Association between hearing loss and development of dementia using formal behavioural audiometric testing within the Mayo Clinic Study of Aging (MCSA): a prospective population-based study

Usability of the Mayo Test Drive remote self-administered web-based cognitive screening battery in adults aged 35-100 with and without cognitive impairment

BACKGROUND

Mayo Test Drive (MTD): Mayo Test Development through Rapid Iteration, Validation and Expansion, is a web-based remote cognitive assessment platform for self-administered neuropsychological measures with previously demonstrated validity and reliability. We examined the usability of MTD and hypothesized that completion rates would be greater than 90%. We explored whether completion and participation rates differed by cognitive status and demographic factors.

METHODS

A total of 1,950 Mayo Clinic Study of Aging and Mayo Alzheimer's Disease Research Center participants (97% White, 99% Non-Hispanic) were invited to participate in this ancillary, uncompensated remote study. Most invitees were cognitively unimpaired (CU; n = 1,769; 90.7%) and 9.3% were cognitively impaired (CI; n = 181). Usability was objectively defined as the percentage of participants who completed a session after initiating a session for a given timepoint (i.e. completion rates).

RESULTS

Baseline session completion rates were 98.5% (n = 1199/1217 participants, mean age 71, SD = 12, range 35-100) and were comparable between CU (98.7%) and CI (95.0%) groups (p = .23). Completion rates did not significantly differ by age groups (p > .10) and remained high in individuals 80+ (n = 251, 97.3%). Participation rates were higher in the CU (n = 1142, 65.4%) versus CI (n = 57, 33.1%) group (p < .001); participants were younger and had more years of education (p's < .001). Adherence (i.e. retention) rate for a 7.5-month follow-up session was 89%. Average session duration was 16 min. Most participants used a personal computer (62.7%), followed by a smartphone (22.2%) or tablet (14.8%). Comments entered by 36.4% of participants reflected several themes including acceptability, face validity, usability, and comments informative for session context.

CONCLUSIONS

MTD demonstrated high usability as defined by completion rates in this research sample that includes a broad age range, though participation rates are lower in individuals with cognitive impairment. Results support good adherence at follow-up, feasibility through mean session duration, and acceptability based on qualitative analysis of participant comments.

Hearing loss and the risk of dementia: A longitudinal analysis of the Korean National Health Insurance Service Senior Cohort

BACKGROUND

Hearing loss is a potentially modifiable risk factor implicated in dementia, with recent research suggesting an association between age-related hearing degradation and dementia.

OBJECTIVE

This study aims to elucidate the relationship between hearing decline and dementia risk.

METHODS

We analyzed data from 511,953 subjects from the Korean National Health Insurance Service-Senior Cohort (2002-2008). After excluding those diagnosed with dementia in 2002, 511,935 subjects were included. Subjects with hearing loss between 2002 and 2008 were selected and matched with a control group without hearing impairment based on age and gender. Statistical analyses, including Pearson's chi-squared test and the Cox proportional hazards model, were conducted, controlling for confounding variables such as household income and residential area. Subgroup analysis was also performed for Alzheimer's disease and vascular dementia.

RESULTS

Subjects with hearing loss had a 1.245 times higher risk of all-cause dementia compared to those without hearing loss (adjusted hazard ratio over 3 years, 95% CI = 1.201-1.290), adjusting for gender, age, residence, and income. The adjusted hazard ratios for Alzheimer's disease over 3, 5, 7, and 10 years from the index date were 1.259 (95% CI = 1.211-1.308), 1.258 (95% CI = 1.208-1.310), 1.269 (95% CI = 1.215-1.325), and 1.235 (95% CI = 1.170-1.304), respectively. No significant association was found for vascular dementia, except for 3 years.

CONCLUSIONS

Hearing loss consistently increased the risk of all-cause dementia and Alzheimer's disease across timespans, suggesting a complex link between hearing loss and neurodegenerative diseases. These findings highlight the importance of early intervention and cognitive monitoring for individuals with hearing loss.

Conductive Hearing Loss Associates With Dementia, and Middle Ear Reconstruction Mitigates This Association: A Multinational Database Study

OBJECTIVE

To test the hypothesis that conductive hearing loss (CHL) is associated with dementia, and that middle ear reconstruction (MER) associates with improved outcomes for these measures in a multinational electronic health records database.

