Effect of Citrate Dialysate on Vascular Calcification

Vascular calcification is a significant problem in dialysis patients that leads to poor outcomes. Currently there is no therapy that directly addresses this problem. Some of the dialysis solutions (dialysates) currently in use contain citrate, a potent inhibitor of calcium precipitation. In particular, citrate can bind to nascent hydroxyapatite crystals and prevent their propagation. Blood citrate levels are greater after dialysis with citrate dialysates than with non-citrate dialysates, which could slow vascular calcification. However, this has never been investigated. Prior research has shown that arterial calcification can be easily detected and reliably measured on routine digital mammograms, with sufficient sensitivity to follow progression. Mammography is more sensitive in detecting arterial calcification than other imaging and associated with far less radiation and cost. This will allow the researchers to detect differences between citrate and non-citrate dialysates in a safe and convenient way. Participants will be dialyzed with one of two standard dialysis solutions, one with and one without citrate, for 12 months and then switched to the other solution for 12 months. Vascular calcification will be measured by mammography every 6 months. The endpoint will be the difference in the rate of progression of breast arterial calcification (BAC) between dialysis with citrate and non-citrate dialysates.