PT  - JOURNAL ARTICLE
AU  - T-C. Yao
AU  - W-I. Lee
AU  - L-S. Ou
AU  - L-C. Chen
AU  - K-W. Yeh
AU  - J-L. Huang
AU  - for the PATCH Study Group [4]
TI  - Reference values of exhaled nitric oxide in healthy asian children age 5 to 18 years
AID  - 10.1183/09031936.00013911
DP  - 2011 Jan 01
TA  - European Respiratory Journal
PG  - erj00139-2011
4099  - http://erj.ersjournals.com/content/early/2011/05/26/09031936.00013911.1.short
4100  - http://erj.ersjournals.com/content/early/2011/05/26/09031936.00013911.1.full
AB  - This study was undertaken to establish reference values of fraction of exhaled nitric oxide (FeNO) and its determinants in healthy Asian children.Six hundred and ninety-three healthy Asian children aged 5–18 years were assessed using a single-breath online FeNO measurement (exhaled flow 50 mL·second−1), questionnaires, anthropometric measurements, spirometry, and total and specific immunoglobulin E (IgE).Geometric mean FeNO and the upper 95% confidence limit were 13.7 ppb and 49.7 ppb, respectively, for healthy children and 11.2 ppb and 30.2 ppb, respectively, for those without allergic sensitization. FeNO was positively associated with age, allergic sensitization, total IgE, ambient nitric oxide, measurement in the afternoon, and drinking water within one hour before testing, and negatively associated with weight. In healthy children without allergic sensitization, age was the single best explanatory variable. The FeNO predicted values were 1–2 ppb higher in Asian than in Caucasian children in earlier studies, while the upper 95% confidence limits were 9–10 ppb higher.In conclusion, the upper limits of normal FeNO in Asian children depend on age, from 21 ppb in young children to 39 ppb in adolescents. Ethnicity, age, allergic sensitization, total IgE, ambient nitric oxide, time of testing, drinking water, and weight are important determinants.