Exhaled Nitric Oxide Decreases in Association with Attendance at an Asthma Summer Camp

Abstract

Attendance at a summer asthma camp has been associated with improved outcomes in children with asthma. We hypothesized that one mechanism involved in improved asthma outcomes is reduction in airway inflammation. To investigate this, we measured the fractional concentration of exhaled nitric oxide (FeNO), lung function (forced expiratory volume in 1 sec, FEV₁) and asthma control (Juniper Asthma Control Questionnaire, ACQ) from children at the beginning and end of a 1-week asthma summer camp. We also obtained a symptoms-only ACQ at 1 and 6 months after the end of camp. We enrolled 10 girls, 17 boys, mean (± SD) age = 9.6 ± 1.3 years. At baseline, FeNO (ppb), median (25–75 IQR) = 11.4 (7.2–21.3); ACQ = 0.86 (0.43–1.21); FEV₁ (%pred, mean ± SD) = 87 ± 10. At the end of camp, FeNO = 6.2 (4.4–8.4), a change of −45%, p < 0.0001; ACQ = 0.71 (0.43–1.14), a fall of 14%, p = 0.72; and mean FEV₁% predicted remained unchanged. There were no significant changes in the follow-up symptoms-only ACQ at 1 and 6 months. We conclude that airway inflammation, as measured by FeNO, improved during 1 week of asthma camp, but there were no significant changes in lung function or asthma control. Since no child had a change in anti-inflammatory therapy during camp, these findings suggest that airway inflammation was reduced because of improved adherence to therapy and/or reduced exposure to pro-inflammatory stimuli in the home environment. The finding of reduced inflammation following attendance at an asthma summer camp should motivate the child, the parents and the clinician to focus their efforts on improving adherence to therapy and reducing exposures at home.

Keywords:

• asthma summer camp
• exhaled nitric oxide
• airway inflammation
• asthma control
• lung function

Abbreviations
ACQ	=	Asthma Control Questionnaire
FEF25–75	=	forced expiratory flow between 25–75% of vital capacity
FeNO	=	fractional concentration of exhaled nitric oxide
FEV1	=	forced expiratory volume in 1 second
FVC	=	forced vital capacity
ICS	=	inhaled corticosteroids
IQR	=	interquartile (25–75%) range
LABA	=	long-acting beta-agonists
PEF	=	peak expiratory flow
SABA	=	short-acting beta-agonist

Abbreviations
ACQ	=	Asthma Control Questionnaire
FEF25–75	=	forced expiratory flow between 25–75% of vital capacity
FeNO	=	fractional concentration of exhaled nitric oxide
FEV1	=	forced expiratory volume in 1 second
FVC	=	forced vital capacity
ICS	=	inhaled corticosteroids
IQR	=	interquartile (25–75%) range
LABA	=	long-acting beta-agonists
PEF	=	peak expiratory flow
SABA	=	short-acting beta-agonist