Abstract

Cognitive health plays an important role in the quality of life and autonomy of older adults. and it is influenced by hearing ability. This article aims to analyze the association between self-perceived hearing status and cognitive impairment in Brazilian older adults. This cross-sectional population-based study was conducted with 4,977 older adults who participated in ELSI Brazil 2015. The cognitive impairment status (outcome. categorized as “yes” and “no”) and variable of interest (self-perceived hearing status. categorized as “good” “fair” and “poor”) were obtained using a self-report method. The following domains were considered for cognition: temporal orientation. memory (short and long term). and language (recent and late). Poisson regression with robust variance estimation was used to assess the self-perceived hearing status-cognitive impairment association in the crude and adjusted analyses. Sociodemographic. lifestyle. and medical history variables were used to adjust the analyses. We found that 31.8% of the participants reported fair or poor hearing and 42% had cognitive impairment. In the adjusted analysis. older adults with poor hearing were revealed to have a stronger association with cognitive impairment than their peers with good hearing. Therefore. in older Brazilian adults. lower self-perceived hearing status is associated higher levels of cognitive impairment.

Key words:
Hearing impairments; Hearing disorders; Cognitive impairment; Older adults

Introduction

Cognition refers to the individual mental process of acquiring, understanding and storing information through one’s senses and experiences. Cognitive functions are the mental abilities that enable the correct interpretation and management of environmental information. These skills are essential to perform everything from the simplest tasks of everyday life to the most complex ones¹1 Forte G, Favieri F, Casagrande M. Heart rate variability and cognitive function: a systematic review. Front Neurosci 2019; 13:710.^,22 Murman DL. The impact of age on cognition. Semin Hear 2015; 36(3):111-121..

Cognitive impairment is when an individual has difficulty remembering or memorizing information, learning new skills, concentrating, or making decisions that affect their daily life, and it can range from mild impairment to dementia³3 Lv X, Li W, Ma Y, Chen H, Zeng Y, Yu X, Hofman A, Wang H. Cognitive decline and mortality among community-dwelling Chinese older people. BMC Med 2019; 17(1):63.. In all situations, cognitive impairment can have a major impact on the individual’s general health and well-being⁴4 Centers for Disease Control and Prevention (CDC). Subjective Cognitive Decline - A Public Health Issue [Internet]. 2019. [cited 2019 jul 30]. Available from: https://www.cdc.gov/aging/data/subjective-cognitive-decline-brief.html
https://www.cdc.gov/aging/data/subjectiv... . Epidemiologic studies have shown that older adults with cognitive impairment have a higher risk of developing Alzheimer’s disease (AD)⁵5 Charchat-Fichman H, Caramelli P, Sameshima K, Nitrini R. Declínio da capacidade cognitiva durante o envelhecimento. Rev Bras Psiquiatr 2005; 27(1):79-82.

6 Davis M, O Connell T, Johnson S, Cline S, Merikle E, Martenyi F, Simpson K. Estimating Alzheimer's disease progression rates from normal cognition through mild cognitive impairment and stages of dementia. Curr Alzheimer Res 2018; 15(8):777-788.^-77 Kirova AM, Bays RB, Lagalwar S. Working memory and executive function decline across normal aging, mild cognitive impairment, and Alzheimer's disease. BioMed Res Int 2015; 2015:748212..

The Global Burden of Disease study determined that between 1990 and 2016, dementia cases increased by 117%, from 20.2 million in 1990 to 43.8 million in 2016⁸8 Launer LJ. Statistics on the burden of dementia: need for stronger data. Lancet Neurol 2019; 18(1):25-27.. In Brazil, about 1.2 million people live with some form of dementia, and 100.000 new cases are diagnosed yearly⁹9 Ministérios da Saúde (MS). Conhecer a demência, conhecer o Alzheimer: o poder do conhecimento - setembro, Mês Mundial do Alzheimer [Internet]. 2021. [acessado 2022 dez 19]. Disponível em: https://bvsms.saude.gov.br/conhecer-a-demencia-conhecer-o-alzheimer-o-poder-do-conhecimento-setembro-mes-mundial-do-alzheimer/
https://bvsms.saude.gov.br/conhecer-a-de... , probably due to the intense and rapid aging process caused by the demographic transition¹⁰10 Centro de Estudos Estratégicos da Fiocruz (CEE). O envelhecimento populacional compromete o crescimento econômico no Brasil? [Internet]. 2020. [acessado 2022 dez 19]. Disponível em: https://cee.fiocruz.br/?q=envelhecimento-populacional-compromete-o-crescimento-economico
https://cee.fiocruz.br/?q=envelhecimento... . Currently, more than 29 million Brazilians are over the age of 60¹¹11 Instituto Brasileiro de Geografia e Estatística (IBGE). População [Internet]. 2020. [acessado 2021 out 20]. Disponível em: https://www.ibge.gov.br/estatisticas/sociais/populacao.html
https://www.ibge.gov.br/estatisticas/soc... .

