LAUSR

Hyperphosphatemia is common in end-stage renal disease (ESRD) because of impaired renal phosphate excretion and is treated by dietary measures, dialysis techniques and the use of phosphate binder medication. It is one of the most important cardiovascular risk factors for dialysis patients. Our goal was to involve dialysis patients in the achievement of phosphate targets by self-adjusting the dose of Phosphate Binders (PB) on a meal-to-meal basis, according to the individual dietary P intake We conducted an interventional prospective single-arm study with a pre-post design. The inclusion criteria were patients with ESRD who had been receiving dialysis for more than three months, with dialysis schedule for four hours per session, three times per week, and who were older than 18 years of age. The primary endpoints of the study were the number of patients who reached the goal of serum phosphate before and after the training program and the weekly mean serum phosphate levels evaluated after the intervention period and compare them with the pre-intervention baseline levels. The secondary end-point was the burden of PB daily. All patients were trained in a self-administer PB program. A self-adjusted PB dose card was developed based on the phosphate food content list published by the National Technical University of Athens. The aim was to allow patients to immediately calculate the iP content of any food they consume easily. Phosphate Equivalent (PEQ) was defined as the weight of phosphorus having the same phosphate impact as a given weight of food. One PEQ corresponded in 100 mg of inorganic phosphorous and to one tablet of PB (one tablet of 800 mg of sevelamer). After 4 weeks (weeks 1-4) of washout from previous phosphate binders, eligible patients with serum phosphorus concentrations ≥ 6 mg/dl were included in the study. All patients received standard dietary phosphate counseling and a fixed dosing regimen of sevelamer PB was prescribed according to KDIGO and dialysis unit protocols for eight weeks (weeks 5-12 – pre-intervention period) In the 13th week, patients were asked to practice the self-administer PB program for eight more weeks. A total of 97 patients were screened for the study. 21 patients were excluded. 74 patients completed the study. The percentage of patients with uncontrolled phosphate levels reduced from 56.76% (42 out of 74) to 36.48 % (27 out of 74) in the post-intervention period. Of 9 patients who initially had a serum phosphorus level ≥9 mg/dl, 8 were reverted to phosphorus levels < 6 mg/dl at the end of the PEQ intervention period. There was a significant reduction of phosphate levels (prePEQ 7.42 ± 1.43 mg/dl vs. postPEQ 5.59 ± 1.82 mg/dL, p=0.036) and Ca × P levels (prePEQ: 67.1 ± 11.5 mg2/dL2; postPEQ: 51.9 ± 13.4 mg2/dL2, p=0.021) after patient education. There was a non-significant increase on serum calcium (pre PEQ: 8.13 ± 1.18 mg/dL; post PEQ: 8.56 ± 0.83mg/dL, p=0.515) and iPTH (prePEQ: 411 ± 376 pg/mL; postPEQ: 381 ± 321 pg/mL,p=0.13) Our work shows that providing the patients with a relatively simple tool about the use of phosphate binders as PEQ is, we had a positive effect on the dialysis patients’ knowledge about the use of PB, phosphate content of their meals, and increase their sense of the necessity of the treatment and it was proved more effective than the standard fixed dose method. Using the PEQ education system was rewarding in an additional 20% of the patients with previous uncontrolled hyperphosphatemia. The PEQ education system is an efficient self-adjustment phosphate binder dosage tool in dialysis patients in reducing the serum phosphate level in our hemodialysis patients.