Abstract 2462: Obstructive Sleep Apnea Treatment Improves the Blood Pressure Behavior in Normotensive Patients: A Randomized Study

Abstract

Introduction: Obstructive sleep apnea (OSA) promotes significant alterations on blood pressure during sleep. In patients with concomitant hypertension, the treatment with continuous positive airway pressure (CPAP) promotes significant reductions on blood pressure. However, the impact of CPAP on 24 hour blood pressure in normotensive patients is poorly understood. Methods: We included 22 apparently healthy patients with severe OSA defined by polysomnography (apnea/hypopnea index (AHI) >30 events/hour). We excluded hypertension according current guidelines by office measurements. They were randomized to no treatment (control) or CPAP for 3 months. At baseline and at the end of the protocol, we performed 24 hour blood pressure (BP) monitoring evaluating daytime and nighttime BP as well as the morning surge (average of systolic BP during the 2 hours after awakening minus the average of systolic BP during the 1 hour that included the lowest nighttime BP) and highest systolic nighttime BP (mean of 3 BP measurements, centered on the highest nighttime reading). Results: After 3 months, patients randomized to CPAP (mean CPAP usage: 6 hours) presented a significant reduction on daytime (80.3±6.3 to 75.3±6.9 mmHg; P=0.02) and nighttime diastolic BP (67.8±9.5 to 61.4±7.5 mmHg; P=0.03). In addition, we observed a significant reduction on highest nighttime systolic BP (120.0±13.6 to 112.0±.9 mmHg; P=0.02) with a trend for a reduction on morning surge (22.3±9.2 to 17.3±.4 mmHg; P=0.08). No significant alterations occurred in the control group. Conclusion: Even in the absence of established hypertension, CPAP therapy improved the behavior of 24 hour BP in patients with severe OSA.