In this context, an important fact is that cognition and hearing are closely related and influence each other. Neurocognitive functions influence speech understanding, especially in challenging acoustic situations¹²12 Völter C, Götze L, Dazert S, Wirth R, Thomas JP. Impact of hearing loss on geriatric assessment. Clin Interv Aging 2020; 15:2453-2467.. According to the Global Burden of Disease study - GBD 2019, hearing loss (HL) is the third leading cause of age-related disability¹³13 GBD 2016 Disease and Injury Incidence and Prevalence Collaborators. Global, regional, and national incidence, prevalence, and years lived with disability for 328 diseases and injuries for 195 countries, 1990-2016: a systematic analysis for the Global Burden of Disease Study 2016. Lancet 2017; 390(10100):1211-1259.. Presbycusis, namely, age-related hearing loss, is the most common sensory impairment observed in older adults¹⁴14 Caruso MFB, Mármora CHC, Delgado FEF. Prevalência de perda auditiva autorrelatada em idosos e fatores associados em Juiz de Fora. Rev Hosp Univ Pedro Ernesto 2019; 17(2):35-42.. The causes of HL include physiological and degenerative changes in hearing-related structures and modifications in cognitive cortical areas¹⁵15 Davis A, McMahon CM, Pichora-Fuller KM, Russ S, Lin F, Olusanya BO, Chadha S, Tremblay KL. Aging and hearing health: the life-course approach. Gerontologist 2016; 56(Suppl. 2):S256-S267.. The onset of symptoms is gradual and subtle, since it primarily affects the detection of high-pitched sounds, interfering with speech understanding in noisy environments but not in quiet environments. Hence, this type of HL is often diagnosed late, thus delaying the onset of treatment¹⁶16 Glick HA, Sharma A. Cortical neuroplasticity and cognitive function in early-stage, mild-moderate hearing loss: evidence of neurocognitive benefit from hearing aid use. Front Neurosci 2020; 14:93..

Therefore, self-reported hearing impairment should be considered and investigated as soon as possible to avoid further long-term damage. Population-based epidemiological studies have used self-reported measures in this field since they are valid tools for screening large populations. Studies indicate that although self-reported hearing health assessment cannot replace an objective audiometric measurement, it is useful for data collection, providing important information on hearing loss among older adults¹⁷17 Yang TH, Chu YC, Chen YF, Chen MY, Cheng YF, Wu CS, Huang H-M. Diagnostic validity of self-reported hearing loss in elderly Taiwanese individuals: diagnostic performance of a hearing self-assessment questionnaire on audiometry. Int J Environ Res Public Health 2021; 18(24):13215.

18 Tsimpida D, Kontopantelis E, Ashcroft D, Panagioti M. Comparison of self-reported measures of hearing with an objective audiometric measure in adults in the English Longitudinal Study of Ageing. JAMA Netw Open 2020; 3(8):e2015009.^-1919 Amieva H, Ouvrard C, Giulioli C, Meillon C, Rullier L, Dartigues JF. Self-reported hearing loss, hearing aids, and cognitive decline in elderly adults: a 25-year study. J Am Geriatr Soc 2015; 63(10):2099-2104..

Importantly, a systematic review and meta-analysis aimed to analyze the association between cognitive function, cognitive impairment, and dementia. In this meta-analysis, the associations between cognitive impairment and dementia were small but significant. These results highlight the importance of further research and randomized controlled trials to examine the implications of treatment for cognition impairment and to explore the possible causal mechanisms underlying this relationship²⁰20 Loughrey DG, Kelly ME, Kelley GA, Brennan S, Lawlor BA. Association of age-related hearing loss with cognitive function, cognitive impairment, and dementia: a systematic review and meta-analysis. JAMA Otolaryngol Head Neck Surg 2018; 144(2):115-126..

Hearing acuity assessment has been widely studied; however, we couldn’t find studies investigating the association between self-perceived hearing and cognitive function. Self-perceived hearing is a good screening tool for HL, as it identifies people who need specific and objective assessments to treat hearing disorders²¹21 Fiamoncini JD, Silva AO, Sousa TR de, Satler CE, Silva IMC, Cera ML. Associação entre o desempenho linguístico-cognitivo e a autopercepção auditiva de idosos. Audiol Commun Res 2022; 27:e2597..

