Multicenter, observational and prospective study, in which patients referred to the sleep unit with suspected apnea will be recruited obstructive sleep. 1000 patients referred to the sleep unit will be recruited with suspected obstructive sleep apnea. The recruited patients will undergo a sleep study for the diagnosis of OSA, ambulatory monitoring of blood pressure (ABP) of 24 hours, clinical variables will be obtained, questionnaires of quality of life, Epworth test for the evaluation of daytime sleepiness, variables biochemistry and obtaining biological samples. OSA patients will be managed following the usual practice. In those patients for whom the treatment with CPAP an evaluation of adherence to treatment will be carried out. OSA patients will be evaluated at baseline, 6, 12, and 24 months.