Int J Occup Med Environ Health 2016;29(6):991-999.

Occupational noise exposure, hearing loss, and notched audiograms in the HUNT Nord-Trøndelag hearing loss study, 1996-1998

Objectives/Hypothesis

To study the prevalence and usefulness of audiometric notches in the diagnosis of noise‐induced hearing loss (NIHL).

Study Design

Audiograms and data on noise exposure from 23,297 men and 26,477 women, aged 20 to 101 years, from the Nord‐Trøndelag Hearing Loss Study, 1996–1998.

Methods

The prevalence of four types of audiometric notches (Coles, Hoffman, Wilson) and 4 kHz notch were computed in relation to occupational noise exposure, age, sex, and report of recurrent ear infections.

Results

The prevalence of notches in the 3 to 6 kHz range (Wilson, Hoffman, and Coles) ranged from 50% to 60% in subjects without occupational noise exposure, and 60% to 70% in the most occupationally noise‐exposed men. The differences were statistically significant only for bilateral notches. For 4 kHz notches, the prevalence varied from 25% in occupationally nonexposed to 35% in the most occupationally exposed men, and the differences were statistically significant for both bilateral and unilateral notches. For women, the prevalence of notches was lower than in men, especially for 4 kHz notches, and the differences between occupationally noise exposed and nonexposed were smaller. Recreational exposure to high music was not associated with notched audiograms.

Conclusions

The detection of bilateral notches and unilateral 4 kHz notches is of some value in diagnosing NIHL, especially in men.

Level of Evidence

4 Laryngoscope, 127:1442–1450, 2017

Noise-induced hearing loss in a longitudinal study of Norwegian railway workers

OBJECTIVE

The aim of this study was to analyse longitudinal data to assess the risk of noise-induced hearing loss (NIHL) in Norwegian railway workers.

DESIGN

Longitudinal.

SETTING

A major Norwegian railway company.

METHODS

We examined data from the first and last audiograms for the period 1991-2014, from 9640 railway workers with varying occupational noise exposure and with an average observation period of 10 years. The course of hearing acuity in seven groups of railway workers (train drivers, conductors, bus drivers, traffic controllers, train maintenance workers, track maintenance workers and others) were compared with each other and with ISO standards (ISO 1999).

RESULTS

The change in hearing threshold during the observation period was 2-3 dB in the 0.5-4 kHz range and 6-7 dB in the 3-6 kHz range adjusted for age and sex, for all occupational groups, which is slightly less than expected (8 dB) according to ISO 1999.

CONCLUSIONS

The risk of NIHL in Norwegian railway workers during the period 1991-2014 has been negligible.

Association Between Childhood Hearing Disorders and Tinnitus in Adulthood

IMPORTANCE

The association between childhood hearing disorders and adult tinnitus has not been examined in longitudinal cohort studies.

OBJECTIVES

To determine the association between different types of childhood hearing loss and tinnitus in adulthood and evaluate whether tinnitus risk is mediated by adult hearing loss.

DESIGN, SETTING, AND PARTICIPANTS

Population-based cohort study of 32 430 adults (aged 20-56 years) who underwent pure-tone audiometry and completed a tinnitus questionnaire in the Nord-Trøndelag Hearing Loss Study, which was a part of the Nord-Trøndelag Health Study 2 (HUNT2). The study was conducted from January 1, 2014, to April 1, 2015. Data analysis was performed from April 1, 2014, to April 1, 2015. As children, the same individuals had undergone screening audiometry in a longitudinal primary school hearing investigation, including ear, nose, and throat examinations when indicated.

INTERVENTIONS

Pure-tone audiometry, questionnaires, and ear, nose, and throat examinations.

MAIN OUTCOMES AND MEASURES

Self-reported tinnitus (yes or no) in adulthood measured by questionnaires.