Since there is a gap in the literature on the association between self-perceived hearing status and cognitive impairment and hearing loss significantly affects the individual’s social participation, which can lead to impairment in cognitive functions³3 Lv X, Li W, Ma Y, Chen H, Zeng Y, Yu X, Hofman A, Wang H. Cognitive decline and mortality among community-dwelling Chinese older people. BMC Med 2019; 17(1):63., this study aims to analyze the association between self-perceived hearing status and cognitive impairment in a sample of older Brazilian adults.

Method

Study design

This cross-sectional study was based on the Brazilian Longitudinal Study of Aging database conducted in 2015-2016 (ELSI-Brazil). ELSI-Brazil is a household-based survey conducted on a nationally representative Brazilian population aged 50 and above. ELSI-Brazil complies with National Health Council resolutions, such as 196/96, and its complementary resolutions, including 292/99, 340/2004, 346/2005, 347/2005, and 466/2012. This study was approved by the Research Ethics Committee (CEP) of the René Rachou Research Center of the Oswaldo Cruz Foundation, and the process is registered in Plataforma Brasil (Protocol no. 886.754)²²22 ELSI-BRASIL. Estudo Longitudinal da Saúde dos Idosos Brasileiros [Internet]. 2015. [acessado 2020 mar 14]. Disponível em: http://elsi.cpqrr.fiocruz.br/
http://elsi.cpqrr.fiocruz.br... .

Participants and eligibility criteria

The ELSI-Brazil survey included 9,400 individual respondents from 70 municipalities in different regions of Brazil. The inclusion criterion for the current study was individuals aged 60 and above who answered the question, “How do you rate your hearing - even if you wear a hearing aid?”²²22 ELSI-BRASIL. Estudo Longitudinal da Saúde dos Idosos Brasileiros [Internet]. 2015. [acessado 2020 mar 14]. Disponível em: http://elsi.cpqrr.fiocruz.br/
http://elsi.cpqrr.fiocruz.br... . Participants with incomplete data were excluded. Thus, the final study sample comprised 4,977 participants.

Cognitive impairment

Cognitive impairment data came from the ELSI - Brazil Study, which uses a battery of tests applied in longitudinal studies conducted in different countries on the health of older adults, an initiative known as “The Health and Retirement Study”²³23 Aliberti MJR, Szlejf C, Lima-Costa MF, de Andrade FB, Alexandre TS, Ferri CP, Suemoto CK. Frailty modifies the association of hypertension with cognition in older adults: evidence from the ELSI-Brazil. J Gerontol A Biol Sci Med Sci 2021; 76(6):1134-1143..

The Health and Retirement Study (HRS) is a nationally representative longitudinal survey of more than 37,000 individuals in the USA over 50. The survey, conducted every two years since 1992, was created to provide a national resource for data on the changing economic and health circumstances associated with aging, both at the individual and population levels. Its multidisciplinary approach focuses on four broad topics: income and wealth; health, cognition, and use of health services; work and retirement; and family connections²⁴24 Sonnega A, Faul JD, Ofstedal MB, Langa KM, Phillips JWR, Weir DR. Cohort profile: the Health and Retirement Study (HRS). Int J Epidemiol 2014; 43(2):576-585..

The cognition section of the HRS is categorized into self-rated metamemory, memory, and mental processing (immediate and delayed recall, timed backward counting, serial subtraction of seven, date/object/president/vice-president naming, vocabulary, numeration, retrieval fluency, number series, and verbal reasoning), and depressive symptoms, with proxy classification of global memory (present and past) and respondent memory change²⁴24 Sonnega A, Faul JD, Ofstedal MB, Langa KM, Phillips JWR, Weir DR. Cohort profile: the Health and Retirement Study (HRS). Int J Epidemiol 2014; 43(2):576-585..

For the cognitive function variable, three domains from the ELSI-Brazil questionnaire²²22 ELSI-BRASIL. Estudo Longitudinal da Saúde dos Idosos Brasileiros [Internet]. 2015. [acessado 2020 mar 14]. Disponível em: http://elsi.cpqrr.fiocruz.br/
http://elsi.cpqrr.fiocruz.br... were considered: temporal orientation, memory (short-term and long-term), and language.

