Risk factors associated to the prevalence of asthma in adolescence.

The ISAAC project (International Study of Asthma and Allergies in Childhood) was developed with the purpose of determining the prevalence of asthma in schoool children, with the definition of two age groups: infancy, when asthma is more frequent, and adolescence, when mortality associated to asthma is greater. However, the study does not address the risk factors associated with this pathology. Our aim is to comparatively analyze the prevalence of respiratory symptoms and the asthma epidemiological factors in the two age groups and in both sexes. Since the results of ISAAC Phase I are available, we can study the variations in risk factors, relating them to the current prevalence of asthma. The prevalence of bronchial asthma in our adolescents is 10 % - this implying a significant increase with respect to the data corresponding to ISAAC Phase I. Likewise, the prevalence of wheezing in the last 12 months has also increased significantly with respect to the data corresponding to ISAAC Phase I. It can be affirmed that familial antecedents of asthma are significantly correlated to the fact of having experienced asthma at some point in time, or to wheezing in the previous 12 months. In the same way as for bronchial asthma, the increase in rhinitis has been significant. The presence of animals in the home is significantly associated to the fact of having experienced asthma at some point in time, though the presence of animals in the home has decreased significantly. An encouraging finding in our study is the fact that smoking has decreased significantly among adolescents in comparison with the previous data. However, the same does not apply to smoking among parents, which shows results similar to those recorded in the previous study - with an influence upon the same habit in the offspring. As in other studies, active smoker status is seen to be associated with the fact of having experienced asthma at some point in time. Although a common observation, the importance of hyper-responsiveness with exercise among adolescents is still not acknowledged, despite its significant correlation to the fact of having experienced asthma at some point in time, or wheezing in the previous 12 months.