STUDY DESIGN

Retrospective cohort study with propensity-score matching (PSM).

SETTING

TriNetX is a research database representing about 110 million patients from the United States, Taiwan, Brazil, and India.

PATIENTS

Subjects older than 50 years with no HL and any CHL (ICD-10: H90.0-2). Subjects of any age with and without any MER (CPT: 1010174).

MAIN OUTCOME MEASURES

Odds ratios (ORs) and hazard ratios with 95% confidence intervals (95% CIs) for incident dementia (ICD-10: F01, F03, G30).

RESULTS

Of 103,609 patients older than 50 years experiencing any CHL, 2.74% developed dementia compared with 1.22% of 38,216,019 patients with no HL (OR, 95% CI: 2.29, 2.20-2.37). Of patients experiencing CHL, there were 39,850 who received MER. The average age was 31.3 years, with 51% female patients. A total of 343,876 control patients with CHL were identified; 39,900 patients remained in each cohort after 1:1 PSM for HL- and dementia-related risk factors. Matched risk for developing dementia among MER recipients was 0.33% compared with 0.58% in controls (OR: 0.58, 0.46-0.72).

CONCLUSIONS

CHL increases the odds for dementia, and MER improves the odds for incident dementia. This study represents the first population study on the topic of CHL, MER, and dementia.

Moderating Role of Neighborhood Environment in the Associations Between Hearing Loss and Cognitive Challenges Among Older Adults: Evidence From US National Study

This study examined the associations between hearing loss and cognitive challenges among community-dwelling older adults and whether neighborhood characteristics (physical disorder and low social cohesion) moderated the associations. Cross-sectional national data from Round 11 of the National Health and Aging Trends Study were adopted (N = 2,515). Multinomial logistic regressions were used to examine associations among variables and interactive analyses were conducted to examine moderating effects. Results indicated significant relationships between the experience of hearing loss and possible dementia and between severe or profound hearing loss and probable dementia. Interactive models suggested that residing in neighborhoods with physical disorder and low social cohesion were negatively associated with possible dementia among older adults with moderate and severe or profound hearing loss, respectively, compared to those without hearing loss. Findings underscore the necessity of environmental and social interventions to enhance cognitive health among older adults with varying degrees of hearing challenges.

Adult-onset hearing loss and incident cognitive impairment and dementia - A systematic review and meta-analysis of cohort studies

BACKGROUND

We comprehensively summarized the cohort evidence to date on adult-onset hearing loss as risk factor for incident cognitive impairment and dementia, and examined the evidence for dose-response, risk for various dementia subtypes, and other moderators. Previous meta-analyses were less comprehensive.

METHODS

We included cohort studies with participants without dementia and with hearing assessments at baseline, minimum 2 years follow-up and incident cognitive outcomes. We used random-effect models and subgroup and meta-regression on moderator analyses.

RESULTS

We identified fifty studies (N=1,548,754). Hearing loss (yes/no) was associated with incident dementia risk (HR=1.35 [95% CI = 1.26 - 1.45), mild cognitive impairment (MCI HR=1.29 [95% CI = 1.11 - 1.50]), cognitive decline not specified as MCI or dementia (HR=1.29 [95% CI = 1.17 - 1.42]), and Alzheimer's disease dementia (ADD, HR=1.56 [95% CI = 1.30 - 1.87]), but not with vascular dementia (HR, 1.30 [95% CI = 0.83 - 2.05]). Each 10-decibel worsening of hearing was associated with a 16% increase in dementia risk (95% CI = 1.07 - 1.27). The effect of hearing loss did not vary across potential moderators.

CONCLUSIONS

Cohort studies consistently support that adult-onset hearing loss increases the risk of incident cognitive decline, dementia, MCI, and ADD.

