To evaluate the impact of a long-term use of CPAP on clinic and ambulatory blood pressure (BP) in patients with resistant hypertension (RHT) and obstructive sleep apnea (OSA)
Design and method:
An observational prospective study was performed in 66 patients with RHT and moderate/severe OSA (AHI > 15/hour), using CPAP for at least 12 months. Clinic BP and 24-hour BP were obtained before and after follow-up. Primary outcomes were changes in clinic and ambulatory BPs, and BP control. The differences of BP from the beginning to the end of the study were evaluated with a paired t test, adjusted by baseline BP. A per-protocol analysis was performed limited to patients with uncontrolled ambulatory BP levels at baseline.
66 patients [64% females, mean (SD) age: 62 (8) years] were followed-up for a median of 20 [15–35] months. They used a median of 5 [3–8] antihypertensive drugs and had mean (SD) clinic BPs of 151 (26)/86 (17) mm Hg and ambulatory 24-hour BPs of 128 (17)/75 (11) mmHg; 61% of them had uncontrolled ambulatory BP levels at baseline. The average use of CPAP treatment was 5 (1.9) hours per night, with 78% using it at least 4 hours per night. A significant reduction of 24-hour (−3.7 [−7.7 to + 0.2] mmHg, p = 0.04) and daytime (−5.6 [−10.1 to – 1.1] mm Hg, p = 0.02) systolic ambulatory BP was found. Controlled ambulatory BP increased from 39% to 57%. In a per-protocol analysis, 48 patients with baseline uncontrolled ABPM were evaluated. They achieved a significant decrease in clinic systolic BP (−7.4 [−11.4 to + 3.2] mmHg, p = 0.04) and in systolic and diastolic ambulatory BP in all periods: 24-hour (14.6 [−21.0 to – 8.2]/−7.4 [−10.8 to −2.8]) mmHg, daytime (−17.3 [−10.8 to – 3.8]/−7.7[−11.3 to −4.3] mmHg) and nighttime (−8.6 [−15.2 to - 1.9) / −4.1 [−7.1 to – 1.0]) mmHg.
The treatment of OSA with long-term use of CPAP significantly reduces blood pressure in patients with resistant hypertension, especially in those with uncontrolled ambulatory BP at baseline.
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