Temporal orientation: refers to the individual’s ability to orient oneself in time and process information related to time, day, month, year, and seasons²⁵25 Breska A, Ivry RB. The human cerebellum is essential for modulating perceptual sensitivity based on temporal expectations. eLife 2021; 10:e66743.. Therefore, ELSI-Brazil participants were asked about the date, month, year, and day of the week, and the accuracy of the answers was checked (question codes q6, q7, q8, and q9 of the individual questionnaire of ELSI-Brazil)²²22 ELSI-BRASIL. Estudo Longitudinal da Saúde dos Idosos Brasileiros [Internet]. 2015. [acessado 2020 mar 14]. Disponível em: http://elsi.cpqrr.fiocruz.br/
http://elsi.cpqrr.fiocruz.br... .

Memory: short-term memory is the ability to receive and store newly acquired information within a short time²⁶26 Norris D. Short-term memory and long-term memory are still different. Psychol Bull 2017; 143(9):992-1009.. In the ELSI-Brazil study, short-term memory was measured by asking the individual to repeat ten words immediately after reading them (question code q13 of the individual questionnaire)²²22 ELSI-BRASIL. Estudo Longitudinal da Saúde dos Idosos Brasileiros [Internet]. 2015. [acessado 2020 mar 14]. Disponível em: http://elsi.cpqrr.fiocruz.br/
http://elsi.cpqrr.fiocruz.br... . Long-term memory is the ability to retain fundamental information, either understanding importance or repetition²⁶26 Norris D. Short-term memory and long-term memory are still different. Psychol Bull 2017; 143(9):992-1009.. In the ESLI-Brazil study, it was measured by asking the individual to repeat ten words five minutes after reading them. Scores were computed separately from 0 to 10 for the number of evoked words (immediate and delayed) (question code q17 of the individual questionnaire)²²22 ELSI-BRASIL. Estudo Longitudinal da Saúde dos Idosos Brasileiros [Internet]. 2015. [acessado 2020 mar 14]. Disponível em: http://elsi.cpqrr.fiocruz.br/
http://elsi.cpqrr.fiocruz.br... .

Language: language comprises a system of signs used to establish communication²⁷27 Sá APS. Linguagem científica: características e importância [Internet]. 2017. [acessado 2021 nov 15]. Disponível em: https://ambitojuridico.com.br/edicoes/revista-166/linguagem-cientifica-caracteristicas-e-importancia/amp/
https://ambitojuridico.com.br/edicoes/re... . For this variable, individuals were asked to name two objects by their characteristics (scissors and banana) and call the current president and vice-president of Brazil at the time of the survey. The answers were computed as correct, incorrect, and do not know (question codes q18, q19, q20, and q21 of the individual questionnaire)²²22 ELSI-BRASIL. Estudo Longitudinal da Saúde dos Idosos Brasileiros [Internet]. 2015. [acessado 2020 mar 14]. Disponível em: http://elsi.cpqrr.fiocruz.br/
http://elsi.cpqrr.fiocruz.br... .

After the tests were verified, analyses were conducted by obtaining the z scores for each domain. For memory analysis, the z score was considered for both tests (short-term and long-term memory). For the temporal orientation and language domains, each correct answer was considered equivalent to 1 point, with a total of 4 points. The z score of each test was calculated from the values obtained, and measures were used in standardized formats: “observed value - mean/average”. Finally, a global z score was generated covering the three domains of cognitive function. The average of the three parameters (temporal orientation, memory, and language) was used for this measure. This was subsequently standardized according to the mean and standard deviation (SD) of the sample studied. Thus, cognitive impairment was defined for participants with a global z score equal to or less than -1SD²³23 Aliberti MJR, Szlejf C, Lima-Costa MF, de Andrade FB, Alexandre TS, Ferri CP, Suemoto CK. Frailty modifies the association of hypertension with cognition in older adults: evidence from the ELSI-Brazil. J Gerontol A Biol Sci Med Sci 2021; 76(6):1134-1143..

Exposure variable

Data on the variable of interest, self-perceived hearing, were obtained from self-reported answers to the question: “How do you rate your hearing - even if you wear a hearing aid?” (question 16 of the individual questionnaire). For this question, the original questionnaire offers the following response options: very good or excellent, good, fair, poor, and very poor. For this study, the responses were categorized as good (including very good or excellent and good), fair, and poor (including poor and very poor)²²22 ELSI-BRASIL. Estudo Longitudinal da Saúde dos Idosos Brasileiros [Internet]. 2015. [acessado 2020 mar 14]. Disponível em: http://elsi.cpqrr.fiocruz.br/
http://elsi.cpqrr.fiocruz.br... .

