[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.

[The relationship of occupational stress and the level of some hormone metabolites in urine].

OBJECTIVE: To explore the possibility for 17-OHCS, 17-KS, VMA and HVA in urine as indicators of occupational stress identification and evaluation. METHODS: 225 policies were investigated by using convenience sampling and cluster sampling methods, occupational stressors, strains, buffer factors and individual factors were measured by questionnaires. The urine 17-OHCS, 17-KS, VMA and HVA level was tested by ELISA and high performance liquid chromatography method respectively. RESULTS: The urine 17-OHCS level of the groups with high coworker support and job control scores was lower than that of the groups with low score group (P < 0.05), the urine 17-OHCS level of the group with high negative affectivity score was higher than that of the group with low score group (P < 0.05). The urine 17-KS level of the group with high job security score was lower than that of the counterparts (P < 0.05). The urine VMA level of the group with high coworker support score was lower than that of the counterparts (P < 0.05). The urine HVA level of the group with high coping strategy score was lower than that of counterpart (P < 0.05). Logistic regression analysis revealed that the job control and respect were the protective factors of urine 17-OHCS level increase (OR = 0.353 and 0.352 respectively), but over-commitment, self-esteem and daily hassles were the risk factors of urine 17-OHCS with level increase (OR = 3.391, 2.439, and 2.584 respectively). The risk of urine 17-KS level increase for the groups high job control and job security scores were respectively 0.387, 0.356 times than that of the counterparts, the risk of urine VMA level increase for the group with high negative affectivity score was 2.643 times than that of the counterparts. CONCLUSION: The urine 17-OHCS, 17-KS and VMA level were potential indicators for occupational stress evaluation.

[Determination of four biogenic amine metabolites in urine by high-performance liquid chromatography].

OBJECTIVE: To establish a method for simultaneously determining vanilmandelic acid (VMA), 5-hydroxyindoleacetic (5-HIAA), 3, 4-dihydroxyphenylacetic acid (DOPAC), and homovanillic acid (HVA) in urine by high-performance liquid chromatography (HPLC). METHODS: After being filtered with a 0.45 µm membrane syringe filter, the urinary samples were injected directly into the HPLC system using a C18 chromatographic column and a fluorescence detector. The excitation and emission wavelengths were chose as 280 nm and 315 nm, respectively, and the urinary samples were carried with a mobile phase of methanol-0.1 mol/L phosphate buffered solution (V/V = 20:80) at a flow rate of 1.0 ml/min and an injection volume of 20 µl. RESULTS: Using the method reported here, the correlation coefficients of VMA, 5-HIAA, DOPAC, and HVA were 0.9999, 0.9998, 0.9997, 0.9999, respectively, over linear ranges of 0-2.5, 0-2.0, 0-2.0, and 0-2.5 µg/ml, the minimum detectable concentrations were 0.006, 0.008, 0.012, and 0.0082 µg/ml, the average precisions were 4.2%, 3.7%, 4.9%, and 3.6%, and the recovery rates were 91%∼102%, 93%∼101%, 94%∼101%, and 89%∼ 102%. CONCLUSION: This determination method is simple, efficient, accurate, and sensitive for the simultaneous detection of VMA, 5-HIAA, DOPAC, and HVA in urine.

[The optimization of 2-thiothiazolidine-4-carboxylic acid back extraction in urine and determination by HPLC].

OBJECTIVE: Establishment of determination method of 2-thiothiazolidine-4-carboxylic acid (TTCA) in urine with HPLC. METHODS: A volume of 0.5 ml hydrochloric acid (2 mol/L) and 0.5 ml pure water was added into 1 ml urine, and then extracted by 4 ml of diethyl ether by shaking for 2 min. Remove the water phase in a tube with plug and extract again, mix the two extraction diethyl ether together, take 4 ml by adding 2 ml borax-monopotassium phosphate buffer and shaking for 2 min to extract, then take the water phase to detect. A C(18) column and UV detector were used for separating and detecting. The wavelength was 273 nm, the flow rate was 1.0 ml/min, and the injection volume was 20 µl. RESULTS: TTCA has a good linearity (r = 0.9995) over the concentration of1 1 ∼ 10 µg and the minimum detectable concentration of TTCA in urine was 0.1 µg/ml. The within-day precision (RSD) were 8.4%, 3.0% and 1.7%, the between-day precision (RSD) were 11%, 3.8%, 1.9%, respectively. The extraction recovery were between 80% ∼ 102%. CONCLUSION: The method was accurate and sensitive to detect TTCA in urine.

