Bibliometric and bioinformatics analysis of genetic literature on susceptibility to noise induced hearing loss / 中华劳动卫生职业病杂志

Objective: To summarize and analyse of literature on the susceptibility genes of noise induced hearing loss (NIHL) , and the key genes were screened and obtained by bioinformatics method, so as to provide reference for the prevention research of NIHL. Methods: In September 2021, Based on CNKI, NCBI Pubmed database and Web of Science database, this paper conducted bibliometric analysis and bioinformatics analysis on the genetic literature related to the susceptibility to noise-induced hearing loss from 1999 to 2020. Endnote X9 software and the WPS office software were used for bibliometric analysis, and online software STRING and Cytoscape software were used for bioinformatics analysis. Results: A total of 131 literatures were included in the study, involving 40 genes in total. Bibliometric analysis shows that 131 papers which included 36 Chinese articles and 95 English articles were published in 63 biomedical journals; the highest number of published articles was 19 in 2020. Bioinformatics analysis suggests that GAPDH、SOD2、SOD1、CAT、CASP3、IL6 and other genes play a key role in the interaction network. The involved pathways mainly include MAP2K and MAPK activations, PTEN regulation, P53-depardent G1 DNA damage response, signaoling by BRAF and RAF fusions and soon. Conclusion: The study of noise induced hearing loss involves multi gene biological information, and bioinformatics analysis is helpful to predict the occurrence and development of noise induced hearing loss.

The circadian timing of noise exposure influences noise-induced inflammatory responses in the mouse cochlea

Abstract Introduction: Noise-induced hearing loss is one of the most common forms of sensorineural hearing loss. Nevertheless, the mechanisms of noise-induced hearing loss are still not fully understood. Objective: To investigate the dynamics of inflammatory responses in the mammalian cochlea following noise trauma at two different times, once during the light cycle and once during the dark. Methods: We challenged C57BL/6J mice with moderate, continuous noise trauma at either 9 a.m. or 9 p.m. Auditory function, histological changes in hair cells, and modifications in gene expression levels of inflammatory mediators were assessed at specific time points. Shifts in auditory brainstem response thresholds were measured at 1, 3, 7 and 14 days after noise exposure to measure potential noise-induced hearing loss. Cochlear basilar-membrane immunofluorescent staining was performed at 3 and 14 days after noise exposure. The mRNA levels of several inflammatory mediators were measured via quantitative real-time polymerase chain reaction before (pre) and after (0, 3, 12, 24 and 72 h) noise exposure. Results: We found that all noise-exposed mice developed a temporary threshold shift and that there were no significant differences between daytime and nighttime noise exposures in terms of inducing hearing-threshold shifts. Similarly, we did not detect significant histological changes in hair cells between these two groups. However, we discovered an interesting phenomenon in that the peak mRNA levels of IL-1β, IL-6, CCL2 and TNF-α were higher in day noise-exposed mice compared to those in night noise-exposed mice, and these mRNA levels subsided more slowly in day noise-exposed mice. Conclusion: Overall, these observations suggest that the circadian timing of noise exposure has a significant effect on noise-induced inflammatory responses in the mouse cochlea and that a greater inflammatory response might occur after daytime exposure.

Is it necessary to perform occupational audiometric testing at 6-months of employment? / É necessário fazer teste audiométrico ocupacional 6 meses após a admissão?

Abstract Introduction: Current Brazilian legislation requires that all workers exposed to noise are to be given an audiogram upon hiring, after 6 months of employment (first periodic test), and annually after the first periodic test. In other countries, the regulations of hearing conservation programs do not include the requirement for audiometric testing at 6 months of employment, but only annually. There is no evidence that the periodicity adopted by Brazilian legislation is the most appropriate. Objective: The present study aimed to evaluate the first 3 occupational audiometric tests of workers exposed to noise. Methods: Historical cohort study with cross-sectional analysis. Participants were all male metallurgy workers aged up to 40 years. The first 3 audiograms of each worker were analyzed: pre-employment audiometric test, periodic audiometric test 1, and periodic audiometric test 2. For each worker, mean frequency thresholds were calculated at 3, 4, and 6 kHz in the left and right ears for each test. Statistical analysis was performed using the nonparametric Wilcoxon test. Results: A total of 988 workers were included. There was a significant difference in auditory thresholds between the pre-employment test and the 2 subsequent periodic tests for the right and left ears. There was no significant difference between Test1 and Test2 in either ear. Conclusion: Given the lack of difference between the first 2 periodic tests, we believe that they could be merged into a single test, i.e., first periodic audiometric testing could be performed at 12 months of employment without compromising workers' health.

Resumo Introdução: A legislação brasileira atual exige que todos os trabalhadores expostos a ruído recebam um audiograma na admissão, 6 meses após a admissão (primeiro teste periódico), e anualmente após o primeiro teste periódico, mas em outros países as regulamentações dos programas de conservação auditiva não incluem a exigência de teste audiométrico após 6 meses de admissão, mas apenas anualmente. Não há evidências de que a periodicidade adotada pela legislação brasileira seja a mais adequada. Objetivo: Avaliar os três primeiros exames audiométricos ocupacionais de trabalhadores expostos ao ruído. Método: Estudo de coorte histórica com análise transversal. Os participantes eram todos trabalhadores metalúrgicos do sexo masculino com até 40 anos. Os três primeiros audiogramas de cada trabalhador foram analisados: teste audiométrico pré-admissão, teste audiométrico periódico 1 e teste audiométrico periódico 2. Para cada trabalhador, os limiares de frequência médios foram calculados em 3, 4 e 6 kHz nas orelhas esquerda e direita para cada teste. A análise estatística foi feita através do teste não paramétrico de Wilcoxon. Resultados: Foram incluídos 988 trabalhadores. Houve uma diferença significante nos limiares auditivos entre o teste pré-admissão e os 2 testes periódicos subsequentes para as orelhas direita e esquerda. Não houve diferença significante entre o teste 1 e o teste 2 em nenhuma das orelhas. Conclusão: Dada a falta de diferença entre os 2 primeiros testes periódicos, acreditamos que eles poderiam ser combinados em um único teste, ou seja, o primeiro teste audiométrico periódico poderia ser feito após 12 meses de admissão sem comprometer a saúde dos trabalhadores.

