Obesity has been proposed to be a risk factor for the development of childhood asthma.
To examine weight status from birth to age 5 years in relation to the occurrence of asthma at age 6 and 8 years.
285 full-term high-risk newborns with at least one asthmatic/atopic parent, enrolled in the Childhood Origin of Asthma (COAST) project, were studied from birth to age 8 years. Overweight was defined by weight-for-length percentiles > 85th prior to age 2 years and body mass index percentile > 85th at ages 2–5 years.
No significant concurrent association was found between overweight and wheezing/asthma occurrence at each year of age. In contrast, longitudinal analyses revealed complex relationships between overweight and asthma. Being overweight at age 1 year was associated with a decreased risk of asthma at age 6 (OR=0.32, p=0.02) and 8 years (OR=0.35, p=0.04) as well as better lung function. However, being overweight beyond infancy was not associated with asthma occurrences. In fact, only children who were overweight at age 5 but not at age 1 year had an increased risk of asthma at age 6 years (OR=5.78, p=0.05).
In children genetically at high risk of developing asthma, overweight at age 1 year was associated with a decreased risk of asthma and better lung function at age 6 and 8 years. However, being overweight beyond infancy did not have any protective effect and even could confer a higher risk for asthma.