Bioimpedance is recently known to be a reliable, reproducible and validated technic allowing determination of hydratation status in patients with chronic kidney disease treated with peritoneal dialysis (PD). Overhydratation attested by bioimpedance is strongly associated with cardio-vascular morbidity and mortality in patients with PD. Overhydratation might concern more than half of patients at PD initiation, though the underlying mechanism remains unknown.

High peritoneal permeability (HPP) might concern about a third of patients starting a PD, although only a few datas are published on this condition. HPP at initiation of PD is associated with a decrease in both technical and patient survival and might be responsible of ultrafiltration failure. The underlying mechanisms of HPP at initiation of PD also remains unknown.

To our knowledge, the correlation between hydratation status and peritoneal permeability at initiation of peritoneal dialysis remains unknown. Moreover, there is no datas concerning the cinetic evolution of peritoneal permeability; demographic or biologic factors associated with HPP in days and months following PD start.

The aim of the present study is to correlate hydratation status (attested by bioimpedance) and peritoneal permeability at early start of peritoneal dialysis. Thus, we investigated early cinetic of peritoneal permeability at different time point during the first year of peritoneal dialysis and we analyzed the demographical and biological factors associated with HPP and overhydratation during this period.

This study is a prospective, multicentric cohort study. Fourty patients recruited in a two years' period in five centers of nephrology will be included. Hydratation status will be determined with Fluid Overload measurement by bioimpedance technic thanks to BCM system (Fresenius Medical Care®). Peritoneal permeability will be determined by modified Peritoneal Equilibration Test with complete drainage at sixty minutes. Datas will prospectively be collected, including: weight, blood pressure, diuretic posology, diuresis, PD modality, dialysate prescribed.

Inclusion criteria:

• End stage chronic kidney disease
• Ambulatory
• Starting a peritoneal dialysis in one of the participant centers
• Accepting the study protocol
• Age > 18yo

Exclusion criteria:

• Age <18yo
• Protected by the law