Hearing Loss and Cognitive Function: Baseline Findings From the Brazilian Longitudinal Study of Adult Health: ELSA-Brasil

Hearing loss and cognitive decline in the Brazilian Longitudinal Study of Adult Health (ELSA-Brasil) during eight years of follow-up

BACKGROUND

Hearing loss (HL) of moderate or higher grades is common in older adults with increasing prevalence as people age, rising from 12% at the age of 60 years to over 58% at 90 years. HL in midlife is one of the main potentially modifiable risk factors for dementia. It is estimated that 7% of dementia cases globally could be avoided if this risk factor was eliminated. However, much of the research conducted has been in high-income countries even though low- and middle-income countries have the highest prevalence of dementia.

OBJECTIVE

To study the association between HL and cognitive decline during eight years of follow-up in a Brazilian sample.

METHODS

Participants from the São Paulo center of the Brazilian Longitudinal Study of Adult Health were evaluated in three study waves (2008-10, 2012-14, and 2017-19). HL was defined as pure-tone audiometry above 25 dB in the better ear. Cognitive performance was evaluated with six tests related to memory, verbal fluency, and trail-making tests. A global cognitive z-score was derived from these tests. The association between HL and cognitive decline was evaluated with linear mixed-effects models adjusted for sociodemographic, lifestyle, and clinical factors.

RESULTS

Of 805 participants (mean age 51 ± 9 years, 52% women, 60% White), 62 had HL. During follow-up, HL was associated with faster global cognitive decline (β = -0.012, 95% CI = -0.023; 0.000, p = 0.039).

CONCLUSIONS

HL was significantly associated with a faster rate of global cognitive decline after a median follow-up of eight years in a sample of middle-income country.

A systematic review of the association of Type I diabetes with sensorineural hearing loss

OBJECTIVES

Type 1 diabetes (T1D) has been associated with several comorbidities such as ocular, renal, and cardiovascular complications. However, the effect of T1D on the auditory system and sensorineural hearing loss (SNHL) is still not clear. The aim of this study was to conduct a systematic review to evaluate whether T1D is associated with hearing impairment.

METHODS

The databases PubMed, Science Direct, Scopus, and EMBASE were searched in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) criteria. Three reviewers independently screened, selected, and extracted data. The Joanna Briggs Institute (JBI) Critical Appraisal Tools for Analytical cross-sectional and case-control studies were used to perform quality assessment and risk of bias analysis on eligible studies.

RESULTS

After screening a total of 463 studies, 11 eligible original articles were included in the review to analyze the effects of T1D on the auditory system. The included studies comprised cross-sectional and case-control investigations. A total of 5,792 patients were evaluated across the 11 articles included. The majority of the studies showed that T1D was associated with hearing impairment compared to controls, including differences in PTAs and OAEs, increased mean hearing thresholds, altered acoustic reflex thresholds, and problems with the medial olivocochlear (MOC) reflex inhibitory effect. Significant risk factors included older age, increased disease duration, and higher HbA1C levels.

CONCLUSIONS

This systematic review suggests that there is a correlation between T1D and impairment on the auditory system. A multidisciplinary collaboration between endocrinologists, otolaryngologists, and audiologists will lead to early detection of hearing impairment in people with T1D resulting in early intervention and better clinical outcomes in pursuit of improving the quality of life of affected individuals.

REGISTRATION

This systematic review is registered in PROSPERO (CRD42023438576).

Residential proximity to major roadways and hearing impairment in Chinese older adults: a population-based study

BACKGROUND

With rapid urban sprawl, growing people are living in the vicinity of major roadways. However, little is known about the relationship between residential proximity to major roadways and hearing impairment (HI).

METHODS

We derived data from the 2018 wave of the Chinese Longitudinal Healthy Longevity Survey, and included 13,775 participants aged 65 years or older. Multivariate logistic regressions were employed to examine the association between residential proximity to major roadways and HI. The effects of corresponding potentially modifiable factors were studied by three-way interaction analyses. Sensitivity analyses were performed to verify the robustness of the results.

