A nested case-control study on association between self-reported occupational sulfur dioxide exposure and hypertension / 环境与职业医学

Background Current evidence on whether occupational sulfur dioxide (SO2) exposure affects the risk of hypertension is still limited, and the research results of the effect of environmental SO2 exposure on risk of hypertension remain inconsistent. Objective To analyze the association between self-reported occupational exposure to SO2 and the risk of hypertension, and the potential dose-response relationship between the years of exposure to SO2 and the risk of hypertension. Methods Based on the Jinchang cohort, a nested case-control study design was adopted. A total of 841 newly diagnosed hypertension patients were followed up as the case group, and the control group was selected with 1∶1 individual matching based on non-occupational factors and occupational factors, respectively. The former matching conditions included age ±2 years old, same gender, working age ±2 years, and home address in the same sub-district. The latter was limited to working in the same workshop on the basis of the former conditions. Finally, the former included 717 controls and the latter included 488 controls. A unified questionnaire was used to collect general demographic characteristics, lifestyle habits, history of diabetes, family history of hypertension, and information on occupational exposure to SO2 (self-reported history of occupational exposure to SO2 and years of exposure to SO2). Conditional logistic regression model was used to analyze the association between occupational exposure to SO2 and hypertension, and the dose-response relationship between the years of SO2 exposure and the risk of hypertension. Results In the nested case-control study matching with the non-occupational factors, the OR of hypertension in workers with self-reported occupational exposure to SO2 was 2.39 (95%CI: 1.68-3.39); while when matching with the occupational factors, the OR of hypertension in workers with self-reported occupational exposure to SO2 was 1.48 (95%CI: 1.04-2.12). The results of the dose-response relationship showed that as the SO2 exposure years increased from 1-9 years, 10-19 years, 20-29 years, and 30 years and above, in the nested case-control study matching with non-occupational factors, the ORs of hypertension were 1.85 (95%CI: 0.68-5.08), 1.46 (95%CI: 0.58-3.67), 1.64 (95%CI: 1.00-2.67), and 4.95 (95%CI: 2.63-9.31), respectively; in the nested case-control study matching with occupational factors, the ORs of hypertension were 0.98 (95%CI: 0.40-2.41), 1.84 (95%CI: 0.72-4.70), 1.37 (95%CI: 0.82-2.29), and 2.44 (95%CI: 1.37-4.35), respectively. The two dose-response relationships were positive by χ2 trend test (Ptrend<0.05). Conclusion Self-reported occupational exposure to SO2 is associated with the risk of hypertension in the study population, and the hypertension risk increases with the increase of SO2 exposure years.

Effects of Outdoor Temperature on Blood Pressure in a Prospective Cohort of Northwest China / 生物医学与环境科学（英文）

Objective@#The relationship between outdoor temperature and blood pressure (BP) has been inconclusive. We analyzed data from a prospective cohort study in northwestern China to investigate the effect of outdoor temperature on BP and effect modification by season.@*Methods@#A total of 32,710 individuals who participated in both the baseline survey and the first follow-up in 2011-2015 were included in the study. A linear mixed-effect model and generalized additive mixed model (GAMM) were applied to estimate the association between outdoor temperature and BP after adjusting for confounding variables.@*Results@#The mean differences in systolic blood pressure (SBP) and diastolic blood pressure (DBP) between summer and winter were 3.5 mmHg and 2.75 mmHg, respectively. After adjusting for individual characteristics, meteorological factors and air pollutants, a significant increase in SBP and DBP was observed for lag 06 day and lag 04 day, a 0.28 mmHg (95% @*Conclusions@#This study demonstrated a significant negative association between outdoor temperature and BP in a high-altitude environment of northwest China. Moreover, BP showed a significant seasonal variation. The association between BP and temperature differed by season and individuals' demographic characteristics (age, gender, BMI), unhealthy behaviors (smoking and alcohol consumption), and chronic disease status (CVDs, hypertension, and diabetes).

