Variation in the normal hearing threshold predicts childhood IQ, linguistic, and behavioral outcomes

Trajectories of Hearing From Childhood to Adulthood

OBJECTIVES

The Dunedin Multidisciplinary Health and Development Study provides a unique opportunity to document the progression of ear health and hearing ability within the same cohort of individuals from birth. This investigation draws on hearing data from 5 to 13 years and again at 45 years of age, to explore the associations between childhood hearing variables and hearing and listening ability at age 45.

DESIGN

Multiple linear regression analyses were used to assess associations between childhood hearing (otological status and mid-frequency pure-tone average) and (a) age 45 peripheral hearing ability (mid-frequency pure-tone average and high-frequency pure-tone average), and (b) age 45 listening ability (listening in spatialized noise and subjective questionnaire on listening experiences). Sex, childhood socioeconomic status, and adult IQ were included in the model as covariates.

RESULTS

Peripheral hearing and listening abilities at age 45 were consistently associated with childhood hearing acuity at mid-frequencies. Otological status was a moderate predicting factor for high-frequency hearing and utilization of spatial listening cues in adulthood.

CONCLUSIONS

We aim to use these findings to develop a foundational model of hearing trajectories. This will form the basis for identifying precursors, to be investigated in a subsequent series of analyses, that may protect against or exacerbate hearing-associated cognitive decline in the Dunedin Study cohort as they progress from mid-life to older age.

Functional topography of the neocortex predicts covariation in complex cognitive and basic motor abilities

Although higher-order cognitive and lower-order sensorimotor abilities are generally regarded as distinct and studied separately, there is evidence that they not only covary but also that this covariation increases across the lifespan. This pattern has been leveraged in clinical settings where a simple assessment of sensory or motor ability (e.g. hearing, gait speed) can forecast age-related cognitive decline and risk for dementia. However, the brain mechanisms underlying cognitive, sensory, and motor covariation are largely unknown. Here, we examined whether such covariation in midlife reflects variability in common versus distinct neocortical networks using individualized maps of functional topography derived from BOLD fMRI data collected in 769 45-year-old members of a population-representative cohort. Analyses revealed that variability in basic motor but not hearing ability reflected individual differences in the functional topography of neocortical networks typically supporting cognitive ability. These patterns suggest that covariation in motor and cognitive abilities in midlife reflects convergence of function in higher-order neocortical networks and that gait speed may not be simply a measure of physical function but rather an integrative index of nervous system health.

Vocal singing skills by cochlear implanted children without formal musical training: Familiar versus unfamiliar songs

OBJECTIVES

Vocal singing skills in pediatric CI users are not much known due to the limited number of studies. The principal aim of the present study was to evaluate vocal singing skills in Italian pediatric CI users. A further aim was to investigate factors that may significantly influence their performance.

METHODS

The participants were twenty-two implanted children and twenty-two hearing peers. Their vocal singing skills for familiar ("Happy Birthday to You") and unfamiliar songs ("Baton Twirler" from Pam Pam 2- Tribute to Gordon) were evaluated in relation to their music perception (the Gordon test). Acoustic analysis was performed using Praat and MATLAB software. Nonparametric statistical tests and principal component analysis (PCA) were used to analyze the data.

RESULTS

Hearing children outperformed implanted peers in both music perception and vocal singing tasks (all measures regarding intonation, vocal range, melody, and memory for the familiar song versus measures regarding intonation and overall melody production for the unfamiliar song). Music perception and vocal singing performances revealed strong correlations. For the familiar and unfamiliar songs, age-appropriate vocal singing was observed in 27.3% versus 45.4% of children, all implanted within 24 months of age. Age at implantation and duration of CI experience were moderately correlated with the total score obtained from the Gordon test.

CONCLUSION

Implanted children show limited vocal singing skills in comparison to their hearing peers. However, some children implanted within 24 months of age seem to achieve vocal singing skills as good as their hearing peers. Future research could be useful to better understand the role of brain plasticity to implement specific training programs for both music perception and vocal singing.