RESULTS

Adults who had hearing loss at the time of the school investigation (n = 3026) reported more tinnitus, measured as odds ratio (95% CI), than did adults with normal childhood hearing (n = 29 404) (1.4 [1.3-1.6]). Childhood hearing disorders associated with tinnitus in adulthood included sensorineural hearing loss, chronic suppurative otitis media, and hearing loss associated with a history of recurrent acute otitis media (2.4 [1.9-3.0], 2.4 [1.5-3.9], and 1.6 [1.3-2.0], respectively). These estimates were adjusted for age, sex, and noise exposure in adulthood. After further analyses that included adjustment for adult hearing threshold, none of these childhood hearing disorders remained positively associated with tinnitus.

CONCLUSIONS AND RELEVANCE

Childhood hearing disorders associated with tinnitus in adulthood include sensorineural hearing loss, chronic suppurative otitis media, and hearing loss associated with a history of recurrent acute otitis media. After adjustment for the adult hearing threshold, none of the childhood hearing disorders was positively associated with tinnitus. Hence, it appears that these significant associations are mediated or transmitted through adult hearing loss.

No Association Between Time of Onset of Hearing Loss (Childhood Versus Adulthood) and Self-Reported Hearing Handicap in Adults

PURPOSE

This study examined the association between time of onset of hearing loss (childhood vs. adulthood) and self-reported hearing handicap in adults.

METHODS

This is a population-based cohort study of 2,024 adults (mean = 48 years) with hearing loss (binaural pure-tone average 0.5-4 kHz ≥ 20 dB HL) who completed a hearing handicap questionnaire. In childhood, the same persons (N = 2,024) underwent audiometry in a school investigation (at ages 7, 10, and 13 years), in which 129 were diagnosed with sensorineural hearing loss (binaural pure-tone average 0.5-4 kHz ≥ 20 dB HL), whereas 1,895 had normal hearing thresholds.

RESULTS

Hearing handicap was measured in adulthood as the sum-score of various speech perception and social impairment items (15 items). The sum-score increased with adult hearing threshold level (p < .001). After adjustment for adult hearing threshold level, hearing aid use, adult age, sex, and socioeconomic status, there was no significant difference in hearing handicap sum-score between the group with childhood-onset hearing loss (n = 129) and the group with adult-onset hearing loss (n = 1,895; p = .882).

CONCLUSION

Self-reported hearing handicap in adults increased with hearing threshold level. After adjustment for adult hearing threshold level, this cohort study revealed no significant association between time of onset of hearing loss (childhood vs. adulthood) and self-reported hearing handicap.

Cardiovascular risk factors and hearing loss: The HUNT study

OBJECTIVE

The purpose of the present paper was to examine the association between prospectively and cross-sectionally assessed cardiovascular risk factors and hearing loss.

DESIGN

Hearing was assessed by pure-tone average thresholds at low (0.25-0.5 kHz), middle (1-2 kHz), and high (3-8 kHz) frequencies. Self-reported or measured cardiovascular risk factors were assessed both 11 years before and simultaneously with the audiometric assessment. Cardiovascular risk factors were smoking, alcohol use, physical inactivity, waist circumference, body mass index, resting heart rate, blood pressure, triglycerides, total serum cholesterol, LDL cholesterol, HDL cholesterol, and diabetes.

STUDY SAMPLE

A population-based cohort of 31 547 subjects.

RESULTS

After adjustment for age, sex, level of education, income, recurrent ear infections, and noise exposure, risk factors associated with poorer hearing sensitivity were smoking, diabetes, physical inactivity, resting heart rate, and waist circumference. Smoking was only associated with hearing loss at high frequencies. The effects were very small, in combination explaining only 0.2-0.4% of the variance in addition to the component explained by age and the other cofactors.

CONCLUSION

This cohort study indicates that, although many cardiovascular risk factors are associated with hearing loss, the effects are small and of doubtful clinical relevance.

