Variations in the Cadherin 23 Gene Associated With Noise-Induced Hearing Loss.

Background: The relationship between CDH23 gene variants and NIHL is unclear. This study investigates the association between cadherin 23 (CDH23) gene variants and noise-induced hearing loss (NIHL). Methods: This is a case-control study. Workers who were exposed to noise from a steel factory in North China were recruited and divided into two groups: the case group (both ears' high-frequency threshold average [BHFTA] ≥40dB) and the control group (BHFTA ≤25 dB). This study used the generalised multifactor dimensionality reduction method to analyse the association among 18 single-nucleotide polymorphisms (SNPs) in CDH23 and NIHL. Logistic regression was performed to investigate the main effects of SNPs and the interactions between cumulative noise exposure (CNE) and SNPs. Furthermore, CNE was adjusted for age, gender, smoking, drinking, physical exercise and hypertension. Results: This study recruited 1,117 participants. The results showed that for rs11592462, participants who carried the GG genotype showed an association with NIHL greater than that of those who carried the CC genotype. Accordingly, genetic variation in the CDH23 gene could play an essential role in determining individual susceptibility to NIHL. Conclusion: Genetic variations in the CDH23 gene may play an important role in determining individual susceptibility to NIHL. These results provide new insight into the pathogenesis and early prevention of NIHL.

Plasma metabolomics analyses highlight the multifaceted effects of noise exposure and the diagnostic power of dysregulated metabolites for noise-induced hearing loss in steel workers.

Noise exposure can lead to various kinds of disorders. Noise-induced hearing loss (NIHL) is one of the leading disorders confusing the noise-exposed workers. It is essential to identify NIHL markers for its early diagnosis and new therapeutic targets for its treatment. In this study, a total of 90 plasma samples from 60 noise-exposed steel factory male workers (the noise group) with (NIHL group, n = 30) and without NIHL (non-NIHL group, n = 30) and 30 male controls without noise exposure (control group) were collected. Untargeted human plasma metabolomic profiles were determined with HPLC-MS/MS. The levels of the metabolites in the samples were normalized to total peak intensity, and the processed data were subjected to multivariate data analysis. The Wilcoxon test and orthogonal partial least square-discriminant analysis (OPLS-DA) were performed. With the threshold of p < 0.05 and the variable importance of projection (VIP) value >1, 469 differential plasma metabolites associated with noise exposure (DMs-NE) were identified, and their associated 58 KEGG pathways were indicated. In total, 33 differential metabolites associated with NIHL (DMs-NIHL) and their associated 12 KEGG pathways were identified. There were six common pathways associated with both noise exposure and NIHL. Through multiple comparisons, seven metabolites were shown to be dysregulated in the NIHL group compared with the other two groups. Through LASSO regression analysis, two risk models were constructed for NIHL status predication which could discriminate NIHL from non-NIHL workers with the area under the curve (AUC) values of 0.840 and 0.872, respectively, indicating their efficiency in NIHL diagnosis. To validate the results of the metabolomics, cochlear gene expression comparisons between susceptible and resistant mice in the GSE8342 dataset from Gene Expression Omnibus (GEO) were performed. The immune response and cell death-related processes were highlighted for their close relations with noise exposure, indicating their critical roles in noise-induced disorders. We concluded that there was a significant difference between the metabolite's profiles between NIHL cases and non-NIHL individuals. Noise exposure could lead to dysregulations of a variety of biological pathways, especially immune response and cell death-related processes. Our results might provide new clues for noise exposure studies and NIHL diagnosis.

[Association between single nucleotides polymorphism of catalase gene and susceptibility to noise-induced hearing loss in occupational population].

OBJECTIVE: To investigate the relationship between single nucleotides polymorphism of catalase(CAT) gene and susceptibility to noise-induced hearing loss(NIHL) in occupational noise exposed population. METHODS: A case-control study of 1∶1 was conducted to select 286 workers with binaural high frequency average hearing threshold ≥40 dB(HL), from 2006 to 2015 in a cohort study of occupational noise exposure workers in Henan Province. According to the type of work, the age difference was not more than 5 years and the length of exposure to noise was not more than 2 years. The polymorphism of 8 single nucleotides in CAT gene was detected by medium SNPscanTM, and the relationship between 8 single nucleotides polymorphism of CAT gene and NIHL susceptibility was analyzed by multivariate conditional logistic regression. RESULTS: Under the dominant model of rs208679 locus of CAT gene [(GA GG)/AA], the risk of NIHL in individuals carrying GA or GG genotype was 1. 431 times higher than that in individuals carrying AA genotype(95%CI 1. 020-2. 009), and P=0. 038. CONCLUSION: G, a mutant at rs208679 site of CAT gene, may be one of the risk factors for NIHL susceptibility.

