PT  - JOURNAL ARTICLE
AU  - Esther I Schwarz
AU  - Pablo Martinez-Lozano Sinues
AU  - Lukas Bregy
AU  - Thomas Gaisl
AU  - Diego Garcia Gomez
AU  - Martin T Gaugg
AU  - Yannick Suter
AU  - Nina Stebler
AU  - Yvonne Nussbaumer-Ochsner
AU  - Konrad E Bloch
AU  - John R Stradling
AU  - Renato Zenobi
AU  - Malcolm Kohler
TI  - Effects of CPAP therapy withdrawal on exhaled breath pattern in obstructive sleep apnoea
AID  - 10.1136/thoraxjnl-2015-207597
DP  - 2016 Feb 01
TA  - Thorax
PG  - 110--117
VI  - 71
IP  - 2
4099  - http://thorax.bmj.com/content/71/2/110.short
4100  - http://thorax.bmj.com/content/71/2/110.full
SO  - Thorax2016 Feb 01; 71
AB  - Background Obstructive sleep apnoea (OSA) is highly prevalent and associated with cardiovascular and metabolic changes. OSA is usually diagnosed by polysomnography which is time-consuming and provides little information on the patient's phenotype thus limiting a personalised treatment approach. Exhaled breath contains information on metabolism which can be analysed by mass spectrometry within minutes. The objective of this study was to identify a breath profile in OSA recurrence by use of secondary-electrospray-ionization-mass spectrometry (SESI-MS).Methods Patients with OSA effectively treated with CPAP were randomised to either withdraw treatment (subtherapeutic CPAP) or continue therapeutic CPAP for 2 weeks. Exhaled breath analysis by untargeted SESI-MS was performed at baseline and 2 weeks after randomisation. The primary outcome was the change in exhaled molecular breath pattern.Results 30 patients with OSA were randomised and 26 completed the trial according to the protocol. CPAP withdrawal led to a recurrence of OSA (mean difference in change of oxygen desaturation index between groups +30.3/h; 95% CI 19.8/h,40.7/h, p<0.001) which was accompanied by a significant change in 62 exhaled features (16 metabolites identified). The panel of discriminating mass-spectral features allowed differentiation between treated and untreated OSA with a sensitivity of 92.9% and a specificity of 84.6%.Conclusion Exhaled breath analysis by SESI-MS allows rapid and accurate detection of OSA recurrence. The technique has the potential to characterise an individual's metabolic response to OSA and thus makes a comprehensible phenotyping of OSA possible.Trial registration number NCT02050425 (registered at ClinicalTrials.gov).