ABSTRACT
BACKGROUND: The prevalence of asthma and overweight/obesity in children and adolescents is continuously increasing over the last decades. It remains unclear if overweight/obesity raises the risk of developing asthma or if an uncontrolled asthma increases the risk of developing overweight/obesity by restricting physical activity. OBJECTIVES: We aimed to elucidate, if children and adolescents with overweight/obesity differ from normal-weight asthmatics in lung functions parameters (FEV1, FEV1/VC, MEF50 and SRtot) and in exhaled nitric oxide (FeNO). METHODS: Totally, n=142 children and adolescents aged 6-18 years were included in this study: group 1 comprised n=44 with overweight/obesity defined as a Body-Mass-Index (BMI)>90th percentile; group 2 n=44 with a doctors diagnosed bronchial asthma according to the GINA-guidelines, and group 3 with n=36 pulmonary healthy controls. N=18 children with both asthma and overweight/obesity were excluded from further analysis. We collected data about socio-demographic variables from a standardized questionnaire, bodyplethysmography (FEV1, FEV1/VC, MEF50 and SRtot) and FeNO. RESULTS: Normal-weight children and adolescents with asthma had significantly lower FEV1/VC (Tiffenau-Index 90,9±12,8) and MEF50 (84.0% predicted±27.6) than children with overweight/obesity (97,6±12,4 p=0.001 respectively 99.1±20.9 p=0.001) and healthy controls (98±13,5 p=0,003; 96.7±19.3 p=0.011). Normal weight asthmatics had a significantly higher FeNO (38.3 ppb) than children and adolescents with overweight/obesity (14.0 ppb p=0.014). CONCLUSIONS: Normal-weight children and adolescents with asthma differ significantly both in their lung function parameters as well as in their exhaled nitric oxide concentration from children and adolescents with overweight/obesity. For clinical practice it is important to note that children and adolescents with overweight/obesity have no signs of an obstructive airway diseases and are as resilient as healthy children and adolescents with regard to their lung function. The possible late-onset of asthma symptoms and lung function changes in children and adolescents with overweight/obesity requires further detailed longitudinal studies.