The general population cohort study in Beijing-Tianjin-Hebei area is a large-scale prospective longitudinal study conducted since 2017, which covers over 114 850 diverse populations from early life to senior age. Up to December 2021, 106 031 people had completed at least one follow-up, with an overall follow-up rate of 92.3%. Considering of the characteristics of the environmental and health problems in Beijing-Tianjin-Hebei area, in this cohort study we have focused on health problems of children and adolescents' growth and development, cardiometabolic diseases and their risk factors, aging and comorbidity, health hazards caused by air pollution. The long-term follow up of the general population cohort study in Beijing-Tianjin-Hebei area will contribute to establishing unique and invaluable data and biobank resource for scientific research. This paper aims to comprehensively describe the background, significance, current status and outcomes, limitations and challenges, and future plan and development of general population cohort study in Beijing-Tianjin-Hebei area, thus to provide reference for professionals both at home and abroad to carry out related research.

OBJECTIVE: To investigate the relationship between the sleep duration on peak melatonin secretion and renal function injury in steel workers. METHODS: A judgment sampling method was used to select 7 655 steel workers in a steel production department for health examination and questionnaire survey, and the relationship between renal function injury and non-peak sleep time(equivalent to the reduction of sleep duration on peak melatonin secretion) was analyzed using restriction cubic spline(RCS) model and multi-factor logistic regression. RESULTS: The detection rate of renal injury in the study subjects was 14.5%(1 110/7 655). RCS model analysis results showed that there was a linear dose-response relationship between non-peak sleep time and renal injury(overall correlation test χ~2=16.85, P<0.01, nonlinear test χ~2=3.70, P>0.05). Multivariate logistic regression analysis results showed that the workers of non-peak sleep time more than or equal to 4 515-day had higher risk of renal function injury than the workers of non-peak sleep time less than 4 515-day(P<0.05), with odds ratio and 95% confidence interval of 1.4(1.2-1.7), after adjustment for the potential influencing factors such as individual factors and occupational factors. CONCLUSION: Reduction of peak melatonin secretion sleep duration is correlated with renal function injury in steel workers.

OBJECTIVE: To explore the relationship between shift work and type 2 diabetes in oil workers. METHODS: A total of 2 666 oil workers in an oil group were selected as the study subjects using the typical sampling method. Questionnaire survey was conducted by a self-designed Questionnaire of Health Assessment for Oil Workers, and blood glucose level was measure. RESULTS: The prevalence of type 2 diabetes in the study subjects was 10.1%(268/2 666). The prevalence of type 2 diabetes in shift workers was higher than that in non-shift workers(13.1% vs 6.0%, P<0.01). After adjusting for the influence of confounding factors such as gender, body mass index, family history of diabetes, history of hypertension, history of hyperlipidemia, and physical exercise, multivariate logistic regression analysis results show that the longer the shift work length, the higher the risk of developing type 2 diabetes(P<0.01), workers with shift work(3 shifts in a day, 2 shifts operating) had a higher risk of type 2 diabetes than that in non-shift workers(P<0.05). CONCLUSION: The shift work length and shift workers with 3 shifts in a day, 2 shifts operating can increase the risk of type 2 diabetes in oil workers.

Objective:To investigate the association between occupational stress and carotid atherosclerosis among the workers in a steel plant.Methods:In October 2018, a total of 2947 workers from a steel plant, who underwent occupational health examination in the center for occupational health examination from March to May 2017, were selected as subjects. Job Content Questionnaire (JCQ) and Effort-Reward Imbalance (ERI) were used to investigate the job content and the degree of occupational stress. According to the results of carotid artery examination, the subjects were divided into normal carotid artery group with 2013 workers, increased carotid intima-media thickness (IMT) group with 277 workers, stable plaque group with 236 workers, and unstable plaque group with 421 workers. A unified questionnaire was distributed to each group, and related physical and biochemical examinations were performed. A multivariate unconditional logistic regression analysis was performed to investigate the risk factors for unstable plaque.Results:There were significant differences between the groups in sex, educational level, marital status, work in shifts, smoking, drinking, age, and working years ( P<0.05) , while there was no significant difference in exercise between groups ( P>0.05) . Based on the JCQ score, 761 (25.8%) had no stress, 959 (32.5%) had mild stress, 699 (23.7%) had moderate stress, and 528 (17.9%) had severe stress; based on the ERI score, 2526 (85.7%) had high effort and low reward and 421 (14.3%) did not have the high-effort and low-reward conditions. There was a significant difference in the composition of JCQ and ERI scores between groups ( P<0.05) . Moderate stress (odds ratio [ OR]=1.695) , severe stress ( OR=5.443) , ERI ( OR=7.391) , work in shift ( OR=1.784) , old age ( OR=1.009) , high systolic blood pressure ( OR=1.105) , high fasting blood glucose ( OR=1.212) , abnormal total cholesterol ( OR=3.693) , abnormal apolipoprotein B ( OR=39.215) , and abnormal high-sensitivity C-reactive protein ( OR=1.632) were the risk factors for unstable plaque. Conclusion:Occupational stress may be involved in the development of carotid atherosclerosis.

