Association between level of asthma control and the fraction of nitric oxide in exhaled breath in adult patients with asthma

Abstract

Current international guidelines of asthma emphasize assessment of the level of control in the management of asthma. While the fraction of nitric oxide in exhaled air (FeNO) has been used as a marker of airway inflammation in asthma, the role of the measurement of FeNO in the assessment of control was not well determined yet. Therefore, we evaluated whether FeNO could reflect the level of asthma control. We enrolled patients with asthma on treatment and normal controls, who have no asthmatic symptoms. Spirometry and FeNO measurement was performed for all subjects according to the recommendations by ATS and ERS. Level of asthma control was evaluated using Asthma Control Test (ACT) score and based on GINA guideline. Fifty one patients with asthma showed significantly higher levels of FeNO compared to normal controls. Levels of FeNO did not show significant difference between controlled patients and partly controlled patients and uncontrolled patients. In addition, levels of FeNO were poorly correlated with ACT scores in asthmatics on treatment. These findings suggest that the measurement of FeNO has an inadequate role in the assessment of asthma control.