Childhood otitis media is associated with dizziness in adulthood: the HUNT cohort study

The objective of the study was to examine the association between otitis media in childhood and dizziness in adulthood. Longitudinal, population-based cohort study of 21,962 adults (aged 20-59 years, mean 40) who completed a health questionnaire in the Nord-Trøndelag Hearing Loss Study was conducted. At 7, 10 and 13 years of age, the same individuals underwent screening audiometry in a longitudinal school hearing investigation. Children found with hearing loss underwent an ear, nose and throat specialist examination. Adults diagnosed with childhood chronic suppurative otitis media (n = 102) and childhood hearing loss after recurrent acute otitis media (n = 590) were significantly more likely to have increased risk of reported dizziness when compared to adults with normal hearing as children at the school investigation and also a negative history of recurrent otitis media (n = 21,270), p < 0.05. After adjusting for adult age, sex and socio-economic status, the odds ratios were 2.1 [95 % confidence interval (CI): 1.4-3.3] and 1.3 (95 % CI: 1.0-1.5), respectively. This longitudinal cohort study suggests that childhood chronic suppurative otitis media and childhood hearing loss after recurrent acute otitis media are associated with increased risk of dizziness in adulthood. This might reflect a permanent effect of inflammatory mediators or toxins on the vestibular system. The new finding stresses the importance of treatment and prevention of these otitis media conditions.

Childhood sensorineural hearing loss: effects of combined exposure with aging or noise exposure later in life

The aim of the study was to examine childhood high-frequency sensorineural hearing loss (HF-SNHL) and the effects of combined exposure with aging or noise exposure on HF hearing thresholds in adulthood. Population-based cohort study of 30,003 adults (mean age 40 years) underwent an audiometry and completed a hearing questionnaire. At age 7-13 years, the same people had participated in a longitudinal school hearing investigation, in which 283 participants were diagnosed with HF-SNHL [PTA 3-8 kHz ≥ 25 dB HL (mean 45 dB HL), worse hearing ear], and 29,720 participants had normal hearing thresholds. The effect of childhood HF-SNHL on adult hearing threshold was significantly moderated by age. Age stratified analyses showed that the difference in HF hearing thresholds between adults with and without childhood HF-SNHL was 33 dB (95 % CI 31-34) in young adults (n = 173, aged 20-39 years) and 37 dB (95 % CI 34-39) in middle-aged adults (n = 110, aged 40-56 years). The combined exposure of childhood HF-SNHL and noise exposure showed a simple additive effect. It appears to be a super-additive effect of childhood-onset HF-SNHL and aging on adult hearing thresholds. An explanation might be that already damaged hair cells are more susceptible to age-related degeneration. To exclude possible birth cohort effects, the finding should be confirmed by a study with several audiometries in adulthood.

Sensorineural hearing loss in children: the association with Apgar score. A registry-based study of 392,371 children in Norway

OBJECTIVES

The causes of congenital permanent hearing loss in children are insufficiently understood. We studied the association of Apgar score 5 min after birth with sensorineural hearing loss diagnosed before the age of 5 years.

METHODS

We performed an epidemiological cohort study with data obtained by linkage between The Medical Birth Registry of Norway and the Norwegian County Registry of Children with Hearing Loss. Cases were 327 children born in Norway during the period 1978-1998 with sensorineural hearing loss. Controls were all children in Norway without sensorineural hearing loss born in the same counties and during the same period as the cases (n=392,044). The associations of Apgar score 5 min after birth with sensorineural hearing loss were estimated as odds ratios (OR) with 95% confidence intervals (CI) by applying logistic regression analyses.

RESULTS

Among children with sensorineural hearing loss 0.9% (3/327) had Apgar score<3, whereas that was true for 0.1% (304/392044) of children without hearing loss (p=0.001, chi square test). The aOR for sensorineural hearing loss was 7.5 [95% CI 2.3-, 24.2] comparing Apgar score<3 to Apgar score 10, after adjustment for birthweight and concurrent birth defects. Most children with sensorineural hearing loss (90%) had Apgar score>8 five minutes after birth.

CONCLUSIONS

Low Apgar score was associated with childhood sensorineural hearing loss. However, most children with sensorineural hearing loss, had Apgar score>8.

