Association of breastfeeding with tidal breathing analysis in infants with bronchiolitis.

Background: Tidal breathing flow-volume (TBFV) analysis provides important information about lung mechanics in infants.

Aim: To assess the effects of breastfeeding on the TBFV measurements of infants who recover from acute bronchiolitis.

Methods: In this cross-sectional study, TBFV analysis was performed in infants with bronchiolitis prior to hospital discharge. The ratio of time to peak expiratory flow to total expiratory time (tPEF/tE) at baseline and after the administration of 400 mcg salbutamol was evaluated.

Results: A total of 56 infants (35 boys), aged 7.4 ± 2.8 mo, were included. Of them, 12.5% were exposed to tobacco smoke and 41.1% were breastfed less than 2 mo. There were no differences in baseline TBFV measurements between the breastfeeding groups; however, those who breastfed longer than 2 mo had a greater change in tPEF/tE after bronchodilation (12% ± 10.4% 0.9% ± 7.1%; < 0.001). Moreover, there was a clear dose-response relationship between tPEF/tE reversibility and duration of breastfeeding ( < 0.001). In multivariate regression analysis, infants who breastfed less (regression coefficient -0.335, = 0.010) or were exposed to cigarette smoke (regression coefficient 0.353, = 0.007) showed a greater change in tPEF/tE after bronchodilation, independent of sex, prematurity, and family history of asthma or atopy.

Conclusion: Infants who recover from bronchiolitis and have a shorter duration of breastfeeding or are exposed to cigarette smoke, have TBFV measurements indicative of obstructive lung disease.