Exhaled breath analysis, a simple tool to study the pathophysiology of obstructive sleep apnoea.

Accelerated airway inflammation may play a crucial role in the pathophysiology of obstructive sleep apnoea (OSA); however this phenomenon has been investigated only in a limited number of studies. The analysis of exhaled breath represents a promising, non-invasive tool to evaluate airway inflammation in this context. The knowledge on exhaled biomarkers in OSA has been growing with an emerging number of methodological studies which help to interpret exhaled breath data. This article not only summarises the results of studies on exhaled breath condensate (EBC) biomarkers, exhaled volatile compounds and exhaled monoxides in OSA, but also aims to critically review methodological limitations and provide some guideline for further research.