Chest
Volume 117, Issue 3, March 2000, Pages 695-701
Journal home page for Chest

Clinical Investigations
COPD
Increased Exhaled Nitric Oxide in Chronic Bronchitis

https://doi.org/10.1378/chest.117.3.695Get rights and content

Study objectives

To test the hypothesis that exhaled nitric oxide (NO) is increased in patients with chronic bronchitis, and to compare the results with exhaled NO in patients with asthma and COPD.

Study design

Cross-sectional survey.

Setting and patients

Veterans Administration pulmonary function laboratory. Patients (n = 179) were recruited from 234 consecutive patients. Two nonsmoking control groups of similar age, with normal spirometry measurements and no lung disease, were used (18 patient control subjects and 20 volunteers).

Measurements

Participants completed questionnaires and spirometry testing. Exhaled NO was measured by chemiluminescence using a single-breath exhalation technique.

Results

Current smoking status was associated with reduced levels of exhaled NO (smokers, 9.2 ± 0.9 parts per billion [ppb]; never and ex-smokers, 14.3 ± 0.6 ppb; p < 0.0001). Current smokers (n = 57) were excluded from further analysis. Among nonsmokers, the levels of exhaled NO were significantly higher in patients with chronic bronchitis (17.0 ± 1.1 ppb; p = 0.035) and asthma (16.4 ± 1.3 ppb; p = 0.05) but not in those with COPD (14.7 ± 1.0 ppb; p = 0.17) when compared with either control group (patient control subjects, 11.1 ± 1.6 ppb; outside control subjects, 11.5 ± 1.5 ppb). The highest mean exhaled NO concentration occurred in patients with both chronic bronchitis and asthma (20.2 ± 1.6 ppb; p = 0.005 vs control subjects).

Conclusions

Exhaled NO is increased in patients with chronic bronchitis. The increase of exhaled NO in patients with chronic bronchitis was similar to that seen in patients with asthma. The highest mean exhaled NO occurred in patients with both chronic bronchitis and asthma. Exhaled NO was not increased in patients with COPD. Although chronic bronchitis and asthma have distinct histopathologic features, increased exhaled NO in patients with both diseases suggests common features of inflammation.

Section snippets

Study Design and Subjects

We conducted a cross-sectional survey of exhaled NO in consecutive patients referred for routine pulmonary function testing to the Veterans Administration Medical Center in Portland, OR. We administered a standardized demographic and pulmonary symptom questionnaire to each subject, and measured exhaled carbon monoxide (CO) and exhaled NO concentrations using standard techniques that are described below. Each subject then performed spirometry before and after receiving an aerosolized

Demographics of the Study Population

The study and control groups were predominantly older white men (Table 1 ). Most members of the study population were ex-smokers (51%) or current smokers (35%) and had ETS exposure (47%). In contrast, the control groups consisted entirely of never smokers or ex-smokers and reported no ETS exposure. As expected for patients referred to a pulmonary function laboratory, the prevalence of lung disease was high, with more than half the study group meeting the criteria for COPD and one third meeting

Discussion

The most important finding of this study was that exhaled NO concentrations are elevated in patients with chronic bronchitis. As expected, subjects with asthma had elevated exhaled NO concentrations, similar in magnitude to those with chronic bronchitis; and the highest NO concentrations were seen in subjects with both chronic bronchitis and asthma. In contrast, exhaled NO concentrations were not elevated in subjects with COPD. Current-smoker status was associated with reduced NO

ACKNOWLEDGMENT

The authors thank Gary Sexton, PhD, for assistance with data analysis.

References (25)

  • SA Kharitonov et al.

    Increased nitric oxide in exhaled air of asthmatic patients

    Lancet

    (1994)
  • WM Thurlbeck

    Pathophysiology of chronic obstructive pulmonary disease

    Clin Chest Med

    (1990)
  • AF Massaro et al.

    Elevated nitric oxide concentrations in isolated lower airway gas of asthmatic subjects

    Am J Respir Crit Care Med

    (1996)
  • SA Kharitonov et al.

    Elevated levels of exhaled nitric oxide in bronchiectasis

    Am J Respir Crit Care Med

    (1995)
  • PJ Barnes et al.

    Exhaled nitric oxide: a new lung function test [editorial]

    Thorax

    (1996)
  • RA Robbins et al.

    Measurement of exhaled nitric oxide by three different techniques

    Am J Respir Crit Care Med

    (1996)
  • SR Rutgers et al.

    Nitric oxide in exhaled air in COPD

    Eur Respir J

    (1996)
  • W Maziak et al.

    Exhaled nitric oxide in chronic obstructive pulmonary disease

    Am J Respir Crit Care Med

    (1998)
  • BG Ferris

    Epidemiology Standardization Project (American Thoracic Society)

    Am Rev Respir Dis

    (1978)
  • SA Kharitonon et al.

    Acute and chronic effects of cigarette smoking on exhaled nitric oxide

    Am J Respir Crit Care Med

    (1995)
  • B Kimberly et al.

    Nasal contribution to exhaled nitric oxide at rest and during breathholding in humans

    Am J Respir Crit Care Med

    (1996)
  • S Kharitonov et al.

    Exhaled and nasal nitric oxide measurements: recommendations; the European Respiratory Society Task Force

    Eur Respir J

    (1997)
  • Cited by (0)

    Supported by the American Lung Association of Oregon.

    View full text