Iodine status during child development and hearing ability: a systematic review

Iodine, through the thyroid hormones, is required for the development of the auditory cortex and cochlea (the sensory organ for hearing). Deafness is a well-documented feature of endemic cretinism resulting from severe iodine deficiency. However, the range of effects of suboptimal iodine intake during auditory development on the hearing ability of children is less clear. We therefore aimed to systematically review the evidence for the association between iodine exposure (i.e. intake/status/supplementation) during development (i.e. pregnancy and/or childhood) and hearing outcomes in children. We searched PubMed and Embase and identified 330 studies, of which thirteen were included in this review. Only three of the thirteen studies were of low risk of bias or of good quality, this therefore limited our ability to draw firm conclusions. Nine of the studies (69 %) were in children (one RCT, two non-RCT interventions and six cross-sectional studies) and four (31 %) were in pregnant women (one RCT, one cohort study and two case reports). The RCT of iodine supplementation in mildly iodine-deficient pregnant women found no effect on offspring hearing thresholds. However, hearing was a secondary outcome of the trial and not all women were from an iodine-deficient area. Iodine supplementation of severely iodine-deficient children (in both non-RCT interventions) resulted in improved hearing thresholds. Five of six cross-sectional studies (83 %) found that higher iodine status in children was associated with better hearing. The current evidence base for the association between iodine status and hearing outcomes is limited and further good-quality research on this topic is needed.

Functional Topography of the Neocortex Predicts Covariation in Complex Cognitive and Basic Motor Abilities

Although higher-order cognitive and lower-order sensorimotor abilities are generally regarded as distinct and studied separately, there is evidence that they not only covary but also that this covariation increases across the lifespan. This pattern has been leveraged in clinical settings where a simple assessment of sensory or motor ability (e.g., hearing, gait speed) can forecast age-related cognitive decline and risk for dementia. However, the brain mechanisms underlying cognitive, sensory, and motor covariation are largely unknown. Here, we examined whether such covariation in midlife reflects variability in common versus distinct neocortical networks using individualized maps of functional topography derived from BOLD fMRI data collected in 769 45-year old members of a population-representative cohort. Analyses revealed that variability in basic motor but not hearing ability reflected individual differences in the functional topography of neocortical networks typically supporting cognitive ability. These patterns suggest that covariation in motor and cognitive abilities in midlife reflects convergence of function in higher-order neocortical networks and that gait speed may not be simply a measure of physical function but rather an integrative index of nervous system health.

Life-Course Persistent Antisocial Behavior and Accelerated Biological Aging in a Longitudinal Birth Cohort

Prior research shows that individuals who have exhibited antisocial behavior are in poorer health than their same-aged peers. A major driver of poor health is aging itself, yet research has not investigated relationships between offending trajectories and biological aging. We tested the hypothesis that individuals following a life-course persistent (LCP) antisocial trajectory show accelerated aging in midlife. Trajectories of antisocial behavior from age 7 to 26 years were studied in the Dunedin Multidisciplinary Health and Development Study, a population-representative birth cohort (N = 1037). Signs of aging were assessed at age 45 years using previously validated measures including biomarkers, clinical tests, and self-reports. First, we tested whether the association between antisocial behavior trajectories and midlife signs of faster aging represented a decline from initial childhood health. We then tested whether decline was attributable to tobacco smoking, antipsychotic medication use, debilitating illnesses in adulthood, adverse exposures in childhood (maltreatment, socioeconomic disadvantage) and adulthood (incarceration), and to childhood self-control difficulties. Study members with a history of antisocial behavior had a significantly faster pace of biological aging by midlife, and this was most evident among individuals following the LCP trajectory (β, 0.22, 95%CI, 0.14, 0.28, p ≤ 0.001). This amounted to 4.3 extra years of biological aging between ages 25-45 years for Study members following the LCP trajectory compared to low-antisocial trajectory individuals. LCP offenders also experienced more midlife difficulties with hearing (β, -0.14, 95%CI, -0.21, -0.08, p ≤ 0.001), balance (β, -0.13, 95%CI, -0.18, -0.06, p ≤ 0.001), gait speed (β, -0.18, 95%CI, -0.24, -0.10, p ≤ 0.001), and cognitive functioning (β, -0.25, 95%CI, -0.31, -0.18, p ≤ 0.001). Associations represented a decline from childhood health. Associations persisted after controlling individually for tobacco smoking, antipsychotic medication use, midlife illnesses, maltreatment, socioeconomic status, incarceration, and childhood self-control difficulties. However, the cumulative effect of these lifestyle characteristics together explained why LCP offenders have a faster Pace of Aging than their peers. While older adults typically age-out of crime, LCP offenders will likely age-into the healthcare system earlier than their chronologically same-aged peers. Preventing young people from offending is likely to have substantial benefits for health, and people engaging in a LCP trajectory of antisocial behaviors might be the most in need of health promotion programs. We offer prevention and intervention strategies to reduce the financial burden of offenders on healthcare systems and improve their wellbeing.