[Relationship between GRM7 gene polymorphisms and the susceptbility to noise-induced hearing loss].

OBJECTIVE: To investigate the relationship between metabolic glutamate receptor 7 gene( GRM7) polymorphisms and the susceptibility to noise-induced hearing loss( NIHL) in Chinese Han occupational population. METHODS: Using a nested case-control study with a 1 ∶ 1 matching, a total of 277 cases of contacting noise workers were selected from a cohort in a steel factory. According to the matching criteria: the same sex, the same type of work, the age difference ≤ 5 years, contact noise length ≤ 2 years, 277 controls were selected. The 8 single nucleotide polymorphisms( SNPs) of the GRM7 gene, rs3749380, rs11928865, rs9877154, rs3828472, rs9819783, rs11920109, rs1485175 and rs9826579, were detected by SNPscanTMmethod. The 4 gene models, the additive model, dominant model, recessive model, codominant model, were constructed to explore the biological association with NIHL susceptibility. The possible diplotype of each subject was constructed using Phase 2. 0. 2 to analyze its relationship with NIHL. According to the layered cumulative noise exposure( CNE), the interactions between the influencing factor were analyzed. The relationship between the GRM7 gene and NIHL was analyzed by single factor and multivariate factors conditional logistic regression analysis. RESULTS: The comparison of general demographic characteristics between the hearing loss group and control group showed that smoking could increase the risk of developing NIHL by 2. 051 times( 95 % CI 1. 456-2. 891, P< 0. 001). No statistically significant difference was found in the analysis of GRM7 polymorphisms and the susceptibility to NIHL. CONCLUSION: Smoking may increase the risk of NIHL. The relationship between GRM7 polymorphisms and the susceptibility to NIHL has not been found in this study.

Effect of GRM7 polymorphisms on the development of noise-induced hearing loss in Chinese Han workers: a nested case-control study.

BACKGROUND: Noise-induced hearing loss (NIHL) is a complex, irreversible disease caused by the interaction of genetic and environmental factors. In recent years, a great many studies have been done to explore the NIHL susceptibility genes among humans. So far, high powerful detections have been founded that genes of potassium ion channel genes (KCNQ4 and KCNE1), catalase (CAT), protocadherin 15 (PCDH15), myosin 14 (MYH14) and heart shock protein (HSP70) which have been identified in more than one population may be associated with the susceptibility to NIHL. As for metabolic glutamate receptor7 gene (GRM7), a lot of researches mainly focus on age-related hearing loss (ARHL) and the results have shown that the polymorphisms of GRM7 are linked to the development of ARHL. However, little is known about the association of GRM7 and the susceptibility to NIHL. Therefore, the aim of this study was to explore the effect of GRM7 polymorphisms on the susceptibility to NIHL. METHODS: A nested case-control study based on the cohort in a Chinese steel factory was implemented in 292 cases and 584 controls matched with the same sex, the age difference ≤ 5 years old, the same type of work, duration of occupational noise exposure ≤2 years. Five single nucleotide polymorphisms (SNPs) of GRM7 were gained through selecting and genotyping SNPs. Conditional logistic regression analysis was used to assess the main effect of GRM7 polymorphisms on the susceptibility to NIHL and the gene-by-environment interaction. Furthermore, the gene-by-gene interactions were analyzed by generalized multiple dimensionality reduction (GMDR). RESULTS: This research discovered for the first time that the mutant allele C in rs1485175 of the GMR7 may decrease individuals' susceptibility to NIHL. The interaction between rs1485175 and cumulative noise exposure (CNE) at high level was found after the stratification according to CNE (p/p bon = 0.014/0.007, OR = 0.550, 95% CI: 0.340-0.891). Permutation test of GMDR suggested that rs1920109, rs1485175 and rs9826579 in GRM7 might interact with each other in the process of developing NIHL (p = 0.037). CONCLUSIONS: The results suggest that the mutant allele C of rs1485175 in GRM7 may reduce the susceptibility to NIHL in Chinese Han population.

Polymorphisms of heat shock protein 70 genes (HSPA1A, HSPA1B and HSPA1L) and susceptibility of noise-induced hearing loss in a Chinese population: A case-control study.

