Exhaled carbon monoxide in asthmatic adults with bronchial reactivity: a prospective study.
OBJECTIVE
We hypothesized that eCO may permit non-invasive assessment of disease activity in adults with asthma and bronchial reactivity.


METHODS
A total of 209 participants 18 to 65 years of age with a diagnosis of asthma and bronchial reactivity provided data for analysis. The association between eCO and bronchial reactivity, forced expiratory volume in one second (FEV(1)), forced vital capacity (FVC), peak expiratory flow rate measurements (PEFR), asthma symptoms score, and bronchodilator use cross-sectionally and within-subject change in eCO were analyzed in relation to change in these variables over 6 weeks.


RESULTS
There was no difference in eCO in those who were taking inhaled corticosteroids and those who were not (p = 0.33). There was also no cross-sectional or within-in subject association between eCO and bronchial reactivity, FEV(1), FVC, PEFR, symptoms score, or bronchodilator use.


CONCLUSIONS
In a population of adults with bronchial reactivity, eCO has no or very limited potential as a biomarker of asthma activity.
Pogson
Zara E K
ZE
Division of Epidemiology and Public Health, University of Nottingham, City Hospital, Nottingham, United Kingdom. zarapogson@hotmail.com
Antoniak
Marilyn D
MD
Mckeever
Tricia M
TM
Lewis
Sarah A
SA
Britton
John R
JR
Fogarty
Andrew W
AW
D000328:Adult; D001249:Asthma / Q000150:complications / Q000188:drug therapy / Q000378:metabolism* / Q000503:physiopathology*; D015415:Biomarkers / Q000378:metabolism; D001944:Breath Tests; D016535:Bronchial Hyperreactivity / Q000175:diagnosis / Q000188:drug therapy / Q000378:metabolism* / Q000503:physiopathology*; D001985:Bronchial Provocation Tests; D001993:Bronchodilator Agents / Q000627:therapeutic use; D002248:Carbon Monoxide / Q000378:metabolism*; D003430:Cross-Sectional Studies; D005260:Female; D005541:Forced Expiratory Volume / Q000502:physiology; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D010366:Peak Expiratory Flow Rate / Q000502:physiology; D011446:Prospective Studies; D016032:Randomized Controlled Trials as Topic; D014797:Vital Capacity / Q000502:physiology
D015415:Biomarkers; D001993:Bronchodilator Agents; D002248:Carbon Monoxide