[The rervising of biological exposure index for carbon disulfide exposuring].

OBJECTIVE: To study the biological exposure index of carbon disulfide in China. METHODS: High-performance liquid chromatography (HPLC) was used to detect the levels of 2-thiothiazolidine-4-carboxylic acid (TTCA) in the urine of the workers after working shift end, Gas chromatography was used to detect the concentrations of the carbon disulfide in the workplace air. The relationship between the urine TTCA levels and the concentrations of the carbon disulfide was analyzed, the biological exposure index and judgement result from PC-TWA were compared. RESULTS: The levels of TTCA in urine of workers occupationally exposed to carbon disulfide were closely and positively related with the concentrations of the carbon disulfide in the workplace air. The regression equation was Y = 0.265X - 0.165, The biological exposure index of carbon disulfide were calculated by regression equation according to occupational exposure limits of carbon disulfide in China. CONCLUSION: The biological exposure index of CS(2) in China might be revised for 1.2 mg/g Cr.

[The relationship between occupational stress and serum glycosylated hemoglobin A1c level].

OBJECTIVE: To explore the relationship between occupational stress and serum glycosylated hemoglobin A1c (HbA1c) level. METHODS: A cross-sectional epidemiological study was conducted in 115 dispatchers. The occupational stressors, personality, occupational strain and coping with stress were measured using Occupational Stress Instrument. Serum HbA1c levels were measured by stratigraphic analysis of cation exchange resin. RESULTS: Serum HbA1c level (6.63% ± 1.93%) in the shiftwork group was significantly higher than that (5.73% ± 1.57%) in the daily relay work group (P < 0.05). Spearman correlation analyses showed the positive correlation between type A behavior and serum HbA1c level (r = 0.221), the negative correlation between organizational commitment and serum HbA1c level (r = -0.218). Variance analyses revealed that serum HbA1c levels among high, middle and low job requirement groups and job control groups were significantly different (P < 0.05). There were significant differences of serum HbA1c levels among different type A behavior, internal control, susceptibility of stress and organizational commitment groups (P < 0.05). Stepwise regression analyses indicated that shiftwork affects obviously serum HbAlc level, internal control and job future were the predictors of serum HbA1c level (R2 = 0.082). CONCLUSION: Serum HbA1c may be a potential biomarker in field investigation of the effects of occupational stress.

[Coping strategy and its effect on occupational stress among rail freight dispatchers].

OBJECTIVE: To analyse the relationship between coping strategy and occupational stress in rail freight dispatchers. METHODS: 115 rail freight dispatchers were investigated by using group sampling method, investigation contents included coping strategies, occupational stressors, strains and personalities. RESULTS: The proportion of using coping strategy in rail freight dispatchers is lower. The scores of job future ambiguity, type A behavior and work locus of control in workers with insufficient coping strategy were higher than those in workers with sufficient strategy (P < 0.05 or P < 0.01), but the score of organization commitment score in workers with insufficient coping strategy was lower than those in workers with sufficient strategy (P < 0.05), the differences of scores of some occupational stressor, strain and personality variables between workers with insufficient and those with sufficient in social support, job-family balance, job involvement coping factors of coping strategy were remarkable significant (P < 0.05 or P < 0.01), the differences of scores of occupational stressor, strain and personality variables between workers with insufficient and those with sufficient in ask, logic and time management factors of coping strategy weren't significant (P > 0.05). Logistic regression analysis showed that risk of being job dissatisfaction and daily life stress in workers with insufficient social support coping was three or four times than those with sufficient coping (OR = 3.06 or 4.38, respectively), risk of being daily life stress in workers with insufficient job involvement coping was three times than those with sufficient coping (OR = 3.26). CONCLUSION: The proportion of using coping strategy in rail freight dispatchers is lower. Coping strategy has influence on the individual's perception of occuaptional stressors, strains and personalities.