The effectiveness of berberine on noise-induced hearing loss: a rat model

SUMMARY OBJECTIVE: Noise-induced hearing loss is a preventable form of hearing loss that has serious social and economic impacts. This study aimed to investigate the protective effect of berberine, a potent antioxidant and anti-inflammatory agent, against Noise-induced hearing loss. METHODS: After applying distortion product otoacoustic emission, 28 female Sprague-Dawley rats were randomly divided into four groups. Group 1 was designated as acoustic trauma group, and rats in this group were exposed to white noise for 12 h at an intensity of 4 kHz 110 dB sound pressure level. Group 2 was the control group. Group 3 was designated as the berberine group, and 100 mg/kg of berberine was administered to rats in this group by intragastric lavage for five consecutive days. Group 4 was designated as the acoustic trauma+berberine group. distortion product otoacoustic emission was repeated on the 6th day of the study and cochlear tissues of rats were dissected for histopathological and immunohistochemical analyses after sacrificing rats. RESULTS: The distortion product otoacoustic emission results showed a significant decrease in signal-noise ratio values at higher frequencies in rats of the trauma group compared to those in other groups. Acoustic trauma caused severe histopathological impairment at cochlear structures together with severe 8-hydroxy-2-deoxyguanosine expression. Rats in the acoustic trauma+berberine group showed mild histopathological changes with mild 8-hydroxy-2-deoxyguanosine expression and better signal-noise ratio values. CONCLUSION: The histopathological and audiological findings of this experimental study showed that berberine provides protection in Noise-induced hearing loss and may have the potential for use in acoustic trauma-related hearing losses.

The relationship between anxiety- and depression-like behavior and regional homogeneity of fMRI in inferior colliculus and ventrolateral orbital cortex in rats with noise-induced hearing loss / 中华行为医学与脑科学杂志

Objective:To investigate the local consistency of inferior colliculus and ventrolateral orbital cortex by resting-state functional magnetic resonance imaging (fMRI) in rats with noise induced deafness and its relationship with anxiety- and depression-like behavior.Methods:Twenty-four clean grade male four-weeks old SD rats were randomly divided into noise group and control group with 12 rats in each group.Rats in the noise group were exposed to 122 dB broadband strong noise for 2 hours to induce severe bilateral hearing loss, while rats in the control group were placed in a quiet environment. Hearing thresholds were assessed by auditory brainstem response (ABR) test. The open field test (OFT) was conducted to examine anxiety-depression related behavior, and the local consistency in the rat brain was evaluated by fMRI.SPM12 software was used to process fMRI data, and Pearson correlation analysis was conducted by SPSS 22.0 software to calculate the correlation between fMRI data and behavior.Results:The results of ABR showed that the full band hearing threshold of rats in the noise group was higher than that of rats in the control group ((85.417±6.463) dB, (20.083±8.853) dB, t=46.168, P<0.001). And compared with control group, the rats in the noise group showed obvious anxiety-depression-like behavior in the open field test, that was, low activity level.The results of OFT showed that the total distance ((39.912±5.696) m, (47.993±10.820)m, t=-2.289, P=0.032), average moving speed ((13.306±1.900)cm/s, (15.998±3.607)cm/s, t=-2.290, P=0.032) and standing times ((13.333±5.960), (23.500±7.323), t=-3.730, P=0.001) of the rats in the noise group were all lower than those in the control group. Compared with the control group, the local consistency of hypothalamus in the noise group was significantly enhanced, while the local consistency of ventrolateral orbital cortex was significantly reduced, and the abnormal neural activity was lateralized. The correlation analysis showed that the neural activity of the inferior colliculus was negatively correlated with the total distance of rats in the noise group moving in the open field( r=-0.691, P=0.013), while the neural activity of the ventrolateral orbital cortex was not significantly correlated with the anxiety-depression-like behavior in the open field. Conclusions:The neural activity of inferior colliculus is closely related to anxious-depression behavior in rats with noise-induced deafness, while the ventrolateral orbital cortex may be related with other behaviors.

Keeping abreast with cutting-edge measurement and assessment techniques for complex noise in the workplace / 环境与职业医学

Complex noise is the dominant type of noise in workplaces. It can cause more serious hearing loss than steady-state noise. The existing noise measurement and evaluation standards based on the "equal energy hypothesis" are not completely suitable for complex noise. This paper introduced the status quo of workplace noise measurement and assessment techniques, and the research progress of workplace complex noise measurement and assessment techniques. In terms of future research in this area, four proposals were made, including to improve associated population database, develop and revise noise-related standards, establish methodology of kurtosis adjustment, and identify the incidence characteristics of kurtosis-related occupational hearing loss. The paper also introduced the special column "Measurement and assessment techniques of complex noise in the workplace".

Síntomas de hipoacusia y exposición al ruido recreativo en jóvenes universitarios, Barranquilla, Colombia / Hearing loss symptoms and leisure noise exposure in university students in Barranquilla, Colombia

RESUMEN Objetivo Investigar la participación de estudiantes universitarios en actividades de ocio productoras de ruido y la relación entre los niveles de exposición semanal al ruido recreativo y síntomas de hipoacusia auto reportados, en la ciudad de Barranquilla, Colombia. Método Se realizó un estudio transversal mediante encuesta virtual, basada en el Cuestionario de Exposición al Ruido, más 11 preguntas de síntomas auditivos, a una muestra aleatoria de 730 sujetos. El nivel de exposición semanal al ruido recreativo se estimó a partir del tiempo dedicado al total de actividades recreativas reportadas por los participantes y su evaluación subjetiva de la intensidad de ruido producida por cada actividad, transformada en niveles de ruido continuo equivalente. La asociación entre la exposición al ruido recreativo y la presencia de síntomas de hipoacusia se analizó mediante la prueba de Chi-cuadrado. Resultados El 93% de los participantes manifestó al menos un síntoma de hipoacusia y la mitad reportó cuatro o más. El síntoma más frecuente de hipoacusia asociada al ruido fue el tinnitus (72%). El 55% tenía una exposición semanal de ruido por encima de 85 dBA y en éstos la prevalencia de síntomas de hipoacusia fue mayor (p < 0.05). Conclusión Se sugiere la presencia de deterioro auditivo en gran parte la población universitaria, asociado con altas dosis de exposición semanal al ruido recreativo. Es necesario fortalecer los programas de promoción de la salud auditiva en la academia, y desde los servicios de salud, la valoración objetiva y periódica de la audición.