RESULTS

The prevalence of HI was 38.3%. Participants living near major roadways were more likely to have a higher socioeconomic status. An exposure-response relation between residential proximity to major roadways and HI was observed (Ptrend < 0.05). Compared with individuals living > 300 m away from major roadways, the adjusted odds ratios (OR) were 1.07 (95% CI: 0.96-1.24), 1.15 (95% CI: 1.07-1.34), and 1.12 (95% CI: 1.01-1.31) for those living 101-200 m, 50-100 m, and < 50 m away from the roadways, respectively. Particularly, the association was more pronounced among individuals exposed to carbon monoxide (CO) pollution or opening windows frequently (Pinteraction < 0.05). Three-way interaction analyses confirmed that participants exposed to CO pollution and frequently leaving windows open had the highest OR of 1.73 (95% CI: 1.58-1.89).

CONCLUSIONS

This nation-wide cohort study suggested that residential proximity to major roadways was significantly associated with an increased exposure-response risk of HI in Chinese older adults. Exposure to CO pollution and opening windows frequently might strengthen the relations.

Hearing loss, depression, and cognition in younger and older adult CI candidates

Background and Aim

Hearing loss in old age is associated with cognitive decline and with depression. Our study aimed to investigate the relationship between hearing loss, cognitive decline, and secondary depressive symptoms in a sample of younger and older cochlear implant candidates with profound to severe hearing loss.

Methods

This study is part of a larger cohort study designated to provide information on baseline data before CI. Sixty-one cochlear implant candidates with hearing loss from adulthood onwards (>18 years) were enrolled in this study. All had symmetrical sensorineural hearing loss in both ears (four-frequency hearing threshold difference of no more than 20 dB, PTA). Individuals with primary affective disorders, psychosis, below-average intelligence, poor German language skills, visual impairment, and a medical diagnosis with potential impact on cognition (e.g., neurodegenerative diseases,) were excluded. Four-frequency hearing thresholds (dB, PTA, better ear) were collected. Using the Abbreviated Profile of Hearing Aid Benefit, we assessed subjective hearing in noise. Clinical and subclinical depressive symptoms were assessed with the Beck Depression Inventory (BDI II). Cognitive status was assessed with a neurocognitive test battery.

Results

Our findings revealed a significant negative association between subjective hearing in noise (APHAB subscale "Background Noise") and BDII. However, we did not observe any link between hearing thresholds, depression, and cognition. Additionally, no differences emerged between younger (25-54 years) and older subjects (55-75 years). Unexpectedly, further unplanned analyses unveiled correlations between subjective hearing in quiet environments (APHAB) and cognitive performance [phonemic fluency (Regensburg Word Fluency), cognitive flexibility (TMTB), and nonverbal episodic memory (Nonverbal Learning Test), as well as subjective hearing of aversive/loud sounds (APHAB)], cognitive performance [semantic word fluency (RWT), and inhibition (Go/Nogo) and depression]. Duration of hearing loss and speech recognition at quiet (Freiburg Monosyllables) were not related to depression and cognitive performance.

Conclusion

Impact of hearing loss on mood and cognition appears to be independent, suggesting a relationship with distinct aspects of hearing loss. These results underscore the importance of considering not only conventional audiometric measures like hearing thresholds but also variables related to hearing abilities during verbal communication in everyday life, both in quiet and noisy settings.

Cognitive control in age-related hearing loss: A narrative review

Recent evidence suggests links between hearing loss and cognitive impairment in older adults with peripheral age-related hearing loss (ARHL). Earliest cognitive changes have been observed in cognitive control; however, a cohesive account of cognitive control alterations in older adults with peripheral ARHL is lacking. Cognitive control refers to cognitive processes that manage and regulate one's behavior to achieve desired goals. This review summarizes behavioral evidence on alterations in three cognitive control processes, including cognitive flexibility, inhibitory control, and working memory updating, in individuals with ARHL. Of the three processes, cognitive flexibility and working memory updating have been most extensively studied, with relatively fewer studies examining inhibitory control. Most consistent evidence is observed for long-term changes in cognitive flexibility, particularly in individuals with greater severity of ARHL. Equivocal evidence is seen for alterations in inhibitory control and working memory updating, with various factors contributing to inconsistencies across studies. Our review summarizes the emerging body of research on cognitive control in individuals with ARHL to guide future work in this area and considerations related to the management of cognitive issues in this population.