[Effects of occupational stress on serum tumor necrosis factor-α and interleukins].

OBJECTIVE: To explore the effect of occupational stress on serum tumor necrosis factor-α (TNF-α), interleukin (IL)-1ß, IL-2 and IL-4. METHODS: A cross-sectional epidemiological study was conducted in 200 workers from the refrigerator assembly line in Henan province in China. Psychosocial work conditions were measured by using the job demand-control model, the effort-reward imbalance model questionnaires and occupational stress measurement scale. Serum TNF-α, IL-1ß, IL-2, and IL-4 concentrations were measured by radioimmunoassay or immunoradiometric assay method respectively. RESULTS: Serum TNF-α concentration was statistically significantly different between workers with higher affective balance level and control groups [(1.947 ± 0.173) and (2.029 ± 0.240) fmol/ml] (P < 0.05). Serum IL-1ß concentration was statistically significantly different between workers with higher effort level and control groups [(0.133 ± 0.034) and (0.118 ± 0.031) ng/ml] (P < 0.05). Serum IL-2 concentration was statistically significantly different between workers with higher role ambiguity level [(1.658 ± 0.376) and (1.491 ± 0.033) ng/ml] and control groups (P < 0.05), as well as between workers with higher role conflict level and control groups [(1.774 ± 0.311) and (1.589 ± 0.380) ng/ml] (P < 0.05), between workers with higher daily life stress level and control groups [(1.759 ± 0.361) and (1.606 ± 0.381) ng/ml] (P < 0.05). Serum IL-4 concentration was statistically significantly different between workers with higher reward level and control groups [(1.449 ± 0.025) and (1.466 ± 0.041) pg/ml] (P < 0.05). Stepwise regression analysis indicated that affective balance was the predictor of serum TNF-α (R(2) = 0.029). Effort and mental health were the predictors of serum IL-1ß (R(2) was 0.029 and 0.055, respectively). Role conflict, daily life stress and role ambiguity were the predictors of serum IL-2 (R(2) was 0.040, 0.078 and 0.104, respectively). Reward was the predictor of serum IL-4 (R(2) = 0.030). CONCLUSION: Unhealthy psychological stress factor might be induce a marked increase in the concentrations of serum TNF-α, IL-1ß, IL-2, as well as IL-4.

[Effect of occupational stress on ambulatory blood pressure].