The effects of sensorial and mobility frailty on the overall and domain-specific cognition performance of Chinese community-dwelling older adults

This study aimed to investigate the different impacts of sensorial and mobility frailty on overall and domain-specific cognitive function. Further, the independent associations between other intricate capacity (IC) dimensions, including vitality and psychological dimensions, and overall and domain-specific cognitive function were investigated. A total of 429 participants (mean age, 72.91 ± 7.014 years; 57.30% female) underwent IC capacity assessment. Other covariates, such as demographics, health-related variables were also assessed. Overall or domain-specific cognitive impairment was used as a dependent variable in logistic regression analyses adjusted for demographic, health-related, and psychosocial confounders. After adjustment for demographic, health-related, and psychosocial confounders, individuals with sensorial frailty (odds ratio [OR] = 0.435; 95% confidence interval [CI] = 0.236-0.801; P = .008) had a significantly lower risk of mild cognitive impairment (MCI), marginally low delayed memory impairment (OR = 0.601, 95% CI = 0.347-1.040; P = .069), and language impairment (OR = 0.534, 95% CI = 0.305-0.936; OR = 0.318, P = .029; OR = 0.318,95% CI = 0.173-0.586; P < .001) by Boston naming and animal fluency tests than did those with both sensorial and mobility frailty or mobility frailty only. Depressive symptoms had a significant negative influence on executive function. Cardiovascular disease and non-skin malignancy were independent determinants of MCI, and diabetes mellitus was independently associated with processing speed, attention, and executive function. Sensorial and mobility frailty were independent risk factors for cognitive impairment. Mobility frailty had a greater negative influence on the overall cognitive function and memory and language function than did sensorial frailty. The reserve decline in the psychological dimension of IC and chronic diseases also had a significant adverse influence on overall and domain-specific cognition function.

Update on modifiable risk factors for Alzheimer's disease and related dementias

PURPOSE OF REVIEW

All human beings undergo a lifelong cumulative exposure to potentially preventable adverse factors such as toxins, infections, traumatisms, and cardiovascular risk factors, collectively termed exposome. The interplay between the individual's genetics and exposome is thought to have a large impact in health outcomes such as cancer and cardiovascular disease. Likewise, a growing body of evidence is supporting the idea that preventable factors explain a sizable proportion of Alzheimer's disease and related dementia (ADRD) cases.

RECENT FINDINGS

Here, we will review the most recent epidemiological, experimental preclinical, and interventional clinical studies examining some of these potentially modifiable risk factors for ADRD. We will focus on new evidence regarding cardiovascular risk factors, air pollution, viral and other infectious agents, traumatic brain injury, and hearing loss.

SUMMARY

While greater and higher quality epidemiological and experimental evidence is needed to unequivocally confirm their causal link with ADRD and/or unravel the underlying mechanisms, these modifiable risk factors may represent a window of opportunity to reduce ADRD incidence and prevalence at the population level via health screenings, and education and health policies.

The Association Between Mitochondrial tRNAGlu Variants and Hearing Loss: A Case-Control Study

Purpose

This study aimed to examine the frequencies of mt-tRNAGlu variants in 180 pediatric patients with non-syndromic hearing loss (NSHL) and 100 controls.

Methods

Sanger sequencing was performed to screen for mt-tRNAGlu variants. These mitochondrial DNA (mtDNA) pathogenic mutations were further assessed using phylogenetic conservation and haplogroup analyses. We also traced the origins of the family history of probands carrying potential pathogenic mtDNA mutations. Mitochondrial functions including mtDNA content, ATP and reactive oxygen species (ROS) were examined in cells derived from patients carrying the mt-tRNAGlu A14692G and CO1/tRNASer(UCN) G7444A variants and controls.

Results

We identified four possible pathogenic variants: m.T14709C, m.A14683G, m.A14692G and m.A14693G, which were found in NSHL patients but not in controls. Genetic counseling suggested that one child with the m.A14692G variant had a family history of NSHL. Sequence analysis of mtDNA suggested the presence of the CO1/tRNASer(UCN) G7444A and mt-tRNAGlu A14692G variants. Molecular analysis suggested that, compared with the controls, patients with these variants exhibited much lower mtDNA copy numbers, ATP production, whereas ROS levels increased (p<0.05 for all), suggesting that the m.A14692G and m.G7444A variants led to mitochondrial dysfunction.

Conclusion

mt-tRNAGlu variants are important risk factors for NSHL.