A cross-sectional study of hearing thresholds among 4627 Norwegian train and track maintenance workers

OBJECTIVE

Railway workers performing maintenance work of trains and tracks could be at risk of developing noise-induced hearing loss, since they are exposed to noise levels of 75-90 dB(A) with peak exposures of 130-140 dB(C). The objective was to make a risk assessment by comparing the hearing thresholds among train and track maintenance workers with a reference group not exposed to noise and reference values from the ISO 1999.

DESIGN

Cross-sectional.

SETTING

A major Norwegian railway company.

PARTICIPANTS

1897 and 2730 male train and track maintenance workers, respectively, all exposed to noise, and 2872 male railway traffic controllers and office workers not exposed to noise.

OUTCOME MEASURES

The primary outcome was the hearing threshold (pure tone audiometry, frequencies from 0.5 to 8 kHz), and the secondary outcome was the prevalence of audiometric notches (Coles notch) of the most recent audiogram.

RESULTS

Train and track maintenance workers aged 45 years or older had a small mean hearing loss in the 3-6 kHz area of 3-5 dB. The hearing loss was less among workers younger than 45 years. Audiometric notches were slightly more prevalent among the noise exposed (59-64%) group compared with controls (49%) for all age groups. They may therefore be a sensitive measure in disclosing an early hearing loss at a group level.

CONCLUSIONS

Train and track maintenance workers aged 45 years or older, on average, have a slightly greater hearing loss and more audiometric notches compared with reference groups not exposed to noise. Younger (<45 years) workers have hearing thresholds comparable to the controls.

Short- and long-term mortality risk associated with the use of antipsychotics among 26,940 dementia outpatients: a population-based study

OBJECTIVE

To investigate short- and long-term mortality risk associated with the use of antipsychotics in dementia outpatients, assessing the risk over specific time frames and quantifying the risk by the individual antipsychotics.

METHODS

This population-based study used data from the Norwegian Prescription Database. The study sample included 26,940 dementia outpatients aged 65 years or older prescribed antidementia drugs and psychotropics from Norwegian pharmacies between 2004 and 2010.

RESULTS

Cox survival analyses, adjusted for age, gender, mean daily defined dose, and severe medical conditions, showed that antipsychotic use compared with other psychotropics involved approximately twice the mortality risk in outpatients with dementia. Furthermore, these results are consistent for all investigated time points after first dispensing the drugs (hazard ratio [HR]30 days = 2.1 [95% confidence interval {CI}: 1.6-2.9] to HR 730-2,400 days = 1.7 [95% CI: 1.6-1.9]). Haloperidol was associated with higher mortality risk (HR 30 days = 1.7 [95% CI: 1.0-3.0] to HR 730-2,400 days = 1.4 [95% CI: 1.0-1.9]) than risperidone.

CONCLUSION

This first study to observe antipsychotic use and mortality in dementia outpatients over more than 6 years clearly shows that antipsychotics involve increased short- and long-term mortality risk. Physicians may justly consider antipsychotics to be the best option for some dementia patients among available nonpharmacologic and pharmacologic treatments. However, although causal conclusions are precluded due to limited adjustments in the analyses, the findings support the current treatment recommendations that antipsychotics should be avoided or used with great caution.

Hearing status among Norwegian train drivers and train conductors

Background

There is a general perception that train drivers and conductors may be at increased risk of developing noise-induced hearing loss.

Aims

To study job-related hearing loss among train drivers and train conductors.

Methods

Audiograms from train drivers and train conductors were obtained from the medical records of the occupational health service of the major Norwegian railway company. The results were compared with audiograms from an internal control group of railway workers and an external reference group of people not occupationally exposed to noise. The monaural hearing threshold level at 4kHz, the mean binaural value at 3, 4 and 6kHz and the prevalence of audiometric notches (≥25 dB at 4kHz) were used for comparison.

Results

Audiograms were available for 1567 drivers, 1565 conductors, 4029 railway worker controls and 15 012 people not occupationally exposed to noise. No difference in hearing level or prevalence of audiometric notches was found between study groups after adjusting for age and gender.

