TitleObesity is a Risk Factor for Exercise-Induced Bronchospasm in Asthmatic Adolescents
INTRODUCTION Exercise-induced bronchospasm (EIB) is common in young asthmatics and obesity is becoming epidemic in this population. Both conditions can give rise or worsen respiratory symptoms upon exercise and may interfere with recreational and sports activities.
OBJECTIVE To investigate the association between obesity and the risk and severity of EIB in asthmatic children and adolescents.
METHODS This study included data from asthmatic patients aged between 7 and 19-years undergoing treadmill running tests to evaluate EIB, defined as a reduction>10% in forced expiratory volume in the first second (FEV 1 ) compared to baseline. Eutrophic, obese and overweight individuals were categorized according to body mass index z score (eutrophic: -0.5<z≤1, overweight: 1<z<2 and obese: z≥2).
RESULTS Of the 156 individuals studied (42% female), 58% were eutrophic, 22% overweight and 19% obese. Seventy-three individuals (47%) presented with EIB, with higher risk among obese (OR: 2.86, 95%CI 1.00-8.14; p=0.05). Asthma severity was another independent risk factor for EIB (OR: 2.95, 95%CI 1.36-6.42; p=0.006). The number of patients in whom FEV1 returned to baseline values (difference<10% from baseline) at the thirtieth minute after challenge was lower in obese individuals compared to eutrophic and overweight ones (p=0.04). Baseline FEV 1 , gender or age were not found to be risk factors for EIB in any of the groups.
CONCLUSION Obese youngsters with asthma present a greater risk for EIB with slower recovery than their non-obese peers. Clinicians should be aware of this association, especially in those with more severe disease, for adequate recognition and treatment. This article is protected by copyright. All rights reserved.