Noise-induced hearing loss (NIHL) is the second-most frequent form of sensorineural hearing loss. When exposed to the same noise, some workers develop NIHL while others do not, suggesting that NIHL may be associated with genetic factors. To explore the relationship between single nucleotide polymorphisms (SNPs) in heat shock protein 70 (HSP70) genes (HSPA1A, HSPA1B and HSPA1L) and susceptibility to NIHL in Han Chinese workers exposed to noise, a case-control association study was carried out with 286 hearing loss cases and 286 matched with gender, age, type of work, and exposure time, drawn from a population of 3790 noise-exposed workers. Four SNPs were selected and genotyped. Subsequently, the effects of the alleles and genotypes of the three HSP70 genes (HSPA1A, HSPA1B and HSPA1L) on NIHL were analyzed by using a conditional logistic regression. A generalized multiple dimensionality reduction (GMDR) was applied to further detect an interaction between the four SNPs. Compared with the combined genotypes CC/TC, carriers of the TT genotype of rs2763979 appeared to show greater susceptibility to NIHL (P = 0.042, adjusted OR = 1.731, 95% CI 1.021-2.935). A significant interaction between rs2763979 and CNE was found (P = 0.029), and a significant association was found between TT of s2763979 and NIHL (P = 0.024, adjusted OR = 5.694, 95%CI 1.256-25.817) in the 96 dB (A)≤CNE<101 dB (A) group. The results suggest that the rs2763979 locus of the HSP70 genes may be associated with susceptibility to NIHL in Chinese individuals, and other HSP70 genes may also be susceptibility genes for NIHL, but the results must be further replicated in additional independent sample sets.

Genetic variation in EYA4 on the risk of noise-induced hearing loss in Chinese steelworks firm sample.

OBJECTIVES: Noise-induced hearing loss is one of the most serious occupational diseases worldwide. It is caused by interactions between environmental and genetic factors. The purpose of this study was to examine the association between the genetic susceptibility of the eye absent homolog 4 (EYA4) gene and the risk of developing noise-induced hearing loss in China. METHODS: A case-control association study was carried out with 326 hearing loss cases and 326 controls matched with age and duration of noise exposure, drawn from a cohort of steel workers. Five single nucleotide polymorphisms (SNPs) in the EYA4 were selected and genotyped. Logistic regression was performed to analyse the main effect of genotypes and interactions between genotypes and individual/environmental factors adjusted for confounding factors. Moreover, generalised multiple dimensionality reduction was applied to further detect interaction among the 5 selected SNPs. RESULTS: Analysis revealed that locus polymorphism of rs3813346 was associated with the risk of developing noise-induced hearing loss in the dominance model, the codominance model and the addictive model (p=0.004, 0.009 and 0.003, respectively). A significant interaction between rs9321402 and cumulative noise exposure was found (p=0.002). A significant main effect p value (p=0.006) was obtained in the high-level exposure group (cumulative noise exposure ≥98 dB(A)). Generalised multiple dimensionality reduction indicated that the combined interaction of the 2 loci-rs3813346 and rs9493627-significantly affected the incidence of noise-induced hearing loss. CONCLUSIONS: The research suggests that EYA4 genetic variant and its interaction with noise levels may modify the susceptibility to develop noise-induced hearing loss in Chinese population.

Genetic Variation in POU4F3 and GRHL2 Associated with Noise-Induced Hearing Loss in Chinese Population: A Case-Control Study.

Noise-induced hearing loss (NIHL) is an important occupational disease worldwide resulting from interactions between genetic and environmental factors. The purpose of this study was to examine whether genetic variations in POU4F3 and GRHL2 may influence susceptibility to NIHL in the Chinese population. A matched case-control study was carried out among 293 hearing loss individuals and 293 normal hearing workers drawn from a population of 3790 noise-exposed workers. Ten single-nucleotide polymorphisms (SNPs) in POU4F3 and GRHL2 were selected and genotyped. Logistic regression was performed to analyze the main effects of SNPs and the interactions between noise exposure and SNPs. Moreover, the interactions between predictor haplotypes and noise exposure were also analyzed. Analysis revealed that the CC genotype of rs1981361 in the GRHL2 gene was associated with a higher risk of NIHL (adjusted OR = 1.59; 95% CI: 1.08-2.32, p = 0.018). Additionally, the GG genotype of rs3735715 in the GRHL2 gene was also a risk genotype (adjusted OR = 1.48; 95% CI: 1.01-2.19, p = 0.046). Significant interactions were found between rs3735715, rs1981361 (GRHL2), rs1368402 as well as rs891969 (POU4F3) and noise exposure in the high-level exposure groups. Furthermore, the protective haplotype CA in the POU4F3 gene and the risk haplotype GCCG in the GRHL2 gene were identified combined with noise exposure. These results indicated that GRHL2 might be an NIHL susceptibility gene, but the effect of POU4F3 on NIHL could only be detected when taking noise exposure into account, and their effects were enhanced by higher levels of noise exposure. However, the differences were not significant after the Bonferroni correction was applied. These results should be seen as suggestive.

Increased levels of urinary biomarkers of lipid peroxidation products among workers occupationally exposed to diesel engine exhaust.

