Influence of dietary protein on serum phosphorous levels in peritoneal dialysis patients with different initial transport function

INTRODUCTION: This cross-sectional study investigated the influence of dietary protein intake (DPI) on serum phosphate levels in peritoneal dialysis (PD) patients and determined the DPI cutoff required to prevent hyperphosphatemia. METHODS: A total of 504 PD patients were categorized into fast (4 h dialysate/plasma [D/P] creatinine clearance ≥0.65) or slow (<0.65) peritoneal transporters. Serum phosphorus and peritoneal solute clearance were compared between the groups with different DPI. RESULTS: The fast peritoneal transporters (n = 233) were older, had lower serum albumin and phosphorus levels, and had higher peritoneal phosphorus clearance (all p < 0.001). Among the slow transporters (n = 271), serum phosphorus levels were significantly higher among patients with DPI > 1.0 g/kg/d (p < 0.001). High DPI only increased the hyperphosphatemia risk in slow transporters (not in high transporters). DPI ≥1.026 g increased the hyperphosphatemia risk in those patients (area under the curve: 0.66, p = 0.001). CONCLUSION: High DPI increases the hyperphosphatemia risk in PD patients with slower peritoneal transport function.