Relations Between Isoprene and Nitric Oxide in Exhaled Breath and the Potential Influence of Outdoor Ozone: A Pilot Study

Details

• Personal Author:
  Blake DR ; Delfino RJ ; Galassetti P ; Khan A ; Staimer N ; Tjoa T
• Description:
  The role of endogenous isoprene in the human body, if any, is unclear because previous research is inconsistent and mechanistic evidence for the biologic function of isoprene is lacking. Given previous evidence that exhaled isoprene is elevated in systemic inflammatory states, we hypothesized that exhaled isoprene would be positively associated with a breath biomarker of airway inflammation, the fractional concentration of exhaled nitric oxide (FENO). We examined relationships of exhaled breath isoprene with FENO and with outdoor ozone given that ozone chemically reacts with isoprene and has been positively associated with FENO in past studies. Sixteen elderly subjects were followed with ≤ 12 weekly exhaled hydrocarbon and FENO collections at the subjects' retirement community. Outdoor ozone concentrations were measured continuously on site. Mixed-effects regression analyses tested relations of FENO with isoprene, and FENO and isoprene with ozone, adjusted for temperature. We found FENO was inversely associated with isoprene, and this was not confounded by ozone. Isoprene was inversely related to ozone. FENO was positively related to ozone and this relation was not confounded by isoprene. In contrast to hypothesized relations, we conclude that exhaled isoprene is inversely associated with FENO as well as outdoor ozone, which suggests possible protective ozone-scavenging functions of endogenous isoprene. Findings may indicate chemical reactions of isoprene oxidation by ozone and by hydroxyl radicals in the presence of O2 that is dependent on NO concentration. These preliminary results need to be confirmed in additional studies of human subjects, particularly as they apply to FENO monitoring in asthma. [Description provided by NIOSH]
• Subjects:
  Biomarkers Nitric Oxide Occupational Health Ozone Respiratory System Safety
• Keywords:
  Airway Obstruction Breath Analysis Breathing Nitric Oxide
• ISSN:
  1752-7155
• Document Type:
  Text
• Funding:
  Grant
• Genre:
  Journal Article
• Place as Subject:
  California ; OSHA Region 9
• CIO:
  National Institute for Occupational Safety and Health (NIOSH)
• Topic:
  Workplace Safety & Health
• Location:
  North America
• Volume:
  7
• Issue:
  3
• NIOSHTIC Number:
  nn:20055911
• Citation:
  J Breath Res 2013 Sep; 7(3):036007
• Contact Point Address:
  Ralph J Delfino, Department of Epidemiology, School of Medicine, University of California, Irvine, CA, USA
• Email:
  rdelfino@uci.edu
• CAS Registry Number:
  Isoprene (CAS RN 78-79-5) ; Nitric oxide (CAS RN 10102-43-9) ; Ozone (CAS RN 10028-15-6)
• Federal Fiscal Year:
  2013
• Performing Organization:
  University of California Los Angeles
• Peer Reviewed:
  True
• Start Date:
  20050701
• Source Full Name:
  Journal of Breath Research
• End Date:
  20270630
• Collection(s):
  National Institute for Occupational Safety and Health
• Main Document Checksum:
  urn:sha-512:f3698c80e5dd0d4d3f16861999d006ec250f123cf06a45ef19adf8bb58fdb80c63e7cb70ce36910efeeff7c3210a5a68d3c8ba5ac746d79d4dff3efea5de8856
• Download URL:
  https://stacks.cdc.gov/view/cdc/213665/cdc_213665_DS1.pdf
• File Type:
  [PDF - 167.86 KB ]