Epidemiological Study On The Pathogenic Mode Of The Occupational Stress In The High Risk Population Of EH

With the economy development and the increased competitive pressures, the prevalence of essential hypertension(EH) has been growing up. Recently, under the transitions of the health view and medical-model, more and more researches have focused on the significance of mental stress in the occurrence and development process of EH. The relationship of occupational stress and EH has become a hot spot in the occupational medicine domain.A lot of researches indicate that occupational stress is essential risk factor for EH among occupational population. Long term and lasting exposures to occupational stress which impact by mental factors such as type A behavior can not only increase the risk of EH, but also induce emotional barriers such as anxiety, on the other hand, mental stresses which are closely related to EH, such as anxiety and type A behavior, might push the procedure of EH induced by occupational stress, both suggesting that analysis based on separating their relationship might be not comprehensive. At present, most researches are limited on analyzing relationship of individual factor and EH, for example, occupational stress and EH. There is no research token a comprehensive view to analyze effects to EH of mental stresses, such as strain and anxiety, which are inducing by occupational stressors.This thesis research the relationship of EH and mental stress induced by occupational stressors. To investigate whether the interaction of occupational mental stresses could affect EH or not, and analyze what path of the occupational mental stresses induce to EH.in the other way,to exploer the roles of Arg/Gly polymorphism in EH induced by occupational mental stress. The aim of the study is to provide scientific foundation and theory evidence for relative intervention policies and measures of EH in occupational population.1 The relationship between occupational mental stress and EHIn our previous study,we selecting the high-risk population of EH from male train police which employed for at least 3 years , currently working.and selecting the low-risk population of EH from male train attendant which have the same work environment,above units making the sample by cluster random sampling method.Using the OSI-R,STAI,A style behavior scale and cross-sectional study method to test the occupational stress, anxiety, type A behavior of occupational population. Analying the distributional character of occupational mental stress, the logistic regression model was used to analyze the role of occupational mental factors and the interaction in the progress of essential hypertension, to calculate odds ratios and 95% confidence intervals.1.1 The relationship between occupational stress and EHThe scores of occupational role questionnaire and personal strain questionnaire in high risk population of EH were separately 161.78±20.23 and 110.29±21.09, the low risk population of EH were separately 155.21±21.88 and 101.60±23.17, both have statistical significance (P<0.05). According to the logistic regression model (adjusting for age, BMI and familial EH history), the occupational stress was a significant risk factor of EH(OR=2.659,95.0%CI: 1.326~5.329) in high risk population of EH. There was dose-action relationship between occupational stress scales and EH ,Odd ratios (95% confidence interval) for medium and high group with low as control ranged from 5.212(95.0%CI: 0.900~30.184) to9.59(95.0% CI: 11.814~50.696).However, only in high level of occupational stress was a risk factor of EH(OR=2.817,95.0% CI: 1.043~7.613) in low risk group. There was statistical difference of prevalence (P<0.05)between two groups in mid- and high-level of occupational stress.According to the logistic regression model (adjusting for age, BMI and familial EH history), the strain was a significant risk factor of EH(OR=2.659,95.0%CI: 1.326~5.329) in high risk population of EH. Compared with low level of strain, in high level of strain was risk factor of EH ,Odd ratios (95% confidence interval) equaled to 20.344 (95.0% CI: 2.249~184.067).1.2 The relationship between anxiety and EHThe scores of S-Anxiety and T-Anxiety in high risk population of EH were separately 49.87±9.14 and 49.07±7.25, the low risk population of EH were separately 45.18±8.06 and 46.00±7.37, both have statistical significance (P<0.05).and both of the prevalence in EH high-risk group were higher than the EH low-risk group. Compared with low level of T-anxiety (adjusting for age and other risk factors), in high level of T-anxiety was risk factor of EH in high- and low-risk groups of EH,Odd ratios (95% confidence interval) were separately 2.465(95.0%CI: 