| [ Summary ] |
Plasma inorganic phosphate level is regulated approximately within a range of 2.5 to 4.5mg/dl in healthy human. The level of phosphate is determined mainly by the balance between intestinal phosphorus absorption and appropriate excretion of phosphorus from the kidney, which are regulated by PTH and 1,25(OH)2D. The causes of hyperphosphatemia can be classified into three major categories; (1) increased exogenous phosphorus load, (2) reduced urinary excretion, and (3) transcellular phosphorus shifts. Most common cause of hyperphosphatemia is renal failure, especially severe decline in GFR (less than 30ml/min) elevates serum phosphorus levels. A rapid elevation of serum phosphorus causes hypocalcemia and may result in tetany. Chronic hyperphosphatemia can result in ectopic calcification. Besides treating the underlying disorder, dietary phosphorus intake should be limited. Removal of phosphorus with chronic renal failure is achieved by dialysis or blocking the absorption of phosphorus using phosphate binder. New phosphate binder, sevelamer may be useful to control of chronic hyperphosphatemia. |