Combination Therapy Associating CPAP and Mandibular Advancement Device in OSA

The aim of this study is to test the efficacy of a combination of Continuous Positive Airway Pressure (CPAP) treatment and a Mandibular Advancement Device (MAD) on the control of nocturnal Blood Pressure over a 3-month period in hypertensive obstructive sleep apnea being low CPAP compliers. This is a prospective, randomized, open-label and multi-centric study. The investigators plan to include 105 hypertensive patients demonstrating low CPAP adherence (less than 4 hours per night). Patients will be randomly assigned to one of the following treatments: Education for improving CPAP adherence ('CPAP Only' group: patients will continue their CPAP treatment and be supported by regular coaching aimed at increasing their compliance to treatment); Mandibular Advancement Device ('MAD Only' group: patients will switch their treatment from CPAP to a MAD); a combination of CPAP and MAD ('CPAP + MAD' group: patients will be treated by both devices used simultaneously). The duration of the study is 3 months. At the selection visit, patients will undergo a polysomnography/respiratory polygraphy followed by 24h- Ambulatory Blood Pressure Monitoring, PROMs (Quality of Life, Epworth Sleepiness Score) and a blood sample for biological parameters analysis. Patients will be then randomized to one of the three groups. Patients assigned to the 'CPAP only group' will be contacted by the homecare provider to arrange coaching sessions in order to improve their compliance to CPAP (phone calls and/or home visits). Patients assigned to the 'MAD Only group' will be proposed a Mandibular Advancement Device. Patients assigned to the 'CPAP+MAD group' will have both CPAP (with coaching) and a MAD. After a 3-month treatment period, the same measurements (24h-Ambulatory Blood pressure, polysomnography/respiratory polygraphy, questionnaires, and blood sample analysis) will be repeated to compare efficacy of the 3 interventions. Tolerance (number of adverse events) and adherence to treatments will also be assessed. The 'CPAP+MAD' group will be compared to the other two groups in order to evaluate the benefit of the combination therapy.