Effect of CPAP treatment on BP in resistant hypertensive patients according to the BP dipping pattern and the presence of nocturnal hypertension

Abstract

High heterogeneity in the blood pressure (BP) response to continuous positive airway pressure (CPAP) exists in patients with resistant hypertension (RH). Only nondipper normotensive and hypertensive patients exhibited BP reductions when treated with CPAP; the baseline BP dipping pattern has been proposed as a predictor of BP response to CPAP but has never been explored in patients with RH. This study aimed to assess the effect of CPAP on BP in subjects with RH with respect to BP dipping pattern or nocturnal hypertension. This is an ancillary study of the SARAH study. RH subjects with an apnea/hypopnea index (AHI) >= 15/h and who received CPAP treatment for 1 year were included. Subjects underwent a sleep study and ambulatory BP monitoring (ABPM) at baseline and at the 1-year follow-up. Eighty-nine RH subjects were included. The subjects were mainly male (77.5%) and obese, with a mean age of 66 years (25th-75th percentile; 59.0; 70.0) and an AHI of 32.7/h (25th-75th percentile; 25.0; 54.7). A total of 68.5% of participants were nondippers, and 71.9% had nocturnal hypertension. After 1 year of CPAP, no significant differences in ABPM parameters were observed between dippers and nondippers. According to nighttime BP, subjects with nocturnal normotension did not show significant changes in ABPM parameters, while nocturnal hypertensive subjects achieved a significant reduction in mean nighttime BP of -4.38 mmHg (-7.10 to -1.66). The adjusted difference between groups was 3.04 (-2.25 to 8.34), which was not significant. This study shows that the BP response to CPAP in patients with RH does not differ according to the BP dipping pattern (dipper and nondipper) and suggests a differential response according to the presence of nocturnal hypertension.