| Objectives This study uses a retrospective cohort analysis method to analyze the effect of shift work on hypertension in non-ferrous metallurgical enterprises,and explores the dose-response relationship between shift years and hypertension.To provide scientific basis for the establishment of enterprise working hours system and effective prevention and control of hypertension in this occupational population.Methods In this study,employees from 11 units of a non-ferrous metallurgical enterprise in Gansu Province who performed a health checkup at an employee health checkup institution from September 2018 to December 2018 were selected as the research subjects to establish a retrospective cohort to analyze the relationship between shifts and shift years and hypertension.The study subjects were divided into an exposed group(shift work)and a control group(day shift)according to whether workers shifted when they entered the factory.The observation period of the cohort was from March 1974 to December 2018.Used a questionnaire surveys and extracts from the contents of health files to collect data.The main survey contents include:(1)The general demographic characteristics of the research subjects:ethnicity,age,gender,education level,marital status,family income,etc.(2)Life and eating habits:smoking,drinking,drinking tea,diet,physical exercise,salt,etc.(3)Past history and medication history:hypertension(hypertensive drugs),diabetes(hypoglycemic drugs),cardiovascular and cerebrovascular diseases.(4)Occupation history:job position,length of service,time to start shift,shift duration,shift type,occupational harmful factors(dust,smoke,fog)exposure,etc.(5)Physical examination items:height,weight and blood pressure.Used the Independent-Samples T Test to compare the differences between groups of continuous variables.Used a chi-square test to compare the differences in the composition of categorical variable groups,and used the Cox proportional hazards model for univariate and multivariate analysis of the relationship between shifts and hypertension,Cochran-Mantel-Haenszel was used for stratified analysis,used Test of Homogeneity of Odds Ratio for homogeneity test,and Kaplan-Meier was used to draw survival curves.Applied the Cox regression model to analyze the relationship between the multiplicative interaction of shifts and dust exposure and hypertension.And used the Multinomial logistic regression model combined with the excel additive interaction calculation table compiled by Anderson to analyze the relationship between the additive interaction of shifts and dust exposure and hypertension.Finally,Applied the Cox regression model based on restrictive cubic splines to analyze the dose-response relationship between the number of shifts and the degree of hypertension.Results In this study,we distributed a total of 2449 questionnaires and retrieved 2366 valid questionnaires.The effective recovery rate of the questionnaires was 96.61%.The total observation person-year was 54526.79 person-years,and the average follow-up person-year was 23.05 person-years.The minimum age for the subjects to enter the cohort was 16 years old and the maximum was 47 years old.The average age for entering the cohort was 24.09±5.27years,and the average working age of the research subjects was 23.97±5.54 years.The minimum duration of shift exposure was 1 year and the maximum duration was 38years.During the follow-up period,a total of 788 outbreaks(hypertension)occurred.The incidence density of hypertension in the study subject was 1445.16/100,000 person years(788/54526.79).1.Comparing the baseline data(sociodemographic characteristics and risk factors for hypertension)between the exposed group(shift work)and the control group(day shift)showed that the composition ratio of gender,age,education level,annual income,smoking,participation in physical exercise and dust exposure was different between the two groups,and the difference was statistically significant(P<0.05).2.The results of single factor Cox regression analysis showed that the risk of hypertension in the exposed group(shift work)was 1.670 times(95%CI:1.476-1.889)of the control group(day shift),the difference was statistically significant(P<0.05).3.The results of multivariate Cox regression analysis showed that the risk of hypertension in the exposed group(shift work)after adjusting for 16 factors such as ethnicity,age,gender,educational level,BMI,smoking,tea,alcohol,salt,and exercise was the control 1.382 times(95%CI:1.215-1.571)of the group(day shift),the difference was statistically significant(P<0.05)4.The results of multi-factor analysis after stratification showed that in each layer shift work is a risk factor for hypertension5.The results of univariate and multivariate Cox regression analysis showed that the five-shift work system had the strongest correlation with hypertension(RR=1.660,95%CI:1.488-2.377).6.Compared with simple day shift,the RR between hypertension and shift only was 1.488(95%CI:1.154-1.920)and was statistically significant(P<0.05).When the two factors of shift work and dust exposure coexisted,the RR was 1.369(95%CI:1.111-1.687),which was statistically significant(all P<0.05).The RR between hypertension and dust exposure alone was 1.042(95%CI:0.867-1.253)was not statistically significant(P>0.05),and there was no additive interaction between shift work and dust exposure.7.There was a correlation between shift years and the occurrence of hypertension(?~2=104.93,P<<0.0011),and the degree of correlation showed a non-linear dose-response relationship(?~2=127.77,P<<0.0011).The risk of hypertension is statistically significant only when the shift duration reaches 5 years(P<0.05).As the shift duration increases,the risk of hypertension is increasing,and the relative risk reaches the highest peak by 14 years.(RR=2.641,95%CI:2.104-3.177),after which it showed a downward trend.Conclusions(1)Shift is an independent risk factor for hypertension;(2)Shift and dust exposure have a combined effect on hypertension.(3)Non-ferrous metallurgical enterprise employees can reduce the risk of hypertension by controlling the shift period within 5 years. |
PDF Full Text Request