Objective:To analyze the relationship between cumulative high temperature exposure and hypertension among steel workers.Methods:We conducted a survey among 7 660 production workers (7 023 males and 637 females) in a large steel mill during February-June 2017 and March-July 2018. Basic information, blood pressure, occupational history and high temperature data in workplace were collected through questionnaire survey, physical measurement and occupational exposure detection. Restrictive cubic spline model was used to analyze the dose-response relationship between cumulative high temperature exposure and hypertension, and the correlation between cumulative high temperature exposure and workers' hypertension was analyzed by logistic regression.Results:The median number of cumulative high temperature exposure was 626.56 ℃·year and 49.20% of workers were exposed to high temperature. The hypertension prevalence rate was 25.60% among the workers. According to the results of the spline model, the cumulative high temperature exposure was divided into three sections: <292.61, 292.61~<720.13, ≥720.13 ℃·year. Taking the exposure <292.61 ℃·year group as a reference, the risk of steel workers' hypertension in the 292.61~<720.13 ℃·year group and ≥720.13 ℃·year group is 1.44 and 2.17 times that of the reference group ( P<0.05) . Conclusion:There was a nonlinear dose-response relationship between cumulative high temperature exposure and steelworkers' hypertension. With the increase of cumulative high temperature exposure, the risk of steelworkers' hypertension increases.

Objective:To investigate the prevalence of pre-diabetes mellitus (PDM) and the impact of occupation-related factors on PDM, among workers from a steel company in Tangshan city, Hebei province.Methods:Clustering sampling method was used to select a steel company and to carry out occupational health-related physical checkup programs for eligible workers who had working in this company for longer than one year. The study began in February and ended up in June, 2017. Workers who were with FPG level as ≤6.9 mmol/L, and free from diabetes, were selected as the subjects for this study. Questionnaires were used and physical examinations and FPG testing conducted.Results:The total number of subjects in this study was 4 173, of which 2 648 appeared as pre-diabetic, with the prevalence rate as 63.4 %. Increase of the PDM prevalence was in parallel with the length of service, among the workers. The risk for the pre-diabetes in those who worked more than 8 hours per day was 1.696 times higher than those who worked less than or equal to 8 h/d (95 %CI:1.517-1.937). Compared with those workers without exposures to heat, noise or carbon monoxides, the proportion of pre-diabetes appeared higher in workers exposed to heat, noise or CO with OR=1.782 (95 %CI: 1.205-2.636), 1.815 (95 %CI: 1.209-2.794) and 1.653 (95 %CI: 1.158-2.361), respectively. Risks for those who were exposed to heat or noise were higher than those who were free from exposure to any occupational hazards ( OR=2.098, 95 %CI: 1.296-3.397). Prevalence rates of pre-diabetes in those who were exposed to heat, noise or CO, were higher than that those who were not. Conclusion:Working hours and exposures to heat, noise or CO appeared as influential factors on PDM.

Objective:To investigate the effect of occupational factor exposures on carotid atherosclerosis (CAS) in steel workers.Methods:A frequency matched case-control study was conducted by age and factory proportion. A total of 1 033 workers with carotid atherosclerosis diagnosed by ultrasonography examination from February to June 2017 were selected as case group, and 1 033 workers without carotid atherosclerosis indicated by physical examination at the same time were selected as control group. The basic information of the workers, such as diet pattern, lifestyle, serum biochemical index and occupation history, were collected. The effects of occupational hazards on carotid atherosclerosis were analyzed by univariate and multivariate logistic regression analyses. The combined effects of various occupational hazards on carotid atherosclerosis were evaluated by environmental risk score (ERS).Results:High temperature, noise, occupational stress and night shift days increased the risk of CAS. With the increase of cumulative high temperature and noise exposure, occupational stress and night shift days, the risk of CAS increased (trend text: χ2=37.53, P<0.01; χ2=16.98, P<0.01; χ2=13.93, P<0.01; χ2=5.59, P<0.05). After adjustment of covariates, compared with P 20 group, the risk of carotid artery in P 40, P 60, P 80 and P 100 groups were as follows: high temperature 1.61 (1.19-2.18), 1.69 (1.25-2.30), 1.84 (1.36-2.49), 2.43 (1.77-3.34); noise 1.70 (1.15-2.52), 1.68 (1.20-2.35), 1.80 (1.34-2.42), 2.23 (1.53-3.26); occupational stress 1.39 (1.04- 1.86), 1.41 (1.06-1.89), 1.45(1.09-1.95), 1.48 (1.10-1.98); night shift days 1.58 (1.08-2.33), 1.66 (1.12-2.47), 1.55 (1.04-2.31), 1.76 (1.17-2.64). The results of the environmental risk score showed that the risk of carotid atherosclerosis increased with the increase of ERS (ERS trend text χ2=51.61, P<0.01); RCS results showed that there was a linear relationship between ERS and CAS in steel workers( P<0.01). Linear dose-response relationship existed between ERS and CAS (nonlinear test P>0.05). Conclusions:High temperature, noise, occupational stress and night shift days were related to carotid atherosclerosis. Linear dose-response relationship existed between ERS and CAS in steel workers.

