title: The dose-response decrease in heart rate variability: any association with the metabolites of polycyclic aromatic hydrocarbons in coke oven workers?
abstract: BACKGROUND
  Air 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.
  
  
  OBJECTIVE
  Our 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.
  
  
  METHODS
  We 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.
  
  
  RESULTS
  Our 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.
  
  
  CONCLUSIONS
  Occupational 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.
authors.affiliation: 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.
authors.forename: Xiaohai
authors.initials: X
authors.lastname: Li
authors.forename: Yingying
authors.initials: Y
authors.lastname: Feng
authors.forename: Huaxin
authors.initials: H
authors.lastname: Deng
authors.forename: Wangzhen
authors.initials: W
authors.lastname: Zhang
authors.forename: Dan
authors.initials: D
authors.lastname: Kuang
authors.forename: Qifei
authors.initials: Q
authors.lastname: Deng
authors.forename: Xiayun
authors.initials: X
authors.lastname: Dai
authors.forename: Dafeng
authors.initials: D
authors.lastname: Lin
authors.forename: Suli
authors.initials: S
authors.lastname: Huang
authors.forename: Lili
authors.initials: L
authors.lastname: Xin
authors.forename: Yunfeng
authors.initials: Y
authors.lastname: He
authors.forename: Kun
authors.initials: K
authors.lastname: Huang
authors.forename: Meian
authors.initials: M
authors.lastname: He
authors.forename: Huan
authors.initials: H
authors.lastname: Guo
authors.forename: Xiaomin
authors.initials: X
authors.lastname: Zhang
authors.forename: Tangchun
authors.initials: T
authors.lastname: Wu
mesh_terms: D000328:Adult; D000393:Air Pollutants / Q000633:toxicity*; D001145:Arrhythmias, Cardiac / Q000453:epidemiology / Q000652:urine; D003077:Coke / Q000633:toxicity*; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008875:Middle Aged; D009784:Occupational Diseases / Q000453:epidemiology / Q000652:urine; D016273:Occupational Exposure / Q000009:adverse effects*; D011084:Polycyclic Aromatic Hydrocarbons / Q000009:adverse effects* / Q000737:chemistry / Q000652:urine*
chemical_list: D000393:Air Pollutants; D003077:Coke; D011084:Polycyclic Aromatic Hydrocarbons