Asthma and obesity in childhood: on the road ahead.

Epidemiological data show a link between asthma and obesity, suggesting many different mechanisms that may underlie the association. However, diagnosis of asthma is often self-reported by patients or caregivers. Definition of asthma is crucial, particularly in childhood. Obesity can be associated with symptoms commonly attributed to asthma, such as wheezing, dyspnoea and sleep apnoea. Obese subjects are less fit and may have more frequent bouts of breathlessness on exertion accompanied by an exaggerated symptom perception. Therefore, the link between the two diseases should be analysed by focusing not only on reported diagnosis of asthma but also on objective markers that can better characterize the asthma phenotype. These markers should include lung function parameters, bronchial hyper-reactivity, atopic sensitization and indices of lung inflammation. As we look back and move forward, a multidisciplinary approach is increasingly necessary to understand the complexity of obesity and asthma, keeping in mind that diet and exercise could influence both diagnosis and treatment. In the meantime, in clinical settings, physicians should be cautious about diagnosing asthma in obese children on the basis of self-reported symptoms alone and should confirm the diagnosis by using objective measurements and marker evaluations that can better identify asthma phenotype and exclude overdiagnosis.