The impact of hearing loss on cognitive impairment: The mediating role of depressive symptoms and the moderating role of social relationships

Background

Given the potentially negative effects of hearing loss on mental health and cognitive function, it is critical to gain a better understanding of the mechanisms underlying the link between hearing loss and cognitive impairment. This study aimed to investigate the moderating effects of social relationships, including their components in the role of depressive symptoms as a mediator between hearing loss and cognitive impairment.

Methods

Cross-sectional analyses were conducted with 8,094 Chinese older adults (aged ≥65 years) from the Chinese Longitudinal Healthy Longevity Survey in 2018. Simple mediation analysis and moderated mediation analysis were conducted to examine the roles of depressive symptoms and social relationships in the association between hearing loss and cognitive impairment.

Results

There is a significant correlation between hearing loss, depressive symptoms, social relationships, and cognitive function. Depressive symptoms partially mediated the association between hearing loss and cognitive function [standardized regression B-coefficient (B) = -0.114; 95% confidence interval (CI): (-0.158, -0.076)]. Social relationships moderated the effect of hearing loss on cognitive function through both path b (depressive symptoms - cognitive function) [B = 0.021; 95% CI: (0.008, 0.034)], and path c' (hearing loss-cognitive function) [B = 0.597; 95% CI: (0.463, 0.730)]. Furthermore, social activities and social networks moderated both the direct and indirect effects of moderated mediation. However, there appeared to be no moderated effect of social support for both the direct and indirect paths.

Conclusion

Social relationships moderated both the direct and indirect effects of depressive symptoms on the association between hearing loss and cognitive impairment. These findings shed light on the mechanisms underlying the relationship between hearing loss and cognitive impairment in Chinese older adults. It might be worthwhile to recommend multidimensional health and social interventions aimed at improving mental health and social inclusion among older adults with hearing loss.

Self-reported hearing loss and cognitive impairment: a cross-sectional analysis of the EpiFloripa Aging study

This study aimed to investigate the association between self-reported hearing loss and cognitive impairment in older adults in a city in Southern Brazil. In this cross-sectional, population-based cohort study of older adults, data were collected in the third wave of the EpiFloripa Aging study (2017/2019), which had been performed since 2009 in the city of Florianópolis, Santa Catarina State. Cognitive impairment was the dependent variable analyzed by the Mini-Mental State Examination (MMSE), and self-reported hearing loss, which was included in the cohort only in the last wave, was the main exposure variable. Logistic regression analyses were conducted, considering the study design and sample weights. Data from 1,335 older adults were evaluated. The prevalence was 20.5% for cognitive impairment and 10.7% for hearing loss. Older adults with hearing loss were 2.66 (95%CI: 1.08-6.54) times more likely to have cognitive impairment than older adults without hearing loss. The association between hearing loss and cognitive impairment highlights the need to integrate the early identification of these problems into primary care, as both are risk factors for healthy aging and potentially preventable and/or treatable conditions.

Risk factors for dementia in Brazil: Differences by region and race

INTRODUCTION

Twelve risk factors (RFs) account for 40% of dementia cases worldwide. However, most data for population attributable fractions (PAFs) are from high-income countries (HIC). We estimated how much these RFs account for dementia cases in Brazil, stratifying estimates by race and socioeconomic level.

METHODS

We calculated the prevalence and communalities of 12 RFs using 9412 Brazilian Longitudinal Study of Aging participants, then stratified according to self-reported race and country macro-regions.

RESULTS

The overall weighted PAF was 48.2%. Less education had the largest PAF (7.7%), followed by hypertension (7.6%), and hearing loss (6.8%). PAF was 49.0% and 54.0% in the richest and poorest regions, respectively. PAFs were similar among White and Black individuals (47.8% and 47.2%, respectively) but the importance of the main RF varied by race.

DISCUSSION

Brazil's potential for dementia prevention is higher than in HIC. Education, hypertension, and hearing loss should be priority targets.