BACKGROUND: Exposure to environmental noise may have a negative impact on a population's mental health. We estimated the prevalence of exposure perception to high environmental noise in the Valencian Community, a region on the Mediterranean coast of Spain, and analysed its association with poor mental health risk, adjusting for demographic, socioeconomic and health status variables. METHODS: Cross-sectional study based on a sample of 5.485 subjects, aged 15 or above, of the 2016 Valencian Community Health Survey. The risk of poor mental health was assessed via Goldberg's questionnaire, a highly standardized self-reported questionnaire designed to screen for general psychological distress in the general population. Noise perception were determined in the home environment based on individuals' responses to the Valencian Survey question about external noise problems. Sociodemographic variables, such as sex, age, level of education, or country of birth, and health variables, such as self-perceived health, or chronic diseases, were also considered. Logistic regression was used to estimate the Odds Ratios and confidence intervals of association between variables according to sex. RESULTS: The prevalence of poor mental health was 26.2% [n = 2665; 95% CI: 24.5-27.9] in men and 33.6% [n = 2820; 95% CI: 31.9-35.3] in women. A total of 7.8% [n = 5485; 95% CI: 6.8-8.8] presented exposure to high noise perception, with no differences according to sex. Being at risk of poor mental health was significantly associated (p < 0.05) with high noise perception after adjusting for the rest of the variables (OR: 2.16 [95% CI: 1.46-3.19] in men; 2.46 [95% CI: 1.72-3.50] in women). CONCLUSIONS Although the prevalence of exposure perception to high noise was not very high, population subgroups presenting high values were detected. High noise perception was related to the risk of poor mental health, regardless of other variables. Poor mental health risk was associated with exposure perception to high noise, other socioeconomic determinants, and health status. Improving noise exposure conditions could reduce the risk of poor mental health.
Humans ; Spain/epidemiology* ; Male ; Female ; Adult ; Middle Aged ; Noise/adverse effects* ; Cross-Sectional Studies ; Young Adult ; Adolescent ; Environmental Exposure/adverse effects* ; Aged ; Mental Health/statistics & numerical data* ; Prevalence ; Mental Disorders/epidemiology* ; Risk Factors

BACKGROUND: Prolonged occupational noise exposure poses potential health risks, but its impact on mitochondrial DNA (mtDNA) damage and methylation patterns remains unclear. METHOD: We recruited 306 factory workers, using average binaural high-frequency hearing thresholds from pure-tone audiometry to assess noise exposure. MtDNA damage was evaluated through mitochondrial DNA copy number (mtDNAcn) and lesion rate, and mtDNA methylation changes were identified via pyrophosphate sequencing. RESULTS: There was a reduction in MT-RNR1 methylation of 4.52% (95% CI: -7.43% to -1.62%) among workers with abnormal hearing, whereas changes in the D-loop region were not statistically significant (β = -2.06%, 95% CI: -4.44% to 0.31%). MtDNAcn showed a negative association with MT-RNR1 methylation (β = -0.95, 95% CI: -1.23 to -0.66), while no significant link was found with D-loop methylation (β = -0.05, 95% CI: -0.58 to 0.48). Mediation analysis indicated a significant increase in mtDNAcn by 10.75 units (95% CI: 3.00 to 21.26) in those with abnormal hearing, with MT-RNR1 methylation mediating 35.9% of this effect. CONCLUSIONS These findings suggest that occupational noise exposure may influence compensatory increases in mtDNA content through altered MT-RNR1 methylation.
Humans ; DNA, Mitochondrial ; DNA Methylation ; Male ; Adult ; Noise, Occupational/adverse effects* ; Middle Aged ; Occupational Exposure/adverse effects* ; Biomarkers/blood* ; Female

