title: Consistently high levels of exhaled nitric oxide in children with asthma.
abstract: BACKGROUND
  Exhaled nitric oxide (eNO) levels in children are unstable because they are regulated by many potent factors. The purpose of the current study was to evaluate the reliability of eNO levels between a long interval and other lung functions in normal and asthmatic children.
  
  
  METHODS
  Eighty-three elementary school children (aged 11-12 years; male : female, 39 : 44) participated in this study. Lung function, airway resistance and eNO levels were measured twice: the first measurement was in autumn 2007, and the second was one year later.
  
  
  RESULTS
  There were 62 non-asthmatic control children (male : female, 31 : 31) and 21 asthmatic children (male : female, 8 : 13). In both the first and the second examination, the levels of eNO in children with asthma were higher than those in children without asthma. The parameters of lung function and the respiratory resistance in children without asthma showed a good correlation between the results of the first and second examinations. The eNO level in non-asthmatic children showed a good correlation between the two. On the other hand, the peripheral airway parameters of lung function and the respiratory resistance in children with asthma were not correlated between the first and the second examinations. The eNO level in these patients was well correlated between the two examinations.
  
  
  CONCLUSIONS
  These data suggest that the eNO level showed good reproducibility in children with and without asthma. The eNO level is therefore considered to be a useful marker for reproducibly evaluating a subject's airway condition.
authors.affiliation: Department of Pediatrics, Tokai University School of Medicine, Shimokasuya, Isehara, Kanagawa, Japan.
authors.forename: Tadakazu
authors.initials: T
authors.lastname: Sakai
authors.forename: Nobuyoshi
authors.initials: N
authors.lastname: Sugiyama
authors.forename: Kota
authors.initials: K
authors.lastname: Hirai
authors.forename: Reiko
authors.initials: R
authors.lastname: Muramatsu
authors.forename: Satomi
authors.initials: S
authors.lastname: Hagiwara
authors.forename: Yasumasa
authors.initials: Y
authors.lastname: Oh
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Mochizuki
authors.forename: Hirokazu
authors.initials: H
authors.lastname: Arakawa
mesh_terms: D001249:Asthma / Q000175:diagnosis* / Q000453:epidemiology; D015415:Biomarkers / Q000032:analysis; D001944:Breath Tests / Q000379:methods*; D016022:Case-Control Studies; D002648:Child; D002908:Chronic Disease; D018450:Disease Progression; D045853:Exhalation; D005260:Female; D005500:Follow-Up Studies; D005541:Forced Expiratory Volume; D006801:Humans; D007564:Japan; D008297:Male; D009569:Nitric Oxide / Q000032:analysis* / Q000378:metabolism; D009991:Oscillometry; D012016:Reference Values; D012129:Respiratory Function Tests; D012720:Severity of Illness Index; D018709:Statistics, Nonparametric
chemical_list: D015415:Biomarkers; D009569:Nitric Oxide