Abstract
Objectives and aims: The aim of the study was to investigate the impact of diurnal variations in healthy subjects and impact of atopy, pollen exposure and pharmacological treatment on exhaled nitric oxide levels (eNO) in patients with allergic rhinitis (AR).
Methods: eNO levels were measured using analyzer NIOX. Measurements of eNO were performed in 81 nonasthmatics with seasonal AR outside and during the pollen season, before and 3 weeks after treatment and in 52 healthy controls in 4-hour intervals.
Results: Diurnal variations of eNO in healthy individuals were not confirmed. Patients with AR had significantly higher levels of eNO than healthy controls not depending on pollen season or pharmacotherapy. Increased eNO levels (p<0,0001) were also found in patients with AR during the pollen season (21,25 ppb; IQR=20,3) compared to the levels outside the season (14,2 ppb; IQR=12,45) before treatment. In AR patients treated by nasal corticosteroids and antihistamines in the season were levels of eNO (18,6 ppb; IQR=14,63) significantly lower (p=0,044) than in the season before treatment (23,15 ppb; IQR=16,63). No difference was found in eNO levels in AR patients outside the season (14,2 ppb; IQR=13,38) and in the season after treatment (16,1 ppb; IQR=15,6).
Conclusion: This study has shown that patients with AR have significantly higher levels of eNO compared to healthy subjects and the levels of eNO increasing after pollen exposure. Application of topic corticosteroids and antihistamines caused significant decrease of eNO (almost to the starting levels) in the pollen season and depressed suspicious inflammation in the lower airways.
Support: VEGA 1/0055/08, Grant MZ 2007/46 UK 11
- © 2011 ERS