OBJECTIVE: To explore the therapeutic effects and underlying mechanisms of Dendrobium officinale (Tiepi Shihu) extract (DOE) on insomnia. METHODS: Forty-two male Sprague-Dawley rats were randomly divided into 6 groups (n=7 per group): normal control, model control, melatonin (MT, 40 mg/kg), and 3-dose DOE (0.25, 0.50, and 1.00 g/kg) groups. Rats were raised in a strong-light (10,000 LUX) and -noise (>80 db) environment (12 h/d) for 16 weeks to induce insomnia, and from week 10 to week 16, MT and DOE were correspondingly administered to rats. The behavior tests including sodium pentobarbital-induced sleep experiment, sucrose preference test, and autonomous activity test were used to evaluate changes in sleep and emotions of rats. The metabolic-related indicators such as blood pressure, blood viscosity, blood glucose, and uric acid in rats were measured. The pathological changes in the cornu ammonis 1 (CA1) region of rat brain were evaluated using hematoxylin and eosin staining and Nissl staining. Additionally, the sleep-related factors gamma-aminobutyric acid (GABA), glutamate (GA), 5-hydroxytryptamine (5-HT), and interleukin-6 (IL-6) were measured using enzyme linked immunosorbent assay. Finally, we screened potential sleep-improving receptors of DOE using polymerase chain reaction (PCR) array and validated the results with quantitative PCR and immunohistochemistry. RESULTS: DOE significantly improved rats' sleep and mood, increased the sodium pentobarbital-induced sleep time and sucrose preference index, and reduced autonomic activity times (P<0.05 or P<0.01). DOE also had a good effect on metabolic abnormalities, significantly reducing triglyceride, blood glucose, blood pressure, and blood viscosity indicators (P<0.05 or P<0.01). DOE significantly increased the GABA content in hippocampus and reduced the GA/GABA ratio and IL-6 level (P<0.05 or P<0.01). In addition, DOE improved the pathological changes such as the disorder of cell arrangement in the hippocampus and the decrease of Nissel bodies. Seven differential genes were screened by PCR array, and the GABA_A receptors (Gabra5, Gabra6, Gabrq) were selected for verification. The results showed that DOE could up-regulate their expressions (P<0.05 or P<0.01). CONCLUSION DOE demonstrated remarkable potential for improving insomnia, which may be through regulating GABA_A receptors expressions and GA/GABA ratio.
Animals ; Dendrobium/chemistry* ; Rats, Sprague-Dawley ; Male ; Sleep Initiation and Maintenance Disorders/blood* ; Plant Extracts/therapeutic use* ; Receptors, GABA-A/metabolism* ; Noise/adverse effects* ; Light/adverse effects* ; gamma-Aminobutyric Acid/metabolism* ; Sleep/drug effects* ; Rats ; Receptors, GABA/metabolism*

Objective:This study aims to investigate the mechanism and potential effects of two exposures to 100 dB sound pressure level（SPL） broadband white noise, with a 14-days interval, on the myelin sheath of the cochlear auditory nerve in mice. The research provides experimental evidence for understanding the pathophysiological processes of noise-induced hearing loss and hidden hearing loss. Methods:Fifteen 6-week-old male C57BL/6J mice with normal hearing thresholds were randomly divided into three groups: a control group（no noise exposure）, a single noise exposure group, and a double noise exposure group. The single noise exposure group was exposed to 100 dB SPL white noise for 2 hours, and ABR thresholds were measured 1 day（P1） and 14 days（P14） after the exposure. The double noise exposure group was exposed to the same conditions of 100 dB SPL white noise for 2 hours, followed by a second identical exposure 14 days later. ABR thresholds were measured 1 day（P15） and 14 days（P28） after the second exposure. The cochleae of all three groups were then collected for immunofluorescence observation of the basilar membrane and transmission electron microscopy to observe changes in the structure of the auditory nerve myelin sheath. Results:In the single noise exposure group, ABR thresholds at all frequencies were significantly elevated compared to the control group at P1. There were no significant changes in ABR thresholds at any frequency at P14. In the double noise exposure group, ABR thresholds at all frequencies were significantly elevated compared to the control group at P15 and P28（P<0.001）. After the first noise exposure, immunofluorescence observation revealed no significant weakening of the auditory nerve myelin sheath signal; transmission electron microscopy showed no significant changes in myelin sheath morphology. However, after the second noise exposure, immunofluorescence observation revealed a weakening of the myelin sheath signal, and transmission electron microscopy showed thinning of the myelin sheath, disruption of the lamellar structure, and separation from the axon, indicating demyelination. Conclusion:Two exposures to 100 dB SPL broadband white noise can lead to damage to the auditory nerve myelin sheath in mice, whereas a single exposure does not cause significant changes.
Animals ; Male ; Myelin Sheath/pathology* ; Mice ; Cochlear Nerve/pathology* ; Mice, Inbred C57BL ; Noise/adverse effects* ; Hearing Loss, Noise-Induced/physiopathology* ; Cochlea ; Evoked Potentials, Auditory, Brain Stem