Conclusions

Norwegian train drivers and conductors have normal hearing threshold levels comparable with those in non-exposed groups.

Otoacoustic emissions, pure-tone audiometry, and self-reported hearing

OBJECTIVE

The aim of the study was to describe the association between otoacoustic emissions (OAEs), pure-tone thresholds, and self-reported hearing disability.

DESIGN

A population-based cohort of 4202 adults was examined with air conduction pure-tone audiometry, transient OAE (TEOAE), and distortion product OAE (DPOAE). Participants completed 15 self-report items on hearing disability.

RESULTS

Correlation coefficients in the range of 0.3 to 0.5 were observed between OAE (TEOAE, and DPOAE) and self-reported hearing depending on age and sex. Pure-tone average hearing thresholds generally predicted self-reported hearing slightly better than did the OAE measures. Adding TEOAE and DPOAE as predictors in a multivariate model together with the scores from pure-tone audiometry did not predict self-reported hearing better than did pure-tone audiometry alone. The relationship between OAE and self-reported hearing was stronger in men than in women and became more manifest with age, a trend also stronger in men.

CONCLUSIONS

OAEs were shown to be a valid measure of self-reported hearing disability of the general population but added no additional information to what pure-tone hearing thresholds had already captured.

Aldersrelatert hørselstap: En kort oppsummering av resultater fra Hørselsundersøkelsen i Nord-Trøndelag

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The effect of emotional distress on persistent pelvic girdle pain after delivery: a longitudinal population study

OBJECTIVE

To study the prognosis for pelvic girdle pain, and to explore the association between presence of emotional distress during pregnancy and pelvic girdle syndrome 6 months after delivery.

DESIGN

Longitudinal population study.

SETTING

Norway, for the period 1999-2008.

POPULATION

A follow-up of 41 421 women in the Norwegian Mother and Child Cohort who reported pelvic girdle pain at 30 weeks of gestation.

METHODS

Data were obtained by self-administered questionnaires in weeks 17 and 30 of gestation, and 6 months after delivery.

MAIN OUTCOME MEASURE

Pelvic girdle syndrome 6 months after delivery, defined as pain in the anterior pelvis and on both sides in the posterior pelvis.

RESULTS

Six months after delivery, 78.0% of the women had recovered, 18.5% reported persistent pain in one or two pelvic locations, 3.0% reported pelvic girdle syndrome and 0.5% reported severe pelvic girdle syndrome. The recovery rates decreased with increasing levels of pain severity in pregnancy. Being emotionally distressed at two time points during pregnancy was associated with the presence of pelvic girdle syndrome (adjusted OR 1.5, 95% CI 1.2-1.9) and severe pelvic girdle syndrome (adjusted OR 1.9, 95% CI 1.1-3.1), after adjustment for pain severity in pregnancy, other medical conditions, body mass index, age at menarche, previous low back pain, and smoking during pregnancy.

CONCLUSIONS

In this follow-up of women with pelvic girdle pain in pregnancy, the recovery rates after delivery were high. Our findings suggest that the presence of emotional distress during pregnancy is independently associated with the persistence of pelvic girdle pain after delivery.

Occupation and the risk of bothersome tinnitus: results from a prospective cohort study (HUNT)

Objectives Estimates of occupation-specific tinnitus prevalence may help identify high-risk occupations where interventions are warranted. The authors studied the effect of occupation on prevalence of bothersome tinnitus and estimated the attributable fraction due to occupation. The authors also studied how much of the effect remained after adjusting for noise exposure, education income, hearing thresholds and other risk factors. Design A prospective cohort study. Setting A health survey of the Nord-Trøndelag county of Norway. Participants A sample of the general adult population (n=49 948). Primary outcome measure The primary outcome measure is bothersome tinnitus. Results Occupation had a marked effect on tinnitus prevalence. The effect of occupation on tinnitus was reduced in men by controlling for self-reported occupational noise exposure and in women by controlling for education and income. Adding hearing loss as a predictor increased the effect of occupation somewhat. In men, age-adjusted prevalence ratios of tinnitus ranged from 1.5 (workshop mechanics) to 2.1 (crane and hoist operators) in the 10 occupations with highest tinnitus prevalence. In women, the most important contribution to the tinnitus prevalence was from the large group of occupationally inactive persons, with a prevalence ratio of 1.5. Conclusion This study found a moderate association between occupation and bothersome tinnitus.