Physical Function Trajectories and Mortality in Older Adults With Multisensory Impairment

Importance

Single sensory impairment is associated with reduced functional resilience and increased mortality, though the effects of multiple sensory deficits are not known.

Objective

To investigate longitudinal associations of the type, severity, and number of sensory impairments with physical function trajectories and mortality in older adults.

Design, Setting, and Participants

This retrospective analysis of a longitudinal cohort study, the Health, Aging, and Body Composition (Health ABC) study, incorporated data from April 1997 to July 2013, featuring a 16-year follow-up with annual examinations and questionnaires. The cohort comprised 3075 men and women, aged 70 to 79 years at baseline, residing in Memphis, Tennessee, and Pittsburgh, Pennsylvania. All participants with complete sensory testing and covariate data at analytical baseline (year 5, 2002) were included. The data were analyzed September 1, 2022.

Exposures

Visual, olfactory, auditory, and touch sensory functions were assessed between 2000 and 2002.

Main Outcomes

The main outcomes included physical functioning trajectories and mortality risk. Physical function was assessed longitudinally using the Health ABC physical performance battery (HABCPPB).

Results

A total of 1825 individuals (mean [SD] age, 77.4 [3.2] years; 957 [52%] female) were included in this study. Multivariable analysis of HABCPPB decline indicated that having 1 sensory impairment (β estimate, -0.01 [95% CI, -0.02 to -0.001]); 2 sensory impairments (β estimate, -0.01 [95% CI, -0.02 to -0.01]); 3 sensory impairments (β estimate, -0.03 [95% CI, -0.04 to -0.02]); or 4 sensory impairments (β estimate, -0.04 [95% CI, -0.05,-0.03]) was significantly associated with a steeper HABCPPB score decline in a dose-dependent manner. Adjusted Cox proportional hazards models indicated that having 1 sensory impairment (hazard ratio [HR], 1.35 [95% CI, 1.01-1.81]), 2 sensory impairments (HR, 1.58 [95% CI, 1.19-2.11]), 3 sensory impairments (HR, 1.79 [95% CI, 1.33-2.42]), or 4 sensory impairments (HR, 1.97 [95% CI, 1.39-2.79]) was significantly associated with increased mortality risk in a similarly dose-dependent manner.

Conclusion

In this retrospective cohort study, the degree and number of multiple sensory impairments were associated with worse physical functioning and increased mortality risk. These findings represent an opportunity for further investigation into the value of screening, prevention, and treatment of sensory impairments to reduce morbidity and mortality in older adults.

Neuroimaging Characteristics of Hearing Loss in the Mayo Clinic Study of Aging

OBJECTIVE

To investigate the association between standard pure tone and speech audiometry with neuroimaging characteristics reflective of aging and dementia in older adults.

STUDY DESIGN

Prospective population-based study.

SETTING

Single tertiary care referral center.

METHODS

Participants from the Mayo Clinic Study of aging 60 years old or older with normal cognition or mild cognitive impairment, baseline neuroimaging, and a behavioral audiogram associated with neuroimaging were eligible for study. Imaging modalities included structural MRI (sMRI) and fluid-attenuated inversion recovery MRI (FLAIR-MRI; N = 605), diffusion tensor imaging MRI (DTI-MRI; N = 444), and fluorodeoxyglucose-positron emission tomography (FDG-PET; N = 413). Multivariable logistic and linear regression models were used to evaluate associations with neuroimaging outcomes.

RESULTS

Mean (SD) pure tone average (PTA) was 33 (15) dB HL and mean (SD) word recognition score (WRS) was 91% (14). There were no significant associations between audiometric performance and cortical thinning assessed by sMRI. Each 10-dB increase in PTA was associated with increased likelihood of abnormal white-matter hyperintensity (WMH) from FLAIR-MRI (odds ratio 1.26, P = .02). From DTI-MRI, participants with <100% WRSs had significantly lower fractional anisotropy in the genu of the corpus callosum (parameter estimate [PE] -0.012, P = .008) compared to those with perfect WRSs. From FDG-PET, each 10% decrease in WRSs was associated with decreased uptake in the anterior cingulate cortex (PE -0.013, P = .001).

