Inspiratory stridor in elite athletes

Area of Science:

• Sports Medicine
• Pulmonary Medicine
• Diagnostic Medicine

Background:

• Exercise-induced bronchospasm (EIB) diagnosis often relies on subjective symptoms, lacking objective spirometric confirmation.
• Inspiratory stridor (IS), a vocal cord dysfunction (VCD) symptom, is frequently misidentified as EIB wheeze in athletes.
• Athletes with exercise-induced IS that resolves post-activity may have VCD, not EIB.

Purpose of the Study:

• To determine the prevalence of inspiratory stridor (IS) in elite athletes.
• To investigate the relationship between IS and exercise-induced bronchospasm (EIB).
• To differentiate IS from EIB using spirometric and pharmacological responses.

Main Methods:

• 370 elite athletes underwent spirometry pre- and post-exercise challenge in cold, dry conditions.
• Exercise-induced bronchospasm (EIB) was defined as a ≥10% postexercise fall in FEV1.
• Athletes were monitored for inspiratory stridor (IS) during exercise; 78.4% had multiple testing sessions.

Main Results:

• EIB was diagnosed in 30% of athletes; IS was observed in 5.1% and resolved post-exercise.
• 53% of IS-positive athletes also had EIB; beta2-agonist treatment failed to resolve IS in most cases.
• Postexercise FEF50/FIF50 ratio > 1.5 was more frequent in IS-positive athletes; IS+/EIB- athletes showed greater FVC fall.

Conclusions:

• Inspiratory stridor (IS) affects 5% of elite athletes and is frequently misdiagnosed as EIB.
• EIB comorbidity is present in 53% of IS-positive athletes.
• Postexercise spirometry and lack of beta2-agonist response aid in distinguishing IS from EIB.