Background and aim: Obstructive sleep apnea (OSA) is a common cause of secondary arterial hypertension. Masked hypertension (MH) is defined as normal office blood pressure and abnormal results in 24 h ambulatory blood pressure monitoring (ABPM). The aim of this study was to evaluate the effect of CPAP therapy on the prevalence of MH in patients with OSA.
Methods: 43 patients (40 men) were included, average age 54.2±10.5 years. All underwent sleep study (PG or PSG) with a diagnosis of OSA indicated for CPAP treatment, average apnea-hypopnea index (AHI) 60.6±23.6. Patients were treated with CPAP for one year. Ambulatory blood pressure monitoring was performed before and after one year of treatment.
Results: Masked hypertension was initially present in 25 (58.1%) and in 26 (60.5%) patients after one year of CPAP therapy. However, there was a statistically significant improvement in BP for all evaluated intervals of ABPM with the exception of systolic pressure during the daytime.
Conclusions: Masked hypertension was very prevalent in these patients with OSA. The CPAP treatment for one year however had no affect on prevalence of masked hypertension although there was a positive effect of CPAP treatment on blood pressure for all assessed intervals of ABPM with the exception of systolic BP during daytime.
Keywords: ambulatory blood pressure monitoring; continuous positive airway pressure; masked hypertension; obstructive sleep apnea.