Relationship between exhaled nitric oxide measured by two offline methods and bronchial hyperresponsiveness in Japanese adults with asthma.
BACKGROUND
Exhaled nitric oxide (eNO) is a useful marker of eosinophilic airway inflammation in asthmatics. There have been no studies to show the relationship between eNO measured by offline methods and the degree of bronchial hyperresponsiveness in asthmatic patients treated with inhaled corticosteroids.


METHODS
The study population comprised asthmatics at our outpatient clinic. We measured eNO levels by two methods ("eNOs" was measured with a Sievers kit; and "eNOc" was measured with a kit from the Center for Environmental Information Science, Japan). We also used spirometry to test bronchial hyperresponsiveness to acetylcholine (PC(20Ach)).


RESULTS
We recruited 192 stable asthmatics. There was a significant relationship between eNOs and eNOc (r = 0.919, p < 0.001). LogPC(20Ach) levels were negatively correlated with eNOs or eNOc levels (eNOs, r = -0.31, p < 0.001; eNOc, r = -0.23, p = 0.0013). We classified the subjects into two groups based on eNOs levels ((A) the subjects with high eNOs levels (n = 92) and (B) the subjects with normal eNOs levels (n = 100)) ; logPC(20Ach) was significantly correlated with eNOs (r = -0.34, p = 0.001) or eNOc (r = -0.28, p = 0.0075) but not correlated with %FEV(1) in (A), whereas logPC(20Ach) was not significantly correlated with eNO but significantly correlated with %FEV(1) (r = 0.33, p = 0.002) in (B).


CONCLUSIONS
Levels of eNOs and eNOc were correlated with the degree of bronchial hyperresponsiveness to acetylcholine in adult asthmatics treated with inhaled corticosteroids. Our findings suggest that offline monitoring of eNO will facilitate the management of bronchial asthma in patients treated with these drugs.
Tsuburai
Takahiro
T
Clinical Research Center for Allergy and Rheumatology, National Hospital Organization, Sagamihara National Hospital. t-tuburai@Sagamihara-hosp.gr.jp
Tsurikisawa
Naomi
N
Morita
Sonoko
S
Hasunuma
Hideki
H
Kanegae
Hiroshi
H
Ishimaru
Yasushi
Y
Fukutomi
Yuma
Y
Tanimoto
Hidenori
H
Ono
Emiko
E
Oshikata
Chiyako
C
Sekiya
Kiyoshi
K
Otomo
Mamoru
M
Maeda
Yuji
Y
Taniguchi
Masami
M
Ikehara
Kunihiko
K
Akiyama
Kazuo
K
D000280:Administration, Inhalation; D000305:Adrenal Cortex Hormones / Q000008:administration & dosage; D000328:Adult; D000368:Aged; D001249:Asthma / Q000175:diagnosis* / Q000188:drug therapy; D001944:Breath Tests / Q000379:methods; D016535:Bronchial Hyperreactivity / Q000175:diagnosis*; D001985:Bronchial Provocation Tests / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009569:Nitric Oxide / Q000032:analysis*; D013147:Spirometry
D000305:Adrenal Cortex Hormones; D009569:Nitric Oxide