Diesel engine exhaust (DEE) was found to induce lipid peroxidation (LPO) in animal exposure studies. LPO is a class of oxidative stress and can be reflected by detecting the levels of its production, such as malondialdehyde (MDA) and 4-hydroxynonenal (4-HNE), and etheno-DNA adducts including 1,N(6)-etheno-2'-deoxyadenosine (ɛdA) and 3,N(4)-etheno-2'-deoxycytidine (ɛdC). However, the impact of DEE exposure on LPO has not been explored in humans. In this study, we evaluated urinary MDA, 4-HNE, ɛdA, and ɛdC levels as biomarkers of LPO among 108 workers with exclusive exposure to DEE and 109 non-DEE-exposed workers. Results showed that increased levels of urinary MDA and ɛdA were observed in subjects occupationally exposed to DEE before and after age, body mass index (BMI), smoking status, and alcohol use were adjusted (all p < 0.001). There was a statistically significant relationship between the internal exposure dose (urinary ΣOH-PAHs) and MDA, 4-HNE, and ɛdA (all p < 0.001). Furthermore, significant increased relations between urinary etheno-DNA adduct and MDA, 4-HNE were observed (all p < 0.05). The findings of this study suggested that the level of LPO products (MDA and ɛdA) was increased in DEE-exposed workers, and urinary MDA and ɛdA might be feasible biomarkers for DEE exposure. LPO induced DNA damage might be involved and further motivated the genomic instability could be one of the pathogeneses of cancer induced by DEE-exposure. However, additional investigations should be performed to understand these observations.

[Analysis of relationship between shift-work and occupational stress among workers from different companies].

OBJECTIVE: To investigate the relationship between work in shifts and occupational stress. METHODS: A total of 5338 employees from 13 companies were investigated by cluster sampling, and occupational stress measuring tools, job content questionnaire, and effort-reward imbalance questionnaire were used to investigate occupational stress factors, stress reaction, and the condition of work in shifts. RESULTS: The employees who worked in shifts accounted for 46.6%. The condition of work in shifts varied significantly across different companies, employees with different individual features (including sex, job title, degree of education, age, working years, smoking, and drinking), and employees with different weekly working times(P<0.01 or P<0.05); health status was associated with work in shifts(P<0.01); compared with the employees who did not work in shifts, those who worked in shifts had significantly lower scores of technology utilization, work control level, psychological need, reward, social support, and job satisfaction(P<0.01 or P<0.05), as well as significantly higher scores of physical demands, effort, depressive symptoms, and negative affectivity(P<0.01). CONCLUSION: Work in shifts can affect health status, and is associated with occupational stress.

Increased levels of etheno-DNA adducts and genotoxicity biomarkers of long-term exposure to pure diesel engine exhaust.

Etheno-DNA adducts are biomarkers for assessing oxidative stress. In this study, the aim was to detect the level of etheno-DNA adducts and explore the relationship between the etheno-DNA adducts and genotoxicity biomarkers of the diesel engine exhaust (DEE)-exposed workers. We recruited 86 diesel engine testing workers with long-term exposure to DEE and 99 non-DEE-exposed workers. The urinary mono-hydroxylated polycyclic aromatic hydrocarbons (OH-PAHs) and etheno-DNA adducts (εdA and εdC) were detected by HPLC-MS/MS and UPLC-MS/MS, respectively. Genotoxicity biomarkers were also evaluated by comet assay and cytokinesis-block micronucleus assay. The results showed that urinary εdA was significantly higher in the DEE-exposed workers (p<0.001), exhibited 2.1-fold increase compared with the non-DEE-exposed workers. The levels of urinary OH-PAHs were positively correlated with the level of εdA among all the study subjects (p<0.001). Moreover, we found that the increasing level of εdA was significantly associated with the increased olive tail moment, percentage of tail DNA, or frequency of micronucleus in the study subjects (p<0.01). No significant association was observed between the εdC level and any measured genotoxicity biomarkers. In summary, εdA could serve as an indicator for DEE exposure in the human population.

[Relationship between occupational stressors and serum levels of thyroid hormones in policemen].

OBJECTIVE: To explore the relationship of occupational stressors with the serum levels of triiodothyronine (T3), thyroxine (T4), and thyroid stimulating hormone (TSH). METHODS: Using convenience sampling and cluster sampling methods, 225 policemen from a local police station in China were enrolled as subjects. Questionnaires were used to investigate demographic features and occupational stressors in those subjects. The serum levels of T3, T4, and TSH were measured by radioimmunoassay. The SPSS 13.0 software was used to perform t test or analysis of variance, partial correlation analysis, and multivariate non-conditional logistic regression analysis. RESULTS: Reward was positively correlated with the level of T3(P<0.05). Daily tension was positively correlated with the level of T4(P<0.05). Psychological demand, effort, and daily tension were negatively correlated with the level of TSH (all P<0.05). The quality of sleep was positively correlated with the level of TSH (P<0.05). The logistic regression analysis revealed that the risk of increase in T3 level in the group with a high score for daily tension was 3.19-fold higher than that in the group with a low score, while the risk of increase in T3 level in the group with a high score for negative emotion was 1.32-fold higher than that in the group with a low score. The risk of increase in TSH level in the group with a high score for negative emotion was 0.43-fold that in the group with a low score. CONCLUSION: The occupational stressors are correlated with the serum levels of thyroid hormones. Occupational stress can result in an increase in T3 level and a decrease in TSH level. However, occupational stress has no effect on T4 level.

