This prospective cohort study was conducted at the Unit of Nephrology of Sisli Etfal Education and Research Hospital, Istanbul, Turkey. Prior to subject recruitment, the study protocol was reviewed and approved by the local ethics committee, in accordance with the ethical principles for human investigations, and written informed consents were obtained from all patients. Between june 2008 and january 2009, 54 age and gender matched continuous ambulatory peritoneal dialysis (CAPD) patients were included in the study consecutively.