Article Main

Exhaled Breath Condensate as a Non-Invasive Biomarker of Oxidative Stress in Smokers: A Cross-Sectional Case–Control Study Oxidative Stress

Hassan H. Al-Salamy
Journal of Progressive Medical Sciences, Vol. 1 No. 3 (2025): Journal of Progressive Medical Sciences
Published: 2025-11-30

Abstract

Introduction: smoking remains a major global health burden, driving disease through persistent oxidative stress and impaired antioxidant defenses. Traditional serum assays provide valuable information but are invasive and impractical for large-scale screening. Exhaled breath condensate (EBC) offers a simple, non-invasive alternative for assessing oxidative biomarkers in the airways.


Objectives: This study aimed to evaluate whether oxidative stress biomarkers measured in EBC reflect systemic oxidative changes in apparently healthy smokers and to determine their diagnostic performance.


Methods: A cross-sectional, case–control study was conducted among 60 adults (30 smokers, 30 non-smokers) aged 18–45 years. EBC was collected using a standardized condenser system, and both EBC and serum samples were analyzed for hydrogen peroxide (H₂O₂), 8-isoprostane, malondialdehyde (MDA), and total antioxidant capacity (TAC). Data were analyzed using t-tests, correlation analyses, and receiver-operating-characteristic (ROC) curves.


Results: Smokers showed markedly higher oxidative-stress biomarkers in both EBC and serum compared with non-smokers. Mean EBC H₂O₂ was 1.84 ± 0.42 µM in smokers versus 0.96 ± 0.28 µM in controls (p < 0.001), and EBC 8-isoprostane levels were 57.4 ± 14.3 pg/mL versus 33.1 ± 10.8 pg/mL (p < 0.001). TAC values were significantly lower in smokers across both matrices. EBC H₂O₂ correlated strongly with serum MDA (r = 0.61, p < 0.01), indicating concordant airway and systemic oxidative stress. ROC analysis showed high diagnostic accuracy for EBC H₂O₂ (AUC = 0.87, 95% CI 0.77–0.95).


Conclusions: EBC biomarkers, particularly H₂O₂ and 8-isoprostane, reliably mirror systemic oxidative stress in cigarette smokers. The strong correlation between EBC and serum markers supports EBC as a non-invasive, reproducible, and clinically relevant tool for early detection of smoking-related oxidative injury. Its simplicity and low cost make it especially promising for preventive health programs and research in low- and middle-income settings

Keywords

Array Array Array Array Array Array Array Array

References

  1. 1. Reitsma, M.B., Flor, L.S., Mullany, E.C., Gupta, V., Hay, S.I. and Gakidou, E. (2021) 'Spatial, temporal, and demographic patterns in prevalence of smoking tobacco use and initiation among young people in 204 countries and territories, 1990–2019', The Lancet Public Health, 6(7), pp. e472–e481.
  2. 2. Dai, X., Gakidou, E. and Lopez, A.D. (2022) 'Evolution of the global smoking epidemic over the past half century: strengthening the evidence base for policy action', Tobacco Control, 31(2), pp. 129–137.
  3. 3. Thakur, J. and Choudhari, S.G. (2024) 'Effectiveness of healthcare interventions on smoking cessation in adolescents in low- and middle-income countries: a narrative review', Cureus, 16(2).
  4. 4. Caliri, A.W., Tommasi, S. and Besaratinia, A. (2021) 'Relationships among smoking, oxidative stress, inflammation, macromolecular damage, and cancer', Mutation Research – Reviews in Mutation Research, 787, p. 108365.
  5. 5. Addissouky, T.A., El Sayed, I.E.T., Ali, M.M., Wang, Y., El Baz, A. and Elarabany, N. et al. (2024) 'Oxidative stress and inflammation: elucidating mechanisms of smoking-attributable pathology for therapeutic targeting', 48(1), p. 16.
  6. 6. Marrocco, I., Altieri, F. and Peluso, I. (2017) 'Measurement and clinical significance of biomarkers of oxidative stress in humans', Oxidative Medicine and Cellular Longevity, 2017, p. 6501046.
  7. 7. Silvestrini, A., Meucci, E., Ricerca, B.M. and Mancini, A. (2023) 'Total antioxidant capacity: biochemical aspects and clinical significance', International Journal of Molecular Sciences, 24(13), p. 10978
  8. 8. Kita, K., Gawinowska, M., Chełmińska, M. and Niedoszytko, M. (2024) 'The role of exhaled breath condensate in chronic inflammatory and neoplastic diseases of the respiratory tract', 25(13), p. 7395.
  9. 9. Seifi, M., Rastkari, N., Hassanvand, M.S., Naddafi, K., Nabizadeh, R. and Nazmara, S. et al. (2021) 'Investigating the relationship between particulate matter and inflammatory biomarkers of exhaled breath condensate and blood in healthy young adults', Scientific Reports, 11(1), p. 12922.
  10. 10. Chrisnasari, R., Ewing, T.A., Hilgers, R., van Berkel, W.J.H., Vincken, J.-P. and Hennebelle, M. (2024) 'Versatile ferrous oxidation–xylenol orange assay for high-throughput screening of lipoxygenase activity', Applied Microbiology and Biotechnology, 108(1), p. 266.
  11. 11. Marek, E., Platen, P., Volke, J., Mückenhoff, K. and Marek, W. (2009) 'Hydrogen peroxide release and acid-base status in exhaled breath condensate at rest and after maximal exercise in young, healthy subjects', European Journal of Medical Research, 14(Suppl 4), pp. 134–139.
  12. 12. Aguilar Diaz De Leon, J. and Borges, C.R. (2020) 'Evaluation of oxidative stress in biological samples using the thiobarbituric acid reactive substances assay', Journal of Visualized Experiments: JoVE, (159).
  13. 13. Vlasceanu, A.M., Gradinaru, D., Stan, M., Nitescu, V.G. and Baconi, D.L. (2023) 'Relationships between serum biomarkers of oxidative stress and tobacco smoke exposure in patients with mental disorders', Antioxidants, 12(6).
  14. 14. Khudhur, Z.O., Smail, S.W., Awla, H.K., Ahmed, G.B., Khdhir, Y.O. and Amin, K. et al. (2025) 'The effects of heavy smoking on oxidative stress, inflammatory biomarkers, vascular dysfunction, and hematological indices', Scientific Reports, 15(1), p. 18251.
  15. 15. Barnes, P.J. (2022) 'Oxidative stress in chronic obstructive pulmonary disease', Antioxidants, 11(5), p. 965.
  16. 16. Möller, W., Heimbeck, I., Weber, N., Saba, G.K., Körner, B. and Neiswirth, M. et al. (2010) 'Fractionated exhaled breath condensate collection shows high hydrogen peroxide release in the airways', Journal of Aerosol Medicine and Pulmonary Drug Delivery, 23(3), pp. 129–135.
  17. 17. Peel, A. (2021) Exhaled biomarkers in acute asthma. PhD thesis. University of East Anglia.
  18. 18. Primavesi, F., Senoner, T., Schindler, S., Nikolajevic, A., Di Fazio, P. and Csukovich, G. et al. (2024) 'The interplay between perioperative oxidative stress and hepatic dysfunction after human liver resection: a prospective observational pilot study', 13(5), p. 590.

Author Biography

Hassan H. Al-Salamy
None
PDF
Download PDF

Article Details