[Depressive symptoms and influencing factors in employees from thirteen enterprises].

OBJECTIVE: To explore depressive symptoms and influencing factors in employees from 13 enterprises. METHODS: A total of 6711 workers from 13 enterprises were investigated by cluster sampling, and data were collected anonymously between November 2008 and June 2009. Job satisfaction, occupational stressors, strains, coping strategy, and social support were measured using occupational stress instruments, job content questionnaire, and effort-reward imbalance questionnaire. RESULTS: Median and P25~P75 values of depression score were 14 and 9~21, respectively. The depression score of male workers (16.31 ± 10.12) was significantly higher than that of female workers(14.50 ± 9.08) (Z=4.09, P<0.01). The depression score of managers was lowest (12.89 ± 8.70), and the front-line workers scored highest (16.02 ± 9.94), with a significant difference between the two groups (χ² =9.90, P<0.01). The depression score of shift workers (16.79 ± 9.974) was significantly higher than that of non-shift workers (14.81 ± 9.63) (Z=53.43, P<0.01). The depression scores of workers with weekly job times of ≤ 40 h, ~50 h, ~59 h, and ≥ 60 h were (14.70 ± 9.94), (15.76 ± 9.84), (15.46 ± 9.91), and (19.70 ± 10.67), respectively (χ² = 31.79, P <0.01). Correlation analysis revealed that depression score was negatively correlated with the scores of job control (r=-0.236, P <0.01), reward (r=-0.443, P<0.01), job satisfaction (r=-0.418, P<0.01), positive affectivity (r=-0.307, P <0.01), superior support (r=-0.287, P<0.01), colleague support (r=-0.235, P<0.01), and coping strategy (r=-0.208, P<0.01), but positively correlated with the scores of external effort (r=0.225, P<0.01), inherent effort (r=0.248, P<0.01), psychological demands (r = 0.246, P <0.01), physical demands (r=0.246, P<0.01), and negative affectivity (r=0.525, P<0.01). Multivariate logistic regression analysis revealed that the risk of depressive symptoms in workers with high negative affectivity was about four times as high as that in workers with low negative affectivity. The risks of depressive symptoms in workers with low reward, having disease in the past six months, and with high inherent effort were 1.62, 1.50, and 1.48 times, respectively, as high as those for their counterparts. CONCLUSION: Occupational stress, individual factors, health status, and shift work affect the depressive symptoms of workers. Reducing negative affectivity and increasing rewards are main measures to relieve depressive symptoms.

[Effects of occupational stress and related factors on depression symptoms in train drivers].

OBJECTIVE: To explore the influence of occupational stress and related factors on depression symptoms in train drives. METHODS: In March 2012, by using cluster sampling method, a cross-sectional epidemiological study was conducted in 1 402 train drivers in China. Questionnaires was investigation was conducted by face to face interview. Sample with missing variables on demographic characteristics questionnaire with missed survey variables, and occupational stress related factors and with over 3 item missing in depression symptoms self-rating scale were exclued. Depression symptoms were measured by Center for Epidemiological Survey Depression Scale. The occupational stress related actors were measured by the revised effort-reward imbalance (ERI) model questionnaires and occupational stress measurement scale. Chi-square test was carried out to analyze the differences of the incidence of depressive symptoms among different general characteristics groups, and multivariate logistic regression analysis was conducted to analyze the influence of occupational stress and related factors on depression symptoms in train drivers. RESULTS: The study showed that the average age of 1 402 subjects was (34.95±9.20) years, the length of service were (13.28±9.78) years, the score of depressive symptoms was (24.14±5.98) scores. 902 subjects (64.3%,902/1 402) were classified as people with depressive symptoms, the incidence of depressive symptoms in EMU or high-speed train drivers were the highest (68.0%,51/75); Incidence of depressive symptoms showed that were statistically significant differences in two groups of technical secondary school and college, and incidence of depressive symptoms in the junior college and above group (68.1%,352/517) was higher than that in the senior high school and below group (62.1%, 550/885) (χ(2)=5.02, P=0.025). The results of the multiple logistic regression analysis revealed that high levels of education (OR=1.63, 95%CI: 1.12-2.19), role conflict (OR=1.65, 95% CI: 1.21-2.24), role ambiguity (OR=1.99, 95% CI: 1.45-2.73), negative emotion(OR=2.87, 95%CI: 2.15-3.82), daily tension(OR=2.86, 95%CI: 2.11-3.86), poor colleagues and family support (OR=1.55, 95% CI: 1.11-2.16 and OR=1.75, 95% CI: 1.27-2.41) were risk factors of depressive symptoms, but positive emotion (OR=0.72, 95% CI: 0.53-0.96), self-esteem (OR=0.22, 95% CI: 0.16-0.30), and job itself satisfaction (OR=0.48, 95%CI: 0.35-0.65) were protective factors of depressive symptoms in train drivers. CONCLUSION: Train drivers, in particular EMU or high-speed train drivers who were prone to depressive symptoms. To arrange reasonably job roles and tasks, increase support from superiors, colleagues, and family, bring up healthy and coordinated personality, keep a good mood, promote job satisfaction, reduce the daily tension have positive effects on reducing the occurrence of depressive symptoms for train drivers.

