Does Physical Activity Lower the Risk of Developing Asthma for Children?

Abstract

Background: Asthma is the leading cause of chronic diseases in children, and its prevalence has been increasing in many countries especially for children. It is the one of the leading factors contributing to school absenteeism and has a sizable impact on health care expenditure. Physical activity was suggested as a protective factor against asthma incidence, with a recent review finding a marginally significant odds ratio supporting this claim for adults. However, there is only one study of this association for children that did not find a significant association. We aim to perform our own analysis of this association on Australian children. Methods: We used two waves of data from the longitudinal study of Australian children, a study that is representative of all Australian children with some exceptions. This study used a double staged clustered design, choosing postcodes before choosing children from those postcodes and they collected data in a cross sectional manner every two years. Children with asthma at baseline were excluded since we are looking at incidence, with the remaining children with complete data entering a multivariable logistic regression. Results: The unadjusted and adjusted analyses found no effect of physical activity on asthma incidence in this study sample of Australian children with an odds ratio of about one and a 95% confidence interval that crosses the null value. There is a possibility that the remaining sample size did not have enough power to detect an effect size of this association, and that there was a misclassification of exposure and outcome. Conclusion: The results of this study do not provide us with enough evidence to support the hypothesis that physical activity is protective against asthma incidence. Further research specific to this association is needed preferably with a larger sample size and objective measures of physical activity and asthma.