Adjustment variables

To adjust the models used, we used sociodemographic variables, such as sex (female and male), age (60-69 years, 70-79 years, and ≥ 80)²⁸28 Baraldi GS, Almeida LC, Borges ACC. Evolução da perda auditiva no decorrer do envelhecimento. Rev Bras Otorrinolaringol 2007; 73(1):64-70., education (never studied, elementary school, high school, undergraduate or more)²⁹29 Instituto de Pesquisa Econômica Aplicada (IPEA). Os níveis de escolaridade no setor público brasileiro [Internet]. 2017. [acessado 2021 nov 15]. Disponível em: https://www.ipea.gov.br/atlasestado/arquivos/rmd/4874-conjunto4v10.html
https://www.ipea.gov.br/atlasestado/arqu... , cognitive impairment (yes and no); lifestyle variables, such as physical activities (practice of physical exercises categorized as none, occasionally, regularly, and daily)³⁰30 Organização Mundial de Saúde (OMS). Atividade física [Internet]. 2020. [acessado 2022 nov 16]. Disponível em: https://www.who.int/news-room/fact-sheets/detail/physical-activity
https://www.who.int/news-room/fact-sheet... , alcohol consumption (yes and no)³¹31 Organização Mundial de Saúde (OMS). I Levantamento nacional sobre os padrões de consumo de álcool na população brasileira [Internet]. 2004. [acessado 2021 nov 17]. Disponível em: https://bvsms.saude.gov.br/bvs/publicacoes/relatorio_padroes_consumo_alcool.pdf
https://bvsms.saude.gov.br/bvs/publicaco... , smoking (yes and no)³²32 Campos MW, Serebrisky D, Castaldelli-Maia JM. Smoking and cognition. Curr Drug Abuse Rev 2016; 9(2):76-79.; use of individual sound amplification device (ISAD) (self-reported as no and yes); and clinical history variables, such as depression, diabetes, hypertension, heart failure, and stroke. These were assessed through self-reports; the participants were asked if they were diagnosed with any of these conditions, and yes and no answers were considered²²22 ELSI-BRASIL. Estudo Longitudinal da Saúde dos Idosos Brasileiros [Internet]. 2015. [acessado 2020 mar 14]. Disponível em: http://elsi.cpqrr.fiocruz.br/
http://elsi.cpqrr.fiocruz.br... .

Data analysis

Data were presented as absolute and relative frequencies, considering the complex sample weights. Thus, the relative frequencies and other analyses were weighted, considering the characteristics of the sample, non-responses, and calibration. Poisson regression models with robust variance estimation were fitted independently for each adjustment variable.

Considering cognitive impairment as a reference category, crude and adjusted prevalence ratios were estimated for sociodemographic variables (Model 1: sex, age, and education), clinical history (Model 2: depression, diabetes, hypertension, heart failure, and stroke), and lifestyle (Model 3: physical activities, alcohol consumption, smoking, and use of ISAD). The adjustment variables were listed based on the literature and analyzed for correlation using the chi-square test. The final model, adjusted for all independent variables, was then used. The results were presented as prevalence ratios (PR) at 95% confidence intervals (95%CI); Tables 1 and 2 consider the weighted proportions obtained by multiplying each value by its respective weight and dividing it by the sum of the weights with a p-value of 0.05 at least for statistical significance. The Sandwich packages in R software²³23 Aliberti MJR, Szlejf C, Lima-Costa MF, de Andrade FB, Alexandre TS, Ferri CP, Suemoto CK. Frailty modifies the association of hypertension with cognition in older adults: evidence from the ELSI-Brazil. J Gerontol A Biol Sci Med Sci 2021; 76(6):1134-1143. were used for all the analyses considering the study’s complex sample design.

Results

The study sample comprised 4,977 older adults from the ELSI-Brazil cohort study baseline. Among these participants, 58% had no cognitive impairment, and 68.2% rated their hearing as good, 26.6% as fair, and 5.2% as poor. Regarding sociodemographic characteristics, 50.1% were female, 62.5% were aged 60-69 years, and 61.9% had completed elementary education (Table 1).

Regarding lifestyle, 42.8% of the sample reported not practicing physical activity, 85.2% reported not smoking, and 71.3% did not consume alcohol. Regarding clinical history, hypertension was the most prevalent chronic disease, affecting 61.6% of the sample. Furthermore, 97.7% reported not using an ISAD (Table 2).

The univariate analysis results of the association between the domains of cognitive impairment and self-perceived hearing status are in Table 3. We emphasize that altered memory, whether short- or long-term, seems to be associated with poor self-perceived hearing status.