ABSTRACT Purpose The aim of this study was to investigate the total weekly exposure to leisure noise among university students and to assess its association with self-reported symptoms of hypoacusis. Methods This is a cross-sectional survey. An online questionnaire based on the "Noise Exposure Questionnaire", plus 11 questions regarding hearing loss were sent to 730 randomly selected students. Participants self-reported time spent on different leisure noise activities and their subjective evaluation of the loudness of these activities, converted into equivalent noise levels, were used to estimate weekly noise exposure levels that were compared to occupational noise limits (> 85 dBA = hazardous). Inference statistics was applied to relate hearing symptoms and "likely or having some degree of hearing loss" with hazardous weekly leisure noise exposure levels. Results Ninety-three percent of the participants reported at least one hypoacusis symptom. The most frequent sound-related ear symptom was tinnitus (72%). Fifty-five percent of the individuals presented weekly exposure to noise >85 dBA. Symptoms of hearing loss were more prevalent in those exposed to weekly noise levels >85 dBA. Conclusion This study suggests that there may be hearing loss caused by exposure to high levels of leisure noise in a large part of the study population. Health promotion of hearing conservation should be emphasized at university level. Objective repeated measurement of hearing acuity should be part of integral health services for the youth population.

Dificuldade auditiva autorreferida em trabalhadores expostos à poeira industrial no sul do Brasil / Self-reported hearing difficulty in workers exposed to industrial dust in southern Brazil

RESUMO Objetivo Investigar a associação entre dificuldade auditiva autorreferida e exposição ocupacional à poeira industrial em trabalhadores do sul do Brasil. Método Trata-se de um estudo transversal analítico, realizado com dados do inquérito da Pesquisa Nacional de Saúde (2013). A variável dependente foi a dificuldade auditiva autorreferida e a variável independente principal foi a exposição ocupacional à poeira industrial. As covariáveis foram: sexo, cor da pele, idade em anos completos, exposição a ruído e exposição à substâncias químicas. As variáveis de exposição ocupacional a ruído e substâncias químicas foram utilizadas como variáveis de ajuste (variáveis de confusão) e as análises foram estratificadas por cada estado (Santa Catarina, Paraná e Rio Grande do Sul), com o intuito de verificar a diferença na magnitude dos resultados por região. Tanto para a análise bruta quanto para a ajustada, a razão de chance foi utilizada como medida de associação, estimada por meio da análise de regressão logística. Os dados foram analisados no software Stata, versão 14. Resultados Com relação a exposição principal, 10,1% da amostra (n=490) afirmou estar exposta à poeira industrial em ambiente ocupacional, ao passo que 7,0% afirmou ter dificuldade auditiva. Na análise final, trabalhadores expostos a poeira industrial apresentaram 1,77 vezes mais chance de mencionar dificuldade auditiva, quando comparados a indivíduos não expostos a este agente. Conclusão Houve associação entre dificuldade auditiva e exposição à poeira industrial em trabalhadores da região Sul do Brasil.

ABSTRACT Purpose To investigate the association between self-reported hearing difficulties and occupational exposure to industrial dust in workers in southern Brazil. Methods This is a cross-sectional analytical study conducted with data from the National Health Survey (Pesquisa Nacional de Saúde, 2013). The dependent variable was self-reported hearing impairment, and the primary independent variable was occupational exposure to industrial dust. The covariables were: sex, skin color, age in complete years, exposure to noise, and exposure to chemical substances. The variables of occupational exposure to noise and chemical substances were used as adjustment variables (confounding variables), and the analyses were stratified per state (Santa Catarina, Paraná, and Rio Grande do Sul) to verify the difference in magnitude results per region. For the crude and adjusted analysis, the odds ratio (OR) was used as a measure of association, estimated through the logistic regression analysis. The data were analyzed through the software Stata, version 14. Results Regarding the main exposure, 10.1% of the sample (n = 490) reported being exposed to industrial dust in an occupational environment, while 7.0% reported hearing impairment. In the final analysis, workers exposed to industrial dust were 1.77 times more likely to report hearing impairment when compared to individuals not exposed to this agent. Conclusion There was an association between hearing impairment and exposure to industrial dust in workers in the southern region of Brazil.

Auditory effects of recreational and occupational noise exposure among dental students: a cross-sectional study / Efectos auditivos producto de la exposición a ruido recreacional y dental en estudiantes de odontología: un estudio transversal

ABSTRACT Purpose: to determine the auditory effects of noise exposure from recreational and occupational sources among dentistry students. Methods: forty-two dentistry students, routinely exposed to occupational noise, and 72 students from other health science schools were recruited (control group). Audiometric testing, otoacoustic emissions and questionnaires to assess recreational and occupational noise were applied to the sample. The presence of a notch was determined for each participant audiometry´s test based on the criteria proposed by Coles et al. Differences in notch prevalence were analyzed by applying univariate regression models as well as a multivariate model adjusted by covariates. Results: non-significant differences in auditory thresholds between groups were found. The controls exhibited a significantly higher prevalence of a notch at 4 kHz than the group exposed to noise. However, the differences were not statistically significant in the multivariate model adjusted by recreational noise exposure. Conclusions: the occupational noise exposure was not significantly associated to auditory system dysfunction. In addition, the differences in notch prevalence could be related to recreational noise exposure.

