title: Effects of dietary induced weight loss on exercise-induced bronchoconstriction in overweight and obese children.
abstract: BACKGROUND
  Previous studies showed that obesity in asthmatic children is associated with more severe exercise-induced bronchoconstriction (EIB), compared with non-obese asthmatic children. This study investigates the effect of weight loss on EIB in overweight and obese asthmatic children.
  
  
  METHODS
  In this intervention study, children aged 8-18 years with EIB and moderate to severe overweight, followed a diet based on healthy daily intake for 6 weeks. Before and after the diet period they underwent an exercise challenge test in cold air. Primary outcome was change in exercise-induced fall in FEV1 and relation between weight loss and EIB. Secondary outcomes were changes in recovery of FEV1 ("area under the curve"; AUC), fraction of exhaled nitric oxide (FeNO) and scores of the Pediatric Asthma Quality of Life Questionnaire (PAQLQ) and Asthma Control Questionnaire (ACQ).
  
  
  RESULTS
  Twenty children completed the study. After the diet period, weight, and body mass index (BMI) were significantly reduced (changes respectively -2.6% and -1.5 kg/m(2), P < 0.01). There was a significant improvement of the percentage exercise-induced fall in FEV1 (30.6% vs. 21.8%, P < 0.01), AUC and PAQLQ score. The reduction in BMI z-score was significantly related to the reduction in the percentage exercise-induced fall in FEV1 in children that lost weight (r = 0.53, P = 0.03). There were no changes in FeNO and ACQ.
  
  
  CONCLUSIONS
  Dietary induced weight loss in overweight and obese asthmatic children leads to significant reduction in severity of EIB and improvement of the quality of life. The reduction in BMI z-score is significantly related to the improvement of EIB.
authors.affiliation: Department of Pediatrics, Medisch Spectrum Twente, Enschede, The Netherlands; University of Groningen, University Medical Center Groningen, Beatrix Children's Hospital, Department of Pediatric Pulmonology, GRIAC Research Institute, Groningen, The Netherlands.
authors.forename: Janneke C
authors.initials: JC
authors.lastname: van Leeuwen
authors.forename: Mira
authors.initials: M
authors.lastname: Hoogstrate
authors.forename: Eric J
authors.initials: EJ
authors.lastname: Duiverman
authors.forename: Boony J
authors.initials: BJ
authors.lastname: Thio
mesh_terms: D000293:Adolescent; D001250:Asthma, Exercise-Induced / Q000517:prevention & control*; D002648:Child; D004038:Diet, Reducing; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D009765:Obesity / Q000178:diet therapy*; D050177:Overweight / Q000178:diet therapy*; D011446:Prospective Studies; D011788:Quality of Life; D015431:Weight Loss
keywords: asthma; diet; exercise-induced asthma; obesity