Persistence of oxidant and protease burden in the airways after smoking cessation

BMC Pulm Med. 2009 May 27;9:25. doi: 10.1186/1471-2466-9-25.

Abstract

Background: Oxidative stress is associated with the pathogenesis of cigarette smoke related lung diseases, but longitudinal effects of smoking cessation on oxidant markers in the airways are unknown.

Methods: This study included 61 smokers; 21 with chronic bronchitis or COPD, 15 asthmatics and 25 asymptomatic smokers followed up for 3 months after smoking cessation. Fractional exhaled nitric oxide (FeNO), sputum neutrophil counts, sputum 8-isoprostane, nitrotyrosine and matrix metalloproteinase-8 (MMP-8) were investigated at baseline and 1 and 3 months after smoking cessation.

Results: After 3 months 15 subjects had succeeded in quitting of smoking and in these subjects symptoms improved significantly. Unexpectedly, however, sputum neutrophils increased (p = 0.046) after smoking cessation in patients with chronic bronchitis/COPD. At baseline, the other markers did not differ between the three groups so these results were combined for further analysis. Sputum 8-isoprostane declined significantly during the follow-up at 3 months (p = 0.035), but levels still remained significantly higher than in non-smokers. The levels of FeNO, nitrotyrosine and MMP-8 did not change significantly during the 3 months after smoking cessation.

Conclusion: Whilst symptoms improve after smoking cessation, the oxidant and protease burden in the airways continues for months.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Asthma / metabolism*
  • Bronchitis, Chronic / metabolism*
  • Dinoprost / analogs & derivatives
  • Dinoprost / metabolism
  • Female
  • Humans
  • Longitudinal Studies
  • Lung / metabolism
  • Male
  • Matrix Metalloproteinase 8 / metabolism
  • Middle Aged
  • Neutrophils / metabolism
  • Nitric Oxide / metabolism
  • Oxidants / metabolism*
  • Oxidative Stress / physiology
  • Peptide Hydrolases / metabolism*
  • Prospective Studies
  • Smoking / adverse effects
  • Smoking / metabolism*
  • Smoking Cessation*
  • Spirometry
  • Sputum / metabolism
  • Young Adult

Substances

  • Oxidants
  • 8-epi-prostaglandin F2alpha
  • Nitric Oxide
  • Dinoprost
  • Peptide Hydrolases
  • Matrix Metalloproteinase 8