RESUMEN Objetivo: determinar los efectos auditivos producto de la exposición a ruido recreacional y ocupacional en estudiantes de Odontología. Métodos: se reclutó a 42 estudiantes de odontología expuestos rutinariamente a ruido ocupacional, y a 72 estudiantes de otras carreras del área de la salud (grupo control). Se evaluó mediante audiometría, emisiones otoacústicas, junto con aplicar cuestionarios para determinar la exposición a ruido ocupacional y recreacional. A partir de los umbrales audiométricos e determinó la presencia de escotoma usando el criterio de Coles et al. Se analizaron las diferencias en prevalencia de escotomas entre los grupos mediante regresiones logísticas, ajustando por otras variables. Resultados: no existieron diferencias significativas en los umbrales audiométricos entre los grupos estudiados. El grupo control mostró mayor prevalencia de escotoma en 4 kHz al ajustar por sexo y edad, sin embargo, dejó de ser significativa al ajustar adicionalmente por exposición a ruido recreacional. Conclusiones: la exposición a ruido ocupacional no se asoció a alteraciones auditivas. Además, las diferencias en prevalencia de escotomas estarían relacionadas a exposición a ruido recreacional.

Analysis of the implementation of Hearing Conservation Programs / Análise de implantação de Programas de Conservação Auditiva

ABSTRACT Purpose: to assess the implementation of hearing conservation programs in two large companies. Methods: an evaluative research that analyzed a type 1b implementation. The study was conducted in three stages, namely: establishing the company's degree of implementation, analyzing the companies' policies and structures, and lastly, analyzing the influence of the companies' policies and structures on their degree of implementation. The following analyses were conducted to collect data: interviews, document analysis, and observation. Results: the hearing conservation program in Company A was classified as implemented (91.1%), while in Company B, it was partially implemented (62.7%). The context in Company A was favorable to implementing the program, whereas in Company B, the context was considered unfavorable, due to disadvantageous categories. Also, the characteristics of the implementation context influenced the placement of the program either positively or negatively. Conclusion: there were satisfactory results regarding the implementation of the hearing conservation program in both companies assessed.

RESUMO Objetivo: avaliar a implantação do programa de conservação auditiva em duas empresas de grande porte. Métodos: trata-se de uma pesquisa avaliativa de análise de implantação do tipo 1b. O estudo foi conduzido em três etapas, sendo: determinação do grau de implantação do Programa de Conservação Auditiva das empresas avaliadas; análise dos contextos políticos e estruturais das empresas avaliadas; e, por fim, uma análise da influência dos contextos políticos e estruturais no grau de implantação nas empresas avaliadas. Foram realizadas as seguintes análises para coleta dos dados: entrevistas, análise documental e observacional. Resultados: o Programa de Conservação Auditiva na 'empresa A' foi classificado como 'implantado' (91,1%) e na 'empresa B' como 'parcialmente implantado' (62,7%). O contexto de implantação da 'empresa A' se apresentou favorável à implantação do programa. Já na 'empresa B' o contexto foi considerado desfavorável, tendo categorias não favoráveis. Foi possível relacionar, também, que as características do contexto de implantação influenciaram positiva ou negativamente na implantação do programa. Conclusão: houve resultados satisfatórios quanto à implantação do Programa de Conservação Auditiva em ambas as empresas avaliadas.

Content and layout validation of indicators to assess the degree of implementation of the Hearing Conservation Program / Validação de conteúdo e aparência de indicadores para avaliação do grau de implantação do Programa de Conservação Auditiva

ABSTRACT Purpose: to validate indicators and parameters to construct an assessment instrument for the Hearing Conservation Program. Methods: methodological research to validate the content and layout of indicators to assess the Hearing Conservation Program, using the Delphi method, as well as the semantic validation of an assessment instrument for the program, in compliance with the procedures used by the European group DISABKIDS. A total of 20 speech-language-hearing therapists participated in the study, answering validation questionnaires. The answers were tabulated and analyzed considering descriptive statistical data, establishing the item content validity index, the scale content validity index, the percentage of absolute agreement, and the content analysis. Results: of the 64 items submitted for validation, two were not considered appropriate. The set of items was considered representative. The validated indicators and parameters provided the means to construct an assessment instrument of the degree of implementation of the Hearing Conservation Program, which proved to be semantically valid. Conclusion: the indicators were validated to meet and represent the functions of quality, control, and follow-up of the Hearing Conservation Program, aiding administrators to carry out their responsibilities and making it possible to construct evaluative instruments.

RESUMO Objetivo: validar indicadores e parâmetros para a construção de um instrumento de avaliação do Programa de Conservação Auditiva. Métodos: pesquisa metodológica de validação de conteúdo e aparência de indicadores para avaliação do Programa de Conservação Auditiva mediante aplicação do método Delphi, bem como a validação semântica de um instrumento de avaliação do programa seguindo os procedimentos adotados pelo grupo europeu DISABKIDS. Participaram do estudo 20 fonoaudiólogos, os quais responderam a questionários de validação. As respostas foram tabuladas e analisadas considerando dados estatísticos descritivos, pelo estabelecimento dos índices de validade de conteúdo por Item (I- IVC), de validade de conteúdo por nível de escala (S-IVC), de nível percentual de concordância absoluta e Análise de Conteúdo. Resultados: dos 64 itens submetidos à validação, dois não foram considerados pertinentes. O conjunto de itens foi considerado representativo. Os indicadores e parâmetros validados subsidiaram a construção de um instrumento para avaliação do grau de implantação do Programa de Conservação Auditiva, o qual se apresentou válido semanticamente. Conclusão: os indicadores foram validados de modo a atender e representar as funções de qualidade, controle e acompanhamento do Programa de Conservação Auditiva, auxiliando os gestores no exercer de suas funções e subsidiando a construção de instrumentos avaliativos.

