Arterial compliance in uraemia.

Aortic and brachial pulse wave velocity were measured in 26 haemodialysis patients in order to assess the effect of uraemic waste-product retention on arterial compliance. Dialysis with a 'low-calcium' dialysate (1.50 mmol/l) did not change the pulse wave velocity, but dialysis with a 'high-calcium' dialysate (1.75 mmol/l) induced a significant increase in both aortic and brachial pulse wave velocity. The results indicate that (1) waste-product retention is not responsible for the increased arterial pulse wave velocity observed in uraemic patients and (2) the increase in serum ionized calcium decreases arterial compliance.