OBJECTIVETo investigate the value of fractional nitric oxide concentration in exhaled breath (FeNO) in assessing the level of asthma control in children.

METHODSA total of 226 asthmatic children were divided into controlled asthma (n= 86), partially controlled asthma (n=63), and uncontrolled asthma groups (n=77). Ninety healthy children were enrolled as controls. FeNO was measured for both asthmatic and healthy children using the Swedish-designed NIOX system.

RESULTSThe control group had an FeNO of 14±6 ppb, the controlled asthma group had an FeNO of 29±26 ppb, the partially controlled asthma group had an FeNO of 32±30 ppb, and the uncontrolled asthma group had an FeNO of 40±32 ppb. The three asthma groups showed significantly higher FeNO than the control group (P<0.05). The uncontrolled asthma group showed significantly higher FeNO than the controlled asthma group (P<0.05), but there were no significant differences in FeNO between the partially controlled and uncontrolled asthma groups and between the partially controlled and controlled asthma groups (P>0.05).

CONCLUSIONSAsthmatic children have significantly higher FeNO than healthy children, and FeNO is correlated with the level of asthma control.