The characteristic of otoacoustic emissions in full-term neonates according to ABO blood groups / Característica das emissões otoacústicas em neonatos a termo segundo grupos sanguíneos do sistema ABO

Abstract Introduction: Previous research has suggested that individuals with different blood groups show varied incidences of noise-induced hearing loss. The reduced otoacoustic emissions amplitudes indicate the higher possibilities of outer hair cell damage for noise exposure. Objective: The objective is to analyze the characteristics of otoacoustic emissions, including the occurrence of spontaneous otoacoustic emission and the amplitudes of distortion product otoacoustic emission at certain frequencies in full term neonates with different ABO blood groups. Methods: A total of 80 selected full-term female neonates who passed the initial newborn hearing screen were enrolled into the study, with equal number of participants in four ABO blood groups (Blood Group A, Blood Group B, Blood Group AB, Blood Group O). Measurements of spontaneous otoacoustic emission and distortion product otoacoustic emission were performed in both ears for all participants. Results: (1) The blood group O participants showed significantly fewer spontaneous otoacoustic emission occurrences than the other three blood groups (A = 70%, B = 80%, AB = 67%, O = 25%, p < 0.05). (2) The blood group O participants showed lower DPOAE amplitudes at 1257 Hz (M = 4.55 dB, SD = 8.36), 1587 Hz (M = 11.60 dB, SD = 6.57), 3174 Hz (M = 7.25 dB, SD = 5.99), 5042 Hz (M = 13.60, SD = 6.70) than participants with the other three blood groups in left ears (p < 0.05). In right ears, the blood group O participants showed reduced amplitudes at 1257 Hz (M = 6.55 dB, SD = 8.36), 1587 Hz (M = 13.60 dB, SD = 6.57), 3174 Hz (M = 7.65 dB, SD = 6.43), 5042 Hz (M = 13.65 dB, SD = 6.50) than participants from non-O blood groups (p < 0.05). Conclusion: Female individuals with blood group O have lower otoacoustic emissions values than individuals with the other three blood groups. We need to further investigate the possible relationships between ABO blood group and cochlear function, including the potential influences of noise damage on cochlear outer hair cells.

Resumo Introdução: Pesquisas anteriores sugeriram que indivíduos de diferentes grupos sanguíneos apresentam incidências distintas de perda auditiva induzida por ruído. As amplitudes reduzidas das emissões otoacústicas indicaram maiores ou menores possibilidades de danos às células ciliadas por exposição a ruídos. Objetivo: Analisar as características das emissões otoacústicas, inclusive a ocorrência de emissões otoacústicas espontâneas e as amplitudes de emissões otoacústicas por produto de distorção em determinadas frequências em neonatos a termo de diferentes grupos sanguíneos do sistema ABO. Método: Foram incluídos 80 neonatos a termo selecionados na triagem auditiva neonatal inicial para participar do estudo, com número igual de participantes de grupos sanguíneos do sistema ABO (grupo sanguíneo A, grupo sanguíneo B, grupo sanguíneo AB e grupo sanguíneo O). As emissões otoacústicas espontâneas e emissões otoacústicas por produto de distorção foram medidas em ambas as orelhas de todos os participantes. Resultados: (1) Os participantes do grupo sanguíneo O apresentaram ocorrências de emissões otoacústicas espontâneas significantemente menores do que os dos outros três grupos sanguíneos (A = 70%, B = 80%, AB = 67%, O = 25%, p < 0,05). (2) Os participantes do grupo sanguíneo O apresentaram amplitudes de emissões otoacústicas por produto de distorção mais baixas a 1257 Hz (M = 4,55 dB, DP = 8,36), 1587 Hz (M = 11,60 dB, DP = 6,57), 3174 Hz (M = 7,25 dB, DP = 5,99), 5042 Hz (M = 13,0, DP = 6,70) do que os participantes dos outros três grupos sanguíneos nas orelhas esquerdas (p < 0,05). Nas orelhas direitas, os participantes do grupo sanguíneo O apresentaram amplitudes reduzidas em 1257 Hz (M = 6,55 dB, DP = 8,36), 1587 Hz (M = 13,60 dB, DP = 6,57), 3174 Hz (M = 7,65 dB, DP = 6,43), 5042 Hz (M = 13,65 dB, DP = 6,50) em comparação aos participantes de grupos sanguíneos não O (p < 0,05). Conclusão: Os indivíduos do sexo feminino do grupo sanguíneo O apresentaram valores menores de emissões otoacústicas do que os indivíduos dos outros três grupos sanguíneos. É necessário continuar a investigar as possíveis relações entre o grupo sanguíneo ABO e a função coclear, inclusive as possíveis influências do dano por ruídos às células ciliadas externas da cóclea.

Heat shock response in noise-induced hearing loss: effects of alanyl-glutamine dipeptide supplementation on heat shock proteins status / Resposta de choque térmico em perda auditiva induzida por ruído: efeitos da suplementação com dipeptídeos de alanil-glutamina sobre o estado das proteínas de choque térmico

Abstract Introduction: The 72 kDa heat shock protein, HSP72, located intracellularly provides cochlear cytoprotective and anti-inflammatory roles in the inner ear during stressful noise challenges. The expression of intracellular HSP72 (iHSP72) can be potentiated by alanyl-glutamine dipeptide supplementation. Conversely, these proteins act as pro-inflammatory signals in the extracellular milieu (eHSP72). Objective: We explore whether noise-induced hearing loss promotes both intracellular and extracellular HSP72 heat shock response alterations, and if alanyl-glutamine dipeptide supplementation could modify heat shock response and prevent hearing loss. Methods: Female 90 day-old Wistar rats (n = 32) were randomly divided into four groups: control, noise-induced hearing loss, treated with alanyl-glutamine dipeptide and noise-induced hearing loss plus alanyl-glutamine dipeptide. Auditory brainstem responses were evaluated before noise exposure (124 dB SPL for 2 h) and 14 days after. Cochlea, nuclear cochlear complex and plasma samples were collected for the measurement of intracellular HSP72 and extracellular HSP72 by a high-sensitivity ELISA kit. Results: We found an increase in both iHSP72 and eHSP72 levels in the noise-induced hearing loss group, which was alleviated by alanyl-glutamine dipeptide treatment. Furthermore, H-index of HSP72 (plasma/cochlea eHSP72/iHSP72 ratio) was increased in the noise-induced hearing loss group, but prevented by alanyl-glutamine dipeptide treatment, although alanyl-glutamine dipeptide had no effect on auditory threshold. Conclusions: Our data indicates that cochlear damage induced by noise exposure is accompanied by local and systemic heat shock response markers. Also, alanyl-glutamine reduced stress markers even though it had no effect on noise-induced hearing loss. Finally, plasma levels of 72 kDa heat shock proteins can be used as a biomarker of auditory stress after noise exposure.

