Fetal growth rather than prematurity determines lung function in children with asthma.

ABSTRACT

BACKGROUND AND OBJECTIVE: Preterm birth or fetal growth has been associated with reduced lung function and asthma during childhood in the general population. We aimed to elucidate whether prematurity or fetal growth has a significant influence on lung function or symptoms in children with stable asthma. METHODS: We included children with stable asthma who participated in the Korean childhood Asthma Study cohort. Asthma symptoms were determined by asthma control test (ACT). Percent predicted values of pre- and post-bronchodilator (BD) lung function including forced expiratory volume in 1 second (FEV1 ), forced vital capacity (FVC), and forced expiratory flow at 25%-75% of FVC (FEF25%-75% ) were measured. Lung function and symptoms were compared according to the history of preterm birth and birth weight (BW) for gestational age (GA). RESULTS: The study population consisted of 566 children (age range 5-18 years). There were no significant differences in lung function and ACT between preterm and term subjects. We observed no significant difference in ACT but significant differences were observed in pre- and post-BD FEV1 , pre- and post-BD FVC, and post-BD FEF25%-75% according to BW for GA in total subjects. Two-way ANOVA revealed that BW for GA rather than prematurity was a significant determining factor for pre- and post-BD lung function. After regression analysis, BW for GA was still a significant determining factor of pre- and post-BD FEV1 and pre- and post-BD FEF25%-75% . CONCLUSION: Fetal growth rather than prematurity appears to have a significant effect on lung function in children with stable asthma.