OBJECTIVE: To explore the effect of occupational stress on ambulatory blood pressure. METHODS: 30 male healthy workers from the refrigerator assembly line in Henan province in China were investigated. Psychosocial work conditions were measured by using the Job Demand-control Model, the Effort-reward Imbalance Model questionnaires and Occupational Stress Measurement Scale. Ambulatory blood pressure(ABP) was measured by using mobile ABP monitor. The t test was utilized to analyze the difference of parameters of ABP monitoring between different groups of occupational stress and other variables scores. The stepwise regression analysis was used to analyse the effect of occupational stress factors on parameters of ABP. RESULTS: (1) As to stressors, systolic blood pressure variability (SBPV), mean arterial blood pressure variability (MABPV) and heart rate at 30 minute after work in workers with high role conflict score were significantly higher than those in workers with low score (P < 0.05). Workers with high skill utilization score had significantly lower mean systolic blood pressure (SBP) at 30 minute after work than workers with low score (P < 0.05). Diastolic blood pressure variability (DBPV) and heart rate variability (HRV) in workers with high decision latitude score were significantly higher than those in workers with low score (P < 0.05). Workers with high job psychological demands score had significantly higher SBPV, DBPV and MABPV than workers with low score (P < 0.05). Heart rate-pressure product(RPP) and SBPV in workers with high effort score were significantly higher than those in workers with low score (P < 0.05). Workers with low rewards score had higher mean heart rate and heart rate at 30 minute after work than workers with high score (P < 0.05). (2) For personalities, workers with high work locus of control score had significantly higher mean diastolic blood pressure (DBP) and mean arterial blood pressure (MABP) than workers with low score (P < 0.05). Workers with high patience score had significantly lower mean SBP at 30 minute after work than workers with low score (P < 0.05). Heart rate at 30 minute after work in workers with high organization commitment score was significantly lower than that in workers with low score (P < 0.05). (3) Concerning buffer factors, HRV in workers with high control strategies score were significantly lower than that in workers with low score (P < 0.05). Workers with low supervisor support score had higher RPP and MABPV than workers with high score (P < 0.05). (4) In the multiple stepwise regression, daily life stress affected SBPV (R2 = 0.12) and MABPV (R2 = 0.05), depression was related to DBPV at 30 minute after work (R2 = 0.15) and SBPV (R = 0.03), mental health was predictor of MABPV (R2 = 0.07) and negative affection was predictor of heart rate at 30 minute after work (R2 = 0.24). CONCLUSIONS: Occupational stressors, personality and social support have effect on parameters of ABP. Parameters of ABP monitoring could be used to evaluate occupational stress in the field research.

Job stress, gene polymorphism of beta2-AR, and prevalence of hypertension.

OBJECTIVE: To study the interactive effect of job stress and genetic susceptibility (or gene polymorphism) on hypertension. METHODS: A cross-sectional epidemiological study was conducted in 452 workers from a thermal power plant in China. Extrinsic effort, occupational reward, and over-commitment were measured. Hypertensive patients were defined by three phases of screening, reexamination, and final diagnosis. beta2-AR genotypes and allele frequencies at amino acid positions 16 (beta2-AR-16: Arg-->Gly) and 27 (beta2-AR-27: Gln-->Glu) were identified by PCR-RFLP. RESULTS: Job stress was related with the prevalence of hypertension in males (P < 0.05), whereas no significant relationship was found in females (P > 0.05). Differences in genotypes and allele frequencies of the beta2-AR-16 were statistically significant between the hypertension and control groups (P < 0.05), whereas those of beta2-AR-27 were not (P > 0.05). The prevalence of hypertension was higher in individuals carrying Gly16 allele than in those carrying Arg16 allele of the high job stress group (P < 0.01 or 0.05). CONCLUSION: High job stress and polymorphism of beta2-AR-16 have an interactive effect on the prevalence of hypertension in male workers.

[Study on the correlation of the biochemical indexes in flouride workers].

OBJECTIVE: To explore the correlation among some biochemical indexes in the fluoride workers. METHODS: The activities of superoxide dismutase(SOD), glutathione peroxidase (GSH-Px), catalase (CAT), alkaline phosphatase (AKP) and the level of calcitonin (CT), parathyroid hormone (PTH), IgG, IgA, IgM, Cu2+, Zn2+, Ca2+, Mg2+ and Se2+, F- in serum and in urine were measured in fifty male fluoride workers and fifty controls. RESULTS: The levels of F-, CT, PTH, AKP and GSH-Px in serum and F- in urine in exposed group were significantly different from that in control group. Correlation analysis indicated that F- in urine and CAT(r = 0.3133, P < 0.05), CT and PTH(r = 0.5173, P < 0.01), Se2+ and CAT(r = 0.4354, P < 0.05) were positively correlated. There were significantly negative correlation between F- in serum and GSH-Px (r = -0.5202, P < 0.01) and positive correlation among Cu2+, Zn2+, Ca2+ and Mg2+ in serum. CONCLUSION: (1) Excess of fluoride may affect secretion of calcium adjusting hormone (CT, PTH); (2) Changes of AKP and GSH-Px may be regarded as health monitoring indexes; (3) The correlation of biochemical indexes plays an important role in studying the mechanism and the early prevention and treatment of industrial fluorosis.