title: [Epidemiological features of exercise-induced bronchial hyperresponsiveness in children aged 13-14 years old in Barcelona (Spain)].
abstract: BACKGROUND
  Conclusive data on the risk factors that modify bronchial hyperresponsiveness after airway exposure to modulating triggers (histamine, methacholine and exercise) are lacking. In recent years some risk factors such as air pollution or infection have been questioned and even considered protective.
  
  
  OBJECTIVE
  To assess the prevalence of bronchial hyperresponsiveness to exercise among schoolchildren and its association with different risk factors.
  
  
  METHODS
  Three thousand thirty-three schoolchildren aged 13-14 years were studied. Participants answered a questionnaire on respiratory symptoms. A total of 2,842 children underwent exercise challenge testing for bronchial hyperresponsiveness. This study was part of the International Study of Asthma and Allergies in Childhood (ISAAC).
  
  
  RESULTS
  A fall in peak expiratory flow rate of (15 % after exercise was found in 324 children (11.4 %), of whom 29 (9 %) also presented symptoms of asthma. Bronchial hyperresponsiveness to exercise was significantly associated with lower age, female sex, high socioeconomic level and attending a private school. No association was found between bronchial hyperresponsiveness and obesity, tobacco or viral infections.
  
  
  CONCLUSIONS
  These findings are not completely consistent with those of other studies, suggesting that local environmental factors may influence the prevalence of bronchial hyperresponsiveness. Further studies are required to clarify these conflicting data.
authors.affiliation: Unidad de Neumología Infantil, Servicio de Pediatría, Hospital del Mar, Universidad Autónoma de Barcelona, Spain. 13018@imas.imim.es
authors.forename: R M
authors.initials: RM
authors.lastname: Busquets Monge
authors.forename: O
authors.initials: O
authors.lastname: Vall Combelles
authors.forename: M A
authors.initials: MA
authors.lastname: Checa Vizcaíno
authors.forename: O
authors.initials: O
authors.lastname: García Algar
mesh_terms: D000293:Adolescent; D000367:Age Factors; D001250:Asthma, Exercise-Induced / Q000453:epidemiology* / Q000503:physiopathology*; D016535:Bronchial Hyperreactivity; D005260:Female; D006801:Humans; D008297:Male; D010366:Peak Expiratory Flow Rate; D015995:Prevalence; D012307:Risk Factors; D012574:Schools; D012737:Sex Factors; D012959:Socioeconomic Factors; D013030:Spain / Q000453:epidemiology; D011795:Surveys and Questionnaires
vernacular_title: Aspectos epidemiológicos de la hiperreactividad bronquial inducida por el ejercicio en niños de 13-14 años en Barcelona.