Purpose of review: To provide perspective to the most recent evidence regarding the association between early weight gain in infancy and the development of asthma and atopy during childhood, and highlight the potential mechanisms involved.
Recent findings: Recently, several birth cohort studies involving more than 25 000 children have found a consistent association between early weight gain in the first 2 years of life and incident asthma during school age. Methodology differs substantially between the studies and complicates the establishment of definite conclusions. Specific mechanisms for this association have been proposed, including impairment in lung development and elevated levels of growth factors and cytokines associated with airway inflammation and remodeling. A limited number of studies indicate that early weight gain in infancy is also associated with recurrent wheezing during preschool age but not with the development of atopy.
Summary: A consistent association between early weight gain in infancy and incident asthma during school age has been observed in several cohort studies. The identification of this modifiable risk factor for the development of asthma opens the possibility of preventive intervention. Additional studies are necessary to clarify the involved mechanisms and some pending questions, such as the influence of early weight gain in asthma phenotypes and severity.
aFederal University of São Paulo, São Paulo, Brazil
bFederal University of Paraná, Curitiba, Brazil
cABC Medical School, Santo André, Brazil
dWashington University School of Medicine
eSt. Louis Children's Hospital, St. Louis, Missouri, USA
Correspondence to Gustavo F. Wandalsen, MD, PhD, Rua dos Otonis 725, São Paulo, SP 04025 002, Brazil. E-mail: email@example.com; firstname.lastname@example.org