Obstructive sleep apnea syndrome (OSAS) has been linked to resistant hypertension, but the effect of treatment of OSAS on the resistant hypertension have no been established. In a double-blind randomized clinical trial patients with resistant hypertension with at least moderate sleep apnea will be randomized to receive therapeutic CPAP or Placebo CPAP for eight weeks in an ambulatory set. The investigators want to determine any difference on hypertension control between the 2 management strategies.

This is a double blind, randomized, placebo controlled trial. Participants were consecutive patients with resistant hypertension, defined as uncontrolled BP, despite the concurrent use of 3 or more antihypertensive agents, including a diuretic, with adherence to treatment and without white coat phenomenon. All participants should have a diagnosis of at least moderate OSAS, defined by AHI > 15 in a portable monitoring sleep exam. Participants were assigned to active CPAP or sham-CPAP. The main outcome was change in 24-hour ambulatory blood pressure (ABP) monitoring values from baseline to two months of active CPAP or sham CPAP

Inclusion Criteria:

• Clinical diagnosis of resistant hypertension
• Apnea/hypopnea index > 15

Exclusion Criteria:

• Cardiac surgery on last 3 months
• Serious arrhythmias
• Insulin dependent diabetes
• Debilitating neurological disease
• severe COPD