Association of History of Psychopathology With Accelerated Aging at Midlife

IMPORTANCE

Individuals with mental disorders are at an elevated risk of developing chronic age-related physical diseases. However, it is not clear whether psychopathology is also associated with processes of accelerated aging that precede the onset of age-related disease.

OBJECTIVE

To test the hypothesis that a history of psychopathology is associated with indicators of accelerated aging at midlife.

DESIGN, SETTING, AND PARTICIPANTS

This prospective cohort study was based on the Dunedin Multidisciplinary Health and Development Study, a population-representative birth cohort of 1037 individuals born between April 1, 1972, and March 31, 1973, in Dunedin, New Zealand. Members were followed up to age 45 years (until April 2019). Data were analyzed from January 6 to December 7, 2020.

EXPOSURES

Mental disorders were assessed in 6 diagnostic assessments from ages 18 to 45 years and transformed through confirmatory factor analysis into continuous measures of general psychopathology (p-factor) and dimensions of internalizing, externalizing, and thought disorders (all standardized to a mean [SD] of 100 [15]).

MAIN OUTCOMES AND MEASURES

Signs of aging (biological pace of aging; declines in sensory, motor, and cognitive functioning; and facial age) were assessed up to age 45 years using previously validated measures including biomarkers, clinical tests, and self-reports.

RESULTS

Of the original 1037 cohort participants, 997 were still alive at age 45 years, of whom 938 (94%) were assessed (474 men [50.5%]). Participants who had experienced more psychopathology exhibited a faster pace of biological aging (β, 0.27; 95% CI, 0.21-0.33; P < .01); experienced more difficulties with hearing (β, 0.18; 95% CI, 0.12-0.24; P < .01), vision (β, 0.08; 95% CI, 0.01-0.14; P < .05), balance (β, 0.20; 95% CI, 0.14-0.26; P < .01), and motor functioning (β, 0.19; 95% CI, 0.12-0.25; P < .01); experienced more cognitive difficulties (β, 0.24; 95% CI, 0.18-0.31; P < .01); and were rated as looking older (β, 0.20; 95% CI, 0.14-0.26; P < .01). Associations persisted after controlling for sex, childhood health indicators, maltreatment, and socioeconomic status and after taking into account being overweight, smoking, use of antipsychotic medication, and the presence of physical disease. Tests of diagnostic specificity revealed that associations were generalizable across externalizing, internalizing, and thought disorders.

CONCLUSIONS AND RELEVANCE

In this cohort study, a history of psychopathology was associated with accelerated aging at midlife, years before the typical onset of age-related diseases. This link is not specific to any particular disorder family but generalizes across disorders. Prevention of psychopathology and monitoring of individuals with mental disorders for signs of accelerated aging may have the potential to reduce health inequalities and extend healthy lives.

