More dietetic time, better outcome? A randomized prospective study investigating the effect of more dietetic time on phosphate control in end-stage kidney failure haemodialysis patients

Abstract

Background/aim: A randomized controlled trial was conducted involving 67 stable adult haemodialysis patients with hyperphosphataemia. The objective was to determine the effect of monthly dietetic consultations on patients' serum phosphate concentrations and calcium x phosphate product.

Methods: The intervention group received monthly dietetic consultations for 6 months using advanced counselling skills aimed at limiting phosphate intake in the diet and improving compliance with phosphate binders, whereas standard care with dietetic consultations every 6 months was provided to the control group.

Results: Serum phosphate concentrations decreased in the intervention group from 2.05 +/- 0.48 to 1.80 +/- 0.48 mmol/l by month 3 (p < 0.05). However, this subsequently increased and by month 6 there was no significant difference from baseline. After controlling for confounding variables, the difference between the groups was approaching significance at month 3, but there was no difference by month 6, or following conclusion of the study. The calcium x phosphate product similarly decreased in both groups, achieving K/DOQI standards, but was not sustained either during the remainder of the study but decreased further by the 12-month follow-up and, although it was not significantly different, it did improve significantly from baseline in both the intervention and control groups.

Conclusion: Increased frequency of dietetic consultations can result in improved phosphate control in the short term, and therefore more innovative strategies appear necessary to sustain longer-term control.