In the crude analysis, the highest association between self-perceived hearing status and cognitive impairment was observed in individuals who reported poor auditory perception (PR = 1.53; 95%CI 1.52-1.56) about those who reported good auditory perception. In the final adjustment model, considering adjustments for sociodemographic and lifestyle variables and clinical history, individuals with poor hearing perception had a 22% higher strength of association for cognitive impairment compared with individuals with good hearing perception (PR = 1.22; 95%CI 1.22-1.25). Individuals with fair hearing perception had a 10% higher strength of association for cognitive impairment compared with individuals with good hearing perception (PR = 1.10; 95%CI% 1.08-1.12) (Table 4).

Discussion

The findings of this study indicate an association between self-perceived hearing status and cognitive impairment, as individuals who reported fair or poor auditory perception had a higher prevalence of cognitive impairment than individuals with good self-perceived hearing status. Furthermore, a higher association between hearing and cognitive impairment is shown when results related to lifestyle factors and clinical history are controlled by cofounders as sociodemographic factors, such as sex, age, education, lifestyle factors, and health conditions, variables known to be associated with cognitive impairment¹1 Forte G, Favieri F, Casagrande M. Heart rate variability and cognitive function: a systematic review. Front Neurosci 2019; 13:710.. In addition, the gradual progress of presbycusis leads to restricted social participation since people with hearing loss adapt their daily activities to avoid situations of communicative difficulty; thus, the cognitive health of older adults is affected³³33 Costa-Guarisco LP, Dalpubel D, Labanca L, Chagas MHN. Percepção da perda auditiva: utilização da escala subjetiva de faces para triagem auditiva em idosos. Cien Saude Colet 2017; 22(11):3579-3588..

Aging is marked by the degeneration processes of several systems, with HL and cognitive impairment usually being the most evident³³33 Costa-Guarisco LP, Dalpubel D, Labanca L, Chagas MHN. Percepção da perda auditiva: utilização da escala subjetiva de faces para triagem auditiva em idosos. Cien Saude Colet 2017; 22(11):3579-3588.. The pathophysiology of presbycusis includes degenerative changes in the structures of the inner ear (e.g., loss of inner and outer hair cells, deterioration of spiral ganglion cells, and atrophy of the stria vascularis) and altered neural processing of auditory input³⁴34 Castiglione A, Benatti A, Velardita C, Favaro D, Padoan E, Severi D, Pagliaro M, Bovo R, Vallesi A, Gabelli C, Martini A. Aging, cognitive decline and hearing loss: effects of auditory rehabilitation and training with hearing aids and cochlear implants on cognitive function and depression among older adults. Audiol Neurotol 2016; 21(Suppl. 1):21-28.. One of the ways to reduce the damage caused by hearing loss is to use an individual sound amplification device (ISAD). However, most of the individuals in this study did not use the device (97.7%).

Moreover, studies have pointed out that clinical indications for hearing aid treatment, including hearing aids and cochlear implants (CI), raise expectations of their potential positive effects on cognitive functions and mood disorders among older individuals. Hearing rehabilitation can improve and restore the auditory perceptual skills needed for speech, thus contributing to social participation and, consequently, to this population’s good functioning and cognitive maintenance³⁴34 Castiglione A, Benatti A, Velardita C, Favaro D, Padoan E, Severi D, Pagliaro M, Bovo R, Vallesi A, Gabelli C, Martini A. Aging, cognitive decline and hearing loss: effects of auditory rehabilitation and training with hearing aids and cochlear implants on cognitive function and depression among older adults. Audiol Neurotol 2016; 21(Suppl. 1):21-28.^,3535 Hear-it. Há muitos benefícios com o uso de aparelhos auditivos [Internet]. 2019. [acessado 2021 set 20]. Disponível em: https://www.hear-it.org/pt/ha-muitos-beneficios-com-o-uso-de-aparelhos-auditivos
https://www.hear-it.org/pt/ha-muitos-ben... .

The influence of years of schooling on cognitive processes should also be highlighted, as a higher level of education is positively associated with increased and maintained cognitive function throughout life³⁶36 Rutherford BR, Brewster K, Golub JS, Kim AH, Roose SP. Sensation and psychiatry: linking age-related hearing loss to late-life depression and cognitive decline. Am J Psychiatry 2018; 175(3):215-224.^,3737 Clouston SAP, Smith DM, Mukherjee S, Zhang Y, Hou W, Link BG, Richards M. Education and cognitive decline: an integrative analysis of global longitudinal studies of cognitive aging. J Gerontol B Psychol Sci Soc Sci 2020; 75(7):e151-e160.. A lengthy study time may delay the onset and rapid progression of symptoms of cognitive impairment since it does not influence the evolutionary process of aging but may affect the time at which accelerated declines occur³⁶36 Rutherford BR, Brewster K, Golub JS, Kim AH, Roose SP. Sensation and psychiatry: linking age-related hearing loss to late-life depression and cognitive decline. Am J Psychiatry 2018; 175(3):215-224.. An essential fact in this context is that individuals with HL have more significant learning difficulties and fewer years of study, a factor that may contribute to the loss of cognitive function in this population³⁸38 Zaidman-Zait A, Most T. Pragmatics and peer relationships among deaf, hard of hearing, and hearing adolescents. Pediatrics 2020; 146(Suppl. 3):S298-S303.