CONCLUSION

Poorer audiometric performance was not significantly associated with cortical thinning but was associated with white matter damage relevant to cerebrovascular disease (increased abnormal WMH, decreased corpus callosum diffusion). These neuroimaging results suggest a pathophysiologic link between hearing loss and cerebrovascular disease.

Estimating the United States Patient Population Size Meeting Audiologic Candidacy for Cochlear Implantation

OBJECTIVE

This study aimed to estimate the size of the United States candidacy pool meeting expanded Center for Medicare Services criteria for cochlear implantation.

STUDY DESIGN

Retrospective cross-sectional.

SETTING

Tertiary care center.

METHODS

Preimplantation audiometric data from 486 patients seen at a single academic medical center were collected retrospectively and used to generate a predictive model of AzBio score based on audiometric pure tone thresholds. This model was then used to estimate nationally representative cochlear implantation (CI)-candidacy using pure tone averages included in the National Health and Nutrition Examination Survey. Qualitative and quantitative analyses were performed.

RESULTS

We find that the estimated prevalence of CI candidacy in individuals 65 years of age or older is expected to more than double with a change in the CI candidacy criteria from ≤40% to ≤60% (from 1.42%, 95% confidence interval [1.33, 1.63] to 3.73% [2.71, 6.56]) on speech testing. We also found the greatest absolute increase in candidacy in the 80+ age group, increasing from 4.14% [3.72, 5.1] of the population meeting the ≤40% criteria to 12.12% [9.19, 18.35] meeting the ≤60% criteria.

CONCLUSION

The United States population size meeting expanded CMS audiologic criteria for cochlear implantation is estimated to be 2.5 million adults and 2.1 million age 65 or older. Changing the CI candidacy criteria from ≤40% to ≤60% on CI testing has the greatest effect on the eligible patient population in the >65-year-old age group. The determination of utilization rates in newly eligible patients will require further study.

An Interprofessional Approach to Aural Rehabilitation for Adults with Hearing Loss and Cognitive Concerns

Individuals with hearing loss are at risk for cognitive decline. The traditional approach to audiological care does not typically involve a team approach that addresses cognitive concerns. While cognitive screening is within the scope of practice in audiology, audiologists are not typically trained in interpreting screening results or providing rehabilitation that supports cognitive health. However, as growing evidence shows that hearing loss is tied to cognitive decline, a team approach is required to support whole-person care. Speech-language pathologists, who specialize in optimizing communication, are best situated to collaborate with audiologists to provide holistic aural rehabilitation. Audiologists and speech-language pathologists who partner to support a client's communication skills and social relationships play an important role in the life of an individual with hearing loss. In this perspective, we describe relevant background information about hearing loss and cognition and present an interprofessional approach to aural rehabilitation for adults with hearing loss who have cognitive concerns. We also discuss implications for future research.

[Relationship Between Hearing Loss and Cognitive Function in Elderly Chinese People: A Study Based on Propensity Score Matching]

Objective

To explore the relationship between hearing loss and cognitive function in the elderly population through propensity score matching method.

Methods

We analyzed the data of 7605 participants aged 60 and above who were included in the 2018 China Health and Retirement Longitudinal Study (CHARLS). The non-substitutable 1∶1 nearest neighbor matching method without caliper value was used for propensity score matching and G-computation was used to estimate the average treatment effect (ATE) of hearing loss on all dimensions of cognitive function.

Results

Before matching, there were 3626 (47.68%) women, with 1409 (18.53%) of whom suffering from hearing loss and 3031 (39.86%) of whom suffering from cognitive impairment. After matching, 1409 subjects were included in the hearing loss group and 1409, in the normal hearing group, with both groups sharing similar distribution of basic demographic characteristics. The results for the average treatment effect of the population indicated that the cognitive function scores of the hearing loss group were lower than those of the normal hearing group, with the overall cognitive function being 0.593 points lower (95% confidence intervel [CI]: －0.916-－0.257, P<0.001), orientation being 0.183 points lower (95% CI: －0.302-－0.055, P=0.004), immediate memory being 0.150 points lower (95% CI: －0.218-－0.085, P<0.001), and language skills being 0.178 points lower (95% CI: －0.303-－0.058, P=0.006). The prevalence of cognitive impairment of the hearing loss group was 4.2% higher than that of the normal hearing group (95% CI: 0.007-0.077, P=0.020).