Resumo Introdução: A proteína de choque térmico de 72 kDa, HSP72 localizada intracelularmente, tem papéis citoprotetores e anti-inflamatórios cocleares na orelha interna durante situações de ruído estressantes. A expressão dessa proteína pode ser potencializada pela suplementação com dipeptídeo de alanil-glutamina. Por outro lado, essas proteínas atuam como sinais pró-inflamatórios no meio extracelular. Objetivo: Investigar se a perda auditiva induzida por ruído promove alterações tanto das proteínas HSP72 intracelulares quanto extracelulares na resposta de choque térmico e se a suplementação com alanil-glutamina pode modificar a resposta de choque térmico e evitar a perda auditiva. Método: Ratos Wistar fêmeas, com 90 dias de idade (n = 32), foram divididos aleatoriamente em quatro grupos: controle, perda auditiva induzida por ruído, tratados com alanil-glutamina e perda auditiva induzida por ruído mais alanil-glutamina. Os potenciais evocados auditivos do tronco encefálico foram avaliados antes da exposição ao ruído (124 dB NPS por 2 h) e 14 dias após. A cóclea, o complexo nuclear coclear e amostras de plasma foram coletadas para mensuração de HSP72 intra e extracelular com um kit Elisa de alta sensibilidade. Resultados: Houve um aumento nos níveis de HSP72 intra e extracelular no grupo perda auditiva induzida por ruído, que foi minimizado pelo tratamento com alanil-glutamina. Além disso, o índice H das HSP72 (razão HSP72 extracelular/HSP72intracelular plasma/cóclea) aumentou no grupo perda auditiva induzida por ruído, mas foi limitado pelo tratamento com alanil-glutamina, embora o alanil-glutamina não tenha efeito no limiar auditivo. Conclusões: Nossos dados indicam que o dano coclear induzido pela exposição ao ruído é acompanhado por marcadores da resposta de choque térmico locais e sistêmicos. Além disso, alanil-glutamina reduziu os marcadores de estresse, mesmo não tendo efeito sobre a perda auditiva induzida por ruído. Finalmente, os níveis plasmáticos de proteínas de choque térmico de 72 kDa podem ser usados como biomarcador do estresse auditivo, após a exposição ao ruído.

Polymorphism in GRHL2 gene may contribute to noise-induced hearing loss susceptibility: a meta-analysis / Polimorfismo no gene GRHL2 pode contribuir para a suscetibilidade à perda auditivainduzida por ruído: uma metanálise

Abstract Instruction: Noise-induced hearing loss is a leading occupational disease caused by gene-environment interaction. The Grainy Like 2, GRHL2, is a candidate gene. In this regard, many studies have evaluated the association between GRHL2 and noise-induced hearing loss, although the results are ambiguous and conflicting. Objective: The purpose of this study was to identify a precise estimation of the association between rs3735715 polymorphism in GRHL2 gene and susceptibility of noise-induced hearing loss. Methods: A comprehensive search was performed to collect data up to July 8, 2018. Finally, 4 eligible articles were included in this meta-analysis comprising 2410 subjects. The pooled odds ratios with 95% confidence intervals were used to evaluate the strength of the association. Results: Significant association was found in the overall population in the dominant model (GA/AA vs. GG, odds ratio = 0.707, 95% confidence interval = 0.594-0.841) and allele model (G allele vs. A allele, odds ratio = 1.189, 95% confidence interval = 1.062-1.333). When stratified by source of the subjects, we also found association between rs3735715 and noise-induced hearing loss risk in the dominant model (GA/AA vs. GG, odds ratio = 0.634, 95% confidence interval = 0.514-0.783) and allele model (G allele vs. A allele, odds ratio = 1.206, 95% confidence interval = 1.054-1.379). Conclusion: Rs3735715 polymorphism in GRHL2 gene may influence the susceptibility of noise-induced hearing loss. Additional large, well-designed and functional studies are needed to confirm this association in different populations.

Resumo Introdução: Perda auditiva induzida por ruído é uma das principais doenças ocupacionais causadas pela interação gene-ambiente. O Grainy Like 2, ou GRHL2 é um gene que tem sido considerado como candidato. Nesse sentido, muitos estudos avaliaram a associação entre o GRHL2 e perda auditiva induzida por ruído, embora os resultados sejam ambíguos e conflitantes. Objetivo: Identificar uma estimativa precisa da associação entre o polimorfismo rs3735715 no gene GRHL2 e a suscetibilidade à perda auditiva induzida por ruído. Método: Uma pesquisa abrangente foi feita para coletar dados até 8 de julho de 2018. No fim, quatro artigos elegíveis foram incluídos nesta metanálise, abrangeram 2.410 indivíduos. As odds ratios agrupadas com intervalos de confiança de 95% foram usadas para avaliar a força da associação. Resultados: Uma associação significante foi encontrada na população geral no modelo de dominância (GA/AA vs. GG, odds ratio = 0,707, intervalo de confiança 95% = 0,594-0,841) e modelo de alelo (alelo G vs. alelo A; odds ratio = 1,189, intervalo de confiança 95% = 1,062 a 1,333). Quando estratificados pelo local de trabalho dos indivíduos, também encontramos associação entre rs3735715 e risco de perda auditiva induzida por ruído no modelo de dominância (GA/AA vs. GG, odds ratio = 0,634, intervalo de confiança 95% = 0,514 ± 0,783) e modelo de alelo (alelo G vs. alelo A; odds ratio = 1,206, intervalo de confiança 95% = 1,054- 1,379). Conclusão: O polimorfismo Rs3735715 no gene GRHL2 pode influenciar a suscetibilidade à perda auditiva induzida por ruído. Estudos adicionais, amplos, bem desenhados e funcionais são necessários para confirmar essa associação em diferentes populações.