Association between psychosocial job characteristics and sickness absence due to low back symptoms using combined DCS and ERI models.

OBJECTIVE: To evaluate the combined demand-control-support (DCS) and effort-reward-overcommitment (ERI-OC) stress models in association with sickness absence due to low back symptoms (SA-LBS). METHODS: A total of 2,737 blue-collar workers recruited from 13 companies in the most populous province (Henan) of China were included in the study. Personal and physical job characteristics, psychosocial scales of the stress models, and SA-LBS data in the preceding year were collected by a self-reported questionnaire and analyzed by a multivariable logistic regression model. Tertile exposure levels (low, medium and high) were constructed to discriminate a risk level. Odds ratios (OR) with 95% confidence intervals (CI) were used as the association with SA-LBS. RESULTS: A large percentage (84.5%) of the Chinese workers did not take sick leave after reporting low back symptoms during the preceding year. High job demand or medium-high reward was associated with SA-LBS. The association of the combined stress models and SA-LBS was not evident. CONCLUSIONS: The ERI-OC model appeared to be more predictive of SA-LBS than the DCS model in the study population. The advantage of using combined stress models for predicting SA-LBS is not evident.

[The effect of occupational stress on depression symptoms among 244 policemen in a city].

OBJECTIVE: To explore the influence of occupational stress related factors on depression symptoms among 244 policemen in a city in China. METHODS: In May 2011, 287 policemen from a city public security bureau were recruited to this survey by cluster sampling method. We deleted questionnaires which include missing variables on demographic characteristics and factors associated with occupational stress questionnaires which include over 3 missing items. 244 policemen were included in this study. Depression symptoms and occupational stressors were measured using Chinese version of depression self-reported questionnaire, job content questionnaire, Chinese version of effort-reward imbalances questionnaire, job hazard scale and occupational stress inventory. Depression symptom scores and the relationship between the variables and occupational stress were analyzed by Spearman correlation analysis and multiple regression analysis. RESULTS: The Median (P25-P75) of depression symptom scores of all respondents was 16.50 (11.00-25.00). 144 were policemen with no depression symptoms and 100 were with depression symptoms. The median (P25-P75) of depression symptoms scores among policemen with length of serves <10, 10-19, 20-29 and ≥30 was 17.00 (8.00-26.00), 16.00 (11.00-24.50), 19.00 (12.00-27.00), and 12.00 (6.25-15.00), respectively. The difference of scores was significant among length of serves groups (χ2=9.52, P=0.023). The scores of psychological demands, sleep disorder, daily life stress and negative affectivity among policemen with depression symptoms were 17.00 (8.00-26.00), 16.00 (11.00-24.50), 19.00 (12.00-27.00), and 12.00 (6.25-15.00), respectively, which were higher than those with no depression symptoms (24.00 (22.00-25.00), 8.00 (5.00-13.00), 8.00 (6.00-10.00), 1.00 (0-2.75)), and the differences were significant (Z=3.82, 5.39, 5.15, 6.41, P<0.001). Spearman correlation analysis revealed that depression symptoms score was positively related to sleep disorder, commitment effort, psychological demands, daily life stress, negative affectivity and job hazards scores. Correlations coefficient were 0.44, 0.28, 0.28, 0.33, 0.38, 0.44, and 0.38, respectively (P<0.001). Multiple linear regression analysis indicated that self-esteem, daily life stress and negative affectivity had bigger contribution on the depression symptoms scores. The standard regression coefficient was -0.46, 0.19 and 0.13, respectively (P<0.001, P=0.001, P=0.030). CONCLUSION: Sleep disorder, commitment effort, psychological demands, daily life stress, negative affectivity and job hazards scores were the inducement of depression symptoms for policemen. To reduce the daily life stress, negative affectivity and improve the quality of sleep, add to self-esteem, reward and social support have positive effects on reducing the occurrence of depressive symptoms for police.

