The obstructive sleep apnea syndrome (OSAS) is a risk factor for cardiovascular diseases The results of epidemiological, observational, and experimental studies support the fact that OSAS is of considerable importance in the development of arterial hypertension via chronic sympathetic activation and sleep-induced neurohumoral changes OSAS is of prime importance in the development of refractory AH CPAP therapy not only eliminates sleep-induced obstructive respiratory impairments, but frequently lowers blood pressure in hypertensive patients, and improves the prognosis of cardiovascular diseases