Screening for exercise-induced bronchoconstriction in college athletes

Abstract

Objective: Previous studies have reported that the prevalence of exercise-induced bronchoconstriction (EIB) in athletes is higher than that of the general population. There is increasing evidence that athletes fail to recognize and report symptoms of EIB. As a result, there has been debate whether athletes should be screened for EIB, particularly in high-risk sports.

Methods: We prospectively studied 144 athletes from six different varsity sports at a large National Collegiate Athletic Association Division I collegiate athletic program. Baseline demographics and medical history were obtained and the presence of asthma symptoms during exercise was documented. Each athlete subsequently underwent a eucapnic voluntary hyperventilation (EVH) test to document the presence of EIB. Exhaled nitric oxide (eNO) quantification was performed immediately before EVH testing. EIB was defined as a ≥10% decline in forced expiratory volume in 1 second compared with baseline.

Results: Only 4 of 144 (2.7%) athletes were EIB-positive after EVH testing. The presence of symptoms was not predictive of EIB as only 2 of the 64 symptomatic athletes (3%) were EIB-positive based on EVH testing. Two of the four athletes who were found to be EIB-positive denied such symptoms. The mean baseline eNO in the four EIB-positive athletes was 13.25 parts per billion (ppb) and 24.5 ppb in the EIB-negative athletes.

Conclusions: Our data argue that screening for EIB is not recommended given the surprisingly low prevalence of EIB in the population we studied. In addition, the presence or absence of symptoms was not predictive of EIB and eNO testing was not effective in predicting EIB.

Figure 1

Decline in forced expiratory volume in 1 second (FEV₁) post-eucapnic voluntary hyperventilation (EVH) testing plotted against percentage of maximum voluntary ventilation (MVV) achieved during EVH testing. Note: Many athletes actually bronchodilated after eucapnic voluntary hyperventilation (EVH) and hence the smallest increase in FEV₁ was used in lieu of a decline in FEV_1.

Figure 2

Decline in forced expiratory volume in 1 second (FEV₁) post-eucapnic voluntary hyperventilation (EVH) testing plotted against baseline exhaled nitric oxide (eNO). Note: Many athletes actually bronchodilated after EVH and hence the smallest increase in FEV₁ was used in lieu of a decline in FEV₁.