Conclusion

Hearing loss adversely affects the orientation, memory, and language skills of the elderly population and forms a potential risk factor for cognitive impairment in the elderly population.

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.

Description of the Baseline Audiologic Characteristics of the Participants Enrolled in the Aging and Cognitive Health Evaluation in Elders Study

PURPOSE

The Aging and Cognitive Health Evaluation in Elders (ACHIEVE) study is a randomized clinical trial designed to determine the effects of a best-practice hearing intervention versus a successful aging health education control intervention on cognitive decline among community-dwelling older adults with untreated mild-to-moderate hearing loss. We describe the baseline audiologic characteristics of the ACHIEVE participants.

METHOD

Participants aged 70-84 years (N = 977; Mage = 76.8) were enrolled at four U.S. sites through two recruitment routes: (a) an ongoing longitudinal study and (b) de novo through the community. Participants underwent diagnostic evaluation including otoscopy, tympanometry, pure-tone and speech audiometry, speech-in-noise testing, and provided self-reported hearing abilities. Baseline characteristics are reported as frequencies (percentages) for categorical variables or medians (interquartiles, Q1-Q3) for continuous variables. Between-groups comparisons were conducted using chi-square tests for categorical variables or Kruskal-Wallis test for continuous variables. Spearman correlations assessed relationships between measured hearing function and self-reported hearing handicap.

RESULTS

The median four-frequency pure-tone average of the better ear was 39 dB HL, and the median speech-in-noise performance was a 6-dB SNR loss, indicating mild speech-in-noise difficulty. No clinically meaningful differences were found across sites. Significant differences in subjective measures were found for recruitment route. Expected correlations between hearing measurements and self-reported handicap were found.

CONCLUSIONS

The extensive baseline audiologic characteristics reported here will inform future analyses examining associations between hearing loss and cognitive decline. The final ACHIEVE data set will be publicly available for use among the scientific community.

SUPPLEMENTAL MATERIAL

https://doi.org/10.23641/asha.24756948.

Perceptions Surrounding Cochlear Implants Among At-Risk and Qualifying Older Adults in the United States

OBJECTIVE

Limited evidence to date has examined public perceptions of cochlear implants among adult hearing aid users with moderate to profound hearing loss. The current work was conceived with the chief objective of characterizing the perceptions surrounding cochlear implants among the prospective candidate pool.

STUDY DESIGN

National cross-sectional survey study.

SETTING

United States.

PATIENTS

Adults between 50 and 80 years of age with self-reported moderate to moderately severe (n = 200) or moderately severe to profound (n = 200) hearing loss currently using hearing aids.

RESULTS

The overall survey response rate was 12%. Median age at time of survey for the 400 respondents was 66 years (interquartile range, 60-71 yr) and included 215 (54%) men. In total, 26% did not think of hearing loss as a medical condition, and another 23% were unsure. Overall, 63% of respondents had heard of cochlear implants, but only 2% indicated they were very familiar with them. Despite 52% of respondents reporting "very positive" or "somewhat positive" feelings about cochlear implants, only 9% indicated they were "very likely" to get a cochlear implant in the future, including 7% of those with estimated moderately severe to profound hearing loss at time of survey.

CONCLUSIONS

Even among people with presumed qualifying levels of hearing loss, there exists a widespread lack of familiarity with cochlear implantation as a viable treatment option. This limited awareness seems influenced by a generally poor appreciation for hearing loss as a chronic disease state that warrants treatment. However, among those familiar with cochlear implants, they are generally viewed favorably.

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

Background

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

Methods

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

Findings

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

Interpretation

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

Funding

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

The Healthy Brain Initiative (HBI): A prospective cohort study protocol

BACKGROUND

The Health Brain Initiative (HBI), established by University of Miami's Comprehensive Center for Brain Health (CCBH), follows racially/ethnically diverse older adults without dementia living in South Florida. With dementia prevention and brain health promotion as an overarching goal, HBI will advance scientific knowledge by developing novel assessments and non-invasive biomarkers of Alzheimer's disease and related dementias (ADRD), examining additive effects of sociodemographic, lifestyle, neurological and biobehavioral measures, and employing innovative, methodologically advanced modeling methods to characterize ADRD risk and resilience factors and transition of brain aging.

