EFFECT OF LONG-TERM USE OF CONTINUOUS POSITIVE AIRWAY PRESSURE TREATMENT ON ARTERIAL STIFFNESS IN PATIENTS WITH OBSTRUCTIVE SLEEP APNEA AND RESISTANT HYPERTENSION

Abstract

Objective: To evaluate the impact of a long-term use of CPAP on arterial stiffness (AS) measured by pulse wave velocity (PWV) in patients with resistant hypertension (RHT) and moderate-severe obstructive sleep apnea (OSA). Design and method: An observational prospective study was performed in 121 patients (38% male, mean age 60.7 ± 7.8 years) with RHT and moderate/severe OSA (AHI> 15/hour) divided in 2 groups using CPAP (CPAP group – n = 62) and not using CPAP (control group – n = 59) and followed for at least 12 months. Pulse wave velocity and ABPM were measured before and after follow-up. Primary outcomes were changes in aortic stiffness. Intergroup comparisons of differences in PWV were assessed by a general linear model with allocation group (CPAP or control) as a fixed factor and adjusted for their respective baseline PWV values in addition to gender, age, and 24-hour SBP values. Per-protocol analysis was performed excluding patients with poor CPAP adherence. Results: Patients were followed-up for a median of 68 [49–81] months. They used a median of 5 [3–8] anti-hypertensive drugs and had mean PWV of 8.41 ± 1.52 m/s. CPAP and control groups were similar in their baseline demographic, anthropometric, office and ambulatory BP, PWV, and laboratory characteristics. Control group had a mean increase in PWV of 0.88m/s (95% CI: 0.52–1.25 m/s, p < 0.001), whereas CPAP group had an average increase in PWV of 1.20 m/s (95% CI: 0.84–1.55 m/s; p < 0.001). After adjustment for initial PWV, gender, age and 24-systolic BP, the mean difference between CPAP and control groups was + 0.32 (95%CI: 0.17–0.83; p = 0.20). In a subgroup analysis with patients with higher PWV (>10m/s) the mean difference adjusted was -0.20 (95%CI: -2.17–1.75, p = 0.83). Conclusions: Long-term treatment with CPAP did not reduce aortic stiffness in RHT with moderate/severe OSA, but it may prevent its worsening in relation to control group in those with baseline increased arterial stiffness.