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 125/80mmHg. 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 +/- 7.3mmHg, P=0.027). Patients who used CPAP>5.8 h showed a greater reduction in daytime diastolic BP {-6.12mmHg [confidence interval (CI) -.45; -0.82], P=0.004}, 24-h diastolic BP (-6.98mmHg [CI -1.86; -12.1], P=0.009) and 24-h systolic BP (-9.71mmHg [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. (C) 2010 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins.