Phosphate binders and management of hyperphosphataemia in end-stage renal disease

Abstract

Keywords: hyperphosphataemia; phosphate binders;renal failure; vascular calcificationsHyperphosphataemia is a known factor contributingto the increased risk of cardiac death both in patientswith end-stage renal disease (ESRD) and in thoseunder renal replacement treatment with dialysis [1,2].In patients with renal disease, in fact, the well-knownrelationship between hyperphosphataemia, secondaryhyperparathyroidism, bone turnover and extra osseouscalcifications has recently been followed by therecognition of a major role played by elevated serumphosphate levels in the induction of vascular calcifi-cation [3–5], cardiac interstitial fibrosis and arterialthickening [6] which highly increase the risk of cardiacdeath [1,2]. In response to these findings, the NationalKidney Foundation Kidney Disease Outcome QualityInitiative (K/DOQI) Clinical Practice Guidelines forbone metabolism and disease in chronic kidney diseasehas recently recommended that more stringent levelsfor controlling serum phosphorus (serum phosphoruslevels be maintained between 3.5 and 5.5mg/dl) andCa/P product in order to improve patients’ qualityof life and longevity [7].The involvement of the so-called ‘bone–coronaryaxis’ is the basis for the high clinical interest for serumconcentration of calcium and phosphate. In particular,the control or reduction of the phosphate levelin dialysis patients has become one of the maintherapeutic targets in the management of ESRD.This review focuses on the treatment of hyper-phosphataemia in patients with ESRD and in thoseunder renal replacement treatment with dialysis, anddiscusses in particular conventional phosphate bindersand emerging therapies aimed at reducing the incidenceof hyperparathyroidism, bone disease and calcificationin these patients.