PURPOSE OF THE STUDY.
To investigate the association of duration and exclusiveness of breastfeeding with asthma outcomes in children aged 6 years and determine association with atopy or infection.
Prospective cohort study of 5675 children from the prenatal period until young adulthood in the Netherlands.
Information about breastfeeding was collected through questionnaires. At age 6, airway resistance and exhaled nitric oxide (FeNO), a marker of eosinophilic airway inflammation, were measured. Follow-up questionnaires inquired about wheezing patterns and current asthma.
Children who were not breastfed had increased risk of late and persistent wheezing (odds ratio [95% confidence interval]: 1.69 [1.06 to 2.69] and 1.44 [1.00 to 2.07], respectively) and lower FeNO levels (estimated percentage difference [95% confidence interval]: −16.0 [−24.5 to −7.5]). Shorter duration of breastfeeding was associated with early wheezing (as was less exclusive breastfeeding) and current asthma at age 6 years. Breastfeeding duration and exclusiveness were not associated with FeNO or airway resistance. The associations were explained partly by lower respiratory tract infections in early life and to a lesser extent by lower respiratory tract infections in later life.
Breastfeeding patterns may influence wheezing and asthma in childhood, which seems to be partly explained by infectious mechanisms.
In this study, the researchers add longitudinal data about breastfeeding and asthma outcomes among a cohort in the Netherlands through age 6 years. Interestingly, those who were never breastfed had increased risk of late and persistent wheezing but lower FeNO levels. In addition, the risk of wheezing associated with lack of breastfeeding seemed to be at least partially mediated by respiratory infections. Limitations include the potential for selection bias because the characteristics of the participants who were lost to follow-up were different than those included in the study. Finally, 70% of participants were of European ethnicity, which may affect generalizability of these findings.
- Copyright © 2017 by the American Academy of Pediatrics