[Investigation of coping strategy for occupational stress among workers in thirteen enterprises].

OBJECTIVE: To investigate the influential factors for the coping strategy for occupational stress among workers in thirteen enterprises. METHODS: An anonymous survey was conducted in 6711 workers in 13 enterprises selected by cluster sampling from November 2008 to June 2009. Coping strategy, occupational stressors, stress response, and social support were measured using occupational stress instruments, job content questionnaire, and effort-reward imbalance questionnaire. The data from 5338 workers were statistically analyzed; the overall response rate was 79.6%. RESULTS: The median coping strategy score was 26 (23-30) (P25∼P75). The coping strategy score of male workers (26.56±5.30) was significantly higher than that of female workers (26.07±5.37) (Z = 10.02, P < 0.01). Coping strategy score was the highest in managers (27.41±4.86) and the lowest in front-line workers (26.28±5.36), with a significant difference between the two groups (χ(2) = 5.38, P < 0.01). The coping strategy scores of workers with weekly job times of ≤40 h, 41-50 h, 51-59 h, and ≥ 60 h were 26.93±5.36, 26.72±5.11, 25.74±5.30, and 25.09±5.83, respectively (χ(2) = 22.12, P < 0.01). Correlation analysis revealed that coping strategy score was positively correlated with decision level (r = 0.183, P < 0.01), reward (r = 0.207, P < 0.01), positive emotion (r = 0.244, P < 0.01), superior support (r = 0.176, P < 0.01), coworker support (r = 0.176, P < 0.01), and job satisfaction (r = 0.171, P < 0.01), but negatively correlated with psychological demands (r = -0.157, P < 0.01), physical demands (r = -0.099, P < 0.01), negative emotion (r = -0.093, P < 0.01), and depressive symptoms scores (r = -0.208, P < 0.01). Compared with those with middle or low coping strategy scores, workers with high coping strategy scores reported higher decision level, reward, social support, job satisfaction, and positive emotion scores (P < 0.01) but lower depressive symptom and negative emotion scores (P < 0.01). CONCLUSION: Enterprise type, individual factors, health status, and work time, have effects on the coping strategy for occupational stress of occupational stress.

[Survey on job satisfaction and its influencing factors among enterprise workers].

OBJECTIVE: To explore the influencing factors of job satisfaction among enterprise workers. METHODS: Between November, 2008 and June, 2009, 6 711 workers from 13 enterprises were recruited to this survey by cluster sampling method. Data about job satisfaction, occupational stressors, strains, coping strategy and social support were collected anonymously by using occupational stress instruments, job content questionnaire and effort-reward imbalance questionnaire. RESULTS: Median (P25-P75) of job satisfaction scores was 40(34-46), which were separately (40.25 ± 7.59) and (38.57 ± 8.62) among female and male workers. The difference showed statistical significance (Z = 6.00, P < 0.01). The job satisfaction score was highest (41.44 ± 6.93) among administrative staff, but lowest (38.89 ± 8.79) among assistant workers. The difference showed statistical significance (χ(2) = 6.64, P < 0.01).Job satisfaction score of shift workers (38.47 ± 8.58) was significantly lower than that of non-shift workers(39.66 ± 8.10) (Z = 4.61, P < 0.01). The job satisfaction scores of workers with weekly job time ≤ 40 h, 41-50 h, 51-59 h and ≥ 60 h were separately (39.86 ± 8.25), (39.23 ± 8.20), (38.68 ± 8.44) and (37.01 ± 8.34). The difference showed statistical significance (χ(2) = 54.06, P < 0.01). Correlation analysis revealed that job satisfaction was positively related to technology utilize degree (r = 0.26, P < 0.01), free decision latitude(r = 0.32, P < 0.01), reward(r = 0.60, P < 0.01), positive affection (r = 0.45, P < 0.01), superior support(r = 0.49, P < 0.01) and coping strategy (r = 0.16, P < 0.01); however, negatively related to external effort(r = -0.33, P < 0.01), psychological demands (r = -0.34, P < 0.01), physical demands(r = -0.30, P < 0.01), negative emotions (r = -0.41, P < 0.01) and depressive symptoms (r = -0.44, P < 0.01). Multivariate logistic regression analysis showed that the risk of job dissatisfaction for workers with low reward was about three times as high as that for workers with high reward (OR = 3.44, 95%CI:2.95-4.01), risks of job dissatisfaction for workers with low negative emotions, high positive affection and social support were about two times as high as that for workers with low positive affection, high negative emotions and low social support, with the OR (95%CI) respectively at 2.42 (2.09-2.82), 2.28 (1.95-2.66) and 2.25 (1.94-2.62). CONCLUSION: Occupational stress, individual features, health status, shiftwork system and work time had great effect on job satisfaction. The main measures of increasing job satisfaction were to improve rewards, increase superior support and decrease negative emotions.

