Swimming Pool Attendance, Asthma, Allergies and Lung Function in the ALSPAC Child Cohort

RATIONALE: Cross-sectional studies have reported inconsistent findings for the association between recreational swimming pool attendance and asthma and allergic diseases in childhood. OBJECTIVES: To examine whether swimming in infancy and childhood was associated with asthma and allergic symptoms at age 7 and 10 years in a UK longitudinal population-based birth cohort (ALSPAC). METHODS: Data on swimming were collected by questionnaire at 6, 18, 38, 42, 57, 65 and 81 months. Data on rhinitis, wheezing, asthma, eczema, hay fever, asthma medication and potential confounders were collected through questionnaire at 7 and 10y. Spirometry and skin prick testing were performed at 7-8y. Data for analysis were available for 5,738 children. MEASUREMENTS AND MAIN RESULTS: At age 7y, >50% of the children swam once/week. Swimming frequency did not increase the risk of any evaluated symptom, either overall or in atopic children. Children with a high versus low cumulative swimming pool attendance from birth to 7y had an odds ratio (OR) of 0.88 (95% confidence interval 0.56-1.38) and 0.50 (0.28-0.87), respectively, for ever and current asthma at 7y, and a 0.20 (0.02-0.39) standard deviation increase in the mid forced expiratory flow. Asthmatic children with a high versus low cumulative swimming had an OR for current asthma at 10y of 0.34 (0.14-0.80). CONCLUSIONS: This first prospective longitudinal study suggests that swimming did not increase the risk of asthma or allergic symptoms in British children. Swimming was associated with increased lung function and lower risk of asthma symptoms, especially among children with pre-existing respiratory conditions. American Journal of Respiratory and Critical Care Medicine. 2010 October 1 doi:10.1164/rccm.201005-0761OC. [Epub ahead of print].