title: Exhaled nitric oxide is age-dependent in asthma.
abstract: We determined whether the exhaled nitric oxide (eNO) level in asthmatics is age-dependent. Eighty-seven asthmatic patients aged 2-41 years were studied. Hyperreactivity to adenosine 5'-monophosphate (AMP) was used to confirm asthma (</= 200 mg/ml). In the younger group of children (2-5 years), AMP challenge was performed by the provocation concentration causing wheeze (PCW) method, while in the older groups of patients (6-41 years), regular spirometry was used. Exhaled NO was measured in the younger group by the tidal breathing method (TBm) and in the older subjects by the slow vital capacity method (SVCm). TBm and SVCm were compared in 21 other subjects, and there was a significant correlation between the two values (r = 0.96, P < 0.0001). The equation of correlation between the two methods was eNOTBm = 0.78eNOSVCm - 0.51. Within asthmatic patients, we found a significant increase in eNO with age (P < 0.0001), while there was no significant difference in AMP reactivity (P = 0.35). We conclude that eNO in asthmatic patients is age-dependent, with lower values in young children.
authors.affiliation: Institute of Pulmonology, Hadassah University Hospital and Hadassah-Hebrew University Medical School, Jerusalem, Israel. avital@hadassah.org.il
authors.forename: Avraham
authors.initials: A
authors.lastname: Avital
authors.forename: Kamal
authors.initials: K
authors.lastname: Uwyyed
authors.forename: Neville
authors.initials: N
authors.lastname: Berkman
authors.forename: Ephraim
authors.initials: E
authors.lastname: Bar-Yishay
authors.forename: Simon
authors.initials: S
authors.lastname: Godfrey
authors.forename: Chaim
authors.initials: C
authors.lastname: Springer
mesh_terms: D000249:Adenosine Monophosphate; D000293:Adolescent; D000328:Adult; D000367:Age Factors; D001249:Asthma / Q000175:diagnosis* / Q000378:metabolism*; D001944:Breath Tests / Q000379:methods; D001985:Bronchial Provocation Tests / Q000379:methods; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D008297:Male; D009569:Nitric Oxide / Q000378:metabolism*; D012129:Respiratory Function Tests / Q000379:methods; D012737:Sex Factors
chemical_list: D009569:Nitric Oxide; D000249:Adenosine Monophosphate