Phosphorus balance calculator: an individualized tool for treatment of hyperphosphatemia in hemodialysis patients

Abstract

Background and hypothesis Lack of evaluations of the dietary phosphorus and dialysis phosphorus removal in daily clinical practice are the common obstacle to assess phosphorus balance and control phosphorus in hemodialysis patients. We aimed to investigate whether the individualized therapy using phosphorus balance calculator improves phosphorus control. Methods A randomized, open-label, multicenter, 4-week clinical trial was conducted. 119 maintenance hemodialysis patients aged 18 to 85 years old and with serum phosphorus level higher than 1.45mmol/l from 3 university teaching hospitals in Shanghai were enrolled. Patients were randomized in a 1:1 ratio to individualized therapy (n=60), or conventional therapy (n=59). The primary outcome was the serum phosphorus concentration after 4-week treatment. Secondary outcomes included the serum calcium and parathyroid hormone (PTH) concentrations, changes in serum phosphorus, calcium and PTH concentrations, and the proportion of patients achieving target ranges of serum phosphorus, calcium and PTH after 4-week treatment. Results Among 119 randomized participants (mean age, 62 years; 68 male[57%]), 116 completed the trial. By using the phosphorus balance calculator, the individualized group achieved a better phosphorus balance state, significantly reduced the serum phosphorus (1.62±0.45mmol/l versus 1.85±0.45 mmol/l, P=0.006), increased the proportions of patients achieving target serum phosphorus range (41% versus 18%, P=0.006), and had greater adjusted mean difference in change in serum phosphorus over the 4 weeks (-0.47 versus -0.23mmol/l, P=0.010) when compared to conventional therapy. No significant changes were observed in serum calcium and PTH levels, the proportion of patients achieving target serum calcium or PTH levels, and adjusted mean difference of serum calcium and PTH levels over the treatment period. Conclusion Phosphorus balance calculator was proved to improve serum phosphorus control in patients undergoing maintenance hemodialysis, offering a new tool for managing hyperphosphatemia.