Study The Association Of Cardiovascular Impairment With RYRs In Lead Exposure Workers

Objective:To study the impact of lead exposure on workers’blood pressure, electrocardiogram(ECG) and test lymphocyte ryanodine receptors level. To explore the mechanism and new biomarker of the change of cardiovascular function in lead exposure workers.Methods:677 lead exposure workers were selected from a lead factory in Jiangxi. Investigated demographic and working information of workers and collected blood samples and urine samples. Analyzed lead level in blood and urine, and Zpp in the blood.Analyzed lymphocyte ryanodine receptors in blood lymphocyte. The 12-lead ECG and blood pressure were tested in the same day. And checked basic helath.Results:(1) Workers basic condition and the analysis of lead burden level1. According to the inclusion and exclusion standard,610 workers were included in the study,108 female and 619 male. Mean(±Standard deviation) age was 34.26±9.11 years and the mean(±Standard deviation) working years was 10.37±9.53 years. The workers were normal in lead-free departments. The rate of normal ones, observed object, and poisoning ones were 72.18%,26.92%,0.89% respectively in the low lead departments; while in high lead departments, the rate were 23.72%、 55.47%、20.80% respectively.2. The mean value(±Standard deviation) of lead blood were 361.73±189.46μg/L, the M (P25,P75) of lead urine and Zpp were 46.00 (23.00,74.00)μg/L,5.10 (2.90,8.55)μg/gHb.A clear upward trend with the increase in lead blood, lead urine and Zpp in exposure to lead opportunities(P<0.05). We used multiple linear regression established blood lead regression model. we found sex, work type, length of service and education were entered the blood lead regression model, the beta coefficients were -0.270、0.540、0.211、-0.130, P<0.01. Age, sex, work type, length of service, education were entered the urine lead regression model, the beta coefficients were-0.129、-0.204、0.499、0.215、-0.183, P<0.05. We used multiple linear regression established ZPP regression model. we found work type, length of service, education and marital status were entered the ZPP regression model, the beta coefficients were 0.499、0.234、-0.149、-0.111, P<0.01.(2) The result of blood pressure and electrocardiogram1. The systolic and diastolic blood pressure of workers were not changed significantly in the different department of lead exposure. The systolic blood pressure of observed object and poisoning workers were significantly higher than the normal workers (P<0.05). While compare with sex, marital status, drinking status, The systolic and diastolic blood pressure was significant difference(P<0.05). We used multiple linear regression established systolic and diastolic blood pressure regression model. we found sex, age, lead blood were entered the systolic blood pressure regression model, the beta coefficients were -0.216、0.330、0.136, P< 0.05.And sex, age, smoking status and drinking status were entered the diastolic blood pressure regression model, the beta coefficients were-0.216、0.287、-0.140、 0.117, P<0.05.2. ECG analysis showed, the normal ECG was 254 and the abnormal was 356 in workers. The largest number of sinus arrhythmia, right ventricular hypertrophy, left ventricular voltage, sinus bradycardia and the rate of them were 21.15%,13.11%, 10.33%,10.33%. The rate of WPW syndrome and incomplete left bundle branch block were 0.16%,0.16%. Patients with left ventricular voltage significantly increased in the lead-exposed workers(P<0.05). Patients with left ventricular voltage and sinus bradycardia significantly increased in the observed object, and poisoning workers (P<0.05). Lead V5 R-wave amplitude as a necessary condition for the diagnosis of left ventricular high voltage in high lead department was significantly higher than the low lead department. On behalf of the ventricular depolarization and repolarization process of the corrected QT interval was significantly lower than normal workers and observed object(P<0.05).(3) The mRNA level of Lymphocytes ryanodine receptorsLymphocytes RYR1 in lead operations department were significantly higher than lead -free operation department workers(P<0.05). RYR1 were significantly higher in workers of left ventricular high voltage and sinus bradycardia than normal workers. The RYR3 mRNA of lymphocyte was not changed significantly. The RYR1 mRNA of lymphocyte in Patients with left ventricular voltage and sinus bradycardia was higher than normal workers(P=0.070;P=0.075).The RYR3 mRNA of lymphocyte was not changed significantly.(4) The relationship between RYRs mRNA of lymphocytes and ECGWe used multiple binary logistic established left ventricular voltage and sinus bradycardia regression model. The lead blood and RYR1 were included in the left ventricular voltage equation, the beta coefficients were 0.005,1.946, OR were 4.176、5.026, P<0.05. The smoking state was included in the sinus bradycardia equation, the beta coefficients were 1.199,OR were 4.266, P<0.05. However, the beta coefficients of lead blood and RYR1 were 0.004 and 1.274,OR were 2.818 and 1.274, P=0.093, P=0.059. The sex and smoking state were entered the lead V5 R-wave amplitude regression model, the beta coefficients were -0.364、-0.223, P< 0.05. The RYR3 was entered the corrected QT interval regression model, the beta coefficient was -0.223, P<0.05.Conclusion:(1) Workers’blood pressure and ECG could changed in lead exposure workers.(2) There was a certain relationship between lead exposure in workers exposed to change in cardiovascular function and lead exposure causes high RYRs expression.