Longitudinal findings from a Norwegian case-cohort study on internalizing problems in children with congenital heart defects

AIM

To examine the association of the severity of congenital heart defects (CHDs) with internalizing problems in 18-month-olds and to explore the extent to which the internalizing problems are influenced by maternal distress and emotional reactivity in the child at age 6 months.

METHODS

We linked prospective data from the Norwegian Mother and Child Cohort Study, conducted by the Norwegian Institute of Public Health, with a nationwide CHD registry and identified 198 18-month-olds with CHDs in a cohort of 47 692 toddlers. Maternal reports on the children's emotional reactivity at age 6 months, the children's internalizing problems (anxiety, sleep problems, emotional reactivity) at age 18 months and maternal distress were assessed by questionnaires.

RESULTS

We found an association at age 18 months between the severity of the CHD and anxiety but not sleep problems or emotional reactivity. Children with severe but not with mild or moderate CHDs were twice as likely to experience the symptoms of anxiety compared with controls. These symptoms are not merely sequelae of earlier psychological reactions or concurrent maternal distress.

CONCLUSION

Should these findings be replicated, future studies ought to investigate the mechanisms leading to elevated anxiety in toddlers with CHDs. In addition, clinical interventions should address the child's anxiety as well as the interaction between the parents and the child.

Effects of changed aircraft noise exposure on experiential qualities of outdoor recreational areas

The literature indicates that sound and visual stimuli interact in the impression of landscapes. This paper examines the relationship between annoyance with sound from aircraft and annoyance with other area problems (e.g., careless bicycle riding, crowding, etc.), and how changes in noise exposure influence the perceived overall recreational quality of outdoor recreational areas. A panel study (telephone interviews) conducted before and after the relocation of Norway's main airport in 1998 examined effects of decreased or increased noise exposure in nearby recreational areas (n = 591/455). Sound from aircraft annoyed the largest proportion of recreationists, except near the old airport after the change. The decrease in annoyance with sound from aircraft was accompanied by significant decreases in annoyance with most of the other area problems. Near the new airport annoyance with most factors beside sound from aircraft increased slightly, but not significantly. A relationship between aircraft noise annoyance and perceived overall recreational quality of the areas was found.

Post-traumatic stress disorder: a right temporal lobe syndrome?

In a recent paper (Georgopoulos et al 2010 J. Neural Eng. 7 016011) we reported on the power of the magnetoencephalography (MEG)-based synchronous neural interactions (SNI) test to differentiate post-traumatic stress disorder (PTSD) subjects from healthy control subjects and to classify them with a high degree of accuracy. Here we show that the main differences in cortical communication circuitry between these two groups lie in the miscommunication of temporal and parietal and/or parieto-occipital right hemispheric areas with other brain areas. This lateralized temporal-posterior pattern of miscommunication was very similar but was attenuated in patients with PTSD in remission. These findings are consistent with observations (Penfield 1958 Proc. Natl Acad. Sci. USA 44 51-66, Penfield and Perot 1963 Brain 86 595-696, Gloor 1990 Brain 113 1673-94, Banceaud et al 1994 Brain 117 71-90, Fried 1997 J. Neuropsychiatry Clin. Neurosci. 9 420-8) that electrical stimulation of the temporal cortex in awake human subjects, mostly in the right hemisphere, can elicit the re-enactment and re-living of past experiences. Based on these facts, we attribute our findings to the re-experiencing component of PTSD and hypothesize that it reflects an involuntarily persistent activation of interacting neural networks involved in experiential consolidation.