Less is known about the relationship between sevelamer treatment and progression of arterial stiffness. To date, there is one single study examining the influence of sevelamer (versus calcium carbonate) on the evolution of arterial stiffness in a very small number (N=15) of haemodialysis patients. These study used the same patients as historical controls, thus being methodologically rather weak. Moreover, the follow-up was quite short - 6 month.