Prevalence of exercise-induced bronchoconstriction in elite Chinese summer sport athletes

ABSTRACT<br/>Background: Exercise-induced bronchoconstriction (EIB) is a prevalent respiratory condition among summer sport elite athletes, yet epidemiological data from Asian populations remain scarce. The objective of this study was to investigate the prevalence, sport-specific patterns, and physiological characteristics of EIB in Chinese summer sport elite athletes.<br/>Methods: A cross-sectional study of 500 summer sport elite athletes across 17 sports was conducted. Participants underwent standardized exercise challenge testing, spirometry, and serum biomarker assessments (eosinophils, interleukin-5 (IL-5), interleukin-8 (IL-8), Clara Cell protein 16 (CC16), immunoglobulin E (IgE), and uric acid (UA)).<br/>Results: EIB prevalence was 27.6% (138/500), with significant variation across sports: highest in swimming (51.52%) and lowest in wrestling (6.45%). Female athletes were more prevalent than males (31.1% vs. 23.7%, p = 0.030). Outdoor sports demonstrated higher rates than indoor disciplines (37.4% vs. 19.3%, p = 0.002). EIB-positive athletes showed pronounced post-exercise declines in forced expiratory volume in 1 s (FEV1) at 5 min (p &lt; 0.001) and elevated inflammatory biomarkers: eosinophils (p &lt; 0.001), neutrophils (p = 0.019), IL-5 (p &lt; 0.001), IL-8 (p &lt; 0.001), CC16 (p &lt; 0.001), IgE (p &lt; 0.001), and UA (p &lt; 0.001) vs. EIB-negative counterparts. <br/>Conclusion: This is the first large-scale study of Chinese athletes to reveal EIB prevalence exceeding global averages. Distinct risk profiles emerge, associated with gender, athletic level, sport type, and environmental factors. The findings outline the need for targeted screening programs and biomarker-guided management to mitigate respiratory health risks in athletic populations.<br/>