pregnancy or lactation

daytime alveolar hypoventilation

severe arterial hypertension (systolic pressure \> 180 mmHg; diastolic pressure \> 110 mmHg)

treatment with anti-hypertensive drugs

cardiovascular disorder other than mild hypertension

severe daytime sleepiness (score on the EPWORTH sleepiness scale ≥15) or at-risk occupation

contra-indication to nCPAP treatment

known allergy to bosentan

active treatment with a drug whose efficacy is reduced by cytochromes P450, 2C9, 3A4 and2C19 isoenzyme activation

active treatment with a drug acting on systemic arterial blood pressure or endothelial function

liver or kidney dysfunction

Preventive Effects of Bosentan on the Systemic Cardiovascular Consequence of Sleep Apnea