Precision-scored parental report questions and HL-scaled tympanometry as informative measures of hearing in otitis media 1: Large-sample evidence on determinants and complementarity to pure-tone audiometry

INTRODUCTION

In otitis media with effusion (OME), hearing loss is a core sign/symptom and basis of concern, with absolute pure-tone threshold sensitivity (in dB HL) by air-conduction providing the default measure of hearing. However several fundamental problems limiting the value of HL measures in otitis media are insufficiently appreciated. To appraise the joint value and implications of multiple hearing measures towards more comprehensive hearing assessment in OM, we examine in two related articles the interrelations and common or diverging determinants of three measures, two of them objective: binaural HL, and ACET (the published quasi-continuous scaling of binaural tympanometry to HL). The third measure is partly subjective: parentally reported hearing difficulties (RHD-4); this is the precision-scored total of the 4 items selected for the OM8-30 general purpose questionnaire for parents in OM.

METHODS

The Eurotitis-2 study (Total N=2886) internationally standardises OM8-30 and its OMQ-14 short form. The clinical and parent-response variables acquired cover many issues in diagnosis, symptomatology and impact of OM. Data acquisition was built upon routine clinic practice, enabling us also to document some properties of that practice, such as patterns of missing HL data. To address possible confounding or loss of representativeness from this, we investigated the implications of substituting tympanometry-based ACET for missing HL to give an HL/ACET hybrid. ACET is the mapping of categorical tympanometry to continuous HL. We simulated degrees of artificial missingness of HL up to 35% on the 1430 complete-data cases, using random deletion, with 1000-version bootstrapping. Correlations of this HL/ACET hybrid with pure (100%) HL then documented the degree of correlation retained under dilution of HL by an admixture of ACET; we also documented distribution shapes. For RHD-4, we then probed the determining influences on severity of score as an auditory disability measure, both background ones (from centre, age, sex, socio-economic status, length of history, diagnosis and season) and the two underlying objective hearing measures (HL, ACET). We ran these multiple regressions (GLMs), for representativeness and generality, both on 1430 complete-data cases (i.e. all 3 hearing variables present) and also on supplemented samples according to data required only for particular analyses (N increased by +56% to +68%). A further method of sample supplementation (by up to +96%) used the HL/ACET hybrid.

RESULTS

Sex made negligible difference in any analysis. The particular collaborating centre, age, season and diagnosis collectively influenced presence/absence of HL data very strongly. (Area under ROC 0.944). Socio-economic status did not influence HL presence; surprisingly, nor did RHD, ACET or length of history, after control for centre, age, diagnosis and season. Of the inter-correlations between hearing measures, only the one between ACET and RHD was influenced (slightly reduced) by the inclusion of cases without HL data. In the simulated substitutions, Pearson correlation of hybrid HL/ACET with true HL remained above 0.90 for substitution by ACET of up to 30% rate of artificially 'missing' HL. Centre differences were adequately summarised by simple absolute additive differences in mean local case severity. In the determinant models for RHD on the 1430 complete-data cases, HL and the set of background determinants collectively explained broadly similar proportions of RHD's variability, totalling 36.8% explained. On the larger maximum case samples, slightly less absolute variability was explicable than on complete-case data, but relative magnitudes of contribution from individual determinants, both background and hearing measures, remained similar. The expected mean differences in RHD between diagnoses (RAOM, OME, and combined) were found, but the patterns of background and objective measure influences determining RHD did not differ significantly between the diagnoses.