Noise is one of the most common environmental hazards to which people are exposed,and the exposure to noise can cause not only hearing but also non-hearing damage.Although noise under safety limits may not affect the auditory system,it can cause changes in stress hormone levels,which is harmful to health.However,the current studies about the impact of noise on health mainly focus on the auditory system,and little is known about the relationship between noise and stress hormone levels.Therefore,this paper reviews the studies involving noise exposure and stress hormone levels,aiming to provide ideas for strengthening the prevention and control of noise hazards.
Humans ; Hearing ; Noise/adverse effects* ; Hormones

Objective: To explore the change of hearing threshold of workers exposed to noise, establish an individual-based hearing loss early warning model, accurately and differentiated the health of workers exposed to noise. Methods: In September 2019, all physical examination data of 561 workers exposed to noise from an enterprise were collected since their employment. Three indicators of average hearing threshold of the better ear, namely, at high frequency, 4000 Hz and speech frequency, were constructed. The generalized estimating equation (GEE) was used to adjust gender and age and establish the warning model of each indicator. Finally, sensitive indicators and warning models were screened according to AUC and Yoden index. Results: Among the 561 workers exposed to noise, 26 (4.6%) workers had hearing loss. The sensitivity indicators were the average hearing threshold at speech frequency ≥20 dB, high frequency ≥30 dB and 4000 Hz ≥25 dB. The AUC of each index was 0.602, 0.794 and 0.804, and the Youden indexes were 0.204, 0.588 and 0.608, respectively. In GEE of hearing loss warning models, high-frequency hearing threshold ≥20 dB and 4000 Hz hearing threshold ≥25 dB were the optimal models, with AUC of 0.862. Conclusion: Combined with the changes of individual hearing threshold over the years, can accurately assess the risk of individual hearing loss of workers exposed to noise.
Humans ; Hearing Loss, Noise-Induced/diagnosis* ; Noise, Occupational/adverse effects* ; Audiometry ; Deafness ; Employment ; Occupational Exposure/adverse effects* ; Occupational Diseases/diagnosis*

Alzheimer Disease/genetics* ; Animals ; Apolipoprotein E4/metabolism* ; Gene-Environment Interaction ; Hippocampus/metabolism* ; Male ; Noise/adverse effects* ; Rats

