The Dose–Response Decrease in Heart Rate Variability: Any Association with the Metabolites of Polycyclic Aromatic Hydrocarbons in Coke Oven Workers?

Abstract

BackgroundAir pollution has been associated with an increased risk of cardiopulmonary mortality and decreased heart rate variability (HRV). However, it is unclear whether coke oven emissions (COEs) and polycyclic aromatic hydrocarbons (PAHs) are associated with HRV.ObjectivesOur goal in the present study was to investigate the association of exposure to COEs and the urinary metabolite profiles of PAHs with HRV of coke oven workers.MethodsWe measured benzene soluble matter, carbon monoxide, sulfur dioxide, particulate matters, and PAHs at different workplaces of a coke oven plant. We determined 10 urinary PAH metabolites and HRV indices of 1333 workers using gas chromatography–mass spectrometry and a 3-channel digital Holter monitor, respectively.ResultsOur results showed that there was a significant COEs-related dose-dependent decrease in HRV, and an inverse relationship between the quartiles of urinary 2-hydroxynaphthalene and five HRV indices (p trend<0.01 for all). After adjustment for potential confounders, elevation per interquartile range (IQR) (1.81 µg/mmol creatinine) of urinary 2-hydroxynaphthalene was associated with a 5.46% (95% CI, 2.50–8.32) decrease in standard deviation of NN intervals (SDNN). As workers worked more years, SDNN gradually declined in the same quartiles of 2-hydroxynaphthalene levels (p trend = 1.40×10−4), especially in workers with the highest levels of 2-hydroxynaphthalene.ConclusionsOccupational exposure to COEs is associated with a dose-response decrease in HRV. In particular, increased exposure to 2-hydroxynaphthalene is associated with significantly decreased HRV. Increase of working years and exposure levels has resulted in a gradual decline of HRV.

Metabolism of benzo(a)pyrene by aortic subcellular fractions in the setting of abdominal aortic aneurysms

“…PAH metabolites have been reported to be associated with reduced heart rate variability, a predictor of adverse cardiovascular effects such as hypertension, coronary artery disease, myocardial infarction etc. in coke oven workers [43]. The association of high levels of PAH metabolites with C-reactive protein [44] points that metabolites may aid in the progression of atherosclerosis through inflammation.…”

Polycyclic Aromatic Hydrocarbons–Associated MicroRNAs and Heart Rate Variability in Coke Oven Workers

“…A comprehensive spectrum of 12 PAHs metabolites, including 1-hydroxynaphthalene, 2-hydroxynaphthalene, 2-hydroxyfluorene, 9-hydroxyfluorene, 1-hydroxyphenanthrene, 2-hydroxyphenanthrene, 3-hydroxyphenanthrene, 4-hydroxyphenanthrene, 9-hydroxyphenanthrene, 1-hydroxypyrene, 6-hydroxychrysene, and 3-hydroxybenzo[a]pyrene were detected in the urinary samples of the coke oven workers by gas chromatography-mass spectrometry. 6 The percentages of samples with metabolites concentrations above the limit of quantification were higher than 90% or nearly 100% (data not shown). For concentrations below the limit of quantification, we used 50% of the limit of quantification in lieu of the specific concentration.…”

“…Our previous study has indicated the significantly positive correlation between the urinary PAH metabolites of the coke oven workers and the airborne concentration of total PAHs in different work places, 6 suggesting that the urinary PAH metabolites are good internal biomarkers of PAHs exposure. A comprehensive spectrum of 12 PAHs metabolites, including 1-hydroxynaphthalene, 2-hydroxynaphthalene, 2-hydroxyfluorene, 9-hydroxyfluorene, 1-hydroxyphenanthrene, 2-hydroxyphenanthrene, 3-hydroxyphenanthrene, 4-hydroxyphenanthrene, 9-hydroxyphenanthrene, 1-hydroxypyrene, 6-hydroxychrysene, and 3-hydroxybenzo[a]pyrene were detected in the urinary samples of the coke oven workers by gas chromatography-mass spectrometry.…”

“…We set up multiple monitors in their workplaces and collected the airborne samples with an average flow rate of 2.0 L/min for 6 h. Measurement for PAH in the collected airborne samples was performed by high-performance liquid chromatography as shown in our previous study. 6 Based on the mean concentrations of total PAHs in each workplace, we defined the 241 workers in offices or at adjunct workplaces as the control group, and the other 124 individuals working at the top, side, or bottom of the coke oven as the exposed group. 12 Written informed consent was obtained from each participant.…”

“…[3][4][5] We have previously demonstrated that in coke oven workers, PAH exposure resulted in a dose-related decrease in HRV indices 6 ; however, the underlying mechanisms remain unknown.…”