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