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

Abstract

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.