Sleep apnoea occurs in 5% to 10% of the general population. Obstructive sleep apnoea (OSA) is the most common disease associated with resistant hypertension. In a paper published by Pedrosa et al, OSA - defined as an apnoea-hypopnoea index (AHI) >15 events/hour measured in polysomnography -was diagnosed in 64% of patients with resistant hypertension. OSA is also considered as an independent risk factor for cardiovascular events: ischaemic heart disease, heart failure, stroke and death. Several mechanisms, including oxidative stress, inflammation and endothelial dysfunction may be responsible for the association between OSA and cardiovascular disease. Continuous positive airway pressure (CPAP) is a treatment of choice to reverse severe OSA and its consequences.