Relationship Between Blood Pressure and Pulse Wave Velocity Measurements in Peritoneal Dialysis

All participants will be monitored over a 6 month period during which 7 monthly visits will be performed. Brachial and aortic blood pressure (BP), wave reflection and arterial stiffness indices will be assessed with the brachial cuff-based oscillometric device Mobil-O-Graph NG (IEM, Stolberg, Germany). The above hemodynamic and arterial wall parameters will be measured for 24-hours on visits 1 (baseline) and 7 (month 6). The monitor will be set to obtain recordings 3 times/hour from 11:00 pm to 06:59 am and 2 times/hour from 07:00 am to 10:59 pm. Measurements will be used for the analysis if \>80% of recordings were valid with no more than two non-consecutive day hours with fewer than two valid measurements, and no more than one night hour without valid recording, according to recommendations for ambulatory BP monitoring. Bioelectrical Impendance Analysis (BIA) with the Fresenius Body Composition Monitor (BCM - Fresenius Medical Care, Bad Homberg, Germany) will be performed on visits 1, 4 and 6 in order to assess the hydration status and body composition parameters of the participants.