Association of plasma IL-6 and Hsp70 with HRV at different levels of PAHs metabolites.

Jian Ye,Xiaoyan Zhu,Liangle Yang,Xiaomin Zhang,Yingying Feng,Qifei Deng,Xiaosheng He,Rui Zhu,Tangchun Wu,Yi-Hsiang Hsu

doi:10.1371/journal.pone.0092964

Jian Ye, Xiaoyan Zhu + Show 8 more

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https://doi.org/10.1371/journal.pone.0092964

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Abstract

BackgroundExposure 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.ObjectivesWe hypothesized that PAHs might induce systemic inflammation and stress response, contributing to altered cardiac autonomic function.MethodsHRV 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.ResultsWe found that significant dose-dependent relationships between four urinary OH-PAHs and IL-6 (all P trend<0.05); and an increase in quartiles of IL-6 was significantly associated with a decrease in total power (TP) and low frequency (LF) (P trend = 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 P trend<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 P trend<0.05). We also observed that both IL-6 and Hsp70 significantly interacted with multiple PAHs metabolites in relation to HRV.ConclusionsIn 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.

Highlights

Polycyclic aromatic hydrocarbons (PAHs) are the major component of coke oven emissions produced during incomplete combustion of natural or synthetic fuels [1,2]
In coke oven workers, increased IL-6 was associated with a dose-response decreased heart rate variability (HRV) in the high-polycyclic aromatic hydrocarbons (PAHs) metabolites groups, whereas increase of heat shock protein 70 (Hsp70) can result in significant dose-related increase in HRV in the low-PAHs metabolites groups
To test the above hypothesis, we examined the association of urinary monohydroxylated PAHs (OH-PAHs) with plasma IL-6 and Hsp70, and the effects of IL-6 and Hsp70 on HRV in 800 workers exposed to different levels of PAHs

Summary

Introduction

Polycyclic aromatic hydrocarbons (PAHs) are the major component of coke oven emissions produced during incomplete combustion of natural or synthetic fuels [1,2]. Recent studies, including those from our lab [3,4], found that increased exposure to PAHs was associated with reduced cardiac autonomic function, assessed by heart rate variability (HRV), which is considered one of the main pathophysiologic pathways for air pollution-mediated adverse cardiac events [5,6,7,8]. 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

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