The effect of weight loss through a low calory diet on exercise induced asthma in children with asthma and moderate overweight.

Previous studies in asthmatic obese children show a relation between obesity and bronchial hyperresponsiveness, a characteristic feature of asthma. Several underlying mechanisms have been suggested to explain the interaction between obesity and asthma. The effect of weight loss on BHR to an indirect stimulus has not yet been studied in adults or children. The aim of our study is to investigate the effect of weight loss through a low calory diet on EIB in children with asthma and moderate overweight. We expect losing weight will improve pulmonary function, decrease symptom scores and diminishes ∆FEV1 after exercise.

Previous studies in asthmatic obese children show a relation between obesity and bronchial hyperresponsiveness, a characteristic feature of asthma. Several underlying mechanisms have been suggested to explain the interaction between obesity and asthma. The effect of weight loss on BHR to an indirect stimulus has not yet been studied in adults or children. The aim of our study is to investigate the effect of weight loss through a low calory diet on EIB in children with asthma and moderate overweight. We expect losing weight will improve pulmonary function, decrease symptom scores and diminishes ∆FEV1 after exercise.

To analyze the relation between reduction in BMI and reduction in the exercise induced fall of FEV1 after a diet-period of 6 weeks. Secondary we analyze the relation between reduction in BMI and the recovery of the lungfunction to baseline (measured as total Area Under the Curve), the increase in baseline FEV1, the reduction in FeNO (measured with the miniNIOX®), quality of life (measured with the Pediatric Asthma Quality of Life Questionnaire) and the asthma control (measured with the Asthma Control Questionnaire).

The measurements will be done before and after the diet period of 6 weeks. Weight, height and bio-electric impedance will also be measured after 2 and 4 weeks.

To measure pulmonary volumes and flow-volume loops we use a MicroLoop spirometer in combination with Spida5 software.

The FENO we measure with the miniNOX.

The quality of life with the pediactric asthma quality of life questionnaire.

The asthma control with the asthma control questionnaire.

All children will follow a low calory diet for 6 weeks in order to lose weight. After that period we measure the change in BMI.