Aim To research the assosiation between E/T(extracellular water to-total body water ratio) and pulse pressure(PP) in patients on continuous ambulatory peritoneal dialysis(CAPD).MethodsClinical stable CAPD patients(n=74,32M/42F) were included.Brachial blood pressure was measured twice in sitting position after patients had rested more than ten minutes.PP was calculated as systolic blood pressure(SBP) minus diastolic blood pressure(DBP) and it was used as an index of large arterial stiffness.Multiple-frequency bioelectrical impedance analysis was used to record the values for ECW,intracellular water(ICW),and total-body water.Based on these data,E/T also was calculated.In addition,some biochemical indices were determined with standard methods.ResultsPP was strongly associated with E/T(extracellular water/total body water)(r=0.691,p<0.001),E/I(extracellular water/intracellular water)(r=0.456,p=0.001),SBP(r=0.78,p<0.001),DBP,(r=-0.402,p<0.001),age(r=0.427,p<0.001),serum albumin(r=-0.36,P=0.002),C-reactive protein(CRP)(r=0.367,P=0.008) and diabetes(r=0.25,P=0.031),respectively.Multiple regression analysis showed that PP was independently determined by E/T(β=0.67,p<0.001)and CRP(β=0.253,P=0.016).They accounted for 55.7% of the total variance and E/T alone reprensented 50.4% of the explained variance.The regression equation:Y=-111.81+326.361X1+0.584X2(Y=PP;X1=E/T;X2= CRP).Conclusion E/T was closely associated with PP in peritoneal dialysis patients.E/T,in addition to CRP,was an independent risk factor for elevated PP in CAPD patients,suggesting that increased arterial stiffness might be the link between fluid overload and cardiovascular events and mortality in dialysis patients.