39 Paatsch L, Toe D. The impact of pragmatic delays for deaf and hard of hearing students in mainstream classrooms. Pediatrics 2020;146(Suppl. 3):S292-S297.^-4040 Ziliotto DM, Souza DJ, Andrade FI. Quando a inclusão não se efetiva: a evasão de alunos surdos ou com deficiência auditiva no ensino superior. Rev Educ Espec 2018; 31(62):727..

Additionally, low levels of schooling, which is a common phenomenon in different regions of Brazil and compromises access to health education - a strategy that enables the adoption of healthy behaviors and social mobilization to improve living conditions - influence adherence to the treatment of chronic diseases and may present difficulties in understanding the guidelines⁴¹41 Lima-Costa MF, Barreto S, Giatti L. A situação socioeconômica afeta igualmente a saúde de idosos e adultos mais jovens no Brasil? Um estudo utilizando dados da Pesquisa Nacional por Amostras de Domicílios PNAD/98. Cien Saude Colet 2002; 7(4):813-824.. In addition to these issues, poverty is related to the health conditions of individuals; a study conducted in Brazil using data from the Brazilian Household Sample Survey (PNAD in Portuguese) from 1998 found that social inequalities affect health conditions and the use of health services among older adults⁴¹41 Lima-Costa MF, Barreto S, Giatti L. A situação socioeconômica afeta igualmente a saúde de idosos e adultos mais jovens no Brasil? Um estudo utilizando dados da Pesquisa Nacional por Amostras de Domicílios PNAD/98. Cien Saude Colet 2002; 7(4):813-824.^,4242 Lima-Costa MF. A escolaridade afeta, igualmente, comportamentos prejudiciais à saúde de idosos e adultos mais jovens? Inquérito de Saúde da Região Metropolitana de Belo Horizonte, Minas Gerais, Brasil. Epidemiol Serv Saude 2004;13(4):201-208..

It is essential to highlight the impact of medical history and lifestyle on individuals and the risks of developing cognitive impairment, both observed in this study sample. Lifestyle factors such as regular physical exercise⁴³43 Brasure M, Desai P, Davila H, Nelson VA, Calvert C, Jutkowitz E, Butler M, Fink HA, Ratner E, Hemmy LS, McCarten JR, Barclay TR, Kane RL. Physical activity interventions in preventing cognitive decline and Alzheimer-type dementia: a systematic review. Ann Intern Med 2018; 168(1):30-38.

44 Guure CB, Ibrahim NA, Adam MB, Said SM. Impact of physical activity on cognitive decline, dementia, and its subtypes: meta-analysis of prospective studies. BioMed Res Int 2017; 2017:9016924.^-4545 Karssemeijer EGA, Aaronson JA, Bossers WJ, Smits T, Olde Rikkert MGM, Kessels RPC. Positive effects of combined cognitive and physical exercise training on cognitive function in older adults with mild cognitive impairment or dementia: a meta-analysis. Ageing Res Rev 2017; 40:75-83., reduced smoking⁴⁶46 Wingbermühle R, Wen KX, Wolters FJ, Ikram MA, Bos D. Smoking, APOE genotype, and cognitive decline: The Rotterdam Study. J Alzheimers Dis JAD 2017; 57(4):1191-1195., and alcohol consumption⁴⁷47 Koch M, Fitzpatrick AL, Rapp SR, Nahin RL, Williamson JD, Lopez OL, DeKosky ST, Kuller LH, Mackey RH, Mukamal KJ, Jensen MK, Sink KM. Alcohol consumption and risk of dementia and cognitive decline among older adults with or without mild cognitive impairment. JAMA Netw Open 2019; 2(9):e1910319. affected HL and, consequently, cognitive function.

