A multi-center study on the normal range of exhaled nitric oxide in 6-18-year-old children in China / 中华实用儿科临床杂志

ABSTRACT

Objective:To investigate the normal range of exhaled nitric oxide (FeNO) in 6-18-year-old children in China, so as to provide a data base for the establishment of FeNO standards for Chinese children.Methods:A multi-center study was conducted on 5 949 children aged 6-18 (3 101 males and 2 848 females) in 16 pro-vinces of 7 administrative districts in China.According to the technical standard recommended by American Thoracic Society/European Respiratory Association, FeNO was measured, and the relationship of FeNO with the sex, age, height, weight, body mass index and region was discussed.Results:The geometric mean FeNO value of Chinese children aged 6-18 was 14.1 ppb, and its 95% confidence interval (skewness distribution) was 1.0-38.2 ppb.The geometric mean FeNO values of children aged 6-11 and 12-18 were 13.1 ppb and 15.7 ppb, respectively, and their 95% confidence intervals (skewness distribution) were 1.0-38.1 ppb and 2.0-38.2 ppb.For children at and under 11 years old, FeNO decreased with age, with a mean decline of 1 ppb per year.The multiple linear regression results suggested that there was a significant correlation between FeNO and age for children aged 6-11, and FeNO of children aged 12-18 was significantly correlated with the gender, height, and region(all P<0.01). Conclusions:FeNO values of Chinese children and adolescents in this study are higher than those obtained by the previous study conducted from 2010 to 2012.For children aged 12-18, 16 ppb is recommended as the clinical cut-off point.For children at or under 11 years old, the influence of age on FeNO should be considered, and the cut-off point of FeNO decreases by 1 ppb as the age is reduced by one year.