1.081~5.621), 6.359(95.0% CI: 2.668~15.155).1.3 The relationship between type A behavior and EHThe scores of type A behavior in high risk population of EH was 41.20±6.60, the low risk population of EH was 38.58±5.53, both have statistical significance (P<0.05). and both of the prevalence in high-risk group were higher than the low-risk group.Compared with low level of type A behavior (adjusting for age and other risk factors), in high level of type A behavior was risk factor of EH ,Odd ratios (95% confidence interval) were separately 4.236(95.0% CI: 1.471~12.199), 12.390(95.0% CI: 5.552~27.648)in high- and low- risk population of EH.2 Effect of the interaction between occupational mental stresses and behaviorsThe odds ratio values (OR) was calculated to determine the addition effects among different factors and measure the interactions by multiplicative model.The results showed that anxiety,type A behavior appeared interaction with strain in EH high-risk group.3 The path analysis in the EH induced by occupational mental stressIn terms of basic psychsocial-epidemiology theory, Using path analysis from structure equation model to Confirm the causal relationship among occupational stress, anxiety, type A behavior and essential hypertension. analyzed the effects of occupational stress, anxiety and type A behavior on their blood pressure; simultaneously, studied the inter-relations of the three occupational mental factors and revealed the results with path diagram explicitly. All the calculations and statistics were performed with the computer program AMONS 7.0 Version.Three hypothesis models set up based on literatures review and outcome of this data analysis. Hypothesis model was tested by path analysis. Result showed combination model was better one among all hypothesis models according to model fit index: The latent variables of stressor lead to strain, anxiety and type A behavior combined and acted to essential hypertension. Absolute model fit indexχ~2/df was 1.648 and RMSEA was 0.059. This model can be acceptive basically.Through introducing strains directly (Standardized Total Effects:0.806) and T-Anxiety under strains indirectly (Standardized Indirect Effect:0.223), occupational stressors impacts EH (Standardized Indirect Effects: 0.271).Type A behavior have direct effect to strain(Standardized Total Effects:0.276), and it have direct or indirect effect to anxiety also.at the same time, strain and anxiety have direct effect to EH(Standardized Direct Effect:0.317,0.160), type A behavior not noly is risk factor of EH(Standardized Direct Effect:0.294),but also have direct or indirect effect to EH(Standardized Indirect Effect:0.104).4. Roles of Arg/Gly Polymorphism in EH induced by occupational mental stressUsing 1:1 matched case-control study, we have identified 95 essential hypertension patients from.A total of 95 controls were selected during the same period and matched to each case by age, trades.Conditional logistic regression was used to analyze the role of occupational mental factors, gene, gene-environmental interaction in the progress of essential hypertension, and to calculate odds ratios and 95% confidence intervals.The distribution of Arg/Arg,Arg/Gly,Gly/Gly in essential hypertension cases and controls was significant difference(χ2=7.889, P=0.018), Gly/Gly had a increased risk of hypertension 2.759(95%CI:1.200~6.347) compared to Arg/Arg. The interaction between genes and occupational mental stress was analyzed by multiplicative model.The results showed that strain, anxiety appeared interaction with Gly/Gly genotype. Conclusion:1 Each of the scores of occupational mental stresses in EH high-risk population were significant higher than the EH low-risk population ; Long term exposure to occupational stress may increase the reactivity to stressors among EH high risk population; In high risk group of EH, amplifying reactions of T-anxiety and type A behavior to EH indicate that mutual influences among occupational mental stresses are high risk of EH.2 Occupational stress ,T-anxiety and type A behavior are risk factors of EH. In occupational population, occupational stressors as inducement of physical and physiological reaction. In the other way, strains indicates the relationship of occupational stress and EH directly. Type A behavior acts as regulation factor of physiological reaction, it not only can induce EH directly, but also can effect EH trough strains and anxiety indirectly. while they interact with each other during the procedure of EH of occupational population. 3 Gly/Gly genotype might be the crucial risk factor for EH among occupational population. Individual who is genotype Gly/Gly, while exposure of strains and T-Anxiety is much easier to get EH.