Phosphorus Changes Affect Dialysis Patient Mortality Risk
ATLANTA—Decreases in serum phosphorus level to a normal range over time may be associated with better survival in hemodialysis (HD) patients, investigators reported at the American Society of Nephrology's Kidney Week 2013 meeting.
Kamyar Kalantar-Zadeh, MD, MPH, PhD, of the University of California Irvine, and colleagues studied 66,084 HD patients whom they stratified according to baseline serum phosphorus levels.
Compared with patients with a serum phosphorus level that stayed above 5.5 mg/dL, those who experienced a decrease from 5.5 or greater to less than 5.5 but not less than 3.5 over six months experienced a 7% decreased mortality risk, in adjusted analyses. An increase in serum phosphorus level from at least 3.5 but less than 5.5 to 5.5 or greater was associated with a 3% increased mortality risk.
Paradoxically, patients whose serum phosphorus decreased to below 3.5 had a 40% increased risk compared with no change in serum phosphorus. The investigators noted that low serum phosphorus in part may be a proxy for poor nutritional state.