Objective: To investigate the relationship between high frequency hearing loss caused by occupational noise and the risk of hypertension. Methods: In March 2020, a case-control study was conducted. All noise exposed workers who participated in occupational health examination in Wuxi City in 2019 were selected as the study subjects (95432 cases in total) . The hypertension group was defined as the case group, and the normotensive group was defined as the control group. According to the hearing threshold, they were divided into the non high frequency hearing loss group (<40 dB) and the high frequency hearing loss group (≥ 40 dB) . Univariate statistical method and binary logistic regression were used to evaluate the relationship between high-frequency hearing loss and hypertension risk. Stratified analysis was used to compare the risk of hypertension among workers with high-frequency hearing loss of different ages and length of service. Results: There were significant differences in gender, age, length of service, enterprise scale, economic type and high-frequency hearing loss between control group and hypertension group (P<0.05) . Binary logistic regression analysis showed that after adjusting for gender, age, length of service, enterprise scale and economic type, the risk of hypertension in the high-frequency hearing loss group was still increased (OR=1.062, 95%CI: 1.007~1.121, P=0.027) . The risk of hypertension in high-frequency hearing loss patients was higher than that in non high-frequency hearing loss patients in 20-39 years old and 40-59 years old age groups (OR=1.536, 95%CI: 1.353~1.743; OR=1.179, 95%CI: 1.111~1.250; P<0.05) . The risk of hypertension in high-frequency hearing loss patients in <5years, 5-9years, 10-14 years, 15-19 years and ≥20 years working age groups were higher than that in non high-frequency hearing loss groups (OR=1.926, 95%CI=1.007-1.121; OR=1.635, 95%CI=1.478-1.810; OR=1.312, 95%CI=1.167-1.474; OR=1.445, 95%CI=1.238-1.686; OR=1.235, 95%CI=1.043-1.463; P<0.05) . Conclusion: There is a certain relationship between high-frequency hearing loss caused by occupational noise and the risk of hypertension, and the risk of hypertension is different among high-frequency hearing loss patients of different ages and working years.
Humans ; Young Adult ; Adult ; Noise, Occupational/adverse effects* ; Hearing Loss, Noise-Induced/etiology* ; Case-Control Studies ; Hearing Loss, High-Frequency ; Occupational Exposure/adverse effects* ; Hypertension/complications* ; Occupational Diseases/complications*

Objective: To understand the current situation of high-frequency hearing loss of workers exposed to occupational noise in Hubei Province and its multi-level influencing factors. Methods: In June 2021, the basic information, occupational history, physical examination results and other relevant information in the "Occupational Health Examinations Case Cards" for noise workers in Hubei Province in 2020 were extracted from the subsystem of the "China Disease Prevention and Control Information System". Multilevel level of logistic model was used to analyze the related factors of high-frequency hearing loss of noise-exposed workers. Results: In 2020, the incidence rate of occupational high-frequency hearing loss in Hubei Province was 8.25% (6450/78152), and the incidence rate in various regions of the province ranged from 1.13% to 19.87%. At the individual level, male, ≥ 30 years of age, 6-10 years of service, small and micro enterprises, as well as construction, mining, manufacturing, transportation and rental services were the risk factors for high-frequency hearing loss (P<0.05). The risk of high-frequency hearing loss among workers in foreign-funded enterprises was significantly lower than that of workers in state-owned/collective enterprises (P<0.05). At the regional level, the younger the age of the employees, the lower the risk of high-frequency hearing loss (P<0.05). There was no significant correlation between the regional economic level and the risk of high-frequency hearing loss (P>0.05) . Conclusion: The incidence rate of occupational high-frequency hearing loss in Hubei Province is low in 2020, but the incidence rate varies greatly in different regions of the province, mainly due to differences in employment age, while the development of regional economic level has not reduced the risk of occupational high-frequency hearing loss.
Male ; Humans ; Child ; Hearing Loss, High-Frequency ; Hearing Loss, Noise-Induced/diagnosis* ; Occupational Diseases/epidemiology* ; Occupational Exposure/adverse effects* ; Noise, Occupational/adverse effects*

High level noise can damage cochlear hair cells, auditory nerve and synaptic connections between cochlear hair cells and auditory nerve, resulting in noise-induced hearing loss (NIHL). Recent studies have shown that animal cochleae have circadian rhythm, which makes them different in sensitivity to noise throughout the day. Cochlear circadian rhythm has a certain relationship with brain-derived neurotrophic factor and glucocorticoids, which affects the degree of hearing loss after exposure to noise. In this review, we summarize the research progress of the regulation of cochlear sensitivity to noise by circadian rhythm and prospect the future research direction.
Animals ; Auditory Threshold ; Circadian Rhythm ; Cochlea ; Evoked Potentials, Auditory, Brain Stem/physiology* ; Hair Cells, Auditory ; Hearing Loss, Noise-Induced ; Noise/adverse effects*