Study on the level of fractional exhaled nitric oxide in healthy preschool children in Beijing / 中华实用儿科临床杂志

ABSTRACT

Objective:To explore the level of fractional exhaled nitric oxide (FeNO) in preschool children in Beijing and analyze the influencing factors.Methods:Preschool students aged 3-5 in Beijing were selected from May to July 2017.Healthy children were screened through questionnaire survey and on-site physical examination, and their FeNO levels were detected.Results:A total of 317 healthy children were enrolled, including 161 males and 156 females.There was no significant difference in FeNO levels between different genders ( P>0.05). The geometric mean value of FeNO was 8.2 ppb in male(95% CI 7.0-9.3 ppb)and 8.7 ppb in female (95% CI 7.4-10.1 ppb). There were statistical differences in FeNO levels among the 3 age groups ( F=4.63, P<0.05). The geometric mean value of FeNO was 7.2 ppb in 3-year-old children (95% CI 5.5-8.9 ppb), 8.8 ppb in 4-year-old children (95% CI 7.4-10.2 ppb), and 9.2 ppb in 5-year-old children (95% CI 7.7-10.7 ppb). The geometric mean value of FeNO of healthy preschool children was 8.5 ppb (95% CI 7.6-9.3 ppb). There was a positive correlation between FeNO and height ( r=0.135, P<0.05), but there was no significant correlation between FeNO and weight. Conclusions:The geometric mean value of FeNO in healthy preschool children in Beijing is 8.5 ppb (95% CI 7.6-9.3 ppb)and the 95% reference value is 23.5 ppb.The level of FeNO changes slightly with the increase of age, and height also affects the FeNO.It is highly feasible to use on-line tidal breathing method to measure FeNO of preschool children.