Hearing prevention program: how speech-language pathologists and audiologists work in the occupational health area / Programa de preservação auditiva: como atuam os fonoaudiólogos da área da saúde do trabalhador

ABSTRACT Objective: to characterize speech-language pathologists/audiologists and their interventions in the occupational health area, regarding the Hearing Prevention Program (HPP). Methods: a cross-sectional, quantitative study with 74 speech-language pathologists/audiologists from several regions of Brazil, working in the areas of Occupational Health and Audiology. The participants answered a questionnaire on their professional and educational profile, as well as on their work related to the HCP components. For data analysis, statistical procedures were used (Chi-Square Test and the test of difference in proportions, at the significance level of 0.05 - 5%), in relation to the variables of gender, age, job position, time since their graduation and academic training in occupational safety and health. Results: the speech-language pathologists/audiologists, mostly women, who reported performing the HPP, were older than 30 years, had specific postgraduate courses, but still had doubts about the Program implementation, they worked for companies with over 1,000 employees, disregarding their employment status, performing interventions, such as: hearing management and guidance on the correct use of ear protectors. Conclusion: a high number of speech-language pathologists in the Occupational Health area have not developed a complete hearing conservation program to this date.

RESUMO Objetivo: caracterizar os fonoaudiólogos e as ações que desenvolvem na área da saúde do trabalhador com relação ao Programa de Preservação Auditiva (PPA). Métodos: estudo quantitativo, transversal, com 74 fonoaudiólogos de diversas regiões do Brasil que trabalham em Saúde do Trabalhador e Audiologia. Os participantes responderam a um questionário sobre seu perfil profissional, formação e atuação em relação aos componentes do PPA. Para a análise dos dados utilizou-se procedimentos estatísticos (teste Qui-Quadrado e o teste de diferença de proporções, ao nível de significância 0,05 - 5%) em relação às variáveis sexo, idade, função, tempo de formado e formação acadêmica em saúde e segurança do trabalho. Resultados: os fonoaudiólogos, a maioria mulheres, que relataram realizar o PPA, tinham idade superior a 30 anos; fizeram cursos de pós-graduação específica, mas ainda apresentavam dúvidas em relação à implantação do Programa; estavam em empresas com mais de 1000 funcionários, independentemente de seu regime de trabalho, realizando ações como: gerenciamento auditivo e orientação sobre utilização correta de protetores auriculares. Conclusão: há ainda um número elevado de fonoaudiólogos na área de Saúde do Trabalhador que não desenvolvem um programa de preservação auditiva na íntegra.

Cochrane method for systematic review and meta-analysis of interventions to prevent occupational noise-induced hearing loss - abridged / Revisão sistemática e metanálise Cochrane de intervenções para prevenção de perda auditiva ocupacional induzida por ruído - abreviada

ABSTRACT Purpose Assess the effect of non-pharmaceutical interventions at work on noise exposure or occupational hearing loss compared to no or alternative interventions. Research strategies Pubmed, Embase, Web of Science, OSHupdate, Cochrane Central and Cumulative Index to Nursing and Allied Health Literature (CINAHL) were searched. Selection criteria Randomized Controlled Trials (RCT), Controlled Before-After studies (CBA) and Interrupted Time-Series studies (ITS) evaluating engineering controls, administrative controls, personal hearing protection devices, and hearing surveillance were included. Case studies of engineering controls were collected. Data analysis Cochrane methods for systematic reviews, including meta-analysis, were followed. Results 29 studies were included. Stricter legislation can reduce noise levels by 4.5 dB(A) (very low-quality evidence). Engineering controls can immediately reduce noise (107 cases). Eleven RCTs and CBA studies (3725 participants) were evaluated through Hearing Protection Devices (HPDs). Training of earplug insertion reduces noise exposure at short term follow-up (moderate quality evidence). Earmuffs might perform better than earplugs in high noise levels but worse in low noise levels (very low-quality evidence). HPDs might reduce hearing loss at very long-term follow-up (very low-quality evidence). Seventeen studies (84028 participants) evaluated hearing loss prevention programs. Better use of HPDs might reduce hearing loss but other components not (very low-quality evidence). Conclusion Hearing loss prevention and interventions modestly reduce noise exposure and hearing loss. Better quality studies and better implementation of noise control measures and HPDs is needed.

RESUMO Objetivo Avaliar o efeito de intervenções no trabalho sobre a exposição ao ruído ou a perda auditiva em comparação com ausência ou intervenções alternativas. Estratégia de pesquisa Buscas em Pubmed, Embase, Web of Science, OSHupdate, Cochrane Central e CINAHL. Critérios de seleção Incluídos ensaios clínicos randomizados (ECR), estudos controlados pré/pós-intervenção (ECPPI) e estudos de séries temporais interrompidas (SIT) avaliando controles de engenharia, administrativos, equipamentos de proteção auditiva (EPAs) e vigilância auditiva. Coletados estudos de caso de engenharia. Análise dos dados Cochrane para revisões sistemáticas, incluindo metanálise. Resultados Foram incluídos 29 estudos. Legislação mais rigorosa pode reduzir níveis de ruído em 4,5 dB(A) (evidência de qualidade muito baixa). Controles de engenharia podem reduzir imediatamente o ruído (107 casos). Onze ECR e ECPPI (3.725 participantes) avaliaram EPAs. Treinamento para inserção do EPA reduz a exposição ao ruído no acompanhamento de curto prazo (evidência de qualidade moderada). Protetores tipo concha podem ter desempenho melhor do que protetores de inserção em níveis altos de ruído, mas piores em níveis mais baixos (evidência de qualidade muito baixa). EPAs podem reduzir a perda auditiva no acompanhamento de muito longo prazo (evidência de qualidade muito baixa). Dezessete estudos (84.028 participantes) avaliaram programas de prevenção de perdas auditivas. Um melhor uso do EPA pode reduzir a perda auditiva, mas outros componentes não (evidência de qualidade muito baixa). Conclusão As intervenções para prevenção da perda auditiva reduzem modestamente a exposição ao ruído e a perda auditiva. Estudos de melhor qualidade e melhor implementação de medidas de controle de ruído e EPA são necessários.