[Effect of occupational stress and effort-reward imbalance on sleep quality of people's policeman].

OBJECTIVE: To explore the effect of occupational stress and effort-reward imbalance on sleep quality of people's police. METHODS: A cluster sampling survey of sleep quality and occupational stress correlated factors was conducted on 287 police from a city public security bureau by questionnaires in May, 2011; the relationship between sleep quality and occupational stress correlated factors was analyzed by one-way ANOVA and multivariate non-conditional logistic regression using effort-reward imbalance model (ERI) and demand-control-support model (DCS). And the subjects were divided into high tension group and low tension group using the 1.0 of ERI and DCS coefficients as the boundary. RESULTS: The sleep quality score of shift work police was higher than day work police (11.95 ± 6.54 vs 9.52 ± 6.43, t = 2.77, P < 0.05).In ERI model, the sleep quality score in high tension group was higher than low tension group (14.50 ± 6.41 vs 8.60 ± 5.53, t = -5.32, P < 0.01), and in DCS model, the sleep quality score in high tension group was also higher than low tension group (13.71 ± 6.62 vs 9.46 ± 6.04, t = -3.71, P < 0.01).For the regression analysis of ERI model as an argument, sex (OR = 3.0, 95%CI:1.16-7.73) , age for 30-39 years (OR = 3.48, 95%CI:1.32-9.16) , intrinsic effort (OR = 2.30, 95%CI:1.10-4.81) and daily hassles (OR = 2.15, 95%CI:1.06-4.33) were risk factors of low sleep quality, and reward (OR = 0.26, 95%CI:0.12-0.52) was the protective factor.For the regression analysis of DCS model as an argument , age for 30-39 years (OR = 2.55, 95%CI:1.02-6.37) , depressive symptom (OR = 2.10, 95%CI:1.14-3.89) and daily hassles (OR = 3.25, 95%CI:1.70-6.19) were risk factors of low sleep quality.While the ERI model and the DCS model were analyzed simultaneously, sex (OR = 3.03, 95%CI:1.15-7.98) , age for 30-39 years (OR = 3.71, 95%CI:1.38-9.98) and daily hassles (OR = 2.09, 95%CI:1.01-4.30) were the risk factors of low sleep quality, and reward (OR = 0.22, 95%CI:0.10-0.48) was the protective factor. CONCLUSION: Occupational stress and effort-reward imbalance affected the sleep quality to people's policeman.

[Effects of occupational stress and related factors to the mood of speed train drivers].

OBJECTIVE: To explore the effect of occupational stress and related factors to the mood of speed train drivers. METHODS: By using cluster sampling method, a cross-sectional study was conducted in 1 352 speed train drivers (including 291 passenger train drivers, 640 freight trains drivers, 342 passenger shunting train drivers, and 79 High Speed Rail drivers) from a Railway Bureau depot. The survey included mood, individual factors, occupational stress factors, personality factors and mitigating factors. The mood status was evaluated by mood scale, and the occupational stress factors, personality factors and mitigating factors were measured by the revised effort-reward imbalance (ERI) model questionnaires and occupational stress measurement scale. RESULTS: Correlation analysis showed that the mood score was negative correlated with age(r = -0.07, P = 0.01), working age (r = -0.07, P = 0.01), ERI(r = -0.53, P < 0.01), extrinsic effort(r = -0.41, P < 0.01), intrinsic effort(r = -0.39, P < 0.01), group conflict(r = -0.12, P < 0.01), role conflict(r = -0.16, P < 0.01), role ambiguity(r = -0.08, P < 0.01), and social support(r = -0.36, P < 0.01), and was positive correlated with rewards(r = 0.42, P < 0.01), self-esteem(r = 0.20, P < 0.01), and coping strategy(r = 0.12, P < 0.01). The mood scores of passenger train drivers, passenger shunting train drivers, freight train drivers and High Speed Rail drivers were 4.88 ± 2.78, 4.72 ± 2.50, 4.28 ± 2.57 and 4.12 ± 3.02, respectively, which the differences had statistical significance(F = 4.23, P = 0.01), unrelated to age and working age. The descending sort of mood corrected mean was passenger train drivers(4.87), passenger shunting train drivers (4.69), freight train drivers (4.29) , and High Speed Rail drivers (4.17). Stepwise regression analysis indicated that ERI, social support, rewards, intrinsic effort, self-esteem, extrinsic effort and coping strategy were the predictors, which could explain the 74.36% of total variance. CONCLUSION: Most occupational stress factors may cause negative mood, but rewards, self-esteem, social support and coping strategy were the protection factors of mood; different train drivers had different mood status, High Speed Rail drivers were the worst, and passenger train drivers were the best.