Understanding and managing hyperphosphatemia in patients with chronic renal disease

Controlling serum phosphorus levels continues to be a challenge in patients with chronic renal disease. Hyperphosphatemia is implicated in the develop ment and worsening of secondary hyperparathyroidism and renal osteodystroph y (ROD) through its effects on serum calcium and calcitriol levels, parathy roid hormone (PTH) overproduction, and parathyroid cell hyperplasia. In the past serum phosphorus control with aluminum-containing phosphate binders w as associated with insidious but serious development of aluminum toxicity. More recent approaches using non aluminum-containing calcium salts as phosp hate binders are limited because of the excessive calcium load resulting fr om concomitant enhanced intestinal calcium absorption. Moreover serum phosp horus does not only result from dietary phosphate intake but also from enha nced bone breakdown due to secondary hyperparathyroidism. Strategies for ma naging ROD including early control of serum phosphorus and PTH, prevention of parathyroid hyperplasia; establishment of optimal PTH levels for bone he alth, and the availability of new therapeutic tools for controlling phospho rus may help prevent complications and improve patient outcomes.