METHODS

HBI is a longitudinal, observational cohort study that will follow 500 deeply-phenotyped participants annually to collect, analyze, and store clinical, cognitive, behavioral, functional, genetic, and neuroimaging data and biospecimens. Participants are ≥50 years old; have no, subjective, or mild cognitive impairment; have a study partner; and are eligible to undergo magnetic resonance imaging (MRI). Recruitment is community-based including advertisements, word-of-mouth, community events, and physician referrals. At baseline, following informed consent, participants complete detailed web-based surveys (e.g., demographics, health history, risk and resilience factors), followed by two half-day visits which include neurological exams, cognitive and functional assessments, an overnight sleep study, and biospecimen collection. Structural and functional MRI is completed by all participants and a subset also consent to amyloid PET imaging. Annual follow-up visits repeat the same data and biospecimen collection as baseline, except that MRIs are conducted every other year after baseline.

ETHICS AND EXPECTED IMPACT

HBI has been approved by the University of Miami Miller School of Medicine Institutional Review Board. Participants provide informed consent at baseline and are re-consented as needed with protocol changes. Data collected by HBI will lead to breakthroughs in developing new diagnostics and therapeutics, creating comprehensive diagnostic evaluations, and providing the evidence base for precision medicine approaches to dementia prevention with individualized treatment plans.

Cognitive Performance, Sociodemographic Factors, Pure-Tone Audiometry, and their Association with Speech Discrimination: A Prospective Population-Based Study of 1,061 Older Adults

OBJECTIVE

Hearing loss is increasingly recognized as a chronic disease state with important health sequelae. Although considered a central component of routine audiometric testing, the degree to which various patient factors influence speech discrimination is poorly characterized to date. The primary objective of the current work was to describe associations of cognitive performance, sociodemographic factors, and pure-tone audiometry with speech discrimination in older adults.

STUDY DESIGN

Prospective study.

SETTING

Olmsted County, Minnesota.

PATIENTS

There were 1,061 study participants 50 years or older at enrollment in the population-based Mayo Clinic Study of Aging between November 2004 and December 2019 who underwent formal audiometric and cognitive testing included in the current investigation.

MAIN OUTCOME MEASURES

The primary outcome measure was word recognition scores (WRSs; measured as <100% vs 100% as well as continuous), with pure-tone averages (PTAs; 0.5, 1, 2, and 3 kHz), age, sex, years of education, state area deprivation index (ADI) quintiles, and global cognition z scores as explanatory features.

RESULTS

The mean (SD) age among the 1,061 participants was 76 (9) years with 528 (50%) males. Participant age [OR (95% CI) for a 10-year increase of 1.8 (1.4-2.3), p < 0.001], male sex [OR = 2.6 (1.9-3.7), p < 0.001], and PTA [OR for a 10-dB hearing loss increase of 2.4 (2.1-2.8), p < 0.001] were all significantly associated with <100% WRSs, with the greatest explanatory ability attributable to the PTA. Years of education ( p = 0.9), state ADI quintile ( p = 0.6), and global cognitive performance ( p = 0.2) were not associated with WRS. The multivariable model demonstrated strong predictive ability for less than perfect WRSs, with a c index of 0.854. Similar results were seen for WRSs analyzed as continuous, with the multivariable model resulting in an R2 value of 0.433.

CONCLUSIONS

Although PTA exhibited the greatest influence on speech discrimination, advancing age and male sex both independently increased the likelihood of having worse speech discrimination among older adults, even after accounting for years of education, neighborhood-level socioeconomic disadvantage, and cognitive function. These findings help identify patient factors that can be instrumental when designing screening programs for adult-onset hearing loss.

