Association of plasma IL-6 and Hsp70 with HRV at different levels of PAHs metabolites.
BACKGROUND
Exposure to polycyclic aromatic hydrocarbons (PAHs) is associated with reduced heart rate variability (HRV), a strong predictor of cardiovascular diseases, but the mechanism is not well understood.


OBJECTIVE
We hypothesized that PAHs might induce systemic inflammation and stress response, contributing to altered cardiac autonomic function.


METHODS
HRV indices were measured using a 3-channel digital Holter monitor in 800 coke oven workers. Plasma levels of interleukin-6 (IL-6) and heat shock protein 70 (Hsp70) were determined using ELISA. Twelve urinary PAHs metabolites (OH-PAHs) were measured by gas chromatography-mass spectrometry.


RESULTS
We found that significant dose-dependent relationships between four urinary OH-PAHs and IL-6 (all Ptrend<0.05); and an increase in quartiles of IL-6 was significantly associated with a decrease in total power (TP) and low frequency (LF) (Ptrend = 0.014 and 0.006, respectively). In particular, elevated IL-6 was associated in a dose-dependent manner with decreased TP and LF in the high-PAHs metabolites groups (all Ptrend<0.05), but not in the low-PAHs metabolites groups. No significant association between Hsp70 and HRV in total population was found after multivariate adjustment. However, increased Hsp70 was significantly associated with elevated standard deviation of NN intervals (SDNN), TP and LF in the low-PAHs metabolites groups (all Ptrend<0.05). We also observed that both IL-6 and Hsp70 significantly interacted with multiple PAHs metabolites in relation to HRV.


CONCLUSIONS
In coke oven workers, increased IL-6 was associated with a dose-response decreased HRV in the high-PAHs metabolites groups, whereas increase of Hsp70 can result in significant dose-related increase in HRV in the low-PAHs metabolites groups.
Department of Occupational and Environmental Health and Ministry of Education Key Lab for Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
Jian
J
Ye
Department of Traditional Chinese Medicine, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
Rui
R
Zhu
Department of Occupational and Environmental Health and Ministry of Education Key Lab for Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
Xiaosheng
X
He
Department of Occupational and Environmental Health and Ministry of Education Key Lab for Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
Yingying
Y
Feng
Department of Occupational and Environmental Health and Ministry of Education Key Lab for Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
Liangle
L
Yang
Department of Occupational and Environmental Health and Ministry of Education Key Lab for Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
Xiaoyan
X
Zhu
Department of Occupational and Environmental Health and Ministry of Education Key Lab for Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
Qifei
Q
Deng
Department of Occupational and Environmental Health and Ministry of Education Key Lab for Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
Tangchun
T
Wu
Department of Occupational and Environmental Health and Ministry of Education Key Lab for Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
Xiaomin
X
Zhang
D000328:Adult; D000395:Air Pollutants, Occupational / Q000032:analysis; D001341:Autonomic Nervous System / Q000187:drug effects; D003077:Coke; D003430:Cross-Sectional Studies; D005260:Female; D008401:Gas Chromatography-Mass Spectrometry; D018840:HSP70 Heat-Shock Proteins / Q000097:blood*; D006321:Heart / Q000187:drug effects; D006339:Heart Rate / Q000187:drug effects*; D006801:Humans; D007249:Inflammation; D015850:Interleukin-6 / Q000097:blood*; D008297:Male; D008875:Middle Aged; D016273:Occupational Exposure; D011084:Polycyclic Aromatic Hydrocarbons / Q000032:analysis* / Q000652:urine; D015203:Reproducibility of Results
D000395:Air Pollutants, Occupational; D003077:Coke; D018840:HSP70 Heat-Shock Proteins; C508600:IL6 protein, human; D015850:Interleukin-6; D011084:Polycyclic Aromatic Hydrocarbons