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Trajectory of spirometric and exhaled nitric oxide measurements in Chinese schoolchildren with asthma
Author(s) -
Leung Ting F.,
Tang Man F.,
Leung Agnes S. Y.,
Tam Wilson W. S.,
Sy Hing Y.,
Wong Gary W. K.
Publication year - 2018
Publication title -
pediatric allergy and immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.269
H-Index - 89
eISSN - 1399-3038
pISSN - 0905-6157
DOI - 10.1111/pai.12836
Subject(s) - medicine , exhaled nitric oxide , asthma , spirometry , body mass index , vital capacity , bronchodilator , longitudinal study , pulmonary function testing , pediatrics , cardiology , lung function , lung , diffusing capacity , pathology
Background Lung function growth occurs in most asthmatic children. A subgroup has subnormal lung function trajectory, but such data are limited in children. This prospective study characterized longitudinal changes of spirometric indices and fractional exhaled nitric oxide level (Fe NO ) among asthmatic children and identified their genetic and environmental determinants. Methods Chinese asthmatic children recruited from pediatric clinics underwent 5‐year follow‐up for pre‐bronchodilator spirometric indices and Fe NO . Fourteen asthma‐associated single nucleotide polymorphisms ( SNP s) were genotyped. Generalized estimating equation was used to analyze longitudinal changes of spirometric indices and Fe NO . Results One hundred and ninety‐three asthmatic children, aged 9.7 (1.9) years, had significant annual decline of 1.3% for forced vital capacity ( FVC ) and annual increase of 1.2% and 3.6% for FEV 1 / FVC and FEF 25‐75 , respectively. Patients who received inhaled corticosteroid ( ICS ) had 2.4% lower baseline FEV 1 / FVC but 0.81% higher annual increase in FEV 1 . Body mass index ( BMI ) was associated inversely with FEV 1 / FVC but positively with FEV 1 % and FVC % changes. Asthma exacerbation was associated with lower FEV 1 % and FVC % but not their longitudinal changes. When classified by FEV 1 curve, one‐quarter of patients had reduced lung function growth which was associated with female gender and lower spirometric and higher Fe NO values at baseline. IL 33 _rs1342326 was associated with spirometric indices and Fe NO , whereas GSDMB _rs2305480 was significantly associated with FEV 1 / FVC change. Conclusion Asthmatic children have annual decline in FVC and increase in FEV 1 / FVC and FEF 25‐75 . Their lung function trajectory is influenced by gender, ICS treatment, BMI , and asthma exacerbations. IL 33 and GSDMB may be candidate genes for their lung function growth.