Task Analysis On Maintenance Worker (Rail Grinder) Of Light Rail Transit (LRT)

@#Rail maintenance routines are necessary to enable the all rail operations to achieve its aim in maintaining a safe and efficient operation. The maintenance tasks expose the workers to vibration and noise, as they handle specialized machineries and heavy self-propelled vehicles. Exposure of noise above the permissible exposure limit and over the daily allowable duration may cause noise-induce hearing loss (NIHL). Investigation on the type of task that has high noise level exposure on the maintenance workers was conducted to justify the needs to further detailed of this study. This paper will describe the task analysis on maintenance workers and to identify possible tasks with exposure to high level of noise. It scopes down to grinding crew of the maintenance department of light rail transit. Methods used were real-time sound measurement using a sound level meter, observation and interviews. Then, data were analysed to understand the situation of exposure of noise during rail maintenance. An ergonomic risk assessment was also conducted by adoption of the latest guideline on Ergonomic Risk Assessment (ERA) at Workplace Guidelines recommended by Department of Occupational Safety and Health (DOSH), Malaysia. A hierarchical task analysis (HTA) was generated on the task of the maintenance worker, focusing on rail grinding crew. The newly generated HTA had allowed better understanding about the nature of work and the task conducted by a rail grinder during the work shifts. Tasks involving high noise level was identified. Data recorded shows that the noise level for the blowing activity was relatively high and exceeded the permissible exposure limit of 90dBA. The exposure level was currently controlled by practicing the usage of hearing protection equipment (HPE) and by controlling exposure time in accordance to recommendations of the Factory and Machinery Act (FMA). Thus, it had confirmed that maintenance workers were exposed to high noise levels when performing their daily task. Further studies are needed to investigate the relationship between the duration of exposure and noise-induce hearing loss (NIHL) with consideration of the lifestyles of the maintenance workers.

An overview of occupational noise-induced hearing loss among workers: epidemiology, pathogenesis, and preventive measures

Occupational noise-induced hearing loss (ONIHL) is the most prevalent occupational disease in the world. The goal of this study was to review the epidemiology, pathogenesis, and preventive measures of ONIHL among workers and provide evidence for the implementation of control measures. Literature studies were identified from the MEDLINE, PubMed, Embase, Web of Science, and Google Scholar using the search terms "noise-induced hearing loss" "prevalence", "pathogenesis", and "preventive measures". The articles reviewed in this report were limited from 2000 to 2020. Articles that were not published in the English language, manuscripts without an abstract, and opinion articles were excluded. After a preliminary screening, all of the articles were reviewed and synthesized to provide an overview of the current status of ONIHL among workers. The mechanism of ONIHL among workers is a complex interaction between environmental and host factors (both genetic and acquired factors). The outcomes of noise exposure are different among individual subjects. Clinical trials are currently underway to evaluate the treatment effect of antioxidants on ONIHL. Noise exposure may contribute to temporary or permanent threshold shifts; however, even temporary threshold shifts may predispose an individual to eventual permanent hearing loss. Noise prevention programs are an important preventive measure in reducing the morbidity of ONIHL among workers.

The Hearing Level among the Workers of Cement Industry

Objective: In this study our main goal is to evaluate thehearing level among the workers of cement industry.Methodology: This Cross-sectional observational study wasconducted at Department of Physiology, Chittagong MedicalCollege, Chittagong and Heidelbargh Cement Bangladesh Ltd.East Halishar, Chittagong, One year (January 2011 toDecember 2011). Where total number of 800 (Eight hundred)subjects were included. During the study, all subjects wereselected purposively on the basis of noise exposure studyprocedure. After selection and proper counseling, the aim,objective and procedure of the study was explained in detailsto all subjects, in the cement industry.Results: During the study highest frequency of hearing losswas found in 30-40 years age group. Most of the patientsworked in production area for 5-10 years. most of the patientsexposed to 70-80dB, 41.4%.51.6% patients exposed >8 hoursdaily and 65.5% patients exposed 42-48 hours weekly.Conclusion: From our study we can conclude that the studyclearly demonstrated that noise is a serious health hazard inthe cement industry. Hearing threshold for the subjectsexposed to noise increase with the progress of age andduration of employment. Further study is needed for betteroutcome.

Types of Hearing Protection Devices and Application / 대한이비인후과학회지

Since noise-induced hearing loss (NIHL) is one of prevalent issues in the occupational settings, hearing protection device (HPD) has been widely used to reduce noise exposure levels and to prevent developing NIHL. This review study aimed to introduce several types of the HPD in terms of current trends, its variety and functions, and application. Including a brief history of the HPD, we explain its two types, i.e., passive and active functions, in the first part of main body. The passive HPD has a flat attenuation across the overall frequency range, whereas the active HPD effectively preserves communication components such as meaningful speech with low intensity stimuli while filtering out the high levels of noise. In the second part of the main body, we discuss some negative issues of hearing functions when users are wearing the HPD. In detail, the active HPD does not much degrade the hearing performance for speech detection/recognition and sound source localization compared to the passive HPD. Rather, reduced sound (or music) quality is improved with active one in general. In the final part, we mention that although various applications in the special fields such as factory, mining, army, airplane, and music have been demonstrated, the usage and awareness of HPD in occupational aspect may not follow its fast technological development. Furthermore, most people do not know about either importance or use method of HPD in the non-occupational setting. For these reasons, we conclude that hearing professionals have to access the latest trends of the HPD and to increase their knowledge on it, and thus they should provide the best HPD prescription for the public as well as employees who have to protect their ears from hazard noise impacts.