A study of the association between exercise-induced wheeze and exercise versus methacholine-induced bronchoconstriction in adolescents

Pediatr Allergy Immunol. 2002 Jun;13(3):203-8. doi: 10.1034/j.1399-3038.2002.01034.x.

Abstract

Among asthmatics, exercise-induced wheeze (EIW) is a frequent symptom, and 40-77% of asthmatics demonstrate exercise-induced bronchoconstriction (EIB). In the North-Trøndelag population-based survey of 8,571 adolescents (YOUNG-HUNT), 26% reported wheeze during the previous 12 months (current wheeze). Of those subjects, 50% reported EIW. The aim of the present study was to investigate the association between EIW and EIB in randomly selected adolescents with EIW as the only or predominant asthma-like symptom, and to relate our findings to results from methacholine bronchoprovocation tests (MT) and measurements of exhaled nitric oxide (ENO). Sixty-three subjects with current wheeze induced by exercise, but not by allergen exposure, were investigated using a treadmill exercise test (ET) and measurements of ENO. Fifty-eight subjects completed a MT on a separate study day. EIB was defined as a fall of >or= 10% in the forced expiratory volume in 1 second (FEV1) after exercise (DeltaFEV1%ex). Twenty-one subjects (33%) had EIB and 33 (57%) had a positive MT. The degree of reported dyspnea during the ET was not correlated to the DeltaFEV1%ex. The correlation between EIB and methacholine-induced bronchoconstriction (MIB) was poor, and the DeltaFEV1%ex was more pronounced in smokers than in non-smokers. Moreover, ENO was not increased in subjects with positive vs. negative ET. Hence, EIW, when reported as the only or predominant asthma-like symptom, was linked to EIB in only one-third of the patients. We conclude that EIW is a poor predictor of EIB in epidemiological studies. The poor correlation between EIB and MIB indicates that these two tests measure different mechanisms of bronchial hyper-responsiveness.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Asthma / diagnosis
  • Asthma / physiopathology*
  • Asthma, Exercise-Induced / diagnosis
  • Asthma, Exercise-Induced / physiopathology*
  • Bronchial Provocation Tests
  • Bronchoconstriction / drug effects
  • Bronchoconstriction / physiology
  • Female
  • Humans
  • Male
  • Methacholine Chloride
  • Nitric Oxide / metabolism
  • Respiratory Sounds / diagnosis
  • Respiratory Sounds / physiopathology*

Substances

  • Methacholine Chloride
  • Nitric Oxide