According to the Brazilian Ministry of Health, approximately 57.4 million people nationwide have at least one chronic non-communicable disease (NCD). Biological factors, such as genetic load, sex, age, and habits and behaviors that affect health, such as physical inactivity, inadequate diet, obesity, smoking, and alcohol abuse, facilitate their development⁴⁸48 Organização Mundial de Saúde (OMS). Doenças e agravos não transmissíveis [Internet]. 2019. [acessado 2021 out 3]. Disponível em: https://www.saude.pr.gov.br/Pagina/Doencas-e-agravos-nao-transmissiveis.
https://www.saude.pr.gov.br/Pagina/Doenc... . Diseases such as hypertension, depression, stroke, and heart failure were notably prevalent in the sample, significantly affecting the results of this study.

Furthermore, in terms of NCDs, hypertension, and diabetes are known to influence cardiovascular changes, such as stroke, which in turn is a risk factor for cognitive impairment⁴⁹49 Menezes TN, Oliveira ECT, Fischer MATS, Esteves GH. Prevalência e controle da hipertensão arterial em idosos: um estudo populacional. Rev Port Saude Publica 2016; 34(2):117-124.

50 Livingston G, Sommerlad A, Orgeta V, Costafreda SG, Huntley J, Ames D, Ballard C, Banerjee S, Burns A, Cohen-Mansfield J, Cooper C, Fox N, Gitlin LN, Howard R, Kales HC, Larson EB, Ritchie K, Rockwood K, Sampson EL, Samus Q, Schneider LS, Selbæk G, Teri L, Mukadam N. Dementia prevention, intervention, and care. Lancet 2017; 390(10113):2673-734.^-5151 Kalaria RN, Akinyemi R, Ihara M. Stroke injury, cognitive impairment and vascular dementia. Biochim Biophys Acta 2016; 1862(5):915-925.. There is strong epidemiological evidence of the relationship between diabetes and cognitive impairment. Furthermore, the study also examined the correlation between hearing impairments and identified various contributing factors⁵²52 Konrad-Martin D, Reavis KM, Austin D, Reed N, Gordon J, McDermott D, et al. Hearing impairment in relation to severity of diabetes in a veteran cohort. Ear Hear 2015; 36(4):381-394.

53 David LZ, Finamor MM, Buss C. Possíveis implicações audiológicas do diabetes melito: uma revisão de literatura. Rev CEFAC 2015; 17(6):2018-2024.^-5454 Biessels GJ, Despa F. Cognitive decline and dementia in diabetes mellitus: mechanisms and clinical implications. Nat Rev Endocrinol 2018; 14(10):591-604..

This study was limited to a cross-sectional analysis of the association between self-perceived hearing status and cognitive impairment, exposing prevalence results in the population studied at the population level. Hence, the causal relationships between the factors under study as well as their incidence in the elderly population were not analyzed. However, this study brings a relevant approach to the analysis of human aging processes, being an essential source of information for public health actions for older adults.

In addition, this study is relevant because it is the first thus far to analyze the association between self-perceived hearing status and cognitive impairment using a complex population-based sample representative of the older Brazilian population. In addition, the data used for the analyses were obtained from the ELSI-Brazil study, concurring with the literature on the reliability and validity of self-report studies²²22 ELSI-BRASIL. Estudo Longitudinal da Saúde dos Idosos Brasileiros [Internet]. 2015. [acessado 2020 mar 14]. Disponível em: http://elsi.cpqrr.fiocruz.br/
http://elsi.cpqrr.fiocruz.br... ^,5555 Morimoto SS, Kanellopoulos D, Manning KJ, Alexopoulos GS. Diagnosis and treatment of depression and cognitive impairment in late life. Ann N Y Acad Sci 2015; 1345(1):36-46. since self-reporting is an easy and practical way to apply population-based surveys⁵⁵55 Morimoto SS, Kanellopoulos D, Manning KJ, Alexopoulos GS. Diagnosis and treatment of depression and cognitive impairment in late life. Ann N Y Acad Sci 2015; 1345(1):36-46..

Conclusion

This study highlights the association between cognitive impairment and fair and poor self-perceived hearing in older Brazilian adults compared to older Brazilian adults with good self-perceived hearing. These findings support the need for hearing screenings, self-perception assessments, and hearing treatment programs at the national level in this population since these measures and actions can prevent changes in cognitive health.

Furthermore, we emphasize that the results obtained in this study point to the need for longitudinal studies on the subject to analyze the causal relationship between hearing and cognitive changes among older adults in Brazil and the potential effects of auditory rehabilitation interventions on the cognitive aspect, with emphasis on early intervention for short- and medium-term memory functions. In addition, other studies that deepen the understanding of the etiopathogenesis of HL and cognitive decline are also necessary so that the mechanisms of their association are elucidated.

References

Publication Dates

History