Exhaled and sputum nitric oxide in bronchiectasis: Correlation with clinical parameters

Abstract

Study objectives: Although there has been tremendous attention on endogenous nitric oxide (NO) production in many respiratory and systemic diseases, little is known on NO production in bronchiectasis. Design and setting: We determined exhaled and sputum NO levels in 109 patients with stable bronchiectasis (71 women; mean ± SD age, 58.2 ± 14.1 years) and 78 control subjects (39 women; mean age, 56.7 ± 12.1 years) by using an automatic chemiluminescence analyzer. Measurements and results: There was no significant difference in exhaled NO between patients with bronchiectasis and control subjects (p = 0.11). Bronchiectasis patients with Pseudomonas aeruginosa infection had a significantly lower exhaled, but not sputum, NO levels than their counterparts and control subjects (p = 0.04 and p = 0.009, respectively). Exhaled NO correlated with 24-h sputum volume in P aeruginosa-infected patients (r = - 0.36; p = 0.002). After adjustment for sputum volume and number of bronchiectatic lung lobes, P aeruginosa-infected patients still had lower exhaled NO levels than their counterparts (p = 0.01). There was no correlation between exhaled NO with FEV1, FVC, and the number of bronchiectatic lung lobes (p > 0.05). Sputum NO levels were not different between patients and control subjects (p = 0.64), and had no correlation with clinical parameters. Conclusion: Exhaled NO appears to be reduced among bronchiectasis patients with P aeruginosa infection independent of other clinical parameters, and further studies on the potential mechanisms and pathogenetic implications of this reduction should be pursued.