Exhaled nitric oxide as a better diagnostic indicator for evaluating wheeze and airway hyperresponsiveness in preschool children.
OBJECTIVE
Fractional concentration of exhaled nitric oxide (FeNO) is a known marker of airway inflammation. The aims of this study were to evaluate FeNO, impulse oscillometry (IOS), and spirometry in preschool children and to investigate their relationship with wheeze and airway hyperresponsiveness (AHR).


METHODS
We performed a population-based, cross-sectional study with 561 children aged 5-6 years. A total of 544 children completed a modified International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire and eligible for the study. We measured FeNO, spirometry, methacholine bronchial provocation, and IOS. AHR was defined as the induction of a 20% decrease in FEV(1)(PC(20)) by a methacholine concentration ≤8.0 mg/dL.


RESULTS
Children who had wheeze or AHR had higher FeNO levels than children without these symptoms. However, neither IOS nor spirometry parameters showed significant differences between children with wheeze or AHR and those without. FeNO was associated with AHR, whereas IOS or spirometry parameters showed no association. Mean FeNO levels were positively correlated with a dose-response slope for methacholine, but neither IOS nor spirometry parameters showed significant correlations.


CONCLUSIONS
FeNO is a more sensitive measurement of AHR and wheeze than spirometry or IOS in preschool children.
a Department of Pediatrics , Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine , Seoul , Korea .
Jung-Won
JW
Lee
a Department of Pediatrics , Kangbuk Samsung Hospital, Sungkyunkwan University School of Medicine , Seoul , Korea .
Jung Yeon
JY
Shim
b Department of Pediatrics , Seoul National University Bundang Hospital , Sungnam , Korea .
Ji-Won
JW
Kwon
c Department of Pediatrics , Pusan National University Yangsan Hospital , Pediatrics , Yangsan , Korea .
Hyung Young
HY
Kim
d Department of Pediatrics , Korea Cancer Center Hospital , Seoul , Korea .
Ju-Hee
JH
Seo
e Department of Environmental Health , College of Medicine University of Cincinnati , Cincinnati , OH , USA .
Byoung-Ju
BJ
Kim
f Department of Pediatrics , Inje University Sanggye Paik Hospital , Seoul , Korea .
Hyo-Bin
HB
Kim
g Department of Pediatrics , Hallym University Sacred Heart Hospital, Hallym University College of Medicine , Anyang , Korea .
So-Yeon
SY
Lee
h Department of Pediatrics , National Health Insurance Corporation Ilsan Hospital , Ilsan , Korea .
Gwang-Cheon
GC
Jang
i Department of Pediatrics , Korea University Guro Hospital, Korea University College of Medicine , Seoul , Korea .
Dae-Jin
DJ
Song
j Department of Pediatrics , Inje University Seoul Paik Hospital , Seoul , Korea .
Woo Kyung
WK
Kim
k Department of Pediatrics , Bundang CHA Medical Center, CHA University School of Medicine , Seongnam , Korea , and.
Young-Ho
YH
Jung
l Department of Pediatrics , Childhood Asthma Atopy Center, Research Center for Standardization of Allergic Diseases, Asan Medical Center, University of Ulsan College of Medicine , Seoul , Korea.
Soo-Jong
SJ
Hong
D001249:Asthma / Q000175:diagnosis*; D001944:Breath Tests; D001985:Bronchial Provocation Tests; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D016210:Methacholine Chloride; D009569:Nitric Oxide / Q000032:analysis*; D012129:Respiratory Function Tests; D012130:Respiratory Hypersensitivity / Q000503:physiopathology; D012135:Respiratory Sounds / Q000503:physiopathology
D016210:Methacholine Chloride; D009569:Nitric Oxide
Airway hyperresponsiveness; airway inflammation; fractional exhaled nitric oxide; impulse oscillometry; lung function; preschool children