Continuous positive airway pressure treatment in sleep apnea patients with resistant hypertension: a randomized, controlled trial

OBJECTIVES: This controlled trial assessed the effect of continuous positive airway pressure (CPAP) on blood pressure (BP) in patients with obstructive sleep apnea (OSA) and resistant hypertension (RH). METHODS: We evaluated 96 patients with resistant hypertension, defined as clinic BP at least 140/90 mmHg despite treatment with at least three drugs at adequate doses, including a diuretic. Patients underwent a polysomnography and a 24-h ambulatory BP monitoring (ABPM). They were classified as consulting room or ABPM-confirmed resistant hypertension, according to 24-h BP lower or higher than 125/80 mmHg. Patients with an apnea-hypopnea index at least 15 events/h (n = 75) were randomized to receive either CPAP added to conventional treatment (n = 38) or conventional medical treatment alone (n = 37). ABPM was repeated at 3 months. The main outcome was the change in systolic and diastolic BP. RESULTS: Sixty-four patients completed the follow-up. Patients with ABPM-confirmed resistant hypertension treated with CPAP (n = 20), unlike those treated with conventional treatment (n = 21), showed a decrease in 24-h diastolic BP (-4. 9 ± 6. 4 vs. 0. 1 ± 7. 3 mmHg, P = 0. 027). Patients who used CPAP > 5. 8 h showed a greater reduction in daytime diastolic BP -6. 12 mmHg confidence interval (CI) -1. 45; -10. 82, P = 0. 004, 24-h diastolic BP (-6. 98 mmHg CI -1. 86; -12. 1, P = 0. 009) and 24-h systolic BP (-9. 71 mmHg CI -0. 20; -19. 22, P = 0. 046). The number of patients with a dipping pattern significantly increased in the CPAP group (51. 7% vs. 24. 1%, P = 0. 008). CONCLUSION: In patients with resistant hypertension and OSA, CPAP treatment for 3 months achieves reductions in 24-h BP. This effect is seen in patients with ABPM-confirmed resistant hypertension who use CPAP more than 5. 8 h.