CONCLUSIONS

(1) In the Eurotitis-2 database, descriptive differences in various background demographic and clinical measures between cases on whom HL data were obtained versus not, were only of material magnitude for length of history and reported hearing difficulties. Such descriptive differences are not necessarily bases of confounding, so using our framework of 6 background adjuster variables, (particular collaborating centre, age, season, diagnosis, socioeconomic status and length of history) we isolated the determinants of HL data presence. The first four listed strongly predicted HL data presence/absence so are sufficient to control analyses well for any bias or confounding by HL data presence. (2) Diagnoses as OME and combined (OME+RAOM) had higher probability of HL data being present relative to RAOM, indicating that HL acquisition is chiefly seen as confirming and quantifying hearing loss in (suspect) OME, not as ruling it out (e.g. in suspected RAOM). Given this, also using RHD and or ACET as pre-triage to efficiently target capacity and/or reduce costs and opportunity costs of acquiring HL would be rational, but there was no evidence of such precise use of initial hearing-related information to decide on HL acquisition. (3) The full six background variables explained comparable variance in Reported Hearing Difficulties (RHD) to what was explained by ACET, but not quite as much as by HL. Achieving a high percentage explained (32-37% from good models) required both classes of determinant to be entered as predictors. The pattern of background determining influences for RHD was largely stable, with or without objective measures as additional predictors, and on maximum or complete-data cases. Length of history strongly determines RHD for a given concurrent HL. (4) Accepting ACET as substitute where HL was missing in OM cases gave a sample-size enhancement of 17% in Eurotitis-2, with negligible difference in the pattern of determinants. This hybrid measure can be recommended as reasonable next-best when moderate percentages of HL data are missing. (5) The stable pattern of prediction of RHD suggests that our six background determinants provide a very promising low-cost yet comprehensive framework for determination. It hence offers pluripotent statistical adjustment against confounding, applicable to RAOM, OME and combined diagnoses in any analysis using this database. Claims that it thereby offers a sufficient framework for full European standardisation of all the scores from the OM8-30 questionnaire measures await parallel demonstrations for symptom areas other than RHD. As 25% of the variance in RHD severity can be explained by the six adjusters in our framework, none of the six variables should be omitted from acquisition and analytic use in future OM research.

Childhood infections, but not early life growth, influence hearing in the Newcastle thousand families birth cohort at age 14 years

Background

While current research priorities include investigations of age-related hearing loss, there are concerns regarding effects on childhood hearing, for example through increased personal headphone use. By utilising historical data, it is possible to assess what factors may have increased hearing problems in children in the past, and this may be used to inform current public health policies to protect children against hearing loss and in turn reduce the long-term burden on individuals and services that may possible evolve. The aim of this study was to investigate which factors in early life significantly impacted on hearing level in childhood using existing data from the Newcastle Thousand Families Study, a 1947 birth cohort.

Methods

Data on early life factors, including growth, socio-economic status and illness, and hearing at age 14 years were collated for a representative subset of individuals from the cohort (n = 147). Factors were assessed using linear regression analysis to identify associations with hearing thresholds.

Results

Males were found to have lower hearing thresholds at 250 Hz, 500 Hz and 1 kHz. Main analyses showed no associations between hearing thresholds and early life growth or socio-economic indicators. An increasing number of ear infections from birth to age 13 years was associated with hearing thresholds at 250Hz (p = 0.04) and 500Hz (p = 0.03), which remained true for females (p = 0.050), but not males (p = 0.213) in sex-specific analysis. Scarlet fever and bronchitis were associated with hearing thresholds at 8 kHz. After adjustment for all significant predictors at each frequency, results remained unchanged.

Conclusions

We found no associations between childhood hearing thresholds and early life growth and socio-economic status. Consistent with other studies, we found associations between childhood infections and hearing thresholds. Current public health strategies aimed at reducing childhood infections may also have a beneficial effect upon childhood hearing.

Childhood IQ, hearing loss, and maternal thyroid autoimmunity in the Baltimore Collaborative Perinatal Project

BACKGROUND

Maternal thyroid autoantibodies during pregnancy have been implicated in neurodevelopmental delays, including early childhood cognitive deficits. We evaluated whether maternal autoantibodies to thyroid peroxidase (TPOaAbs) during late pregnancy were associated with childhood intelligence quotient (IQ) scores in their offspring and how the children's TPOaAb-associated sensorineural hearing loss (HL) might affect the result.

METHODS

We evaluated banked third-trimester sera corresponding to 1,733 children for whom childhood cognitive test scores and audiology data were available. The mothers and their children participated in the National Institutes of Health (NIH)-sponsored Collaborative Perinatal Project (CPP) that ran from 1959 to 1974.

