Effects of positive pressure on blood pressure in patients with obstructive sleep apnea in a Costa Rican cohort

Abstract

Introduction: obstructive Sleep Apnea Syndrome (OSAHS) is characterized by the cessation of breathing during sleep, in the long term it favors arterial hypertension. Objective: to evaluate the effects of at least 1 month of continuous positive airway pressure (CPAP) therapy on diurnal blood pressure (BP), heart rate (HR) and oxygen saturation (SatO₂) in patients with OSAHS. Methods: 449 adults with a diagnosis of OSAHS were studied between 2015 and 2018, with a minimum 1 month of treatment with a daily monthly documentary record of BP, HR and SatO₂. The effects of CPAP were determined by the change in the mean values ​​at the beginning, first month and six months of treatment, comparisons were made according to subgroups based on adequate adherence and low adherence to treatment.  Results: the group  with adequate adherence, shows a statistically significant decrease in systolic BP at 6 months of treatment of 5.4 mmHg (95% CI: -2.9-7.88; p=0.00002) and diastolic BP by 2,77 mmHg (95% CI: -1.19-4.34; p=0.00005), while in the group with low adherence at 6 months the systolic BP decreased by 13.12 mmHg (95% CI: -1, 44-27.68; p=0.07) and diastolic BP decreased 2.55 mmHg (95% CI: -7.72-12.82; p=0.61), with statistically non-significant changes. HR and SatO₂ did not show any significant change.  Conclusion: CPAP treatment for more than 4 weeks, with adequate adherence to treatment (minimum average of 4 hours per day on more than 80% therapy days), significantly reduces BP in people with OSAHS.