Sleep apnea-hypopnea syndrome is characterised by daytime sleepiness, cognitive-behavioural, respiratory, cardiac, metabolic or inflammatory disorders, secondary to repeated obstruction of the upper airway during sleep. Numerous studies have shown that SAHS is associated with the presence of arterial hypertension and the development of cardiovascular diseases. Similarly, there is an excess of mortality associated with SAHS. An increase in the activity of the sympathetic nervous system and endothelial dysfunction are considered as mediating mechanisms, together with phenomena of oxidative stress, platelet aggregation and thrombosis.