Exhaled nitric oxide as a marker of asthma control in smoking patients

¹ Chest Dept - CUB Erasme, Brussels, Belgium
² Chest Dept - CHU Sart-Tilmant, Liège, Belgium
³ Chest Dept- CHU André Vésale, Montigny- le-Tilleul, Belgium

^* To whom correspondence should be addressed. E-mail: avmuylem{at}ulb.ac.be.

	Abstract

Fractionated exhaled nitric oxide (FeNO) which is a reliable marker of eosinophilic airway inflammation, is partially suppressed by tobacco smoking. Consequently, its potential as a biomarker in asthma management has never been evaluated in smoking patients. In the present study, we tested the validity of FeNO to predict asthma control in this population.

To do this, FeNO and the Asthma Control Questionnaire (ACQ) were recorded at least once in 411 non-smoking (345 with at least two visits) and 59 smoking (51 with at least two visits) asthma patients.

Despite similar mean ACQ scores (1.5 vs1.7-p>0.1) FeNO was reduced in smoking asthmatics (18, 1 ppb vs 33, 7 ppb; p<0.001). A decrease in FeNO <20% precludes asthma control improvement in non-smoking (NPV 78%) and in smoking patients (NPV 72%). An increase in FeNO <30% is unlikely to be associated with deterioration in asthma control in both groups of patients (NPV=86% and 84%).

It is concluded that, even in smokers, sequential changes in FeNO have a relationship to asthma control. This is the first study indicating that cigarette smoking does not obviate the clinical value of measuring FeNO in asthma among smokers.

This article has been cited by other articles:

				A. I. Papaioannou, M. Minas, K. Tanou, K. I. Gourgoulianis, and K. Kostikas Exhaled NO may predict loss of asthma control: the effect of concomitant allergic rhinitis Eur. Respir. J., October 1, 2009; 34(4): 1006 - 1007. [Full Text] [PDF]