The Healthy Brain Initiative (HBI): A prospective cohort study protocol

Background

The Health Brain Initiative (HBI), established by University of Miami's Comprehensive Center for Brain Health (CCBH), follows racially/ethnically diverse older adults without dementia living in South Florida. With dementia prevention and brain health promotion as an overarching goal, HBI will advance scientific knowledge by developing novel assessments and non-invasive biomarkers of Alzheimer's disease and related dementias (ADRD), examining additive effects of sociodemographic, lifestyle, neurological and biobehavioral measures, and employing innovative, methodologically advanced modeling methods to characterize ADRD risk and resilience factors and transition of brain aging.

Methods

HBI is a longitudinal, observational cohort study that will follow 500 deeply-phenotyped participants annually to collect, analyze, and store clinical, cognitive, behavioral, functional, genetic, and neuroimaging data and biospecimens. Participants are ≥50 years old; have no, subjective, or mild cognitive impairment; have a study partner; and are eligible to undergo magnetic resonance imaging (MRI). Recruitment is community-based including advertisements, word-of-mouth, community events, and physician referrals. At baseline, following informed consent, participants complete detailed web-based surveys (e.g., demographics, health history, risk and resilience factors), followed by two half-day visits which include neurological exams, cognitive and functional assessments, an overnight sleep study, and biospecimen collection. Structural and functional MRI is completed by all participants and a subset also consent to amyloid PET imaging. Annual follow-up visits repeat the same data and biospecimen collection as baseline, except that MRIs are conducted every other year after baseline.

Ethics and expected impact

HBI has been approved by the University of Miami Miller School of Medicine Institutional Review Board. Participants provide informed consent at baseline and are re-consented as needed with protocol changes. Data collected by HBI will lead to breakthroughs in developing new diagnostics and therapeutics, create comprehensive diagnostic evaluations, and provide the evidence base for precision medicine approaches to dementia prevention with individualized treatment plans.

Hearing loss and its link to cognitive impairment and dementia

Hearing loss is an important risk factor for the development of dementia, particularly Alzheimer's disease (AD). Mid-life hearing loss increases the risk of developing dementia by double any other single factor. However, given this strong connection between hearing loss and AD, the mechanisms responsible for this link are still unknown. Data from observational studies relating hearing loss and cognitive impairment, measured with standardized questionnaires, has shown a strong relationship between them. Similar findings have emerged from animal studies, showing that the induction of hearing loss via prolonged loud sound exposure or ear canal blocking, can impair cognitive abilities. Interestingly, patients with age-related hearing impairment exhibit increased phosphorylated tau in the cerebrospinal fluid, but no such relationship has been identified for amyloid-β. In addition, hearing loss predisposes to social isolation precipitating the development of dementia through a supposed reduction in cognitive load and processing requirements. Given this link between hearing loss and dementia, the question arises whether the restoration of hearing might mitigate against the onset or progress of AD. Indeed, there is a growing body of research that suggests that those who wear hearing aids for age-related hearing problems maintain better cognitive function over time than those who do not. These are compelling findings, as they suggest the use of hearing aids has the potential to be a cost-effective treatment for those with hearing loss both prior (for those at high risk for AD) and after the development of symptoms. This review aims to summarize the current theories that relate hearing loss and cognitive decline, present the key findings of animal studies, observational studies and summarize the gaps and limitations that need to be addressed in this topic. Through this, we suggest directions for future studies to tackle the lack of adequately randomized control trials in the field. This omission is responsible for the inability to provide a conclusive verdict on whether to use hearing interventions to target hearing-loss related cognitive decline.

Detection and treatment of Alzheimer's disease in its preclinical stage

Longitudinal multimodal biomarker studies reveal that the continuum of Alzheimer's disease (AD) includes a long latent phase, referred to as preclinical AD, which precedes the onset of symptoms by decades. Treatment during the preclinical AD phase offers an optimal opportunity for slowing the progression of disease. However, trial design in this population is complex. In this Review, we discuss the recent advances in accurate plasma measurements, new recruitment approaches, sensitive cognitive instruments and self-reported outcomes that have facilitated the successful launch of multiple phase 3 trials for preclinical AD. The recent success of anti-amyloid immunotherapy trials in symptomatic AD has increased the enthusiasm for testing this strategy at the earliest feasible stage. We provide an outlook for standard screening of amyloid accumulation at the preclinical stage in clinically normal individuals, during which effective therapy to delay or prevent cognitive decline can be initiated.