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.
ABSTRACT
Objective To investigate six yearsˊ outcome of children with asthma. Methods Children with asthma diagnosed in the epidemiological survey of childhood asthma in urban area of Beijing in 2010 were selected in this study. The field follow-up was conducted in 2016(6 years later)to obtain information about asthma attack,di-sease control,medication usage,and comorbidities of allergic diseases. The skin prick test,lung function and exhaled ni-tric oxide were performed during field follow - up stage. Results Sixty - four children,aged 7 - 19 years old [(13. 59 ± 3. 48)years old],completed the field follow-up survey. Among 35. 9%(23/64 cases)children,the asth-ma symptoms still persisted within 2 years(without remission),while 64. 1%(41/64 cases)children had no symp-toms within 2 years and above(remission). The course of children without remission(9. 0 years)was significantly lon-ger than that of children with remission(5. 5 years),and there was statistical significance(z＝ -3. 775,P<0. 001). Among the children without remission,the number of uncontrolled children in the last month accounted for 13. 0%(3/23 cases),partially controlled for 17. 4%(4/23 cases),and under controlled for 69. 6%(16/23 cases). The majority of unrelieved children were treated with intermittent control drug[43. 5%(10/23 cases)υs. 12. 2%(5/41 cases), χ2 ＝8. 036,P<0. 01]. A total of 47. 8%(11/23 cases)of children without remission were completely unaffected by physical activity,while 92. 7%(38/41 cases)of children with clinical remission were completely unaffected by physi-cal activity(χ2 ＝14. 117,P<0. 001). The proportion of children without remission with eczema and atopic dermatitis lasting longer than 6 years old was 56. 5%(13/23 cases),which was significantly higher than that of children with re-mission[29. 3%(12/41 cases),χ2 ＝4. 598,P<0. 05]. In 2010 and 2016,there were 46 children with allergen re-sults. Compared with 2010,the proportion of animal fur and pollen allergy increased in 2016[19. 6%(9/46 cases)υs. 52. 2%(24/46 cases),36. 9%(17/46 cases)υs. 67. 4%(31/46 cases)],and there were statistical significances (χ2 ＝10. 632,8. 538,all P<0. 01). In 2016,the number and degree of total allergens in the clinical unrelieved chil-dren were higher than that in the relieved children. Further analysis showed that the unrelieved children had higher cigarette allergy positivity(21. 7% υs. 2. 5%,χ2 ＝4. 239,P<0. 05). There was no significant difference in lung func-tion and exhaling nitric oxide between the clinical unrelieved children and the relieved children. Conclusions Six years later,the proportion of animal fur and pollen allergy increased in children with asthma. Compared with children with remission,the children without remission had more treatment with intermittent control drug,with higher proportion of eczema and atopic dermatitis over six years old,and higher percentage of cigarette allergy positivity.