Exhaled nitric oxide indicates poorly athlete's asthma

Authors


  • Authorship and contributorship

    Mikko Voutilainen has examined the athletes, has done the manuscript and statistics; Leo Pekka Malmberg has taken part in the manuscript and research plan and he is the supervisor of the research. Tommi Vasankari has taken part in the manuscript and has recruited the athletes to the research. Tari Haahtela has taken part in the manuscript and research plan.

  • Ethics

    The study protocol was approved by the Ethics Committee of Medicine, Helsinki University Central Hospital.

  • Conflict of interests

    The authors have stated explicitly that there are no conflicts of interest in connection with this article.

  • The study was reviewed by the appropriate ethics committee and was performed in accordance with the ethical standards laid down in appropriate version of the 2000 Declaration of Helsinki.

Abstract

Introduction

In athletes, exercise-induced respiratory symptoms are common and their assessment is time and resource consuming.

Objective

The objective was to evaluate fractional concentration of exhaled nitric oxide (FENO) as a predictor of bronchial hyperresponsiveness (BHR) and of asthma.

Materials and Methods

Eighty-seven elite athletes and a control group of 87 sedentary patients with symptoms suggesting asthma underwent measurements of FENO and of BHR by using methacholine provocation test (MCH) and eucapnic voluntary hyperpnoea (EVH) (athletes) or histamine provocation test (HIST) (controls).

Results

In athletes, elevated FENO (>30 ppb) was not associated with lung function-confirmed asthma or with MCH positivity, but receiver operating characteristics (ROC) analysis showed some predictive value for EVH positivity [Area Under Curve (AUC) 0.652, 95% confidence interval (CI): 0.53 to 0.78, P = 0.020]. However, the sensitivity (55%) and the specificity (71%) were poor. In sedentary patients, FENO was significantly associated with both confirmed asthma and HIST positivity, ROC analysis showing FENO to be significantly predictive for HIST positivity (AUC 0.83, 95% CI: 0.70 to 0.96, P = 0.001) and for asthma (AUC 0.74, 95% CI: 0.63 to 0.85, P < 0.001).

Conclusion

The results suggest that in contrast to sedentary patients, FENO seems to be a poor predictor of BHR and of clinical asthma in elite athletes. We find it unlikely that FENO could be a useful screening tool in athletes with exercise-induced respiratory symptoms.

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