Objective:To investigate the association between occupational stress and carotid atherosclerosis among the workers in a steel plant.Methods:In October 2018, a total of 2947 workers from a steel plant, who underwent occupational health examination in the center for occupational health examination from March to May 2017, were selected as subjects. Job Content Questionnaire (JCQ) and Effort-Reward Imbalance (ERI) were used to investigate the job content and the degree of occupational stress. According to the results of carotid artery examination, the subjects were divided into normal carotid artery group with 2013 workers, increased carotid intima-media thickness (IMT) group with 277 workers, stable plaque group with 236 workers, and unstable plaque group with 421 workers. A unified questionnaire was distributed to each group, and related physical and biochemical examinations were performed. A multivariate unconditional logistic regression analysis was performed to investigate the risk factors for unstable plaque.Results:There were significant differences between the groups in sex, educational level, marital status, work in shifts, smoking, drinking, age, and working years ( P<0.05) , while there was no significant difference in exercise between groups ( P>0.05) . Based on the JCQ score, 761 (25.8%) had no stress, 959 (32.5%) had mild stress, 699 (23.7%) had moderate stress, and 528 (17.9%) had severe stress; based on the ERI score, 2526 (85.7%) had high effort and low reward and 421 (14.3%) did not have the high-effort and low-reward conditions. There was a significant difference in the composition of JCQ and ERI scores between groups ( P<0.05) . Moderate stress (odds ratio [ OR]=1.695) , severe stress ( OR=5.443) , ERI ( OR=7.391) , work in shift ( OR=1.784) , old age ( OR=1.009) , high systolic blood pressure ( OR=1.105) , high fasting blood glucose ( OR=1.212) , abnormal total cholesterol ( OR=3.693) , abnormal apolipoprotein B ( OR=39.215) , and abnormal high-sensitivity C-reactive protein ( OR=1.632) were the risk factors for unstable plaque. Conclusion:Occupational stress may be involved in the development of carotid atherosclerosis.

Objective:To analyze the relationship between cumulative high temperature exposure and hypertension among steel workers.Methods:We conducted a survey among 7 660 production workers (7 023 males and 637 females) in a large steel mill during February-June 2017 and March-July 2018. Basic information, blood pressure, occupational history and high temperature data in workplace were collected through questionnaire survey, physical measurement and occupational exposure detection. Restrictive cubic spline model was used to analyze the dose-response relationship between cumulative high temperature exposure and hypertension, and the correlation between cumulative high temperature exposure and workers' hypertension was analyzed by logistic regression.Results:The median number of cumulative high temperature exposure was 626.56 ℃·year and 49.20% of workers were exposed to high temperature. The hypertension prevalence rate was 25.60% among the workers. According to the results of the spline model, the cumulative high temperature exposure was divided into three sections: <292.61, 292.61~<720.13, ≥720.13 ℃·year. Taking the exposure <292.61 ℃·year group as a reference, the risk of steel workers' hypertension in the 292.61~<720.13 ℃·year group and ≥720.13 ℃·year group is 1.44 and 2.17 times that of the reference group ( P<0.05) . Conclusion:There was a nonlinear dose-response relationship between cumulative high temperature exposure and steelworkers' hypertension. With the increase of cumulative high temperature exposure, the risk of steelworkers' hypertension increases.

Objective: To explore the influence of heat and noise exposure on the risk of hypertension in workers,and to provide evidence for prevention of hypertension in occupational population. Methods: Cluster sampling method was used to recruit 2 130 steel workers from four factories（north iron-making,long steel,cold steel and power department）of some steel company. A cross-sectional study was conducted to collect physical examination results,heat and noise exposure. Logistic regression models were used to analyze the effects of noise,heat and their interaction on hypertension. Results: Totally 1 971 valid questionnaires were collected,and the response rate was 92.54%. There were 654 workers suffering from hypertension,with a prevalence rate of 33.18%. There were 1 006 workers exposed to noise,accounting for 51.04%;and 853 workers exposed to heat,accounting for 43.28%. The prevalence rates of hypertension in workers exposed to noise and heat were higher than those in workers without the above exposure（P<0.05）. The prevalence rates of hypertension increased with the increase of age and working years（P<0.05）. The results of multivariate logistic regression analysis showed that noise（OR=1.711,95%CI：1.380-2.121）,heat（OR=1.721,95%CI：1.394-2.125）were risk factors for hypertension;the interaction between noise and heat on hypertension was not statistically significant（P>0.05）,while the interaction between noise and age（OR=1.086,95%CI：1.057-1.115）,between heat and age（OR=1.087,95%CI：1.059-1.115）both increased the risk of hypertension. Conclusion Occupational exposure to heat and noise are risk factors for hypertension. These two occupational hazards also interact with age,which can increase the risk of hypertension in workers.