Prospective study of relationship between metabolic diseases and stroke in Jinchang Cohort / 中华流行病学杂志

Objective@#To understand the incidence of stroke in the population of Jinchang Cohort and the relationship between metabolic diseases and stroke, and provide scientific evidence for the prevention and treatment of stroke in the population.@*Methods@#The epidemiological investigation data and physical examination data of the 33 042 follow-up participants in Jinchang Cohort were collected for a prospective cohort study. Restricted cubic splines functions was used to analyze the dose-response relationship between metabolic indexes and the risk of stroke incidence.@*Results@#1) The incidence rate of stroke in Jinchang Cohort was 1.59%, and the standardized incidence rate was 3.99%. 2) Hypertension (male HR=2.20, female HR=4.45) and dyslipidemia (male HR=1.49, female HR=1.79) were the risk factors of stroke incidence in the population and diabetes had influence on the incidence of stroke only in the males (HR=1.79), while obesity had influence only in the females (HR=1.64). The more kinds of metabolic diseases, the higher risk of stroke incidence was. 3) Systolic blood pressure had a non-linear dose-response correlation with the risk of stroke incidence, while diastolic blood pressure had a positive linear correlation with the risk of stroke incidence.@*Conclusions@#The incidence of stroke in Jinchang Cohort population was high compared with both domestic level and oversea level. The patients with metabolic diseases were the population at high-risk for stroke, and more attention should be paid to them in the prevention and treatment of stroke. Diastolic blood pressure might be more closely related to stroke.

Association between fatty liver and type 2 diabetes in the baseline population of Jinchang Cohort / 中华流行病学杂志

Objective To explore the association between fatty liver and type 2 diabetes mellitus (T2DM) in the baseline-population of Jinchang cohort study.Methods Data from all the participants involved in the baseline-population of Jinchang cohort study was used,to compare the risks of T2DM in fatty liver and non fatty liver groups and to explore the interaction between family history or fatty liver of diabetes and the prevalence of T2DM.Results Among all the 46 861 participants,10 574 were diagnosed as having fatty liver (22.56％),with the standardized rate as 20.66％.Another 3 818 participants were diagnosed as having T2DM (8.15％) with standardized rate as 6.90％.The prevalence of T2DM increased in parallel with the increase of age (trendx2 =2 833.671,trend P＜ 0.001).The prevalence of T2DM in the fatty liver group was significantly higher than that in the non-fatty liver group,both in men or women and in the overall population.Compared with the group of non-fatty liver,the risks of T2DM in fatty liver group were seen 1.78 times higher in males,2.33 times in women and 2.10 times in the overall population,after adjustment for factors as age,levels of education,smoking,drinking,physical exercise,BMI,family history of diabetes and some metabolic indicators (pressure,TC,TG,uric acid,ALT,AST,gamma-glutamyl transferase).Date from the interaction model showed that fatty liver and family history of diabetes present a positive additive interaction on T2DM (RERI=1.18,95％CI:0.59-1.78;AP=0.24,95％CI:0.14-0.34;S=1.43,95％CI:1.21-1.69).Conclusions Fatty liver could significantly increase the risk of T2DM and a positive additive interaction was also observed between fatty liver and family history of diabetes on T2DM.It was important to strengthen the prevention program on T2DM,in order to effectively control the development of fatty liver.

Association between fatty liver and type 2 diabetes in the baseline population of Jinchang Cohort / 中华流行病学杂志

Objective To explore the association between fatty liver and type 2 diabetes mellitus (T2DM) in the baseline-population of Jinchang cohort study.Methods Data from all the participants involved in the baseline-population of Jinchang cohort study was used,to compare the risks of T2DM in fatty liver and non fatty liver groups and to explore the interaction between family history or fatty liver of diabetes and the prevalence of T2DM.Results Among all the 46 861 participants,10 574 were diagnosed as having fatty liver (22.56％),with the standardized rate as 20.66％.Another 3 818 participants were diagnosed as having T2DM (8.15％) with standardized rate as 6.90％.The prevalence of T2DM increased in parallel with the increase of age (trendx2 =2 833.671,trend P＜ 0.001).The prevalence of T2DM in the fatty liver group was significantly higher than that in the non-fatty liver group,both in men or women and in the overall population.Compared with the group of non-fatty liver,the risks of T2DM in fatty liver group were seen 1.78 times higher in males,2.33 times in women and 2.10 times in the overall population,after adjustment for factors as age,levels of education,smoking,drinking,physical exercise,BMI,family history of diabetes and some metabolic indicators (pressure,TC,TG,uric acid,ALT,AST,gamma-glutamyl transferase).Date from the interaction model showed that fatty liver and family history of diabetes present a positive additive interaction on T2DM (RERI=1.18,95％CI:0.59-1.78;AP=0.24,95％CI:0.14-0.34;S=1.43,95％CI:1.21-1.69).Conclusions Fatty liver could significantly increase the risk of T2DM and a positive additive interaction was also observed between fatty liver and family history of diabetes on T2DM.It was important to strengthen the prevention program on T2DM,in order to effectively control the development of fatty liver.