A non-dipping profile has been found in 50–85% of patients with OSA and its frequency increases with OSA severity. Also, lack of nocturnal dipping is related to an increased risk of cardiovascular (CV) events. Our aim was to assess the effect of continuous positive airway pressure (CPAP) therapy in patients with moderate-severe OSA and difficul-to-control arterial hypertension (DtC-HTN).Design and method:
We included 101 hypertensive patients with moderate-severe OSA referred to our department for uncontrolled hypertension between 2012 and 2015. For each patient we recorded demographic and anthropometric data, parameters obtained through blood pressure (BP) monitoring (ABPM/24 h using ABPM-05, Meditech device; BP recordings at 15 minutes intervals during daytime and 30 minutes intervals during nighttime) and dipping status. Inclusion criteria were: DtC-HTN in spite of taking at least three antihypertensive drugs at optimal doses, including a diuretic, with mean 24h-BP values >130/80 mmHg and moderate-severe OSA diagnosed through respiratory polygraphy (no electroencephalography recordings) and defined as apnea-hypopnea index (AHI) greater than 15 events per hour. Exclusion criteria were presence of secondary causes of resistant HTN, estimated glomerular filtration rate (eGFR) using CKD-EPI study equation < 30 ml/min/1.73 m2, previous or current use of CPAP therapy, poor adherence to antihypertensive drugs and insomnia. All patients underwent CPAP treatment (manual titration). After 3 months an ABPM/24 h was performed. No changes were made to antihypertensive medication between the two ABPM recordingsResults:
See table. After 3 months of CPAP therapy, these patients displayed a significant reduction in daytime (−4.04 mmHg) and especially nighttime systolic BP (−7.24 mmHg), with no significant variations in diastolic BP. Thus, there was an increase in the percentage of patients who recovered their dipping profile.Conclusions:
In adults with moderate-severe OSA and DtC-HTN under maximal antihypertensive therapy, 3-months treatment with CPAP has improved the mean 24h-BP values. Thus, CPAP treatment may reduce risk of incidence of fatal and non-fatal CV events in OSA patients as compared with untreated OSA patients.