RESULTS

A modest, statistically significant, effect of TPOaAbs on cognitive performance observed at 4 y of age lessened in both magnitude and P value by the age of 7 y. Children with sensorineural HL (SNHL) had lower IQ scores at both ages.

CONCLUSION

Our data suggest that the reported effect of maternal TPOaAbs on IQ may involve early developmental delays or transient effects rather than permanent deficits. Reports associating TPOaAbs directly with IQ may reflect a portion with unexamined TPOaAb-associated SNHL. Whether the TPOaAb-associated SNHL is in the neurodevelopmental pathway of later cognitive delays or is independently associated with IQ requires investigation in other studies.

Occupational styrene exposure and hearing loss: a cohort study with repeated measurements

OBJECTIVE

Associations between occupational styrene exposure and impairment of hearing function were investigated, guided by three questions: are there hearing losses concerning high frequency and standard audiometric test? Are there dose-response relationships and measurable thresholds of effects? Are there signs of reversibility of possible effects if the workers are examined during times of improvement from their work?

METHODS

A group of workers from a boat building plant, some of whom were laminators, were examined in subgroups of current low (n = 99, mean mandelic acid MA + phenylglyoxylic acid PGA = 51 mg/g creatinine), medium (n = 118, mean 229 mg/g creat.) and high (n = 31, mean 970 mg/g creat.) exposure to styrene. In addition, subgroups chronically exposed to high-long (n = 17) and low-short (n = 34) styrene levels were analysed. The examinations were carried out during normal work days and during the company holidays. Hearing thresholds and transient evoked otoacoustic emissions (TEOAE) were measured. Statistics included multiple co-variance analyses with repeated measures, linear regressions, and logistic regressions.

RESULTS

The analyses of all participants demonstrated no clear exposure effects. Particularly no sufficient proof of dose-response relationship measured against parameters of current exposure (MA + PGA, styrene/blood) and of chronic exposure (cumulative and average life time exposure resp.) was found. The analyses of groups exposed to high levels show elevated thresholds at frequencies up to 1,500 Hz among the subgroup exposed to high styrene levels (e.g. 40-50 ppm as average) for a longer period of time (e.g. more than 10 years). These participants also demonstrated signs of "improvement" at frequencies above 2,000 Hz during work holidays, when they were not exposed to styrene. A significantly elevated odds ratio for cases of hearing loss (more than 25 dB (A) in one ear, 3,000-6,000 Hz) was found among the group exposed to high levels (above 30 ppm as average) for a longer period of time (more than 10-26 years). The measurements of TEOAE did not exhibit significant results related to exposure.

CONCLUSION

This study found, that chronic and intensive styrene exposure increases the hearing thresholds. At levels of about 30-50 ppm as an average inhaled styrene per work day over a period of about 15 years with higher exposure levels above 50 ppm in the past, an elevated risk for impaired hearing thresholds can be expected. The formerly published results on ototoxic effects below 20 ppm could not be confirmed. With few exceptions (at frequencies of 1,000 and 1,500 Hz) no dose-response relationship between threshold and exposure data was found. Improvements of hearing thresholds during work- and exposure-free period are possible.

Childhood hearing is associated with growth rates in infancy and adolescence

It is known that shorter stature is associated with sensorineural hearing loss; and that cochlear development is associated with activity of IGF 1, as are many important aspects of neurodevelopment. We hypothesized that this relation might be extrapolated to a normally hearing group, and that the strongest relation between hearing level and growth rate would be in late puberty, when serum IGF-1 levels are highest. We examined the statistical relation between childhood hearing threshold and rate of growth in height at different times during the life course up to age 32. We found mixed support for the hypothesis. The strongest relations were observed in late puberty, at the ages which previous research shows are associated with the highest serum concentrations of IGF-1 in males and females, but also in infancy and early childhood. The association between hearing and height is present in a normally hearing, general population sample, and is associated with growth in late adolescence. Our findings support the idea that childhood hearing threshold may be predictive of IGF-1 mediated developmental characteristics.